@import url('https://fonts.googleapis.com/css2?family=DM+Mono:wght@400;500&family=Noto+Sans+SC:wght@400;500;600;700;800&display=swap');

:root {
  --ink: #182030;
  --muted: #657086;
  --faint: #929bad;
  --line: #e3e6ee;
  --paper: #ffffff;
  --canvas: #f7f8fc;
  --soft: #f0f2f8;
  --accent: #5c54e8;
  --accent-dark: #443ccb;
  --accent-soft: #eeedff;
  --cyan: #4cc7c0;
  --warning: #d98b25;
  --warning-soft: #fff7e7;
  --success: #2d9c71;
  --sidebar: 276px;
  --topbar: 72px;
  --shadow: 0 18px 50px rgba(35, 43, 72, .09);
  --radius: 18px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 98px; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--canvas);
  font-family: "Noto Sans SC", "Microsoft YaHei", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
.inline-link { color: var(--accent); font-weight: 700; }
.inline-link:hover { text-decoration: underline; }
button { font: inherit; }
code, kbd { font-family: "DM Mono", Consolas, monospace; }
code {
  padding: .12em .42em;
  border-radius: 6px;
  color: #5149d5;
  background: var(--accent-soft);
  font-size: .9em;
}
kbd {
  display: inline-flex;
  min-width: 1.8em;
  min-height: 1.75em;
  padding: .12em .48em;
  align-items: center;
  justify-content: center;
  color: #30384a;
  background: #fff;
  border: 1px solid #ccd1dd;
  border-bottom-width: 3px;
  border-radius: 6px;
  font-size: .78em;
  font-weight: 600;
  line-height: 1.3;
  white-space: nowrap;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 8px;
  left: 8px;
  padding: 8px 14px;
  color: #fff;
  background: var(--accent);
  border-radius: 7px;
  transform: translateY(-150%);
}
.skip-link:focus { transform: none; }

.topbar {
  position: fixed;
  z-index: 100;
  inset: 0 0 auto 0;
  height: var(--topbar);
  display: flex;
  align-items: center;
  padding: 0 28px;
  background: rgba(255, 255, 255, .88);
  border-bottom: 1px solid rgba(218, 222, 233, .86);
  backdrop-filter: blur(16px);
}
.brand { display: flex; align-items: center; gap: 11px; }
.brand-mark {
  width: 38px;
  height: 38px;
  display: inline-grid;
  place-items: center;
  flex: 0 0 auto;
  color: #fff;
  background: linear-gradient(145deg, #7069f2, #4a42d7);
  border-radius: 11px 11px 11px 4px;
  box-shadow: 0 8px 18px rgba(92, 84, 232, .25);
  font: 800 20px/1 "Noto Sans SC", sans-serif;
}
.brand > span:last-child { display: flex; align-items: baseline; gap: 9px; }
.brand b { font-size: 17px; letter-spacing: -.2px; }
.brand small { color: var(--muted); font-size: 12px; }
.top-actions { margin-left: auto; display: flex; align-items: center; gap: 24px; font-size: 14px; font-weight: 600; }
.top-actions a:hover { color: var(--accent); }
.top-actions .download-link { padding: 9px 15px; color: #fff; background: var(--ink); border-radius: 9px; }
.top-actions .download-link:hover { color: #fff; background: var(--accent); }
.menu-button, .sidebar-close { display: none; }

.page-shell { min-height: 100vh; padding-top: var(--topbar); }
.sidebar {
  position: fixed;
  z-index: 90;
  top: var(--topbar);
  bottom: 0;
  left: 0;
  width: var(--sidebar);
  display: flex;
  flex-direction: column;
  background: #fbfbfd;
  border-right: 1px solid var(--line);
}
.sidebar-head { display: none; }
.toc { flex: 1; overflow-y: auto; padding: 27px 20px 24px; scrollbar-width: thin; }
.toc-group + .toc-group { margin-top: 22px; }
.toc-group p {
  margin: 0 0 6px;
  padding: 0 12px;
  color: #a0a7b6;
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 1.5px;
  text-transform: uppercase;
}
.toc-group a {
  position: relative;
  display: block;
  margin: 1px 0;
  padding: 6px 12px;
  color: #626c80;
  border-radius: 8px;
  font-size: 13px;
  line-height: 1.5;
  transition: .18s ease;
}
.toc-group a:hover { color: var(--ink); background: #f0f1f6; }
.toc-group a.active { color: var(--accent-dark); background: var(--accent-soft); font-weight: 700; }
.toc-group a.active::before {
  content: "";
  position: absolute;
  top: 50%;
  left: -20px;
  width: 3px;
  height: 24px;
  background: var(--accent);
  border-radius: 0 4px 4px 0;
  transform: translateY(-50%);
}
.sidebar-foot {
  padding: 15px 30px 19px;
  color: var(--faint);
  border-top: 1px solid var(--line);
  font-size: 11px;
}
.status-dot { display: inline-block; width: 7px; height: 7px; margin-right: 7px; background: var(--success); border-radius: 50%; box-shadow: 0 0 0 3px rgba(45,156,113,.12); }
.sidebar-backdrop { display: none; }

