:root {
  --paper: #f7f4ee;
  --paper-white: #ffffff;
  --ink: #2b2620;
  --ink-soft: #63594c;
  --vermilion: #8b2e2e;
  --vermilion-soft: #b65c4a;
  --press-blue: #2f4858;
  --press-blue-soft: #5c7688;
  --rule: #c9c0ac;
  --rule-soft: #ded6c4;
  --shadow: rgba(43, 38, 32, 0.12);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  background: var(--paper);
  color: var(--ink);
  font-family: "Noto Serif JP", serif;
  line-height: 1.9;
  overflow-x: hidden;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

::selection {
  background: var(--vermilion);
  color: var(--paper-white);
}

a {
  color: inherit;
}

.mincho {
  font-family: "Shippori Mincho", serif;
}
.gothic {
  font-family: "Zen Kaku Gothic New", sans-serif;
}
.mono {
  font-family: "JetBrains Mono", monospace;
}

:focus-visible {
  outline: 2px solid var(--vermilion);
  outline-offset: 3px;
}

/* ============ 共通レイアウト ============ */
.wrap {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 32px;
}

section {
  position: relative;
}

.eyebrow {
  font-family: "Zen Kaku Gothic New", sans-serif;
  font-size: 11px;
  letter-spacing: 0.32em;
  color: var(--vermilion);
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.eyebrow::before {
  content: "";
  display: inline-block;
  width: 22px;
  height: 1px;
  background: var(--vermilion);
}

.section-title {
  font-family: "Shippori Mincho", serif;
  font-weight: 700;
  font-size: clamp(28px, 4vw, 44px);
  letter-spacing: 0.04em;
  line-height: 1.5;
  margin-top: 18px;
}

.section-lede {
  margin-top: 20px;
  max-width: 46em;
  color: var(--ink-soft);
  font-size: 16px;
  line-height: 2;
}

/* ============ ヘッダー ============ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(247, 244, 238, 0.86);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule-soft);
}
.site-header .wrap {
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  font-family: "Shippori Mincho", serif;
  font-weight: 700;
  font-size: 19px;
  letter-spacing: 0.06em;
  display: flex;
  align-items: baseline;
  gap: 8px;
}
.brand .seal {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  background: var(--vermilion);
  color: var(--paper-white);
  font-size: 12px;
  border-radius: 2px;
  transform: translateY(1px);
}
.nav-links {
  display: flex;
  gap: 36px;
  font-family: "Zen Kaku Gothic New", sans-serif;
  font-size: 13.5px;
  letter-spacing: 0.03em;
}
.nav-links a {
  text-decoration: none;
  color: var(--ink-soft);
  transition: color 0.2s;
}
.nav-links a:hover {
  color: var(--vermilion);
}
.header-cta {
  font-family: "Zen Kaku Gothic New", sans-serif;
  font-size: 13px;
  font-weight: 700;
  background: var(--ink);
  color: var(--paper);
  padding: 9px 20px;
  border-radius: 3px;
  text-decoration: none;
  letter-spacing: 0.05em;
  transition: background 0.2s;
}
.header-cta:hover {
  background: var(--vermilion);
}

@media (max-width: 780px) {
  .nav-links {
    display: none;
  }
}

/* ============ ヒーロー ============ */
.hero {
  padding: 148px 0 90px;
  position: relative;
  overflow: hidden;
}

.hero-grain {
  position: absolute;
  inset: 0;
  opacity: 0.5;
  pointer-events: none;
  background-image:
    radial-gradient(
      circle at 15% 20%,
      rgba(43, 38, 32, 0.035) 0,
      transparent 45%
    ),
    radial-gradient(
      circle at 85% 65%,
      rgba(47, 72, 88, 0.05) 0,
      transparent 40%
    );
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 64px;
  align-items: center;
  position: relative;
}

.hero-copy .eyebrow {
  margin-bottom: 22px;
}

.hero-title {
  font-family: "Shippori Mincho", serif;
  font-weight: 800;
  font-size: clamp(40px, 5.4vw, 68px);
  line-height: 1.35;
  letter-spacing: 0.02em;
}
.hero-title .accent {
  color: var(--vermilion);
}

.hero-sub {
  margin-top: 28px;
  font-size: 17px;
  color: var(--ink-soft);
  max-width: 34em;
  line-height: 2.05;
}

