:root {
  --orange: #ffa51f;
  --orange-deep: #f28f00;
  --yellow: #ffe38a;
  --cream: #fff3dc;
  --ink: #1e2231;
  --ink-soft: #3a3f52;
  --space: #0b0f24;
  --white: #ffffff;
  --teal: #a8dcd1;
  --head: 'M PLUS Rounded 1c', 'Hiragino Maru Gothic ProN', 'Hiragino Sans', sans-serif;
  --logo: 'Fredoka', 'M PLUS Rounded 1c', sans-serif;
  --body: -apple-system, BlinkMacSystemFont, 'Hiragino Sans', 'Segoe UI', sans-serif;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--body);
  background: var(--white);
  color: var(--ink);
  line-height: 1.7;
  overflow-x: hidden;
}
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }
h1, h2, h3, .display { font-family: var(--head); font-weight: 900; line-height: 1.25; letter-spacing: 0.01em; }

/* ---------- nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 20;
  background: var(--orange);
}
.nav .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 60px;
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.brand img { width: 32px; height: 32px; border-radius: 8px; }
.brand span { font-family: var(--logo); font-weight: 700; font-size: 22px; color: var(--white); }
.nav-cta {
  font-family: var(--head); font-weight: 800; font-size: 14px;
  background: var(--ink); color: var(--white);
  display: inline-flex; align-items: center; height: 36px; padding: 0 14px; border-radius: 8px; text-decoration: none;
}

/* ---------- hero ---------- */
.hero { background: var(--orange); color: var(--white); position: relative; z-index: 2; }
.hero .wrap {
  display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 24px; align-items: end;
  padding-top: 56px;
}
.hero-text { padding-bottom: 72px; }
.eyebrow {
  display: inline-block;
  font-family: var(--head); font-weight: 800; font-size: 14px;
  color: var(--ink); background: var(--yellow);
  padding: 4px 12px; border-radius: 999px; margin-bottom: 20px;
}
.hero h1 { font-size: 64px; line-height: 1.15; }
.hero h1 .mark {
  background: linear-gradient(transparent 62%, var(--yellow) 62%);
  color: var(--white);
  padding: 0 4px;
}
.hero .tag { font-family: var(--head); font-weight: 900; font-size: 30px; margin-top: 10px; }
.hero .lead { color: var(--ink); font-size: 17px; margin-top: 22px; max-width: 460px; }
.cta { display: flex; align-items: center; gap: 16px; margin-top: 28px; flex-wrap: wrap; }
.badge img { height: 56px; width: auto; }
.cta-note { font-size: 13px; color: var(--ink); font-weight: 700; opacity: 0.85; }
.qr { display: none; align-items: center; gap: 10px; margin-left: 8px; }
.qr img { width: 72px; height: 72px; border-radius: 8px; background: var(--white); padding: 4px; }
.qr span { font-size: 12px; color: var(--ink); opacity: 0.7; white-space: nowrap; }
@media (hover: hover) and (pointer: fine) and (min-width: 861px) { .qr { display: flex; } }
.hero-art { align-self: end; }
.hero-art .bon { width: 100%; max-width: 480px; margin: 0 auto; }
video.bon { display: block; height: auto; object-fit: contain; background: transparent; }

/* ---------- numbers ---------- */
.stats { background: var(--ink); color: var(--white); padding: 40px 0; }
.stats .wrap { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.stat { text-align: center; }
.stat .num { font-family: var(--logo); font-weight: 700; font-size: 44px; line-height: 1; color: var(--yellow); }
.stat .num small { font-family: var(--head); font-weight: 900; font-size: 20px; margin-left: 2px; color: var(--white); }
.stat .label { font-family: var(--head); font-weight: 800; font-size: 14px; margin-top: 8px; opacity: 0.85; }

/* ---------- screenshots ---------- */
.shots { background: var(--orange); padding: 0; }
.shots-track {
  display: flex; gap: 0; max-width: 1240px; margin: 0 auto;
  overflow-x: auto; scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch; scrollbar-width: none;
}
.shots-track::-webkit-scrollbar { display: none; }
.shots-track img { flex: 0 0 auto; width: 25%; scroll-snap-align: start; }

/* ---------- features ---------- */
.feature { padding: 88px 0; }
.feature.cream { background: var(--cream); }
.feature.white { background: var(--white); }
.feature .wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.feature.flip .art { order: 2; }
.feature .num { font-family: var(--logo); font-weight: 700; font-size: 16px; color: var(--orange-deep); letter-spacing: 0.08em; }
.feature h2 { font-size: 36px; margin-top: 8px; }
.feature p { font-size: 16px; color: var(--ink-soft); margin-top: 18px; max-width: 440px; }
.feature .art { display: flex; justify-content: center; }
.feature .art .bon { width: 100%; max-width: 340px; }
.phone {
  width: 250px; padding: 10px; border-radius: 40px; background: var(--ink);
}
.phone img { border-radius: 30px; }

.more { background: var(--white); padding: 0 0 88px; }
.more h3 { font-size: 18px; text-align: center; color: var(--ink-soft); }
.chips { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-top: 18px; }
.chip {
  font-family: var(--head); font-weight: 800; font-size: 14px;
  background: var(--cream); color: var(--ink); padding: 9px 16px; border-radius: 999px;
}

/* ---------- audience ---------- */
.who { background: var(--yellow); padding: 88px 0; position: relative; overflow: hidden; }
.who .wrap { position: relative; z-index: 1; }
/* ショップ画面の漂流オブジェクト(無重力で左→右に流れて回る)を背景に流す */
.who-junk { position: absolute; inset: 0; pointer-events: none; overflow: hidden; }
/* 流れる高さは見出しの上の余白 (--y) と文の下の余白 (--yb) の 2 本だけ。文字を横切らない */
.jk { position: absolute; left: 0; top: var(--y, auto); bottom: var(--yb, auto); width: var(--s); transform: translateX(-160px); animation: junkDrift var(--d) linear infinite; animation-delay: var(--dl); will-change: transform; }
.jk img { display: block; width: 100%; height: auto; -webkit-user-drag: none; animation: junkSpin var(--d) linear infinite, junkBob 3.9s ease-in-out infinite; animation-delay: var(--dl), var(--bd, 0s); }
@keyframes junkDrift { from { transform: translateX(-160px); } to { transform: translateX(calc(100vw + 60px)); } }
@keyframes junkSpin { from { rotate: 0deg; } to { rotate: var(--r); } }
@keyframes junkBob { 0%, 100% { translate: 0 -5px; } 50% { translate: 0 5px; } }
@media (max-width: 600px) { .jk { width: calc(var(--s) * 0.8); } }
@media (min-width: 861px) { .jk { width: calc(var(--s) * 1.35); } }
@media (prefers-reduced-motion: reduce) { .jk, .jk img { animation: none; } .jk { left: var(--x); transform: none; } }
.who h2 { font-size: 36px; text-align: center; }
.who-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px 32px; margin-top: 40px; }
/* 押せる箱に見えないよう、地に直接・頭にチェックの印 (2026-10-16) */
.who-card { padding: 0; }
.who-card h3 { font-size: 20px; display: flex; align-items: flex-start; gap: 10px; }
.who-card h3::before { content: ''; flex: none; width: 24px; height: 24px; margin-top: 2px; border-radius: 50%; background: var(--ink) url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3.2' stroke-linecap='round' stroke-linejoin='round'><path d='M6 12.5l4 4 8-9'/></svg>") center / 15px no-repeat; }
.who-card p { font-size: 15px; color: var(--ink-soft); margin-top: 8px; padding-left: 34px; }

/* ---------- pricing ---------- */
.free { background: var(--white); padding: 72px 0; text-align: center; }
.free h2 { font-size: 32px; }
.free p { color: var(--ink-soft); margin-top: 12px; max-width: 560px; margin-left: auto; margin-right: auto; }

/* ---------- final cta ---------- */
.final { background: var(--orange); color: var(--white); overflow: hidden; }
.final .wrap { display: grid; grid-template-columns: 1fr auto; align-items: end; gap: 32px; padding-top: 64px; }
.final .text { padding-bottom: 64px; }
.final h2 { font-size: 44px; }
.final .sub { color: var(--ink); font-size: 16px; margin-top: 12px; }
.final .cta { margin-top: 24px; }
.final .bon { width: 260px; }

/* ---------- footer ---------- */
footer { background: var(--ink); color: var(--white); padding: 40px 0; }
footer .wrap { display: flex; flex-direction: column; align-items: center; gap: 14px; }
footer .links { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px 24px; }
footer a { font-size: 13px; text-decoration: none; opacity: 0.7; }
footer a:hover { opacity: 1; }
footer .copy { font-size: 12px; opacity: 0.55; }
footer .social { display: flex; gap: 22px; }
footer .social a { display: inline-flex; align-items: center; gap: 6px; font-size: 13px; }
footer .social svg { width: 16px; height: 16px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  .hero .wrap { grid-template-columns: 1fr; padding-top: 40px; }
  .hero-text { padding-bottom: 32px; text-align: center; }
  .hero .lead { margin-left: auto; margin-right: auto; }
  .cta { justify-content: center; }
  .hero h1 { font-size: 46px; }
  .hero .tag { font-size: 24px; }
  .hero-art .bon { max-width: 360px; }
  .stats .wrap { grid-template-columns: repeat(2, 1fr); }
  .stat .num { font-size: 36px; }
  .shots-track img { width: 76%; }
  .feature { padding: 64px 0; }
  .feature .wrap { grid-template-columns: 1fr; gap: 28px; text-align: center; }
  .feature.flip .art { order: 0; }
  .feature h2 { font-size: 28px; }
  .feature p { margin-left: auto; margin-right: auto; }
  .feature .art .bon { max-width: 240px; }
  .phone { width: 220px; }
  .who { padding: 64px 0; }
  .who h2 { font-size: 28px; }
  .who-grid { grid-template-columns: 1fr; }
  .final .wrap { grid-template-columns: 1fr; text-align: center; gap: 0; }
  .final .text { padding-bottom: 32px; }
  .final h2 { font-size: 32px; }
  .final .cta { justify-content: center; }
  .final .bon { width: 200px; margin: 0 auto; }
}

/* ---------- document pages (privacy / terms / support) ---------- */
.doc { background: var(--cream); }
.doc-wrap { max-width: 720px; margin: 0 auto; padding: 48px 24px 88px; }
.doc h1 { font-size: 34px; }
.doc .updated, .doc .subtitle { font-size: 14px; color: var(--ink-soft); opacity: 0.75; margin: 8px 0 40px; }
.doc h2 { font-size: 20px; margin: 40px 0 12px; }
.doc p, .doc li { font-size: 15px; color: var(--ink-soft); margin-bottom: 12px; }
.doc ul { padding-left: 20px; }
.doc li { margin-bottom: 6px; }
.doc strong { color: var(--ink); }
.doc-wrap a { color: var(--orange-deep); text-decoration: underline; text-underline-offset: 3px; }
.faq-item { background: var(--white); border-radius: 20px; padding: 20px 22px; margin-bottom: 12px; }
.faq-q { font-family: var(--head); font-weight: 800; font-size: 16px; color: var(--ink); margin-bottom: 6px; }
.faq-a { font-size: 14px; margin: 0; }
.contact-box { background: var(--yellow); border-radius: 24px; padding: 32px 24px; margin-top: 40px; text-align: center; }
.contact-box p { color: var(--ink); margin-bottom: 16px; }
.contact-box a {
  display: inline-block; background: var(--ink); color: var(--white);
  font-family: var(--head); font-weight: 800; font-size: 15px;
  padding: 12px 28px; border-radius: 999px; text-decoration: none;
}
@media (max-width: 860px) { .doc h1 { font-size: 28px; } }