main { margin-left: var(--sidebar); }
.hero, .manual-section, .manual-footer { width: min(920px, calc(100% - 72px)); margin-inline: auto; }
.hero {
  position: relative;
  padding: 92px 0 76px;
  overflow: hidden;
}
.hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  top: 48px;
  right: -105px;
  width: 430px;
  height: 430px;
  background: radial-gradient(circle, rgba(92,84,232,.16) 0 2px, transparent 2.5px) 0 0 / 23px 23px;
  mask-image: radial-gradient(circle, #000, transparent 70%);
  opacity: .8;
}
.eyebrow { display: flex; align-items: center; gap: 9px; color: var(--accent); font: 700 11px/1 "DM Mono", monospace; letter-spacing: 1.8px; }
.eyebrow span { width: 26px; height: 2px; background: var(--cyan); }
.hero h1 { margin: 22px 0; max-width: 720px; font-size: clamp(46px, 6.2vw, 78px); line-height: 1.08; letter-spacing: -4px; }
.hero h1 em { color: var(--accent); font-style: normal; }
.hero-lead { max-width: 680px; margin: 0; color: var(--muted); font-size: 18px; line-height: 1.9; }
.hero-actions { display: flex; gap: 12px; margin-top: 34px; }
.button { display: inline-flex; min-height: 46px; padding: 0 21px; align-items: center; justify-content: center; gap: 14px; border-radius: 10px; font-size: 14px; font-weight: 700; transition: .2s ease; }
.button.primary { color: #fff; background: var(--accent); box-shadow: 0 10px 25px rgba(92,84,232,.25); }
.button.primary:hover { background: var(--accent-dark); transform: translateY(-1px); }
.button.secondary { background: #fff; border: 1px solid var(--line); }
.button.secondary:hover { border-color: #c2c5d0; transform: translateY(-1px); }
.hero-facts { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 68px; padding-top: 24px; border-top: 1px solid var(--line); }
.hero-facts div { display: flex; flex-direction: column; gap: 3px; padding: 0 22px; border-left: 1px solid var(--line); }
.hero-facts div:first-child { padding-left: 0; border-left: 0; }
.hero-facts b { font: 600 15px/1.5 "DM Mono", "Noto Sans SC", monospace; }
.hero-facts span { color: var(--faint); font-size: 12px; }

.manual-section {
  position: relative;
  margin-bottom: 38px;
  padding: 58px 56px;
  background: var(--paper);
  border: 1px solid #eaecf2;
  border-radius: 22px;
  box-shadow: 0 5px 28px rgba(31, 40, 70, .035);
}
.section-heading { display: flex; align-items: flex-start; gap: 17px; margin-bottom: 30px; }
.section-number { display: grid; width: 42px; height: 42px; place-items: center; flex: 0 0 auto; color: var(--accent); background: var(--accent-soft); border-radius: 12px; font: 700 12px/1 "DM Mono", monospace; }
.section-heading p { margin: 1px 0 4px; color: var(--cyan); font: 700 10px/1.4 "DM Mono", monospace; letter-spacing: 1.6px; }
.section-heading h2 { margin: 0; font-size: 30px; line-height: 1.25; letter-spacing: -1px; }
.section-intro { margin: -8px 0 30px; color: var(--muted); font-size: 16px; }
.minor-title, .subsection-title { margin: 0 0 15px; font-size: 18px; }
.subsection-title { margin-top: 45px; padding-top: 36px; border-top: 1px solid var(--line); font-size: 21px; }