.hero-actions {
  margin-top: 40px;
  display: flex;
  gap: 16px;
  align-items: center;
  flex-wrap: wrap;
}

.btn-primary {
  font-family: "Shippori Mincho", serif;
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.08em;
  background: var(--vermilion);
  color: var(--paper-white);
  padding: 16px 34px;
  border-radius: 3px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  box-shadow: 0 10px 24px -8px rgba(139, 46, 46, 0.45);
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 28px -8px rgba(139, 46, 46, 0.5);
}

.btn-ghost {
  font-family: "Zen Kaku Gothic New", sans-serif;
  font-size: 14px;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--ink);
  padding-bottom: 3px;
  transition:
    color 0.2s,
    border-color 0.2s;
}
.btn-ghost:hover {
  color: var(--vermilion);
  border-color: var(--vermilion);
}

.hero-meta {
  margin-top: 44px;
  display: flex;
  gap: 30px;
  font-family: "Zen Kaku Gothic New", sans-serif;
  font-size: 12.5px;
  color: var(--ink-soft);
  letter-spacing: 0.02em;
}
.hero-meta span {
  display: flex;
  align-items: center;
  gap: 7px;
}
.hero-meta span::before {
  content: "";
  width: 5px;
  height: 5px;
  background: var(--vermilion);
  border-radius: 50%;
}

/* ---- ヒーロー：紙面ビジュアル ---- */
.hero-paper-stage {
  position: relative;
  display: flex;
  justify-content: center;
}
.paper-sheet {
  width: min(360px, 86vw);
  aspect-ratio: 128 / 182;
  background: var(--paper-white);
  box-shadow:
    0 30px 60px -20px var(--shadow),
    0 3px 0 var(--rule-soft);
  border-radius: 1px;
  position: relative;
  padding: 34px 30px;
  color: var(--ink);
  overflow: hidden;
  transform: rotate(-1.2deg);
  display: flex;
  flex-direction: column;
}
.paper-sheet::before {
  content: "";
  position: absolute;
  inset: 14px;
  border: 1px solid var(--rule-soft);
  pointer-events: none;
}
.paper-sheet-body {
  flex: 1;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: "Shippori Mincho", serif;
  font-size: 15.5px;
  line-height: 2.15;
  letter-spacing: 0.04em;
}
.paper-sheet .ruby {
  font-size: 0.5em;
}
.paper-sheet .stamp {
  position: absolute;
  top: 26px;
  left: 26px;
  width: 34px;
  height: 34px;
  background: var(--press-blue);
  color: var(--paper-white);
  font-family: "Shippori Mincho", serif;
  font-size: 12px;
  writing-mode: horizontal-tb;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 2px;
  opacity: 0.92;
  letter-spacing: 0.1em;
  z-index: 2;
}
.paper-behind {
  position: absolute;
  width: min(360px, 86vw);
  aspect-ratio: 128 / 182;
  background: var(--paper-white);
  box-shadow: 0 20px 40px -18px var(--shadow);
  transform: rotate(4deg) translate(18px, 10px);
  z-index: -1;
  opacity: 0.7;
}
.spec-tag {
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--press-blue);
  border-top: 1px solid var(--rule-soft);
  padding-top: 10px;
  margin-top: 10px;
  text-align: center;
  position: relative;
  z-index: 2;
}

/* ============ 課題提起の帯 ============ */
.problem-strip {
  background: var(--ink);
  color: var(--paper);
  border-top: 1px solid var(--rule-soft);
  border-bottom: 1px solid var(--rule-soft);
}
.problem-grid {
  padding: 68px 32px;
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 48px;
  align-items: center;
}
.problem-line {
  font-size: clamp(22px, 2.6vw, 30px);
  line-height: 1.7;
  letter-spacing: 0.03em;
}
.problem-sub {
  font-size: 14.5px;
  line-height: 2;
  color: #b9af9e;
}

@media (max-width: 860px) {
  .problem-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

/* ============ 目玉機能：出力の一貫性 ============ */
.output-feature {
  padding: 130px 0 100px;
}

.output-grid {
  margin-top: 56px;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 60px;
  align-items: center;
}