/* ---------- mini quiz (feature 01) ---------- */
.quiz { background: var(--white); border-radius: 16px; padding: 22px 22px 22px; width: 100%; max-width: 400px; text-align: left; box-shadow: 0 10px 28px rgba(30,34,49,0.10); }
.quiz-head { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; }
.quiz-bon { width: 52px; height: auto; display: block; }
.quiz-title { font-family: var(--head); font-weight: 900; font-size: 20px; }
.quiz-body { opacity: 0; transform: translateY(4px); transition: opacity .22s ease, transform .22s ease; }
.quiz-body.is-in { opacity: 1; transform: none; }
.quiz-label {
  display: inline-block; font-family: var(--head); font-weight: 800; font-size: 12px;
  color: var(--ink); background: var(--yellow); padding: 3px 10px; border-radius: 6px;
}
.quiz-prompt { font-size: 22px; min-height: 92px; display: flex; align-items: center; justify-content: center; padding: 6px 0 10px; overflow-x: auto; }
.quiz-prompt .katex-display { margin: 0; }
.quiz-choices { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.quiz-choice {
  font: inherit; font-size: 17px; color: var(--ink); background: var(--yellow);
  border: 0; border-radius: 8px; min-height: 64px; padding: 8px 10px; cursor: pointer;
  display: flex; align-items: center; justify-content: center; overflow: hidden;
  transition: background-color .15s ease, opacity .15s ease, transform .1s ease;
}
.quiz-choice:hover:not(:disabled) { background: #ffd35a; }
.quiz-choice:active:not(:disabled) { transform: scale(0.98); }
.quiz-choice:disabled { cursor: default; }
.quiz-choice.is-right { background: #9fdcb7; }
.quiz-choice.is-wrong { background: #f5b8c3; }
.quiz-choice.is-dim { background: var(--cream); opacity: 0.7; }
.quiz-result { margin-top: 16px; display: grid; grid-template-rows: 22px 48px 26px; row-gap: 12px; }
.quiz .quiz-msg { font-family: var(--head); font-weight: 800; font-size: 15px; color: var(--ink); line-height: 22px; margin: 0; max-width: none; text-align: center; }
.quiz-msg a { color: var(--orange-deep); }
.quiz .quiz-msg.is-hint { color: var(--ink-soft); font-weight: 700; opacity: 0.7; }
.quiz-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.quiz-actions[hidden] { display: none; }
.quiz-app {
  font-family: var(--head); font-weight: 800; font-size: 14px; text-decoration: none;
  background: var(--ink); color: var(--white); border-radius: 8px; line-height: 1;
  display: flex; align-items: center; justify-content: center; height: 48px; padding: 0 12px;
}
.quiz-next { font: inherit; font-family: var(--head); font-weight: 800; font-size: 14px; color: var(--ink); background: var(--yellow); border: 0; border-radius: 8px; height: 48px; padding: 0 12px; cursor: pointer; line-height: 1; }
@media (max-width: 860px) { .quiz { max-width: 420px; margin: 0 auto; } }
@media (prefers-reduced-motion: reduce) { .quiz-body { transition: none; } }