.choice-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 24px 0 28px; }
.choice-card { position: relative; padding: 25px; background: var(--soft); border: 1px solid transparent; border-radius: var(--radius); }
.choice-card.featured { background: #f6f5ff; border-color: #d8d5ff; }
.choice-tag { display: inline-block; padding: 3px 8px; color: var(--accent); background: #fff; border-radius: 6px; font-size: 10px; font-weight: 800; }
.choice-card h3 { margin: 13px 0 7px; font-size: 18px; }
.choice-card p { margin: 0 0 9px; color: var(--muted); font-size: 14px; }
.choice-card a { color: var(--accent); font-size: 13px; font-weight: 700; }
.choice-card small { color: var(--faint); font-size: 11px; }

.steps { display: grid; gap: 17px; margin: 27px 0; padding: 0; list-style: none; }
.steps li { display: flex; gap: 14px; align-items: flex-start; }
.steps li > span { display: grid; width: 29px; height: 29px; place-items: center; flex: 0 0 auto; color: var(--accent); background: var(--accent-soft); border-radius: 50%; font: 700 11px/1 "DM Mono", monospace; }
.steps b { font-size: 14px; }
.steps p { margin: 3px 0 0; color: var(--muted); font-size: 13px; }
.steps i { margin: 0 4px; color: var(--faint); font-style: normal; }
.steps.compact { gap: 14px; margin: 0; }

.screenshot { margin: 32px 0 0; }
.screenshot-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; margin-top: 32px; }
.screenshot-grid.three { grid-template-columns: repeat(3, 1fr); }
.screenshot-grid .screenshot { margin-top: 0; }
.screenshot-grid .shot-placeholder { min-height: 220px; padding: 22px; }
.screenshot > img { display: none; width: 100%; height: auto; border: 1px solid var(--line); border-radius: 13px; box-shadow: var(--shadow); }
.screenshot.has-image > img { display: block; }
.screenshot.has-image .shot-placeholder { display: none; }
.shot-placeholder { min-height: 330px; display: flex; padding: 32px; flex-direction: column; align-items: center; justify-content: center; color: var(--faint); background: linear-gradient(135deg, #f7f7fb, #f0f1f7); border: 1px dashed #cbd0dc; border-radius: 14px; text-align: center; }
.screenshot.small .shot-placeholder { min-height: 300px; }
.shot-icon { display: grid; width: 52px; height: 52px; margin-bottom: 15px; place-items: center; color: var(--accent); background: var(--accent-soft); border-radius: 14px; font-size: 25px; }
.shot-placeholder b { color: #5d6679; font-size: 14px; }
.shot-placeholder small { margin: 4px 0 13px; font-size: 12px; }
.shot-placeholder code { color: #7e8495; background: rgba(255,255,255,.8); font-size: 10px; }
.screenshot figcaption { margin-top: 9px; color: var(--faint); font-size: 11px; text-align: center; }

.split-content { display: grid; grid-template-columns: 1.35fr .8fr; gap: 32px; align-items: start; }
.split-content.balanced { grid-template-columns: 1fr 1fr; }
.split-content > .screenshot { margin-top: 0; }
.callout { position: relative; margin: 25px 0; padding: 19px 22px 19px 49px; color: #4f586b; background: #f5f6fa; border-left: 3px solid #8992a4; border-radius: 0 12px 12px 0; }
.callout::before { position: absolute; left: 19px; top: 18px; width: 20px; height: 20px; display: grid; place-items: center; border: 1px solid currentColor; border-radius: 50%; font: 700 11px/1 serif; }
.callout.warning { background: var(--warning-soft); border-color: var(--warning); }
.callout.warning::before { content: "!"; color: var(--warning); }
.callout.info { background: #f0f4ff; border-color: #6687e8; }
.callout.info::before { content: "i"; color: #6687e8; }
.callout.tip { background: #effaf7; border-color: var(--success); }
.callout.tip::before { content: "✓"; color: var(--success); }
.callout b { color: var(--ink); font-size: 13px; }
.callout p { margin: 3px 0 0; font-size: 12px; line-height: 1.75; }