.output-visual {
  display: flex;
  justify-content: center;
}

.press-paper {
  position: relative;
  width: min(460px, 100%);
  aspect-ratio: 128 / 182;
  background: var(--paper-white);
  box-shadow: 0 30px 60px -20px var(--shadow);
  padding: 40px 34px 28px;
  display: flex;
  flex-direction: column;
}
.press-paper-cols {
  flex: 1;
  display: flex;
  flex-direction: row-reverse;
  gap: 26px;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: "Shippori Mincho", serif;
  font-size: 13.5px;
  line-height: 2;
  color: var(--ink);
  border-left: 1px solid var(--rule-soft);
  padding-left: 26px;
}
.press-col {
  flex: 1;
}
.press-col p {
  margin: 0;
  text-indent: 1em;
}
.press-col p.no-indent {
  text-indent: 0;
}
.press-col p + p {
  margin-top: 1.5em;
}
.press-footer {
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid var(--rule-soft);
  display: flex;
  justify-content: space-between;
  font-size: 10px;
  letter-spacing: 0.06em;
  color: var(--press-blue);
}

.output-specs {
  display: flex;
  flex-direction: column;
  gap: 34px;
}
.spec-item {
  border-top: 1px solid var(--rule-soft);
  padding-top: 18px;
}
.spec-num {
  font-size: 13px;
  color: var(--press-blue);
  letter-spacing: 0.04em;
}
.spec-item p {
  margin-top: 10px;
  color: var(--ink-soft);
  font-size: 14.5px;
  line-height: 1.95;
}

@media (max-width: 900px) {
  .output-grid {
    grid-template-columns: 1fr;
  }
}

/* ============ ロゴ的な帯（対象読者） ============ */
.audience-strip {
  border-top: 1px solid var(--rule-soft);
  border-bottom: 1px solid var(--rule-soft);
  background: var(--paper-white);
}
.audience-strip .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 40px;
  padding: 26px 32px;
  justify-content: center;
  align-items: center;
}
.audience-strip .label {
  font-family: "Zen Kaku Gothic New", sans-serif;
  font-size: 12px;
  letter-spacing: 0.15em;
  color: var(--ink-soft);
  margin-right: 8px;
}
.audience-item {
  font-family: "Shippori Mincho", serif;
  font-size: 15.5px;
  color: var(--ink);
  display: flex;
  align-items: center;
  gap: 40px;
}
.audience-item span:not(:last-child)::after {
  content: "／";
  color: var(--rule);
  margin-left: 40px;
}

/* ============ 機能セクション（紙面が変わる） ============ */
.features {
  padding: 100px 0 100px;
}

.feature-row {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 70px;
  align-items: center;
  padding: 86px 0;
  border-bottom: 1px solid var(--rule-soft);
}
.feature-row:first-of-type {
  padding-top: 56px;
}
.feature-row:last-of-type {
  border-bottom: none;
}
.feature-row.reverse {
  grid-template-columns: 1.05fr 0.95fr;
}
.feature-row.reverse .feature-visual {
  order: 2;
}
.feature-row.reverse .feature-text {
  order: 1;
}

.feature-index {
  font-family: "Shippori Mincho", serif;
  font-size: 13px;
  color: var(--vermilion);
  letter-spacing: 0.1em;
}
.feature-title {
  font-family: "Shippori Mincho", serif;
  font-weight: 700;
  font-size: clamp(24px, 2.6vw, 32px);
  margin-top: 14px;
  line-height: 1.6;
}
.feature-desc {
  margin-top: 20px;
  color: var(--ink-soft);
  font-size: 15.5px;
  line-height: 2.05;
  max-width: 32em;
}
.feature-tags {
  margin-top: 26px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.feature-tags span {
  font-family: "Zen Kaku Gothic New", sans-serif;
  font-size: 11.5px;
  color: var(--ink-soft);
  border: 1px solid var(--rule);
  padding: 5px 12px;
  border-radius: 999px;
  letter-spacing: 0.03em;
}