/* ---------- unit pages (/p, /about) ---------- */
.doc.unit { background: var(--white); }
.unit .doc-wrap { padding-top: 28px; }
.unit-hero { background: var(--orange); color: var(--white); padding: 22px 0 34px; }
.unit-hero .wrap { max-width: 720px; }
.unit-hero .crumbs { font-size: 13px; color: rgba(30,34,49,0.8); margin: 0; }
.unit-hero .crumbs a { color: rgba(30,34,49,0.8); }
.unit-tag { display: inline-block; font-family: var(--head); font-weight: 800; font-size: 12px; color: var(--ink); background: var(--yellow); padding: 3px 10px; border-radius: 6px; margin: 16px 0 10px; }
.unit-hero h1 { font-size: 34px; line-height: 1.25; }
.unit-hero .lead { color: var(--ink); font-size: 17px; margin-top: 10px; }
.atom .formula { background: var(--ink); color: var(--white); border-radius: 12px; padding: 22px 24px; margin: 28px 0 18px; overflow-x: auto; font-size: 22px; }
.atom .formula .katex { color: var(--white); }
.atom .formula .katex-display { margin: 0; }
.atom .formula .katex-display > .katex { transform-origin: center; }
.atom .point { font-size: 16px; color: var(--ink-soft); line-height: 1.9; }
.atom .point + .point { margin-top: 12px; }
.atom .point-eq { margin: 10px 0 12px; padding: 8px 0; font-size: 18px; overflow-x: auto; overflow-y: visible; scrollbar-width: none; }
.atom .point-eq .katex-display > .katex { padding: 4px 0; }
.atom .point-eq .katex-display { margin: 0; }
.atom .point-eq::-webkit-scrollbar { display: none; }
.atom .graph { margin: 22px auto 8px; max-width: 520px; }
.atom .graph svg { display: block; width: 100%; height: auto; border-radius: 14px; background: var(--white); box-shadow: 0 1px 0 rgba(30,34,49,0.06); }
.atom .graph figcaption { margin-top: 10px; font-size: 13px; color: var(--ink-soft); line-height: 1.7; text-align: center; }
.atom .graph svg { touch-action: pan-y; user-select: none; -webkit-user-select: none; }
.atom .graph .handle { cursor: grab; }
.atom .graph .handle:active { cursor: grabbing; }
.atom .graph-read { margin-top: 10px; font-family: var(--body); color: var(--ink); font-variant-numeric: tabular-nums; min-height: 1.4em; text-align: center; }
.atom .graph-read .pri { display: flex; flex-wrap: wrap; justify-content: center; gap: 4px 18px; font-size: 19px; font-weight: 800; line-height: 1.5; }
.atom .graph-read .sec { display: flex; flex-wrap: wrap; justify-content: center; gap: 2px 14px; margin-top: 4px; font-size: 13px; font-weight: 500; color: var(--ink-soft); }
.atom .graph-read b { color: var(--orange-deep); }
.atom .graph-read .blue { color: #1c7ed6; }
.atom .graph-hint { display: block; margin-top: 4px; font-size: 12px; color: var(--ink-soft); opacity: 0.8; }
.atom .graph.is-static .graph-hint { display: none; }
.atom .graph .halo { transform-box: fill-box; transform-origin: center; opacity: 0.35; animation: graphHalo 1.6s ease-out infinite; pointer-events: none; }
@keyframes graphHalo { 0% { transform: scale(1); opacity: 0.38; } 100% { transform: scale(2.4); opacity: 0; } }
.atom .graph .dlabel { pointer-events: none; }
@media (prefers-reduced-motion: reduce) { .atom .graph .halo { animation: none; opacity: 0.25; } }
.atom h2 { font-size: 22px; margin: 40px 0 14px; }
.atom .examples { list-style: none; padding: 0; }
.atom .examples > li { background: var(--cream); border-radius: 12px; margin-bottom: 10px; }
.atom .ex-ans summary { list-style: none; cursor: pointer; display: grid; grid-template-columns: auto auto 1fr auto; align-items: center; column-gap: 12px; padding: 16px 16px; }
.atom .ex-ans summary::-webkit-details-marker { display: none; }
.atom .ex-ans .num { font-family: var(--logo); font-weight: 700; font-size: 14px; color: var(--orange-deep); }
.atom .ex-ans .label { font-family: var(--head); font-weight: 800; font-size: 12px; color: var(--ink); background: var(--yellow); padding: 2px 8px; border-radius: 6px; white-space: nowrap; }
.atom .ex-q { font-size: 20px; overflow-x: auto; overflow-y: hidden; padding: 10px 0; scrollbar-width: none; text-align: center; }
.atom .ex-q::-webkit-scrollbar, .atom .ex-a::-webkit-scrollbar { display: none; }
.atom .ex-q .katex, .atom .ex-a .katex { white-space: nowrap; }
.atom .ex-toggle { font-family: var(--head); font-weight: 800; font-size: 13px; color: var(--ink); background: var(--white); padding: 6px 12px; border-radius: 8px; white-space: nowrap; }
.atom .ex-toggle .t-close { display: none; }
.atom .ex-ans[open] .ex-toggle .t-open { display: none; }
.atom .ex-ans[open] .ex-toggle .t-close { display: inline; }
/* ⚠ 答えは**白い面**に載せる。問題と同じ地色・同じ中央揃えだと、どちらがどちらか読めない
   (実機で指摘)。枠線では区切らない。角丸はカードの下端に合わせる。 */
.atom .ex-ans .a { display: flex; align-items: center; gap: 12px; padding: 10px 16px; font-size: 20px;
  background: var(--white); border-radius: 10px; margin: 0 8px 8px; }
/* 答えの開き方。⚠ **高さは share.js が動かす** (CSS だけでは動かないブラウザがある。
   閉じている間 <details> の中身は描画されないので transition が走らない)。
   ここは中身のフェードだけを持つ。JS が無くても答えは必ず出る。 */
/* JS が入らないとき (素の <details>) 用のフェード。JS 版とは二重にしない。 */
.atom .ex-ans:not(.js-fold)[open] .a { animation: ex-reveal .42s cubic-bezier(.22,1,.36,1) both; }
@keyframes ex-reveal { from { opacity: 0; transform: translateY(-10px); } to { opacity: 1; transform: none; } }
/* JS 版。⚠ details は常に open なので、見た目は .is-open だけで決める
   (共有シートと同じやり方。どのブラウザでも同じ経路で動く)。 */
.atom .ex-ans.js-fold .a-wrap { height: 0; overflow: hidden; opacity: 0;
  transition: height .42s cubic-bezier(.22,1,.36,1), opacity .3s ease .06s; }
.atom .ex-ans.js-fold.is-open .a-wrap { opacity: 1; }
.atom .ex-ans.js-fold:not(.is-open) .ex-toggle .t-close { display: none; }
.atom .ex-ans.js-fold:not(.is-open) .ex-toggle .t-open { display: inline; }
.atom .ex-ans.js-fold.is-open .ex-toggle .t-open { display: none; }
.atom .ex-ans.js-fold.is-open .ex-toggle .t-close { display: inline; }
.atom .ex-ans.js-fold:not(.is-open) .ex-toggle { background: var(--white); color: var(--ink); }
.atom .ex-ans.js-fold.is-open .ex-toggle { background: var(--ink); color: var(--white); }
/* 押したことが分かるように。⚠ 影は付けない(このLPは面と余白で組んでいる) */
.atom .ex-toggle { transition: background-color .18s ease, color .18s ease, transform .12s ease; }
.atom .ex-ans summary:hover .ex-toggle { background: var(--yellow); }
.atom .ex-ans summary:active .ex-toggle { transform: scale(.96); }
.atom .ex-ans[open] .ex-toggle { background: var(--ink); color: var(--white); }
@media (prefers-reduced-motion: reduce) {
  .atom .ex-ans[open] .a { animation: none; }
  .atom .ex-ans.js-fold .a-wrap { transition: none; }
  .atom .ex-toggle { transition: none; }
}
.atom .ex-ans .atag { font-family: var(--head); font-weight: 800; font-size: 12px; color: var(--white); background: var(--ink); padding: 2px 8px; border-radius: 6px; }
/* 例題の解き方 (アプリの途中式)。答えと同じ白い面の続きに、答えを開けばそのまま出す。 */
.atom .ex-ans .a:has(+ .sol) { border-radius: 10px 10px 0 0; margin-bottom: 0; }
.atom .sol { background: var(--white); border-radius: 0 0 10px 10px; margin: 0 8px 8px; padding: 2px 16px 16px; }
.atom .sol-h { font-family: var(--head); font-weight: 800; font-size: 13px; line-height: 1.3; color: var(--orange-deep); padding-top: 8px; }
.atom .sol-steps { list-style: none; padding: 4px 0 0; display: flex; flex-direction: column; gap: 10px;
  overflow-x: auto; overflow-y: hidden; scrollbar-width: none; }
.atom .sol-steps::-webkit-scrollbar { display: none; }
.atom .sol-steps .st-note { font-size: 15px; line-height: 1.75; color: var(--ink); }
/* 続けて並んだ式のかたまり。左の列 = & の左 (右寄せ)、右の列 = & の右 */
.atom .sol-steps .st-eqs { width: max-content; display: grid; grid-template-columns: max-content max-content; align-items: baseline;
  column-gap: 4px; row-gap: 8px; font-size: 18px; white-space: nowrap; padding-left: 4px; }
.atom .sol-steps .st-eqs .l { text-align: right; }
.atom .sol-steps .st-eqs .w { grid-column: 1 / -1; }
.atom .ex-a { flex: 1; overflow-x: auto; overflow-y: hidden; padding: 6px 0; scrollbar-width: none; text-align: left; }
/* ラベルが長い単元: 全画面幅で 2 段組み(ラベル行 / 式行)。式のない問題は式行を出さない */
.atom .examples.long .ex-ans summary { grid-template-columns: auto 1fr auto; grid-template-areas: "num label toggle" "q q q"; row-gap: 6px; }
.atom .examples.long .ex-ans .num { grid-area: num; }
.atom .examples.long .ex-ans .label { grid-area: label; justify-self: start; white-space: normal; line-height: 1.6; padding: 3px 10px; }
.atom .examples.long .ex-toggle { grid-area: toggle; }
.atom .examples.long .ex-q { grid-area: q; padding: 8px 0 2px; }
.atom .ex-ans.noq summary { grid-template-areas: "num label toggle"; }
.atom .ex-ans.noq .ex-q { display: none; }
.atom .faq dt { font-family: var(--head); font-weight: 800; font-size: 16px; margin-top: 18px; }
.atom .faq dd { margin: 6px 0 0; color: var(--ink-soft); }
.unit-cta { background: var(--orange); border-radius: 12px; padding: 20px 24px; margin-top: 40px; display: flex; align-items: center; gap: 18px; }
.unit-cta img.bon { width: 92px; height: auto; flex: 0 0 auto; }
.unit-cta p { color: var(--white); font-family: var(--head); font-weight: 900; font-size: 18px; margin: 0 0 10px; }
.unit-cta .badge img { height: 48px; width: auto; }
/* 前提 → この単元 → 次 の流れ図。色は「この単元」だけ、他は文字のみで静かに */
.unit-path { display: grid; grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr) auto minmax(0, 1fr); gap: 14px 18px; align-items: center; margin-top: 44px; }
.up-col { display: flex; flex-direction: column; gap: 10px; min-width: 0; align-self: start; }
.up-items { display: flex; flex-direction: column; align-items: flex-start; gap: 8px; }
.up-k { font-family: var(--logo); font-weight: 700; font-size: 12px; letter-spacing: 0.08em; color: var(--ink-soft); }
.up-arrow { display: flex; align-self: center; color: rgba(30,34,49,0.35); }
.up-arrow svg { width: 18px; height: 18px; }
.up-muted { font-size: 14px; color: var(--ink-soft); }
.doc-wrap .unit-path .chip-link { display: inline-block; max-width: 100%; padding: 0; background: transparent; color: var(--ink); font-size: 15px; font-weight: 700; line-height: 1.5; }
.doc-wrap .unit-path a.chip-link:hover { color: var(--ca); }
.doc-wrap .unit-path .chip-link.current { padding: 6px 12px; margin: -6px -12px; border-radius: 10px; background: var(--cb); color: var(--ink); }
.doc-wrap .unit-path .chip-muted { box-shadow: none; color: var(--ink-soft); }
.doc-wrap .unit-path .chip-muted small { display: block; margin: 0 0 2px; font-family: var(--logo); font-size: 10px; letter-spacing: 0.08em; white-space: nowrap; color: var(--ink-soft); opacity: 1; }
@media (max-width: 600px) { .unit-path { grid-template-columns: minmax(0, 1fr); gap: 10px; } .up-arrow { justify-self: start; margin-left: 2px; } .up-arrow svg { transform: rotate(90deg); } }
/* 同じ章の単元(番号付きリスト。流れ図とは別物) */
.unit-ch { margin-top: 40px; }
.ch-list { list-style: none; padding: 0; margin: 10px 0 0; display: grid; grid-template-columns: 1fr 1fr; gap: 2px 24px; }
@media (max-width: 600px) { .ch-list { grid-template-columns: 1fr; } }
.ch-list a { display: flex; gap: 10px; align-items: baseline; padding: 6px 0; text-decoration: none; color: var(--ink); font-size: 14px; font-weight: 600; }
.ch-list .no { flex: none; min-width: 30px; font-family: var(--logo); font-weight: 700; font-size: 13px; color: var(--ink-soft); }
.ch-list li.current a { font-weight: 800; }
.ch-list li.current .no { color: var(--ca); }
.ch-list a:hover { color: var(--ca); }
.doc-wrap .chip-link { background: var(--cream); color: var(--ink); text-decoration: none; padding: 7px 12px; border-radius: 8px; font-size: 14px; font-weight: 700; }
.chip-link.current { background: var(--yellow); }
.atom .updated { font-size: 12px; color: var(--ink-soft); opacity: 0.7; margin-top: 28px; }
.atom .print-link { font-size: 15px; font-weight: 700; margin-top: 14px; }   /* 例題のすぐ下・演習プリントへ */
.atom-cta { background: var(--orange); border-radius: 12px; padding: 24px; margin-top: 36px; text-align: center; }
.atom-cta p { color: var(--white); font-family: var(--head); font-weight: 900; font-size: 18px; margin-bottom: 14px; }
.atom-cta .badge img { height: 48px; width: auto; margin: 0 auto; }
.atom .related { font-size: 14px; color: var(--ink-soft); margin-top: 28px; }
.atom .related a { color: var(--orange-deep); }
.plist { list-style: none; padding: 0; margin: 14px 0 34px; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 12px; }
@media (max-width: 600px) { .plist { grid-template-columns: minmax(0, 1fr); } }
/* 章ごとの色(番号・見出しの丸・カード地)。茶色寄りの amber は使わない */
.ch1 { --ca: #e8850c; --cb: #fff3df; --chv: #ffe6bf; }
.ch2 { --ca: #1c7ed6; --cb: #e9f3ff; --chv: #d3e7ff; }
.ch3 { --ca: #d6336c; --cb: #ffe9f1; --chv: #ffd3e2; }
.ch4 { --ca: #0f8f5f; --cb: #e6f7ee; --chv: #cdefdc; }
.ch5 { --ca: #6f4bd8; --cb: #efeaff; --chv: #e0d8ff; }
.plist li { min-width: 0; background: var(--cb, var(--cream)); border-radius: 14px; }
.plist li[hidden], .pl-ch[hidden], .plist[hidden] { display: none; }
.plist li a { display: flex; flex-direction: column; height: 100%; box-sizing: border-box; min-height: 176px; padding: 16px 18px 14px; color: var(--ink); text-decoration: none; border-radius: 14px; -webkit-tap-highlight-color: rgba(30,34,49,0.08); }
.plist li a:hover { background: var(--chv, var(--yellow)); }
.pl-no { font-family: var(--logo); font-weight: 700; font-size: 14px; letter-spacing: 0.06em; color: var(--ca, var(--orange-deep)); }
.pl-title { display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; margin-top: 4px; font-family: var(--head); font-weight: 800; font-size: 17px; line-height: 1.35; }
.pl-f { display: flex; align-items: center; min-width: 0; height: 44px; margin-top: 8px; overflow: hidden; white-space: nowrap; font-size: 15px; -webkit-mask-image: linear-gradient(90deg, #000 86%, transparent); mask-image: linear-gradient(90deg, #000 86%, transparent); }
.pl-f .katex { display: inline-block; flex: none; width: max-content; max-width: none; font-size: 1.15em; transform-origin: left center; }
.pl-f .katex, .pl-f .katex-html { white-space: nowrap; }
.pl-f.is-fit { -webkit-mask-image: none; mask-image: none; }
.pl-meta { margin-top: auto; padding-top: 10px; font-family: var(--body); font-size: 12px; font-weight: 500; color: var(--ink-soft); letter-spacing: 0.01em; }
.pl-ch { display: flex; align-items: baseline; gap: 12px; }
.pl-ch .ch-no { display: inline-flex; align-items: center; justify-content: center; min-width: 38px; height: 28px; padding: 0 8px; border-radius: 999px; background: var(--ca, var(--orange-deep)); color: var(--white); font-family: var(--logo); font-weight: 700; font-size: 14px; letter-spacing: 0.08em; }
.pl-ch { align-items: center; }
/* 検索窓(ヒーロー内)と章チップ */
.psearch { position: relative; display: flex; align-items: center; max-width: 560px; margin-top: 22px; background: var(--white); border-radius: 14px; color: var(--ink); }
.psearch svg { position: absolute; left: 14px; width: 20px; height: 20px; color: var(--ink-soft); pointer-events: none; }
.psearch input { flex: 1; min-width: 0; height: 48px; padding: 0 12px 0 44px; border: 0; background: transparent; border-radius: 14px; font-family: var(--body); font-size: 16px; color: var(--ink); outline: none; -webkit-appearance: none; appearance: none; }
.psearch input::placeholder { color: rgba(30,34,49,0.45); }
.psearch input::-webkit-search-cancel-button { -webkit-appearance: none; appearance: none; height: 16px; width: 16px; margin-right: 4px; background: rgba(30,34,49,0.25); -webkit-mask: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M18 6 6 18M6 6l12 12' stroke='black' stroke-width='3' stroke-linecap='round'/></svg>") center/contain no-repeat; mask: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M18 6 6 18M6 6l12 12' stroke='black' stroke-width='3' stroke-linecap='round'/></svg>") center/contain no-repeat; cursor: pointer; }
.psearch:focus-within { box-shadow: 0 0 0 3px rgba(255,255,255,0.55); }
.ps-n { flex: none; padding: 0 14px; font-family: var(--logo); font-weight: 700; font-size: 13px; color: var(--ink-soft); white-space: nowrap; }
.ps-n:empty { display: none; }
.pchips { display: flex; flex-wrap: wrap; gap: 8px; margin: 4px 0 8px; }
.pchip { display: inline-flex; align-items: center; height: 34px; padding: 0 14px; border-radius: 999px; background: var(--cb); color: var(--ca); font-family: var(--head); font-weight: 800; font-size: 14px; text-decoration: none; }
.pchip:hover { background: var(--chv); }
.ps-none { margin: 18px 0 40px; padding: 18px 20px; border-radius: 14px; background: var(--cream); color: var(--ink-soft); font-size: 15px; }
.ps-none[hidden] { display: none; }
.pl-ch .ch-n { margin-left: auto; font-family: var(--body); font-size: 13px; font-weight: 600; color: var(--ink-soft); white-space: nowrap; }
@media (max-width: 860px) { .atom .formula { font-size: 16px; padding: 14px 16px; } .atom .ex-q, .atom .ex-ans .a { font-size: 18px; } .atom .ex-ans summary { column-gap: 8px; } .quiz-prompt { font-size: 22px; } .unit-hero h1 { font-size: 27px; } .unit-cta { flex-direction: column; text-align: center; } .unit-cta .badge img { margin: 0 auto; } }
@media (max-width: 600px) {
  .atom .ex-ans summary { grid-template-columns: auto 1fr auto; grid-template-areas: "num label toggle" "q q q"; row-gap: 6px; }
  .atom .ex-ans .num { grid-area: num; }
  .atom .ex-ans .label { grid-area: label; justify-self: start; }
  .atom .ex-toggle { grid-area: toggle; }
  .atom .ex-q { grid-area: q; padding: 10px 0 4px; }
}