.demo-flow { display: grid; grid-template-columns: 1fr auto 1fr auto 1fr; gap: 15px; align-items: center; margin: 28px 0 34px; }
.demo-flow > div { padding: 19px; background: #f7f7fb; border: 1px solid var(--line); border-radius: 13px; }
.demo-flow div > span { color: var(--cyan); font: 700 10px/1 "DM Mono", monospace; }
.demo-flow b { display: block; margin: 7px 0 3px; font-size: 14px; }
.demo-flow p { margin: 0; color: var(--muted); font-size: 11px; }
.demo-flow > i { color: #b1b7c4; font-style: normal; }
.feature-list { display: grid; grid-template-columns: 1fr 1fr; gap: 13px; }
.feature-list article { display: flex; gap: 14px; padding: 20px; background: #fafafd; border: 1px solid var(--line); border-radius: 14px; }
.feature-icon { display: grid; width: 36px; height: 36px; place-items: center; flex: 0 0 auto; color: var(--accent); background: var(--accent-soft); border-radius: 10px; font: 600 16px/1 "DM Mono", sans-serif; }
.feature-list h3 { margin: 0 0 5px; font-size: 14px; }
.feature-list p { margin: 0; color: var(--muted); font-size: 12px; }
.feature-list.numbered .feature-icon { border-radius: 50%; }

.setting-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 13px; }
.setting-grid article { padding: 22px; background: #f8f8fb; border-radius: 14px; }
.setting-grid article > span { color: var(--accent); font-size: 10px; font-weight: 800; letter-spacing: 1px; }
.setting-grid h3 { margin: 8px 0 6px; font-size: 15px; }
.setting-grid p { margin: 0; color: var(--muted); font-size: 12px; }
.term-table { overflow: hidden; border: 1px solid var(--line); border-radius: 13px; }
.term-row { display: grid; grid-template-columns: 1.1fr 1.5fr 1.3fr; gap: 15px; padding: 14px 17px; align-items: center; border-top: 1px solid var(--line); }
.term-row:first-child { border-top: 0; }
.term-row.head { color: var(--faint); background: #f6f7fa; font-size: 10px; font-weight: 800; letter-spacing: .6px; }
.term-row b { font-size: 12px; }
.term-row p { margin: 0; color: var(--muted); font-size: 12px; }
.term-row small { color: var(--faint); font-size: 11px; }

.chapter-break { width: min(920px, calc(100% - 72px)); margin: 70px auto 42px; padding: 48px 56px; color: #fff; background: linear-gradient(130deg, #262d43, #3d386f); border-radius: 22px; box-shadow: var(--shadow); }
.chapter-break span { color: #8ee0d8; font: 700 10px/1 "DM Mono", monospace; letter-spacing: 2px; }
.chapter-break h2 { margin: 12px 0 5px; font-size: 34px; letter-spacing: -1px; }
.chapter-break p { margin: 0; color: #c9cce0; font-size: 14px; }

.command-demo { display: flex; min-height: 52px; margin: 10px 0; padding: 10px 14px; align-items: center; gap: 14px; background: #f6f6fa; border: 1px solid var(--line); border-radius: 11px; }
.command-demo span { color: var(--faint); font-size: 10px; font-weight: 700; }
.command-demo code { min-width: 100px; padding: 5px 10px; color: var(--accent); background: #fff; border: 1px solid #dddfeb; font-size: 12px; }
.command-demo i { color: #abb1bf; font-style: normal; }
.command-demo strong { font-size: 12px; }
.command-demo.wide { margin-top: 15px; }
.key-banner { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; margin: 0 0 26px; overflow: hidden; background: #434a5e; border-radius: 13px; }
.key-banner > div { display: flex; padding: 18px 22px; align-items: center; justify-content: space-between; color: #fff; background: #252c40; }
.key-banner small { color: #aeb5c8; font-size: 11px; }
.key-banner kbd { color: #fff; background: #3b4359; border-color: #596178; }