.feature-visual {
  display: flex;
  justify-content: center;
}
.mini-paper {
  width: min(300px, 78vw);
  background: var(--paper-white);
  box-shadow: 0 24px 48px -20px var(--shadow);
  padding: 30px 26px;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: "Shippori Mincho", serif;
  font-size: 15px;
  line-height: 2.05;
  color: var(--ink);
  min-height: 380px;
  position: relative;
}
.mini-paper p {
  margin: 0;
  text-indent: 0.72em;
}
.mini-paper p + p {
  margin-top: 1.6em;
}
.mini-paper p.no-indent {
  text-indent: 0;
}
.mini-paper .ruby-demo ruby rt {
  font-size: 0.48em;
  color: var(--ink-soft);
}
.mini-paper .bouten-demo {
  text-emphasis-style: dot;
  text-emphasis-color: var(--vermilion);
}
.mini-paper .center-demo {
  display: block;
  text-align: center;
  color: var(--ink-soft);
  font-size: 0.86em;
}
.mini-paper .align-samples {
  display: flex;
  flex-direction: column;
  gap: 26px;
  height: 100%;
  justify-content: space-between;
}

.mini-paper.dark {
  background: #2b2620;
  color: #efe9dc;
}
.mini-paper.dark .bouten-demo {
  text-emphasis-color: var(--vermilion-soft);
}

/* ============ 目玉機能：一冊の本にする（中表紙） ============ */
.bookform-feature {
  padding: 130px 0 100px;
}
.bookform-grid {
  margin-top: 56px;
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 60px;
  align-items: center;
}
.bookform-visual {
  display: flex;
  justify-content: center;
}
.cover-mock {
  position: relative;
  width: min(340px, 100%);
  aspect-ratio: 128 / 182;
  background: var(--paper-white);
  box-shadow: 0 30px 60px -20px var(--shadow);
  padding: 28px;
}
.cover-mock-frame {
  height: 100%;
  border: 1.5px solid var(--ink);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px 16px;
}
.cover-mock-content {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  gap: 0.9em;
}
.cover-mock-title {
  font-family: "Shippori Mincho", serif;
  font-weight: 700;
  font-size: 25px;
  letter-spacing: 0.14em;
  color: var(--ink);
}
.cover-mock-sub {
  font-family: "Shippori Mincho", serif;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--ink-soft);
}
.cover-mock-rule {
  width: 1px;
  height: 55%;
  background: var(--rule-soft);
}
.cover-mock-author {
  font-family: "Shippori Mincho", serif;
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
}
.bookform-specs {
  display: flex;
  flex-direction: column;
  gap: 34px;
}

/* ============ こだわりセクション（罫線リスト） ============ */
.craft {
  padding: 130px 0 110px;
}
.craft-list {
  margin-top: 60px;
  border-top: 1px solid var(--rule-soft);
}
.craft-item {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 40px;
  padding: 34px 0;
  border-bottom: 1px solid var(--rule-soft);
  align-items: baseline;
}
.craft-item .num {
  font-family: "Shippori Mincho", serif;
  font-size: 14px;
  color: var(--vermilion);
  letter-spacing: 0.08em;
}
.craft-item h3 {
  font-family: "Shippori Mincho", serif;
  font-weight: 700;
  font-size: 19px;
  line-height: 1.7;
}
.craft-item p {
  margin-top: 8px;
  color: var(--ink-soft);
  font-size: 14.5px;
  line-height: 1.95;
  max-width: 46em;
}

@media (max-width: 700px) {
  .craft-item {
    grid-template-columns: 1fr;
    gap: 10px;
  }
}

/* ============ フッターCTA ============ */
.final-cta {
  background: var(--paper-white);
  border-top: 1px solid var(--rule-soft);
  padding: 130px 0;
  text-align: center;
}
.final-cta .section-title {
  margin: 0 auto;
}
.final-cta .section-lede {
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}
.final-cta .hero-actions {
  justify-content: center;
  margin-top: 44px;
}

footer {
  background: var(--ink);
  color: #a79d8a;
  padding: 50px 0 40px;
}
.footer-grid {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 30px;
}
.footer-brand {
  font-family: "Shippori Mincho", serif;
  color: var(--paper);
  font-size: 16px;
}
.footer-note {
  margin-top: 10px;
  font-family: "Zen Kaku Gothic New", sans-serif;
  font-size: 12.5px;
  line-height: 1.9;
  max-width: 30em;
  color: #8c826f;
}
.footer-links {
  display: flex;
  gap: 28px;
  font-family: "Zen Kaku Gothic New", sans-serif;
  font-size: 12.5px;
}
.footer-links a {
  text-decoration: none;
  color: #a79d8a;
}
.footer-links a:hover {
  color: var(--paper);
}