/* ---------- share button + preview sheet ---------- */
.share { position: relative; display: inline-block; }
.share-main {
  font: inherit; font-family: var(--head); font-weight: 800; font-size: 13px; cursor: pointer;
  display: inline-flex; align-items: center; gap: 6px; border: 0; border-radius: 8px;
  background: var(--ink); color: var(--white); padding: 9px 14px; line-height: 1;
}

.share-menu { position: absolute; left: 0; top: calc(100% + 8px); z-index: 30; width: 300px; background: var(--white); color: var(--ink); border-radius: 12px; padding: 12px 12px 10px; box-shadow: 0 12px 32px rgba(30,34,49,0.18); text-align: left;
  visibility: hidden; opacity: 0; transform: translateY(-6px); transition: opacity .18s ease, transform .18s ease, visibility 0s linear .18s; }
.share.is-open .share-menu { visibility: visible; opacity: 1; transform: none; transition: opacity .18s ease, transform .18s ease, visibility 0s; }
.share-head { display: flex; align-items: center; justify-content: space-between; font-size: 12px; color: var(--ink-soft); }
.share-close { font: inherit; font-size: 18px; line-height: 1; color: var(--ink-soft); background: transparent; border: 0; padding: 2px 6px; cursor: pointer; border-radius: 6px; }
.share-close:hover { background: var(--cream); }
.share-text { font-family: var(--head); font-weight: 800; font-size: 14px; color: var(--ink); margin: 8px 0 2px; line-height: 1.5; }
.share-url { font-size: 12px; color: var(--ink-soft); margin: 0 0 10px; word-break: break-all; }
.share-item { display: block; width: 100%; text-align: center; font: inherit; font-family: var(--head); font-weight: 800; font-size: 14px; color: var(--ink); background: var(--cream); border: 0; border-radius: 8px; padding: 10px 12px; cursor: pointer; text-decoration: none; }
.share-item:hover { background: var(--yellow); }
.share-item[hidden] { display: none; }
.share-primary { background: var(--ink); color: var(--white); }
.share-primary:hover { background: var(--ink-soft); }
.share-quiz { justify-self: center; }
.share-quiz .share-main { background: transparent; color: var(--ink-soft); padding: 4px 8px; font-size: 12px; }
.share-quiz .share-main:hover { background: var(--cream); color: var(--ink); }
.share-quiz .share-menu { left: 50%; transform: translate(-50%, 6px); top: auto; bottom: calc(100% + 8px); }
.share-quiz.is-open .share-menu { transform: translate(-50%, 0); }
.share-quiz[hidden] { display: none; }
@media (max-width: 600px) {
  .share-menu, .share-quiz .share-menu { position: fixed; left: 0; right: 0; bottom: 0; top: auto; width: auto; border-radius: 18px 18px 0 0; padding: 14px 16px calc(14px + env(safe-area-inset-bottom)); box-shadow: 0 -8px 40px rgba(30,34,49,0.25);
    transform: translateY(105%); transition: transform .28s cubic-bezier(.2,.8,.2,1), opacity .2s ease, visibility 0s linear .28s; }
  .share.is-open .share-menu, .share.is-open.share-quiz .share-menu { transform: none; transition: transform .28s cubic-bezier(.2,.8,.2,1), opacity .2s ease, visibility 0s; }
  .share::before { content: ''; position: fixed; inset: 0; background: rgba(30,34,49,0.35); z-index: 29; opacity: 0; visibility: hidden; transition: opacity .25s ease, visibility 0s linear .25s; }
  .share.is-open::before { opacity: 1; visibility: visible; transition: opacity .25s ease, visibility 0s; }
}
@media (prefers-reduced-motion: reduce) { .share-menu, .share.is-open .share-menu, .share::before { transition: none; } }
.nav-right { display: flex; align-items: center; gap: 8px; }
.share-nav .share-main { padding: 0; width: 36px; height: 36px; justify-content: center; border-radius: 8px; background: rgba(30,34,49,0.12); color: var(--ink); }
.share-nav .share-main:hover { background: rgba(30,34,49,0.2); }
.share-nav .share-menu { left: auto; right: 0; top: calc(100% + 10px); }
@media (max-width: 600px) { .share-nav .share-menu { left: 12px; right: 12px; top: auto; } }
.share-img { display: block; width: auto; max-width: 100%; max-height: 170px; border-radius: 10px; margin: 8px auto 6px; }
.share-img[hidden] { display: none; }
.share-apps { display: flex; justify-content: center; gap: 2px; margin-top: 10px; flex-wrap: wrap; }
.share-app { min-width: 54px; }
.share-app { flex: 1; display: flex; flex-direction: column; align-items: center; gap: 6px; font: inherit; font-size: 11px; font-weight: 700; color: var(--ink-soft); background: transparent; border: 0; padding: 6px 0; cursor: pointer; text-decoration: none; border-radius: 8px; line-height: 1.2; text-align: center; }
.share-app:hover { background: var(--cream); }
.share-app img, .share-app .ic { width: 44px; height: 44px; border-radius: 12px; display: flex; align-items: center; justify-content: center; }
.share-app .ic { background: var(--cream); color: var(--ink); }
.share-app .ic svg { width: 22px; height: 22px; }
.share-app .ic-x { background: #000; color: #fff; }
.share-app[hidden] { display: none; }
.share-hint { font-size: 12px; color: var(--ink-soft); margin: 8px 0 0; }
.share-hint[hidden] { display: none; }
.nav-link { font-family: var(--head); font-weight: 800; font-size: 14px; color: var(--ink); text-decoration: none; display: inline-flex; align-items: center; height: 36px; padding: 0 12px; border-radius: 8px; background: rgba(30,34,49,0.12); }
.nav-link:hover { background: rgba(30,34,49,0.2); }
.plist-sec { background: var(--cream); padding: 80px 0; }
.plist-sec .num { font-family: var(--logo); font-weight: 700; font-size: 16px; color: var(--orange-deep); letter-spacing: 0.08em; }
.plist-sec h2 { font-size: 32px; margin-top: 8px; }
.plist-sec .sub { font-size: 16px; color: var(--ink-soft); margin-top: 12px; max-width: 620px; }
.pgrid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; margin: 26px 0 22px; }
.pcard { display: flex; flex-direction: column; justify-content: center; min-height: 104px; background: var(--white); border-radius: 12px; padding: 16px 20px; text-decoration: none; color: var(--ink); }
.pcard:hover { background: var(--yellow); }
.pcard h3 { font-size: 18px; }
.pcard p { font-size: 13px; color: var(--ink-soft); margin-top: 6px; line-height: 1.6; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.btn-ink { display: inline-block; font-family: var(--head); font-weight: 800; font-size: 15px; color: var(--white); background: var(--ink); text-decoration: none; padding: 12px 20px; border-radius: 8px; }
/* 問題集の下・印刷用プリントへの入口 (章のカードと同じ白・横長でアイコンつき) */
.print-card { display: flex; align-items: center; gap: 16px; margin-top: 32px; padding: 18px 20px; background: var(--white); border-radius: 12px; color: var(--ink); text-decoration: none; }
.print-card svg { flex: none; width: 34px; height: 34px; color: var(--ink-soft); }
.print-card .pc-t { flex: 1; display: flex; flex-direction: column; gap: 2px; }
.print-card strong { font-family: var(--head); font-weight: 800; font-size: 18px; }
.print-card small { font-size: 14px; color: var(--ink-soft); }
.print-card .pc-go { font-family: var(--head); font-weight: 800; font-size: 20px; }
.print-card:hover .pc-go { transform: translateX(3px); }
@media (max-width: 860px) { .plist-sec { padding: 56px 0; } .plist-sec h2 { font-size: 26px; } .pgrid { grid-template-columns: 1fr; } .nav-link { padding: 0 10px; font-size: 13px; } .nav-cta { padding: 0 12px; font-size: 13px; } }
.quiz { position: relative; overflow: visible; }
.quiz-fx { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; z-index: 5; }
@keyframes qpop { 0% { transform: scale(1); } 35% { transform: scale(1.08); } 70% { transform: scale(0.97); } 100% { transform: scale(1); } }
@keyframes qshake { 0%, 100% { transform: translateX(0); } 20% { transform: translateX(-7px); } 40% { transform: translateX(6px); } 60% { transform: translateX(-4px); } 80% { transform: translateX(3px); } }
@keyframes bonjump { 0%, 100% { transform: translateY(0); } 30% { transform: translateY(-10px) rotate(-4deg); } 60% { transform: translateY(0); } 80% { transform: translateY(-4px); } }
.quiz-choice.pop { animation: qpop .45s cubic-bezier(.2,.8,.2,1); }
.quiz-choice.shake { animation: qshake .4s ease; }
.quiz-bon.jump { animation: bonjump .6s ease; }
.share-apps.is-busy { opacity: 0.45; pointer-events: none; }
.nav-ic { width: 18px; height: 18px; display: none; }
.nav-link, .nav-cta { gap: 6px; }
@media (max-width: 600px) {
  .nav-ic { display: block; }
  .nav-link span, .nav-cta span { display: none; }
  .nav-link, .nav-cta { width: 36px; height: 36px; padding: 0; justify-content: center; }
  .nav-right { gap: 8px; }
}
.nav-right { position: relative; }
.nav-pop { position: absolute; right: 0; top: calc(100% + 10px); z-index: 31; width: 240px; background: var(--white); color: var(--ink); border-radius: 12px; padding: 14px; box-shadow: 0 12px 32px rgba(30,34,49,0.18); text-align: left; }
.nav-pop p { font-family: var(--head); font-weight: 800; font-size: 14px; line-height: 1.5; margin: 0 0 10px; }
.nav-pop-go { display: block; text-align: center; font-family: var(--head); font-weight: 800; font-size: 14px; color: var(--white); background: var(--ink); text-decoration: none; padding: 11px 12px; border-radius: 8px; }
.nav-pop-x { display: block; width: 100%; margin-top: 6px; font: inherit; font-family: var(--head); font-weight: 800; font-size: 13px; color: var(--ink-soft); background: transparent; border: 0; padding: 8px; cursor: pointer; border-radius: 8px; }
.nav-pop-x:hover { background: var(--cream); }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 3px solid var(--ink); outline-offset: 2px; border-radius: 8px; }
.nav a:focus-visible, .share-main:focus-visible { outline-color: var(--white); }
/* オレンジ地の白い見出し: 可読性のためのごく薄い影 */
.hero h1, .hero .tag, .unit-hero h1, .final h2, .unit-cta p { text-shadow: 0 1px 2px rgba(30,34,49,0.22); }
.doc-wrap .chip-muted { background: transparent; color: var(--ink-soft); box-shadow: inset 0 0 0 1.5px var(--cream); cursor: default; }
.chip-muted small { font-size: 10px; margin-left: 6px; opacity: 0.8; }
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .45s ease, transform .45s ease; }
.reveal.is-in { opacity: 1; transform: none; }
.who-card.reveal:nth-child(2) { transition-delay: .08s; } .who-card.reveal:nth-child(3) { transition-delay: .16s; }
/* ランクアップの区画: 宇宙背景＋岩 */
.feature.space { background: var(--space); color: var(--white); }
.feature.space h2 { color: var(--white); }
.feature.space p { color: rgba(255,255,255,0.78); }
.feature.space .num { color: var(--yellow); }
.feature.space .art { position: relative; min-height: 440px; }
.feature.space .phone { position: relative; z-index: 2; background: #2a2f44; }
.rock { position: absolute; z-index: 1; height: auto; pointer-events: none; animation: rockFloat var(--fd) ease-in-out infinite; animation-delay: var(--fdl); will-change: transform; }
/* 手前(大)ほど大きくゆっくり、奥(小)ほど小さく速く上下する。回転はしない(背景スプライトの規則) */
.rock.r1 { --fd: 7.5s; --fdl: -1.2s; --fa: -16px; }
.rock.r2 { --fd: 6.2s; --fdl: -3.4s; --fa: -11px; }
.rock.r3 { --fd: 5.4s; --fdl: -0.6s; --fa: -8px; }
.rock.r4 { --fd: 6.8s; --fdl: -4.1s; --fa: -13px; }
@keyframes rockFloat { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(var(--fa)); } }
@media (prefers-reduced-motion: reduce) { .rock { animation: none; } }
.rock.r1 { width: 120px; left: 2%; top: 6%; opacity: 0.95; }
.rock.r2 { width: 76px; right: 6%; top: 14%; opacity: 0.8; }
.rock.r3 { width: 56px; left: 10%; bottom: 8%; opacity: 0.7; }
.rock.r4 { width: 96px; right: 0; bottom: 4%; opacity: 0.9; }
@media (max-width: 860px) { .feature.space .art { min-height: 0; } .rock.r1 { width: 90px; left: 0; top: 0; } .rock.r2 { width: 58px; right: 0; top: 10%; } .rock.r3 { width: 44px; left: 4%; bottom: 6%; } .rock.r4 { width: 72px; right: 2%; bottom: 0; } }