.code-card { margin: 17px 0; overflow: hidden; background: #f6f7fa; border: 1px solid var(--line); border-radius: 12px; }
.code-card header { display: flex; min-height: 42px; padding: 0 14px 0 17px; align-items: center; justify-content: space-between; color: var(--muted); background: #edeff4; border-bottom: 1px solid var(--line); font-size: 10px; font-weight: 700; }
.copy-button { padding: 4px 9px; color: var(--muted); background: #fff; border: 1px solid #d8dbe4; border-radius: 6px; cursor: pointer; font-size: 10px; font-weight: 700; }
.copy-button:hover { color: var(--accent); border-color: #aaa5ee; }
.code-card pre { margin: 0; padding: 17px 19px; overflow: auto; line-height: 1.7; }
.code-card pre code { padding: 0; color: #3a4355; background: none; font-size: 11px; }
.code-card.dark { background: #202638; border-color: #343b50; }
.code-card.dark header { color: #b8bed0; background: #292f43; border-color: #3c4358; }
.code-card.dark .copy-button { color: #d4d7e4; background: #373e54; border-color: #4d556d; }
.code-card.dark pre code { color: #dce0ee; }
.sample-json pre { max-height: 440px; }

.accent-section { border-top: 4px solid var(--accent); }
.prerequisite { display: flex; gap: 16px; margin: 24px 0 17px; align-items: flex-start; }
.prerequisite-mark { display: grid; width: 38px; height: 38px; place-items: center; flex: 0 0 auto; color: #fff; background: var(--accent); border-radius: 50%; font-weight: 800; }
.prerequisite h3 { margin: 0 0 4px; font-size: 16px; }
.prerequisite p { margin: 0; color: var(--muted); font-size: 13px; }
.action-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.action-cards article { padding: 20px; background: #f7f7fb; border: 1px solid var(--line); border-radius: 14px; }
.action-cards article > span { color: var(--accent); font-size: 24px; line-height: 1; }
.action-cards h4 { margin: 12px 0 6px; font-size: 14px; }
.action-cards p { margin: 0; color: var(--muted); font-size: 11px; }
.case-stack { display: grid; gap: 16px; }
.case-card { overflow: hidden; border: 1px solid var(--line); border-radius: 16px; }
.case-card > header { display: flex; padding: 18px 21px 0; align-items: center; gap: 13px; }
.case-card > header span { color: var(--cyan); font: 700 10px/1 "DM Mono", monospace; letter-spacing: 1px; }
.case-card h4 { margin: 0; font-size: 15px; }
.case-goal { margin: 9px 21px 15px; color: var(--muted); font-size: 12px; }
.prompt-box { position: relative; margin: 0 20px 17px; padding: 16px 100px 16px 17px; background: #f5f4ff; border-radius: 11px; }
.prompt-box > span { color: var(--accent); font-size: 9px; font-weight: 800; letter-spacing: .6px; }
.prompt-box p { margin: 6px 0 0; color: #4d5670; font-size: 12px; }
.prompt-box .copy-button { position: absolute; top: 14px; right: 14px; }
.verify-list { display: flex; padding: 13px 20px; gap: 18px; color: var(--muted); background: #fafafd; border-top: 1px solid var(--line); font-size: 10px; }
.verify-list b { color: var(--ink); }
.verify-list span::before { content: "✓"; margin-right: 5px; color: var(--success); font-weight: 800; }

.shortcut-grid { display: grid; grid-template-columns: 1fr 1fr; overflow: hidden; border: 1px solid var(--line); border-radius: 14px; }
.shortcut-grid > div { display: flex; min-height: 58px; padding: 12px 17px; align-items: center; justify-content: space-between; gap: 15px; border-bottom: 1px solid var(--line); }
.shortcut-grid > div:nth-child(odd) { border-right: 1px solid var(--line); }
.shortcut-grid > div:nth-last-child(-n+2) { border-bottom: 0; }
.shortcut-grid span { color: var(--muted); font-size: 12px; }
.shortcut-grid b { font-size: 11px; white-space: nowrap; }

.manual-footer { display: flex; margin-top: 70px; padding: 36px 0 52px; align-items: center; justify-content: space-between; border-top: 1px solid var(--line); }
.manual-footer > div { display: flex; align-items: center; gap: 12px; }
.manual-footer p { display: flex; margin: 0; flex-direction: column; }
.manual-footer b { font-size: 13px; }
.manual-footer small { color: var(--faint); font-size: 10px; }
.manual-footer nav { display: flex; gap: 18px; color: var(--muted); font-size: 11px; }
.manual-footer a:hover { color: var(--accent); }
.copy-toast { position: fixed; z-index: 300; right: 22px; bottom: 22px; padding: 10px 16px; color: #fff; background: #252c40; border-radius: 8px; box-shadow: var(--shadow); font-size: 12px; opacity: 0; pointer-events: none; transform: translateY(8px); transition: .2s ease; }
.copy-toast.show { opacity: 1; transform: none; }

