/* =========================================================
 * Chunkbook LP
 * デザイントークンは apps/web/src/index.css（課題45・v4実測値）と同一。
 * LPはライトモードのみ（メンテコスト優先）。ビルド不要の素のCSS。
 * 多言語化は i18n.js（data-i18n属性の差し替えのみ）。
 * スマホ画面内のUIは docs/mockup-current.html（実アプリと同じCSS）から移植。
 * ========================================================= */
:root {
  --bg: #f7f7f4;
  --surface: #fff;
  --muted: #eff1ed;
  --text: #1f2421;
  --sub: #66706a;
  --border: #dde1dc;
  --primary: #1f6b4f;
  --primary-soft: #e4f0e9;
  --danger: #a84442;
  --radius: 12px;
  --shadow: 0 1px 2px rgba(20, 30, 23, 0.05), 0 10px 28px rgba(20, 30, 23, 0.06);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", "Noto Sans JP", -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Yu Gothic UI", sans-serif;
  line-height: 1.75;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; }
a { color: inherit; text-decoration: none; }
.container { max-width: 1080px; margin: 0 auto; padding: 0 24px; }
.sp { display: none; }

/* ---------- header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; gap: 18px; height: 60px; }
.brand { font-weight: 800; font-size: 19px; letter-spacing: -0.02em; color: var(--primary); }
.site-nav { display: flex; gap: 22px; margin-left: auto; font-size: 14px; color: var(--sub); }
.site-nav a:hover { color: var(--text); }
.lang-select {
  height: 36px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
  color: var(--text);
  font-size: 13px;
  font-weight: 600;
  padding: 0 8px;
  cursor: pointer;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  border: 1px solid transparent;
  font-weight: 700;
  transition: background 0.15s ease, border-color 0.15s ease;
  white-space: nowrap;
}
.btn.primary { background: var(--primary); color: #fff; }
.btn.primary:hover { background: color-mix(in srgb, var(--primary) 85%, black); }
.btn.ghost { background: var(--surface); border-color: var(--border); color: var(--text); }
.btn.ghost:hover { border-color: var(--primary); color: var(--primary); }
.btn.sm { height: 36px; padding: 0 16px; font-size: 13px; }
.btn.lg { height: 50px; padding: 0 28px; font-size: 15px; }

/* ---------- hero ---------- */
.hero { overflow: hidden; }
.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
  padding: 84px 24px 72px;
}
.eyebrow {
  display: inline-block;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 13px;
  font-weight: 700;
  border-radius: 999px;
  padding: 4px 14px;
  margin: 0 0 18px;
}
h1 {
  font-size: clamp(34px, 4.6vw, 52px);
  line-height: 1.28;
  letter-spacing: -0.02em;
  margin: 0 0 20px;
  font-weight: 800;
}
h1 em {
  font-style: normal;
  color: var(--primary);
  background: linear-gradient(transparent 68%, var(--primary-soft) 68%);
}
.lead { color: var(--sub); font-size: 16.5px; margin: 0 0 28px; max-width: 34em; }
.cta-row { display: flex; gap: 14px; flex-wrap: wrap; }
.cta-note { color: var(--sub); font-size: 13px; margin-top: 12px; }

/* ---------- phone mock（実機風フレーム） ---------- */
.hero-visual { display: flex; justify-content: center; }
.phone {
  position: relative;
  width: 302px;
  height: 622px;
  border-radius: 48px;
  background: linear-gradient(160deg, #3d453f, #1a1f1b 28%, #11140f 90%);
  padding: 11px;
  box-shadow:
    0 30px 60px rgba(22, 28, 24, 0.28),
    0 6px 18px rgba(22, 28, 24, 0.18),
    inset 0 1px 1px rgba(255, 255, 255, 0.25);
  animation: rise 0.7s ease both;
}
.phone::before {
  /* 電源ボタン（右） */
  content: "";
  position: absolute;
  right: -2px;
  top: 168px;
  width: 3px;
  height: 66px;
  border-radius: 2px;
  background: #262b23;
}
.phone::after {
  /* 音量ボタン（左） */
  content: "";
  position: absolute;
  left: -2px;
  top: 128px;
  width: 3px;
  height: 96px;
  border-radius: 2px;
  background: #262b23;
}
.phone-island {
  position: absolute;
  top: 22px;
  left: 50%;
  transform: translateX(-50%);
  width: 86px;
  height: 24px;
  border-radius: 999px;
  background: #0b0e0b;
  z-index: 3;
}
@keyframes rise {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: none; }
}
.phone-screen {
  width: 280px;
  height: 600px;
  border-radius: 38px;
  overflow: hidden;
  background: var(--bg);
}