/* ---------- フレンドのプロフィールカード(アプリの ProfileCard/RankMedal の定義値に合わせる) ---------- */
.fcard-wrap { width: 100%; max-width: 360px; perspective: 1000px; user-select: none; -webkit-user-select: none; }
.fcard { position: relative; width: 100%; aspect-ratio: 1.4 / 1; transform-style: preserve-3d; transition: transform .5s cubic-bezier(.2,.8,.2,1); cursor: pointer; outline: none; touch-action: none; -webkit-tap-highlight-color: transparent; }
.fcard.is-flipped { transform: rotateY(180deg); }
.fcard, .fcard * { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "Hiragino Sans", Arial, sans-serif; }
.fcard img { -webkit-user-drag: none; user-select: none; pointer-events: none; }
.fcard-face { position: absolute; inset: 0; border-radius: 22px; backface-visibility: hidden; -webkit-backface-visibility: hidden; overflow: hidden; box-shadow: 0 6px 12px rgba(0,0,0,0.35); border: 2px solid rgba(255,255,255,0.7); }
.fcard-front { color: var(--white); background-image: url("data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%27http%3A//www.w3.org/2000/svg%27%20viewBox%3D%270%200%20360%20230%27%3E%3Ccircle%20cx%3D%22122%22%20cy%3D%2279%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22247%22%20cy%3D%2241%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%2212%22%20cy%3D%22104%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22115%22%20cy%3D%22135%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2290%22%20cy%3D%22213%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22111%22%20cy%3D%228%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22101%22%20cy%3D%2244%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22323%22%20cy%3D%22224%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22312%22%20cy%3D%2288%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%2293%22%20cy%3D%2265%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2247%22%20cy%3D%22211%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22151%22%20cy%3D%22148%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22213%22%20cy%3D%22110%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22233%22%20cy%3D%2243%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22134%22%20cy%3D%22210%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%2225%22%20cy%3D%22120%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22177%22%20cy%3D%2239%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22213%22%20cy%3D%2253%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2296%22%20cy%3D%2293%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22326%22%20cy%3D%22144%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2253%22%20cy%3D%22216%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22144%22%20cy%3D%22197%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22171%22%20cy%3D%2247%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%2215%22%20cy%3D%2212%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22148%22%20cy%3D%22190%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22167%22%20cy%3D%2275%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22335%22%20cy%3D%22107%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22318%22%20cy%3D%2251%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2271%22%20cy%3D%2266%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22171%22%20cy%3D%22148%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2224%22%20cy%3D%22118%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22187%22%20cy%3D%2276%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22108%22%20cy%3D%22110%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%2232%22%20cy%3D%2217%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22306%22%20cy%3D%22175%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22281%22%20cy%3D%22127%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2220%22%20cy%3D%2233%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22335%22%20cy%3D%2253%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22125%22%20cy%3D%22114%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%2220%22%20cy%3D%2258%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22129%22%20cy%3D%22167%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22257%22%20cy%3D%2250%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22132%22%20cy%3D%2266%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22120%22%20cy%3D%22108%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22168%22%20cy%3D%2215%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22293%22%20cy%3D%22105%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3C/svg%3E"), linear-gradient(to bottom right, #223065 0%, #141a3c 100%); background-size: 100% 100%, 100% 100%; }
.fcard-top { position: absolute; left: 18px; right: 18px; top: 18px; height: 32px; display: flex; align-items: center; gap: 6px; }
/* 六角メダル: 厚み(edge, 下にずらす)→面→ハイライト→境目リング→紺の中央→紋章 */
.fcard-medal { position: relative; width: 32px; height: 32px; display: block; flex: none; }
.fcard-medal img { position: absolute; left: -12px; top: -12px; width: 56px; height: 56px; max-width: none; }
.fcard-rank { font-weight: 800; font-size: 13px; }
.fcard-streak { margin-left: auto; align-self: flex-start; display: inline-flex; align-items: center; gap: 5px; font-weight: 800; font-size: 18px; line-height: 1.2; font-variant-numeric: tabular-nums; }
.fcard-streak .flame { width: auto; height: 19px; }
.fcard-planet { position: absolute; left: 50%; top: 50%; width: 28%; height: auto; transform: translate(-50%, -50%); filter: drop-shadow(0 5px 12px rgba(0,0,0,0.45)); }
.fcard-bottom { position: absolute; left: 18px; right: 18px; bottom: 18px; display: flex; justify-content: space-between; align-items: flex-end; gap: 8px; }
.fcard-lv { font-weight: 800; font-size: 20px; line-height: 1.2; color: #fbbf24; }
.fcard-name { font-weight: 800; font-size: 16px; line-height: 1.2; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.fcard-sheen { position: absolute; inset: 0; pointer-events: none; background: linear-gradient(115deg, transparent 40%, rgba(255,255,255,0.2) 50%, transparent 60%); background-size: 200% 100%; opacity: 0; transition: opacity .2s; }
.fcard.is-tilting .fcard-sheen { opacity: 1; }
.fcard-hint { font-size: 12px; color: var(--ink-soft); margin-top: 12px; text-align: center; }
/* 裏面 */
.fcard-back { transform: rotateY(180deg); background: linear-gradient(180deg, #f7f8fc 0%, #e9edf6 100%); color: #1b2440; display: flex; flex-direction: column; }
.fb-top { flex: 0 0 56%; background-image: url("data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%27http%3A//www.w3.org/2000/svg%27%20viewBox%3D%270%200%20360%20230%27%3E%3Ccircle%20cx%3D%22122%22%20cy%3D%2279%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22247%22%20cy%3D%2241%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%2212%22%20cy%3D%22104%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22115%22%20cy%3D%22135%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2290%22%20cy%3D%22213%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22111%22%20cy%3D%228%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22101%22%20cy%3D%2244%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22323%22%20cy%3D%22224%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22312%22%20cy%3D%2288%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%2293%22%20cy%3D%2265%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2247%22%20cy%3D%22211%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22151%22%20cy%3D%22148%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22213%22%20cy%3D%22110%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22233%22%20cy%3D%2243%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22134%22%20cy%3D%22210%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%2225%22%20cy%3D%22120%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22177%22%20cy%3D%2239%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22213%22%20cy%3D%2253%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2296%22%20cy%3D%2293%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22326%22%20cy%3D%22144%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2253%22%20cy%3D%22216%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22144%22%20cy%3D%22197%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22171%22%20cy%3D%2247%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%2215%22%20cy%3D%2212%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22148%22%20cy%3D%22190%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22167%22%20cy%3D%2275%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22335%22%20cy%3D%22107%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22318%22%20cy%3D%2251%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2271%22%20cy%3D%2266%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22171%22%20cy%3D%22148%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2224%22%20cy%3D%22118%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%22187%22%20cy%3D%2276%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22108%22%20cy%3D%22110%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%2232%22%20cy%3D%2217%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22306%22%20cy%3D%22175%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22281%22%20cy%3D%22127%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.7%22/%3E%3Ccircle%20cx%3D%2220%22%20cy%3D%2233%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22335%22%20cy%3D%2253%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22125%22%20cy%3D%22114%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%2220%22%20cy%3D%2258%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3Ccircle%20cx%3D%22129%22%20cy%3D%22167%22%20r%3D%221.4%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22257%22%20cy%3D%2250%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22132%22%20cy%3D%2266%22%20r%3D%220.9%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22120%22%20cy%3D%22108%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.5%22/%3E%3Ccircle%20cx%3D%22168%22%20cy%3D%2215%22%20r%3D%221.1%22%20fill%3D%22%23fff%22%20opacity%3D%220.35%22/%3E%3Ccircle%20cx%3D%22293%22%20cy%3D%22105%22%20r%3D%220.7%22%20fill%3D%22%23fff%22%20opacity%3D%220.9%22/%3E%3C/svg%3E"), linear-gradient(to bottom right, #223065 0%, #141a3c 100%); background-size: 100% 100%, 100% 100%; color: var(--white); display: flex; align-items: center; justify-content: center; gap: 24px; }
.fb-stat { display: flex; flex-direction: column; align-items: center; gap: 2px; padding: 0 8px; }
.fb-v { display: inline-flex; align-items: baseline; gap: 6px; font-weight: 900; font-size: 28px; line-height: 1; font-variant-numeric: tabular-nums; }
.fb-v .flame { width: auto; height: 22px; align-self: center; }
.fb-v small { font-size: 13px; font-weight: 900; }
.fb-l { font-size: 10px; font-weight: 600; opacity: 0.85; margin-top: 4px; }
.fb-sep { width: 1px; height: 36px; background: rgba(255,255,255,0.12); }
.fb-days { flex: 1; display: flex; align-items: center; justify-content: space-between; padding: 0 16px; }
.fd { display: flex; flex-direction: column; align-items: center; gap: 4px; }
.fd-w { font-size: 10px; font-weight: 700; color: rgba(27,36,64,0.4); }
.fd-c { width: 30px; height: 30px; border-radius: 50%; background: rgba(27,36,64,0.07); color: rgba(27,36,64,0.45); font-size: 11px; font-weight: 600; display: flex; align-items: center; justify-content: center; }
.fd-c .flame { width: auto; height: 14px; }
.fd.done .fd-c { background: linear-gradient(180deg, #fb923c, #f97316); color: var(--white); }
.fd.today .fd-c { box-shadow: inset 0 0 0 2px #f5a623; color: rgba(27,36,64,0.7); }
@media (max-width: 860px) { .fcard-wrap { margin: 0 auto; } }