/* ============ スクロールリビール ============ */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 0.8s ease,
    transform 0.8s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }
  .hero-paper-stage {
    margin-top: 50px;
  }
  .feature-row,
  .feature-row.reverse {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .feature-row.reverse .feature-visual,
  .feature-row.reverse .feature-text {
    order: initial;
  }
}

@media (max-width: 480px) {
  .wrap {
    padding: 0 20px;
  }
  .hero {
    padding: 128px 0 70px;
  }
}

/* ============ 取扱説明書 (manual.html) ============ */

/* 共通の CSS カスタムプロパティ（フォントファミリー定義） */
html[data-theme="dark"],
html[data-theme="standard"],
html[data-theme="sepia"] {
  --ui-font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
    "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Meiryo", sans-serif;
  --doc-font-family:
    "Shippori Mincho", "Yu Mincho", "游明朝", "YuMincho",
    "Hiragino Mincho ProN", "Noto Serif JP", serif;
}

html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #121316;
  --panel: #1a1b1e;
  --panel-sub: #16171a;
  --input-bg: #101113;
  --text: #e6e6e6;
  --muted: #8c8c8c;
  --line: #2c2d33;
  --accent: #c29b61;
  --accent-dark: #2c2d33;
  --accent-soft: rgba(194, 155, 97, 0.12);
  --shadow: 0 16px 40px rgba(0, 0, 0, 0.5);
}

html[data-theme="standard"] {
  color-scheme: light;
  --bg: #f5f4f0;
  --panel: #ffffff;
  --panel-sub: #faf9f6;
  --input-bg: #ffffff;
  --text: #1a1917;
  --muted: #737068;
  --line: #e2ded4;
  --accent: #8c6239;
  --accent-dark: #6e4c2b;
  --accent-soft: rgba(140, 98, 57, 0.08);
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.06);
}

html[data-theme="sepia"] {
  color-scheme: light;
  --bg: #eee8dc;
  --panel: #f7f3eb;
  --panel-sub: #f0eae1;
  --input-bg: #fffcf7;
  --text: #2b2521;
  --muted: #7d7268;
  --line: #dcd2c4;
  --accent: #9e6a3f;
  --accent-dark: #7a502f;
  --accent-soft: rgba(158, 106, 63, 0.1);
  --shadow: 0 12px 32px rgba(43, 37, 33, 0.08);
}

html[data-theme],
html[data-theme] body {
  margin: 0;
  min-height: 100%;
  font-family: var(--ui-font-family);
  background: var(--bg);
  color: var(--text);
  letter-spacing: 0.01em;
  line-height: normal;
}

html[data-theme] a {
  color: var(--accent);
}

html[data-theme] code {
  font-family: "SF Mono", "Menlo", "Consolas", monospace;
  background: var(--input-bg);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.1em 0.4em;
  font-size: 0.9em;
  color: var(--accent);
}

.app-shell {
  display: flex;
  min-height: 100vh;
}

/* ---- サイドバー（目次固定） ---- */
.toc-sidebar {
  width: 260px;
  flex-shrink: 0;
  background: var(--panel);
  border-right: 1px solid var(--line);
  padding: 24px 0;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.toc-brand {
  padding: 0 24px 20px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 16px;
}

.toc-brand-title {
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.toc-brand-sub {
  font-size: 0.75rem;
  color: var(--muted);
  margin-top: 2px;
}

.toc-theme-row {
  padding: 0 24px 20px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.toc-theme-row label {
  font-size: 0.75rem;
  color: var(--muted);
}

.toc-theme-row select {
  font-family: var(--ui-font-family);
  font-size: 0.8rem;
  background: var(--input-bg);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 4px 6px;
}

.toc-nav {
  display: flex;
  flex-direction: column;
}

.toc-nav a {
  text-decoration: none;
  color: var(--text);
  padding: 8px 24px;
  font-size: 0.85rem;
  border-left: 2px solid transparent;
  transition:
    background 0.15s,
    border-color 0.15s,
    color 0.15s;
}

.toc-nav a:hover {
  background: var(--accent-soft);
}

.toc-nav a.active {
  color: var(--accent);
  border-left-color: var(--accent);
  background: var(--accent-soft);
  font-weight: 600;
}