/* 画面内は実アプリ（apps/web）のUIを docs/mockup-current.html から移植。
 * 390px基準でレイアウトし、280pxに縮小表示（280 / 390 = 0.7179）。 */
.phone-app {
  width: 390px;
  height: 836px;
  transform: scale(0.7179);
  transform-origin: 0 0;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  font-family: "Noto Sans JP", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
}
.s-statusbar {
  height: 54px;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  padding: 0 30px 6px;
  font-size: 13px;
  font-weight: 700;
}
.s-topbar { height: 56px; display: flex; align-items: center; padding: 0 16px; }
.s-title { font-size: 23px; font-weight: 700; }
.s-content { flex: 1; overflow: hidden; padding: 4px 16px 24px; }
.s-eyebrow { font-size: 12px; font-weight: 700; color: var(--primary); letter-spacing: 0.06em; }
.s-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin: 12px 0;
}
.s-english { font-family: "Inter", "Segoe UI", sans-serif; font-weight: 650; line-height: 1.45; }
.s-english-lg { font-size: 20px; }
.s-hit { color: var(--danger); font-weight: 700; }
.s-jp { font-size: 13px; color: var(--sub); line-height: 1.55; margin-top: 4px; }
.s-jp-lg { font-size: 15px; margin-top: 10px; }
.s-speak-set {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
}
.s-speak {
  width: 38px;
  height: 38px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--surface);
  font-size: 15px;
  display: grid;
  place-items: center;
}
.s-rspeed {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  padding: 2px;
}
.s-rspeed-btn {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-size: 14px;
  color: var(--sub);
}
.s-rspeed-val {
  min-width: 34px;
  text-align: center;
  font-size: 12px;
  font-variant-numeric: tabular-nums;
}
.s-section-title { font-size: 14px; font-weight: 750; margin: 18px 0 6px; }
.s-chips { display: flex; flex-wrap: wrap; gap: 7px; margin: 8px 0; }
.s-chip {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  font-size: 12px;
  color: var(--sub);
}
.s-chip.is-on { background: var(--primary-soft); color: var(--primary); border-color: transparent; font-weight: 700; }
.s-chip.s-add { border-style: dashed; color: var(--primary); }
.s-hint { font-size: 12px; color: var(--sub); line-height: 1.55; margin: 6px 0; }
.s-hint.s-center { text-align: center; }
.s-chunk { padding: 11px 0; border-bottom: 1px solid var(--border); }
.s-chunk:last-child { border-bottom: 0; }
.s-chunk .s-english { font-size: 16px; }
.s-btn {
  min-height: 48px;
  border-radius: 9px;
  border: 1px solid var(--primary);
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  padding: 11px 16px;
  margin-top: 10px;
  text-align: center;
  font-size: 14px;
}
.s-study { flex: 1; display: flex; flex-direction: column; padding: 0 16px 26px; }
.s-study-head { display: grid; grid-template-columns: 44px 1fr 44px; align-items: center; height: 52px; }
.s-x { font-size: 24px; color: var(--sub); }
.s-count { text-align: center; font-size: 12px; color: var(--sub); }
.s-progress { height: 4px; border-radius: 3px; background: var(--border); overflow: hidden; }
.s-progress span { display: block; height: 100%; background: var(--primary); }
.s-study-card {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 20px 8px;
}
.s-prompt { font-family: "Inter", "Segoe UI", sans-serif; font-size: 29px; line-height: 1.45; font-weight: 700; margin: 0; }
.s-answer { font-size: 18px; line-height: 1.55; margin: 22px 0 0; color: var(--primary); font-weight: 700; }
.s-context {
  font-size: 13px;
  line-height: 1.6;
  color: var(--sub);
  margin: 22px 0 0;
  padding: 14px;
  background: var(--muted);
  border-radius: 9px;
}
.s-rating { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.s-rate {
  min-height: 58px;
  border: 1px solid var(--border);
  background: var(--surface);
  border-radius: 9px;
  font-weight: 700;
  font-size: 14px;
  text-align: center;
  padding: 8px 6px;
}
.s-rate small { display: block; font-size: 10px; color: var(--sub); font-weight: 500; margin-top: 3px; }
.s-rate.is-good { background: var(--primary-soft); border-color: var(--primary); color: var(--primary); }

/* ---------- strip ---------- */
.strip { border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); background: var(--surface); }
.strip-inner {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  padding: 22px 24px;
}
.strip-item { display: flex; flex-direction: column; align-items: center; text-align: center; }
.strip-item strong { font-size: 14.5px; }
.strip-item span { font-size: 12px; color: var(--sub); }

/* ---------- sections ---------- */
.section { padding: 88px 0; }
.section.alt { background: var(--surface); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
h2 { font-size: clamp(26px, 3.4vw, 36px); line-height: 1.4; letter-spacing: -0.02em; margin: 0 0 14px; font-weight: 800; }
.section-sub { color: var(--sub); max-width: 40em; margin: 0 auto 42px; }
.section-sub.left { margin: 0 0 22px; }
.center { text-align: center; }
.center-text { text-align: center; margin-bottom: 28px; }
.narrow { max-width: 720px; }

/* ---------- cards3 ---------- */
.cards3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 42px; }
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 26px 24px;
  box-shadow: var(--shadow);
}
.section.alt .card { box-shadow: none; }
.card-num { font-size: 13px; font-weight: 800; color: var(--primary); letter-spacing: 0.08em; margin-bottom: 10px; }
.card h3 { font-size: 18px; margin: 0 0 10px; }
.card p { font-size: 14px; color: var(--sub); margin: 0; }
#routes h2 { text-align: center; }
#routes .section-sub { text-align: center; }