/* 太陽系の惑星(アプリの素材)。使うのは LP 無料セクションの白地の帯だけ。上下にゆっくり浮く(回転なし) */
@keyframes plFloat { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(var(--fa, -8px)); } }
.pl-float { animation: plFloat var(--fd, 6s) ease-in-out infinite; animation-delay: var(--fdl, 0s); will-change: transform; }
@media (prefers-reduced-motion: reduce) { .pl-float { animation: none; } }
.free .orbit { display: flex; justify-content: center; align-items: center; gap: 22px; margin-bottom: 30px; }
.free .orbit img { width: var(--s, 60px); height: auto; filter: drop-shadow(0 4px 6px rgba(30,34,49,0.1)); }
@media (max-width: 600px) { .free .orbit { gap: 7px; } .free .orbit img { width: calc(var(--s, 60px) * 0.56); } }

/* FAQ: アプリの会話風カード(ボンが質問 → タップで答えの吹き出し) */
.atom .faqg { display: grid; gap: 12px; margin-top: 14px; }
.atom .faq-card { background: var(--cream); border-radius: 18px; }
.atom .faq-card summary { list-style: none; cursor: pointer; display: grid; grid-template-columns: 44px 1fr auto; align-items: center; column-gap: 12px; padding: 14px 16px; }
.atom .faq-card summary::-webkit-details-marker { display: none; }
.atom .faq-avatar { width: 44px; height: 44px; border-radius: 50%; overflow: hidden; background: #000; }
.atom .faq-avatar img { width: 100%; height: 100%; display: block; object-fit: cover; }
.atom .faq-q { font-family: var(--head); font-weight: 800; font-size: 16px; line-height: 1.5; color: var(--ink); }
.atom .faq-tag { display: inline-block; margin-right: 8px; padding: 1px 8px; border-radius: 8px; background: var(--ink); color: var(--white); font-family: var(--logo); font-weight: 700; font-size: 12px; letter-spacing: 0.06em; vertical-align: 2px; }
.atom .faq-btn { font-family: var(--head); font-weight: 800; font-size: 13px; color: var(--ink); background: var(--yellow); padding: 8px 12px; border-radius: 999px; white-space: nowrap; }
.atom .faq-btn .c { display: none; }
.atom .faq-card[open] .faq-btn .o { display: none; }
.atom .faq-card[open] .faq-btn .c { display: inline; }
.atom .faq-card[open] .faq-btn { background: var(--white); }
.atom .faq-a { display: grid; grid-template-columns: 44px 1fr; column-gap: 12px; padding: 0 16px 16px; animation: faqPop .28s cubic-bezier(.2,.8,.2,1); }
.atom .faq-atag { width: 44px; height: 44px; border-radius: 50%; background: var(--orange); color: var(--white); font-family: var(--logo); font-weight: 700; font-size: 18px; display: flex; align-items: center; justify-content: center; }
.atom .faq-ab { position: relative; background: var(--white); border-radius: 16px 16px 16px 4px; padding: 12px 16px; font-size: 15px; line-height: 1.8; color: var(--ink); }
.atom .faq-ab::before { content: ''; position: absolute; left: -8px; top: 14px; border: 6px solid transparent; border-right-color: var(--white); }
@keyframes faqPop { from { transform: translateY(6px) scale(0.98); opacity: 0; } to { transform: none; opacity: 1; } }
@media (max-width: 600px) { .atom .faq-card summary { grid-template-columns: 36px 1fr; row-gap: 8px; } .atom .faq-avatar { width: 36px; height: 36px; } .atom .faq-btn { grid-column: 2; justify-self: start; } .atom .faq-a { grid-template-columns: 36px 1fr; } .atom .faq-atag { width: 36px; height: 36px; font-size: 15px; } }
@media (prefers-reduced-motion: reduce) { .atom .faq-a { animation: none; } }

/* ---------- 単元ページの整え (2026-10-13) ----------
   ⚠ 本人の指摘: 「全部丸い角でメリハリがない」「開く・閉じるでボタンの位置がずれる」「余白に余裕がない」「まとまりがない」。
   決まり: 角は 3 段 (囲み 4px / ボタン 8px / 札は作らず文字だけ)。例題とよくある質問は同じカードの形。
   開閉ボタンは幅を固定して、文字が変わっても位置が動かない。 */
.unit .doc-wrap { padding-left: 24px; padding-right: 24px; }
.unit-tag { border-radius: 3px; }
.atom .formula { border-radius: 4px; margin: 32px 0 24px; }
.atom h2 { font-size: 22px; margin: 64px 0 20px; }
.atom .point + .point { margin-top: 16px; }

/* 例題カード: 1 段目 = 番号・問いかけ・ボタン、2 段目 = 式 (問いかけと左をそろえる) */
.atom .examples > li { background: var(--cream); border-radius: 4px; margin-bottom: 12px; }
.atom .ex-ans summary, .atom .examples.long .ex-ans summary { grid-template-columns: 28px 1fr auto; grid-template-areas: "num label toggle" ". q q";
  column-gap: 10px; row-gap: 4px; align-items: center; padding: 18px 18px 18px 16px; }
.atom .ex-ans .num { grid-area: num; font-size: 15px; }
.atom .ex-ans .label, .atom .examples.long .ex-ans .label { grid-area: label; justify-self: start; background: none; padding: 0; border-radius: 0;
  white-space: normal; font-size: 14px; line-height: 1.6; color: var(--ink); }
.atom .ex-q, .atom .examples.long .ex-q { grid-area: q; text-align: left; padding: 10px 0 2px; }
.atom .ex-ans.noq summary { grid-template-areas: "num label toggle"; }
.atom .ex-toggle { grid-area: toggle; box-sizing: border-box; width: 76px; text-align: center; padding: 8px 0; border-radius: 8px; }
.atom .ex-ans .a { margin: 0 12px 12px 54px; border-radius: 4px; padding: 14px 16px; }
.atom .ex-ans .a:has(+ .sol) { border-radius: 4px 4px 0 0; margin-bottom: 0; }
.atom .sol { margin: 0 12px 12px 54px; border-radius: 0 0 4px 4px; padding: 0 16px 18px; }
.atom .ex-ans .atag, .atom .sol-h { background: none; padding: 0; border-radius: 0; color: var(--orange-deep);
  font-family: var(--head); font-weight: 800; font-size: 13px; line-height: 1.3; }
.atom .sol-h { padding-top: 10px; }
.atom .sol-steps { padding-top: 8px; gap: 12px; }

/* よくある質問も同じカード */
.atom .faqg { gap: 12px; margin-top: 20px; }
.atom .faq-card { border-radius: 4px; }
.atom .faq-card summary { grid-template-columns: 1fr auto; column-gap: 10px; padding: 18px 18px 18px 16px; }
.atom .faq-avatar, .atom .faq-atag { display: none; }
.atom .faq-q { font-size: 15px; display: block; position: relative; padding-left: 38px; }
.atom .faq-tag { position: absolute; left: 0; top: 1px; background: none; color: var(--orange-deep); padding: 0; margin: 0; border-radius: 0; font-size: 15px; }
.atom .faq-btn { box-sizing: border-box; width: 76px; text-align: center; padding: 8px 0; border-radius: 8px; background: var(--white); }
.atom .faq-card[open] .faq-btn { background: var(--ink); color: var(--white); }
.atom .faq-a { display: block; padding: 0 12px 12px 54px; animation: none; }
.atom .faq-ab { border-radius: 4px; padding: 14px 16px; }
.atom .faq-ab::before { display: none; }
@media (max-width: 600px) {
  .atom .faq-card summary { grid-template-columns: 1fr auto; }
  .atom .faq-btn { grid-column: auto; justify-self: auto; }
  .atom .faq-a { grid-template-columns: none; }
}

/* アプリの案内と学習の流れ */
.unit-cta { border-radius: 4px; margin-top: 64px; padding: 28px 24px; }
.unit-path { margin-top: 56px; }
.doc-wrap .unit-path .chip-link.current { border-radius: 4px; }
.unit-ch { margin-top: 48px; }
.atom .updated { margin-top: 40px; }
@media (max-width: 600px) {
  /* 学習の流れ: スマホでは「前提 / この単元 / 次」を左の見出しにした表にする (矢印は出さない) */
  .unit-path { grid-template-columns: 1fr; gap: 0; background: var(--cream); border-radius: 4px; padding: 6px 18px; }
  .unit-path .up-arrow { display: none; }
  .unit-path .up-col { display: grid; grid-template-columns: 72px 1fr; align-items: baseline; gap: 0 12px; padding: 12px 0; }
  .unit-path .up-k { font-family: var(--head); font-weight: 800; font-size: 12px; letter-spacing: 0; color: var(--ink-soft); }
  .doc-wrap .unit-path .chip-link.current { padding: 0; margin: 0; background: none; color: var(--ca); }
}
/* 数式はできるだけ中央・答えの面は左を空けずにカードの幅いっぱい (本人の指摘 2026-10-13) */
.atom .ex-ans summary, .atom .examples.long .ex-ans summary { grid-template-areas: "num label toggle" "q q q"; }
.atom .ex-q, .atom .examples.long .ex-q { text-align: center; }
.atom .ex-ans .a { margin: 0 12px 12px; flex-direction: column; align-items: stretch; gap: 2px; }
.atom .ex-ans .a .atag { align-self: flex-start; }
.atom .ex-a { text-align: center; }
.atom .sol { margin: 0 12px 12px; }
.atom .sol-steps .st-eqs { align-self: center; }
.atom .faq-a { padding: 0 12px 12px; }