.toc-nav .toc-group-label {
  padding: 16px 24px 6px;
  font-size: 0.7rem;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.toc-nav .toc-group-label:first-child {
  padding-top: 0;
}

/* ---- メインコンテンツ ---- */
.content-area {
  flex: 1;
  min-width: 0;
  padding: 48px clamp(24px, 5vw, 72px) 120px;
  max-width: 880px;
}

.mobile-toc-toggle {
  display: none;
}

@media (max-width: 860px) {
  .app-shell {
    flex-direction: column;
  }
  .toc-sidebar {
    position: fixed;
    left: 0;
    top: 0;
    z-index: 40;
    transform: translateX(-100%);
    transition: transform 0.2s ease;
    width: 82vw;
    max-width: 300px;
    box-shadow: var(--shadow);
  }
  .toc-sidebar.open {
    transform: translateX(0);
  }
  .mobile-toc-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    position: sticky;
    top: 0;
    z-index: 30;
    background: var(--panel);
    border-bottom: 1px solid var(--line);
    padding: 12px 20px;
    font-size: 0.85rem;
    color: var(--text);
    cursor: pointer;
  }
  .content-area {
    padding: 24px 20px 100px;
  }
  .toc-scrim {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 35;
  }
  .toc-scrim.open {
    display: block;
  }
}

.doc-header {
  margin-bottom: 40px;
}

.doc-eyebrow {
  font-size: 0.78rem;
  color: var(--accent);
  letter-spacing: 0.08em;
  font-weight: 600;
}

.doc-title {
  font-size: 2rem;
  font-weight: 800;
  margin: 8px 0 12px;
  letter-spacing: 0.01em;
}

.doc-lead {
  color: var(--muted);
  font-size: 0.98rem;
  line-height: 1.9;
  max-width: 60ch;
}

section.doc-section {
  margin-bottom: 56px;
  scroll-margin-top: 24px;
}

section.doc-section h2 {
  font-size: 1.3rem;
  font-weight: 700;
  border-bottom: 1px solid var(--line);
  padding-bottom: 10px;
  margin-bottom: 20px;
  display: flex;
  align-items: baseline;
  gap: 10px;
}

section.doc-section h2 .section-no {
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 700;
}

section.doc-section h3 {
  font-size: 1.02rem;
  font-weight: 700;
  margin: 28px 0 10px;
  color: var(--accent);
}

section.doc-section p {
  line-height: 1.95;
  margin: 0 0 14px;
  font-size: 0.92rem;
}

section.doc-section ul,
section.doc-section ol {
  line-height: 1.9;
  font-size: 0.92rem;
  padding-left: 1.4em;
  margin: 0 0 16px;
}

section.doc-section li {
  margin-bottom: 6px;
}

section.doc-section li ul {
  margin-top: 6px;
  margin-bottom: 6px;
}

.panel-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 18px 20px;
  margin: 18px 0;
}

.panel-card-title {
  font-size: 0.78rem;
  color: var(--muted);
  letter-spacing: 0.04em;
  margin-bottom: 10px;
  text-transform: uppercase;
}

table.ref-table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0;
  font-size: 0.85rem;
}

table.ref-table th,
table.ref-table td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

table.ref-table td.font-sample {
  font-size: 1.15rem;
  letter-spacing: 0.02em;
}

table.ref-table th {
  color: var(--muted);
  font-weight: 600;
  font-size: 0.78rem;
  letter-spacing: 0.02em;
}

.sample-preview {
  font-family: var(--doc-font-family);
  background: var(--panel-sub);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px 18px;
  font-size: 0.95rem;
  color: var(--text);
}

.tip-box {
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  padding: 12px 16px;
  border-radius: 0 8px 8px 0;
  font-size: 0.87rem;
  line-height: 1.8;
  margin: 16px 0;
}

.tip-box strong {
  color: var(--accent);
}

.steps-list {
  counter-reset: step;
  list-style: none;
  padding-left: 0;
}

.steps-list li {
  counter-increment: step;
  position: relative;
  padding-left: 2.2em;
  margin-bottom: 14px;
}

.steps-list li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  width: 1.5em;
  height: 1.5em;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 700;
  font-size: 0.8rem;
  display: flex;
  align-items: center;
  justify-content: center;
}