@media (max-width: 980px) {
  :root { --sidebar: 248px; }
  .hero, .manual-section, .chapter-break, .manual-footer { width: min(800px, calc(100% - 44px)); }
  .manual-section { padding: 46px 38px; }
  .split-content { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  :root { --topbar: 62px; }
  .topbar { padding: 0 17px; }
  .brand > span:last-child { display: block; line-height: 1.1; }
  .brand small { display: block; margin-top: 3px; }
  .top-actions { display: none; }
  .menu-button { display: flex; width: 42px; height: 42px; margin-left: auto; padding: 10px; flex-direction: column; justify-content: center; gap: 5px; background: transparent; border: 0; }
  .menu-button span { width: 22px; height: 2px; background: var(--ink); border-radius: 2px; }
  .sidebar { top: 0; z-index: 210; width: min(310px, 84vw); transform: translateX(-105%); transition: transform .25s ease; box-shadow: 24px 0 55px rgba(20,26,45,.18); }
  body.menu-open { overflow: hidden; }
  body.menu-open .sidebar { transform: none; }
  .sidebar-head { min-height: 62px; display: flex; padding: 0 18px 0 30px; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); font-size: 13px; font-weight: 800; }
  .sidebar-close { display: block; width: 38px; height: 38px; color: var(--muted); background: transparent; border: 0; font-size: 25px; cursor: pointer; }
  .sidebar-backdrop { position: fixed; z-index: 200; inset: 0; width: 100%; height: 100%; padding: 0; background: rgba(20,25,40,.35); border: 0; opacity: 0; pointer-events: none; transition: .25s ease; }
  body.menu-open .sidebar-backdrop { display: block; opacity: 1; pointer-events: auto; }
  main { margin-left: 0; }
  .hero, .manual-section, .chapter-break, .manual-footer { width: calc(100% - 26px); }
  .hero { padding: 66px 8px 50px; }
  .hero h1 { margin: 18px 0; font-size: 45px; letter-spacing: -2.5px; }
  .hero-lead { font-size: 15px; }
  .hero-facts { grid-template-columns: 1fr; gap: 15px; margin-top: 45px; }
  .hero-facts div, .hero-facts div:first-child { padding: 0 0 0 13px; border-left: 2px solid var(--accent-soft); }
  .manual-section { margin-bottom: 18px; padding: 34px 22px; border-radius: 17px; }
  .section-heading { gap: 12px; margin-bottom: 24px; }
  .section-number { width: 36px; height: 36px; border-radius: 10px; }
  .section-heading h2 { font-size: 24px; }
  .section-intro { font-size: 14px; }
  .choice-grid, .feature-list, .setting-grid, .split-content.balanced, .action-cards, .shortcut-grid, .screenshot-grid, .screenshot-grid.three { grid-template-columns: 1fr; }
  .term-row { grid-template-columns: 1fr; gap: 4px; }
  .term-row.head { display: none; }
  .demo-flow { grid-template-columns: 1fr; }
  .demo-flow > i { transform: rotate(90deg); text-align: center; }
  .shot-placeholder { min-height: 250px; padding: 23px; }
  .chapter-break { margin-block: 38px 22px; padding: 35px 28px; }
  .key-banner { grid-template-columns: 1fr; }
  .key-banner > div { padding: 15px; }
  .prompt-box { padding: 15px; }
  .prompt-box .copy-button { position: static; margin-top: 10px; }
  .verify-list { flex-direction: column; gap: 4px; }
  .shortcut-grid > div, .shortcut-grid > div:nth-child(odd) { border-right: 0; border-bottom: 1px solid var(--line); }
  .shortcut-grid > div:nth-last-child(2) { border-bottom: 1px solid var(--line); }
  .manual-footer { margin-top: 40px; padding: 28px 6px 40px; flex-direction: column; align-items: flex-start; gap: 22px; }
  .manual-footer nav { flex-wrap: wrap; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}