/* ---------- 問題集の一覧 (2026-10-13 作り直し) ----------
   スマホ: 章の切り替えは上に貼りつく横 1 列・カードは 1 列で詰める。
   パソコン: 左に章の目次を固定し、右にカードを 2 列。角は単元ページと同じ 4px、丸い札は作らない。 */
.doc-wrap.pindex { padding-top: 0; }
.pside { display: flex; gap: 4px; position: sticky; top: 60px; z-index: 10; background: var(--white);
  margin: 0 -24px; padding: 0 24px; overflow-x: auto; scrollbar-width: none; }
.pside::-webkit-scrollbar { display: none; }
.doc-wrap .ps-ch { flex: none; display: flex; align-items: baseline; gap: 6px; padding: 16px 10px 14px; text-decoration: none; color: var(--ink); }
.ps-ch:first-child { padding-left: 0; }
.ps-no { font-family: var(--logo); font-weight: 700; font-size: 13px; color: var(--ca); }
.ps-t { font-family: var(--head); font-weight: 800; font-size: 14px; white-space: nowrap; }
.ps-c { display: none; }
.ps-ch.on .ps-t { color: var(--ca); }
.pindex .pl-ch { margin: 40px 0 16px; gap: 10px; align-items: baseline; }
.pindex .pl-ch .ch-no { min-width: 0; height: auto; padding: 0; border-radius: 0; background: none; color: var(--ca); font-size: 18px; }
.pindex .plist { gap: 10px; margin: 0 0 8px; }
.pindex .plist li, .pindex .plist li a { border-radius: 4px; }
.pindex .plist li a { display: grid; grid-template-columns: 36px 1fr; grid-template-areas: "no title" "f f" "meta meta"; align-items: baseline;
  min-height: 0; padding: 16px 18px 14px; }
.pindex .pl-no { grid-area: no; font-size: 13px; }
.pindex .pl-title { grid-area: title; margin: 0; font-size: 16px; }
.pindex .pl-f { grid-area: f; justify-content: center; height: 48px; margin-top: 8px; }
.pindex .pl-f .katex { transform-origin: center; }
.pindex .pl-meta { grid-area: meta; padding-top: 6px; }
@media (min-width: 861px) {
  body:has(.pindex) .unit-hero .wrap { max-width: 1080px; }
  .doc-wrap.pindex { max-width: 1080px; display: grid; grid-template-columns: 240px minmax(0, 1fr); column-gap: 48px; padding-top: 48px; }
  .pside { flex-direction: column; gap: 2px; top: 92px; align-self: start; margin: 0; padding: 0; overflow: visible; background: none; }
  .doc-wrap .ps-ch, .ps-ch:first-child { display: grid; grid-template-columns: 28px 1fr auto; padding: 10px 12px; border-radius: 4px; }
  .ps-c { display: inline; font-family: var(--body); font-size: 12px; font-weight: 600; color: var(--ink-soft); }
  .ps-t { white-space: normal; line-height: 1.45; min-width: 0; word-break: keep-all; overflow-wrap: anywhere; }
  .doc-wrap .ps-ch, .ps-ch:first-child { align-items: start; }
  .ps-ch:hover { background: var(--cream); }
  .ps-ch.on { background: var(--cb); }
  .ps-ch.on .ps-t { color: var(--ink); }
  .pindex .pl-ch { margin: 0 0 18px; }
  .pindex .plist + .pl-ch { margin-top: 56px; }
  .pindex .plist { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 16px; }
  .pindex .plist li a { grid-template-columns: 1fr; grid-template-areas: "no" "title" "f" "meta"; min-height: 196px; padding: 22px 24px 18px; }
  .pindex .pl-title { margin-top: 4px; font-size: 17px; }
  .pindex .pl-f { height: 64px; margin-top: 12px; font-size: 16px; }
  .pindex .pl-meta { align-self: end; padding-top: 12px; }
}
/* 一覧の遊び (画像は使わない): 大きな数式と章の番号を画面の左右の端からはみ出させる */
.pidx-hero { position: relative; overflow: hidden; }
.pidx-hero .wrap { position: relative; z-index: 1; }
.ph-math { position: absolute; inset: 0; pointer-events: none; color: var(--white); }
.ph-math > span { position: absolute; opacity: 0.22; white-space: nowrap; transform: rotate(-4deg); }
.ph-math .katex { color: var(--white); }
.ph-math .m1 { font-size: 92px; right: -46px; top: -6px; --fd: 9s; --fdl: -2s; --fa: -10px; }
.ph-math .m2 { font-size: 44px; left: -30px; bottom: -14px; --fd: 11s; --fdl: -5s; --fa: 8px; }
.ph-math .m3 { display: none; }
body:has(.pindex) { overflow-x: hidden; }
.pindex .pl-ch { position: relative; }
.pindex .pl-ch::before { content: attr(data-no); position: absolute; z-index: -1; left: -46px; top: 50%; transform: translateY(-58%);
  font-family: var(--logo); font-weight: 700; font-size: 120px; line-height: 1; color: var(--cb); pointer-events: none; }
.pindex .pl-ch:nth-of-type(even)::before { left: auto; right: -46px; }
.pindex .pl-ch .ch-no { font-size: 22px; }
.pindex .pl-ch .ch-t { font-size: 22px; line-height: 1.3; }
.pindex .pl-ch .ch-n { align-self: center; }
.pindex .plist li a { transition: transform .22s cubic-bezier(.2,.8,.2,1), background-color .18s ease; }
.pindex .plist li a:active { transform: scale(.98); }
.pindex .pl-f .katex { transition: scale .25s cubic-bezier(.2,.8,.2,1); }
.pindex .plist li a:hover .pl-f .katex { scale: 1.06; }
.pindex .pl-meta { display: flex; align-items: baseline; }
.pl-go { margin-left: auto; font-family: var(--logo); font-weight: 700; font-size: 16px; color: var(--ca); opacity: 0; transform: translateX(-6px);
  transition: opacity .2s ease, transform .2s ease; }
.pindex .plist li a:hover .pl-go { opacity: 1; transform: none; }
@media (hover: none) { .pl-go { opacity: 1; transform: none; } }
@media (min-width: 861px) {
  .pidx-hero .lead { max-width: 620px; }
  .ph-math .m1 { font-size: 120px; right: -70px; top: auto; bottom: -34px; }
  .ph-math .m2 { display: none; }
  .ph-math .m3 { display: block; font-size: 52px; left: -40px; top: 34%; --fd: 10s; --fdl: -7s; --fa: -8px; }
  /* パソコン: 左は目次があるので、番号は右の画面の端からはみ出させる (本文の右端から画面の右端まで = 50vw - 516px) */
  .pindex .pl-ch::before, .pindex .pl-ch:nth-of-type(even)::before { left: auto; right: max(-60px, calc(516px - 50vw - 30px)); font-size: 170px; }
  .pindex .pl-ch .ch-n { margin-left: 4px; align-self: baseline; }
}
@media (prefers-reduced-motion: reduce) { .ph-math > span { animation: none; } .pindex .plist li a, .pindex .pl-f .katex, .pl-go { transition: none; } }

/* ---------- 単元ページ: パソコンとスマホで別の形 (2026-10-13) ----------
   ヘッダーにその単元の公式と番号を大きく透かし、画面の端からはみ出させる (画像は使わない)。
   パソコンは本文の右に「アプリ・学習の流れ・章の単元」を貼りつけ、スマホは今のまま縦に並べる。 */
.aunit-hero { position: relative; overflow: hidden; }
.aunit-hero .wrap { position: relative; z-index: 1; }
.aunit-hero .ph-math .m1 { font-size: 46px; left: 46%; right: auto; top: auto; bottom: -8px; opacity: 0.2; --fd: 10s; --fdl: -3s; --fa: -8px;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 30%); mask-image: linear-gradient(90deg, transparent, #000 30%); }
.aunit .unit-path { grid-template-columns: 1fr; gap: 0; background: var(--cream); border-radius: 4px; padding: 6px 18px; }
.aunit .unit-path .up-arrow { display: none; }
.aunit .unit-path .up-col { display: grid; grid-template-columns: 72px 1fr; align-items: baseline; gap: 0 12px; padding: 12px 0; }
.aunit .unit-path .up-k { font-family: var(--head); font-weight: 800; font-size: 12px; letter-spacing: 0; color: var(--ink-soft); }
.doc-wrap.aunit .unit-path .chip-link.current { padding: 0; margin: 0; background: none; color: var(--ca); }
.aunit .unit-cta .badge img { margin: 0; }
@media (max-width: 860px) {
  .aunit .unit-cta { text-align: left; align-items: flex-start; }
}
@media (min-width: 861px) {
  body:has(.aunit) .unit-hero .wrap { max-width: 1080px; }
  .aunit-hero .ph-math .m1 { font-size: 84px; left: 58%; bottom: -16px; }
  .doc-wrap.aunit { max-width: 1080px; display: grid; grid-template-columns: minmax(0, 1fr) 300px; column-gap: 64px; align-items: start; }
  .aunit .amain { min-width: 0; }
  .aunit .aside { position: sticky; top: 84px; padding-top: 32px; }
  .aunit .unit-cta { margin-top: 0; display: block; padding: 22px 22px 20px; }
  .aunit .unit-cta p { font-size: 15px; line-height: 1.5; }
  .aunit .unit-path { margin-top: 20px; }
  .aunit .unit-ch { margin-top: 28px; }
  .aunit .ch-list { grid-template-columns: 1fr; }
  .aunit .updated { grid-column: 1 / -1; }
}

/* 「どれ？」の例題は選択肢を 4 つ並べる。答えを開くと正解に色が付く */
.atom .ex-ans summary:has(.ex-ch), .atom .examples.long .ex-ans summary:has(.ex-ch) { grid-template-areas: "num label toggle" "q q q" "ch ch ch"; }
.atom .ex-ans.noq summary:has(.ex-ch) { grid-template-areas: "num label toggle" "ch ch ch"; }
.atom .ex-ch { grid-area: ch; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; margin-top: 10px; }
.atom .ex-ch .c { display: grid; grid-template-columns: 18px minmax(0, 1fr); align-items: center; gap: 8px; background: var(--white); border-radius: 4px; padding: 10px 12px; min-width: 0; }
.atom .ex-ch .k { font-family: var(--head); font-weight: 800; font-size: 13px; color: var(--ink-soft); }
.atom .ex-ch .v { font-size: 17px; text-align: center; overflow-x: auto; overflow-y: hidden; scrollbar-width: none; }
.atom .ex-ch .v::-webkit-scrollbar { display: none; }
.atom .ex-ch .v .katex { white-space: nowrap; }
/* js-fold のときは details がいつも open なので、開いた印は .is-open で見る */
.atom .ex-ans:not(.js-fold)[open] .ex-ch .c.ok, .atom .ex-ans.js-fold.is-open .ex-ch .c.ok { background: var(--yellow); }
.atom .ex-ans:not(.js-fold)[open] .ex-ch .c.ok .k, .atom .ex-ans.js-fold.is-open .ex-ch .c.ok .k { color: var(--orange-deep); }
.atom .ex-ans:not(.js-fold)[open] .ex-ch .c:not(.ok), .atom .ex-ans.js-fold.is-open .ex-ch .c:not(.ok) { opacity: .45; }
.atom .ex-ch .c { transition: background .25s, opacity .25s; }
@media (max-width: 600px) { .atom .ex-ch { grid-template-columns: minmax(0, 1fr); } .atom .ex-ch .v { font-size: 16px; } }