/* ---------- split (learn / voice) ---------- */
.split { display: grid; grid-template-columns: 1fr 1.1fr; gap: 56px; align-items: center; }
.split.reverse { grid-template-columns: 1.1fr 1fr; }
.split-visual { display: flex; justify-content: center; }
.feature-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 14px; }
.feature-list li {
  font-size: 14.5px;
  color: var(--sub);
  padding-left: 26px;
  position: relative;
}
.feature-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--primary);
  font-weight: 800;
}
.feature-list strong { color: var(--text); }

/* ---------- voice ---------- */
.voice-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  padding: 28px;
  max-width: 380px;
}
.section .voice-card { margin: 0 auto; }
.voice-line { font-size: 16px; font-weight: 700; margin: 0 0 18px; line-height: 1.6; }
.voice-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.voice-chip {
  font-size: 12.5px;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 6px 12px;
  color: var(--sub);
  background: var(--bg);
}
.voice-chip.is-on { background: var(--primary-soft); border-color: var(--primary); color: var(--primary); font-weight: 700; }
.voice-note { font-size: 12px; color: var(--sub); margin: 16px 0 0; }

/* ---------- langs ---------- */
.lang-chips { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
.lang-chip {
  font-size: 13.5px;
  border: 1px solid var(--border);
  background: var(--bg);
  border-radius: 999px;
  padding: 8px 16px;
  font-weight: 600;
}
.lang-chip.more { background: var(--primary-soft); color: var(--primary); border-color: transparent; }

/* ---------- pricing ---------- */
.plans { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; text-align: left; }
.plan {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px 24px;
}
.plan.featured { border-color: var(--primary); box-shadow: var(--shadow); }
.plan-badge {
  position: absolute;
  top: -12px;
  left: 24px;
  background: var(--primary);
  color: #fff;
  font-size: 11px;
  font-weight: 800;
  border-radius: 999px;
  padding: 3px 12px;
  margin: 0;
}
.plan-name { font-weight: 800; font-size: 15px; margin: 0 0 6px; }
.plan-price { font-size: 34px; font-weight: 800; letter-spacing: -0.02em; margin: 0 0 14px; }
.plan-price span { font-size: 14px; font-weight: 600; color: var(--sub); }
.plan ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 9px; }
.plan li { font-size: 13.5px; padding-left: 22px; position: relative; }
.plan li::before { content: "✓"; position: absolute; left: 0; color: var(--primary); font-weight: 800; }
.plan li.dim { color: var(--sub); }
.plan li.dim::before { content: "–"; color: var(--sub); }
.plan-note { font-size: 12.5px; color: var(--sub); margin-top: 22px; }

/* ---------- faq ---------- */
details {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0 20px;
  margin-bottom: 10px;
}
.section:not(.alt) details { background: var(--surface); }
summary {
  cursor: pointer;
  font-weight: 700;
  font-size: 14.5px;
  padding: 16px 0;
  list-style: none;
  position: relative;
  padding-right: 28px;
}
summary::-webkit-details-marker { display: none; }
summary::after {
  content: "+";
  position: absolute;
  right: 2px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--primary);
  font-size: 18px;
  font-weight: 700;
}
details[open] summary::after { content: "–"; }
details p { font-size: 14px; color: var(--sub); margin: 0 0 16px; }

/* ---------- final CTA / footer ---------- */
.cta-final { padding: 96px 0; }
.cta-final .cta-note { margin-top: 14px; }
.site-footer { border-top: 1px solid var(--border); background: var(--surface); }
.footer-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 26px 24px;
  flex-wrap: wrap;
}
.brand.small { font-size: 15px; margin: 0; font-weight: 800; color: var(--primary); }
.footer-nav { display: flex; gap: 18px; font-size: 12.5px; color: var(--sub); margin-right: auto; flex-wrap: wrap; }
.footer-nav a:hover { color: var(--text); }
.copyright { font-size: 12px; color: var(--sub); margin: 0; }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .site-nav { display: none; }
  .header-inner { gap: 12px; }
  .hero-grid { grid-template-columns: 1fr; padding: 56px 24px 48px; gap: 40px; }
  .strip-inner { grid-template-columns: repeat(2, 1fr); row-gap: 18px; }
  .cards3 { grid-template-columns: 1fr; }
  .split, .split.reverse { grid-template-columns: 1fr; gap: 36px; }
  .split.reverse .split-copy { order: 0; }
  .split.reverse .split-visual { order: 1; }
  .plans { grid-template-columns: 1fr; }
  .section { padding: 64px 0; }
  .sp { display: inline; }
}

/* Voice sample playback (issue 141) */
button.voice-chip { font: inherit; cursor: pointer; }
.voice-chip.is-playing { background: var(--primary); border-color: var(--primary); color: #fff; font-weight: 700; }