/* アプリの案内: ロケットのボンを右下に置き、頭は枠の上へはみ出す (本人の依頼 2026-10-14) */
.aunit .unit-cta { position: relative; }
.aunit .unit-cta > div { position: relative; z-index: 1; }
.aunit .unit-cta img.bon { position: absolute; right: -10px; bottom: -4px; width: 124px; margin: 0; pointer-events: none; }
@media (min-width: 861px) { .aunit .unit-cta > div { padding-right: 64px; } .aunit .unit-cta img.bon { width: 190px; right: -46px; bottom: 18px; transform: rotate(-8deg); } }
@media (max-width: 860px) { .aunit .unit-cta { padding-right: 132px; } .aunit .unit-cta img.bon { width: 180px; right: -20px; bottom: 26px; transform: rotate(-8deg); } }

/* PC のヘッダーの App Store に乗せると QR (スマホはホバーが無いので出さない) */
.nav-qr { display: none; }
@media (hover: hover) and (pointer: fine) and (min-width: 861px) {
  .nav-cta { position: relative; }
  .nav-qr { position: absolute; top: calc(100% + 10px); right: 0; z-index: 60; display: flex; flex-direction: column; align-items: center; gap: 6px;
            background: var(--white); color: var(--ink); border-radius: 8px; padding: 12px 12px 10px; box-shadow: 0 8px 24px rgba(30,34,49,.18);
            opacity: 0; visibility: hidden; transform: translateY(-4px); transition: opacity .15s, transform .15s, visibility .15s; }
  .nav-qr img { width: 120px; height: 120px; display: block; }
  .nav-qr small { font-size: 12px; font-weight: 700; white-space: nowrap; opacity: .75; }
  .nav-cta:hover .nav-qr, .nav-cta:focus-visible .nav-qr { opacity: 1; visibility: visible; transform: none; }
  .unit-cta .qr { margin: 12px 0 0; }
  .unit-cta .qr { flex-direction: column; align-items: flex-start; gap: 6px; }
  .unit-cta .qr span { color: var(--ink); opacity: .85; font-weight: 700; }
}

/* ---------- 学習の流れ (路線図): 前 → いまここ → 次 を 1 本の線でつなぐ ---------- */
.route { margin-top: 48px; background: var(--cream); border-radius: 4px; padding: 18px 18px 22px; }
.route .rt-h { font-family: var(--head); font-weight: 800; font-size: 15px; color: var(--ink); margin: 0 0 14px; }
.rt-sec, .rt-here { position: relative; padding-left: 30px; }
.rt-sec::before, .rt-here::before { content: ''; position: absolute; left: 7.5px; top: 0; bottom: 0; width: 3px; border-radius: 2px; background: color-mix(in srgb, var(--ca) 40%, transparent); }
.rt-sec:first-of-type::before { top: 26px; }
.rt-sec:last-child { padding-bottom: 14px; }
.rt-sec:last-child::before { bottom: 6px; }
.rt-sec:last-child::after { content: ''; position: absolute; left: 2.5px; bottom: 5px; width: 10px; height: 10px; border-right: 3.5px solid color-mix(in srgb, var(--ca) 55%, transparent); border-bottom: 3.5px solid color-mix(in srgb, var(--ca) 55%, transparent); border-radius: 0 0 2px 0; transform: rotate(45deg); }
.rt-k { display: block; font-family: var(--head); font-weight: 800; font-size: 11px; color: var(--ink-soft); opacity: .75; padding: 2px 0 6px; }
.rt-list { list-style: none; margin: 0; padding: 0 0 12px; display: flex; flex-direction: column; gap: 2px; }
.rt-stop { position: relative; }
.rt-stop::before { content: ''; position: absolute; left: -27px; top: 50%; width: 8px; height: 8px; margin-top: -6px; border-radius: 50%; background: var(--cream); border: 2px solid var(--ca, var(--ink-soft)); }
.rt-stop a, .rt-row { display: flex; align-items: baseline; gap: 10px; padding: 7px 10px; margin: 0 -10px; border-radius: 4px; color: var(--ink); text-decoration: none; -webkit-tap-highlight-color: rgba(30,34,49,0.08); }
.rt-no { flex: 0 0 auto; min-width: 26px; font-family: var(--logo); font-weight: 700; font-size: 12px; letter-spacing: .04em; color: var(--ca, var(--ink-soft)); }
.rt-name { min-width: 0; font-weight: 700; font-size: 14.5px; line-height: 1.45; word-break: keep-all; overflow-wrap: anywhere; }
.rt-stop.is-soon::before, .rt-stop.is-none::before { border-color: rgba(30,34,49,.22); }
.rt-stop.is-soon .rt-no { font-family: var(--head); font-size: 10px; letter-spacing: 0; color: var(--ink-soft); background: rgba(30,34,49,.07); border-radius: 4px; padding: 1px 6px; align-self: center; }
.rt-stop.is-soon .rt-name, .rt-stop.is-none .rt-name { color: var(--ink-soft); font-weight: 500; }
.rt-here { padding-top: 2px; padding-bottom: 14px; }
.rt-here .rt-row { background: var(--white); padding: 10px 12px; margin: 0 -8px 0 -12px; box-shadow: 0 1px 0 rgba(30,34,49,.04); }
.rt-here .rt-name { font-size: 15.5px; font-weight: 800; color: var(--ca); }
.rt-here .rt-row { position: relative; }
.rt-here .rt-row::before { content: ''; position: absolute; left: -14px; top: 50%; margin-top: -5px; width: 10px; height: 10px; border-radius: 50%; background: var(--ca); box-shadow: 0 0 0 3px var(--cream), 0 0 0 6px color-mix(in srgb, var(--ca) 30%, transparent); }
.rt-here .rt-k { color: var(--ca); opacity: 1; }
@media (hover: hover) and (pointer: fine) {
  .rt-stop a:hover { background: rgba(255,255,255,.75); }
  .rt-stop a:hover .rt-name { color: var(--ca); }
}
@media (min-width: 861px) { .aunit .route { margin-top: 20px; } }
/* スマホ: 押しやすい高さ、行の右に › */
@media (max-width: 860px) {
  .route { padding: 20px 16px 22px; }
  .rt-stop a, .rt-here .rt-row { min-height: 46px; align-items: center; }
  .rt-stop a { padding-right: 30px; position: relative; }
  .rt-stop a::after { content: ''; position: absolute; right: 14px; top: 50%; width: 7px; height: 7px; margin-top: -4px; border-right: 2px solid rgba(30,34,49,.35); border-top: 2px solid rgba(30,34,49,.35); transform: rotate(45deg); }
  .rt-name { font-size: 15px; }
  .rt-stop::before { top: 50%; }
}

/* ---------- よくある質問: 章の色の地・Q の丸・開閉の ＋ (例題のクリーム地+「答え」と見分ける) ---------- */
.atom .qa { display: grid; gap: 10px; margin-top: 20px; }
.qa-item { background: var(--cb); border-radius: 4px; }
.qa-item summary { list-style: none; cursor: pointer; display: grid; grid-template-columns: 30px minmax(0, 1fr) 30px; align-items: center; column-gap: 14px; padding: 16px; border-radius: 4px; -webkit-tap-highlight-color: transparent; }
.qa-item summary::-webkit-details-marker { display: none; }
.qa-mark { width: 30px; height: 30px; border-radius: 50%; background: var(--ca); color: var(--white); font-family: var(--head); font-weight: 900; font-size: 15px; line-height: 1; display: flex; align-items: center; justify-content: center; }
.qa-text { font-family: var(--head); font-weight: 800; font-size: 16px; line-height: 1.6; color: var(--ink); }
.qa-ic { position: relative; width: 30px; height: 30px; border-radius: 50%; background: var(--white); transition: transform .2s ease, background .2s ease; }
.qa-ic::before, .qa-ic::after { content: ''; position: absolute; left: 50%; top: 50%; width: 12px; height: 2.5px; margin: -1.25px 0 0 -6px; border-radius: 2px; background: var(--ink); }
.qa-ic::after { transform: rotate(90deg); }
.qa-item[open] .qa-ic { transform: rotate(45deg); background: var(--ca); }
.qa-item[open] .qa-ic::before, .qa-item[open] .qa-ic::after { background: var(--white); }
.qa-a { display: grid; grid-template-columns: 30px minmax(0, 1fr); column-gap: 14px; align-items: start; padding: 0 16px 16px; margin-top: -6px; }
.qa-a .qa-mark { background: var(--white); color: var(--ca); margin-top: 8px; }
.qa-body { background: var(--white); border-radius: 4px; padding: 13px 16px; font-size: 15px; line-height: 1.85; color: var(--ink); }
@media (hover: hover) and (pointer: fine) { .qa-item summary:hover { background: var(--chv); } }
/* スマホ: 答えは幅いっぱい (A の丸は外す)・押しやすい高さ */
@media (max-width: 600px) {
  .qa-item summary { grid-template-columns: 28px minmax(0, 1fr) 28px; column-gap: 12px; padding: 14px 12px; min-height: 56px; }
  .qa-mark { width: 28px; height: 28px; font-size: 14px; }
  .qa-ic { width: 28px; height: 28px; }
  .qa-text { font-size: 15px; }
  .qa-a { display: block; padding: 0 10px 10px; }
  .qa-a .qa-mark { display: none; }
  .qa-body { padding: 12px 14px; }
}
@media (prefers-reduced-motion: reduce) { .qa-ic { transition: none; } }
.qa-item.is-closing .qa-ic { transform: none; background: var(--white); }
.qa-item.is-closing .qa-ic::before, .qa-item.is-closing .qa-ic::after { background: var(--ink); }

/* ---------- 査読 (2026-10-15) で見つけた細かいところ ---------- */
footer p.copy { color: var(--white); }
.nw { white-space: nowrap; }
html[lang="ja"] .qa-text, html[lang="ja"] .atom .label, html[lang="ja"] .unit-hero .lead, html[lang="ja"] .atom .point, html[lang="ja"] .qa-body, html[lang="ja"] .unit-cta p { word-break: auto-phrase; }
.unit-cta p { text-wrap: balance; }
html { overflow-x: clip; }
.aunit .unit-ch .up-k { line-height: 1.5; }
/* 例題の「答え」: パソコンで乗せたら黄色 (js-fold でも効くように) */
@media (hover: hover) and (pointer: fine) { .atom .ex-ans.js-fold:not(.is-open) summary:hover .ex-toggle { background: var(--yellow); } }
@media (max-width: 860px) {
  .ch-list a { min-height: 44px; align-items: center; padding: 4px 0; }
  footer .links a { display: inline-flex; align-items: center; min-height: 40px; }
  .aunit-hero .ph-math .m1 { bottom: -24px; opacity: .15; }
}
/* グラフ: 図の上では縦スクロールでき、つまみだけはどの向きにもドラッグできる */
.atom .graph .handle { touch-action: none; }