/* course2md landing page. A faithful port of the "Landing page" artboards
   (LandingEn.dc.html / Landing.dc.html) in the course2md Material canvas:
   inline styles became classes, values are unchanged. */

/* Design helmet ------------------------------------------------------------ */

body { margin: 0; background: #EEF1F8; }
:where(a) { color: #2B5BB5; }
:where(a):hover { color: #0E2F6B; }
button { font: inherit; }
img { display: block; }

@keyframes c2m-blink { 0%, 49% { opacity: 1; } 50%, 100% { opacity: 0; } }
@keyframes c2m-spin { to { transform: rotate(360deg); } }
@keyframes c2m-marquee { from { transform: translateX(0); } to { transform: translateX(-50%); } }
@keyframes c2m-rise { from { opacity: 0; transform: translateY(56px) scale(.97); } to { opacity: 1; transform: none; } }
@keyframes c2m-grow { from { opacity: .4; transform: scale(.9); border-radius: 96px; } to { opacity: 1; transform: none; border-radius: 48px; } }
@keyframes c2m-float-a { 0%, 100% { transform: rotate(-7deg) translateY(0); } 50% { transform: rotate(-7deg) translateY(-10px); } }
@keyframes c2m-float-b { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-14px); } }
@keyframes c2m-float-c { 0%, 100% { transform: rotate(6deg) translateY(0); } 50% { transform: rotate(6deg) translateY(-8px); } }
@keyframes c2m-nudge { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(6px); } }

.caret { display: inline-block; width: 2px; height: 1.1em; vertical-align: -0.15em; background: currentColor; margin-left: 1px; animation: c2m-blink 1s steps(1) infinite; }
.spin { animation: c2m-spin .9s linear infinite; transform-origin: 50% 50%; }
.marquee { animation: c2m-marquee 70s linear infinite; }
.marquee-wrap:hover .marquee { animation-play-state: paused; }
.fan-a { animation: c2m-float-a 7s ease-in-out infinite; }
.fan-b { animation: c2m-float-b 6s ease-in-out infinite; }
.fan-c { animation: c2m-float-c 8s ease-in-out infinite; }
.nudge { animation: c2m-nudge 1.6s ease-in-out infinite; }

@supports (animation-timeline: view()) {
  .reveal { animation: c2m-rise linear both; animation-timeline: view(); animation-range: entry 0% cover 28%; }
  .reveal-2 { animation: c2m-rise linear both; animation-timeline: view(); animation-range: entry 10% cover 34%; }
  .reveal-3 { animation: c2m-rise linear both; animation-timeline: view(); animation-range: entry 20% cover 40%; }
  .grow { animation: c2m-grow linear both; animation-timeline: view(); animation-range: entry 0% cover 40%; }
}

/* Fallback without scroll-driven animations: site.js marks elements as they
   enter the viewport and plays the same keyframes once. */
@supports not (animation-timeline: view()) {
  .io .reveal, .io .reveal-2, .io .reveal-3, .io .grow { opacity: 0; }
  .io .reveal.seen { animation: c2m-rise .7s cubic-bezier(.2, .8, .2, 1) both; }
  .io .reveal-2.seen { animation: c2m-rise .7s cubic-bezier(.2, .8, .2, 1) .08s both; }
  .io .reveal-3.seen { animation: c2m-rise .7s cubic-bezier(.2, .8, .2, 1) .16s both; }
  .io .grow.seen { animation: c2m-grow .8s cubic-bezier(.2, .8, .2, 1) both; }
}

@media (prefers-reduced-motion: reduce) {
  .caret, .spin, .marquee, .fan-a, .fan-b, .fan-c, .nudge, .reveal, .reveal-2, .reveal-3, .grow { animation: none !important; }
  .io .reveal, .io .reveal-2, .io .reveal-3, .io .grow { opacity: 1; }
}

/* Page --------------------------------------------------------------------- */

.page {
  min-height: 100vh;
  background: #EEF1F8;
  color: #1A1B20;
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', 'PingFang SC', 'Noto Sans SC', system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  overflow-x: clip;
  -webkit-font-smoothing: antialiased;
}
html:lang(zh) .page {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei UI', 'Noto Sans SC', system-ui, sans-serif;
}
.mono { font-family: ui-monospace, 'SF Mono', Menlo, 'JetBrains Mono', Consolas, monospace; }
.visually-hidden { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
[hidden] { display: none !important; }

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; box-sizing: border-box; width: 100%; }

.mark { width: 36px; height: 36px; border-radius: 11px; background: #1F63E0; color: #FFFFFF; display: flex; align-items: center; justify-content: center; }
.mark-sm { width: 24px; height: 24px; border-radius: 7px; }

/* Header */
.site-header { max-width: 1200px; margin: 0 auto; padding: 16px 24px; box-sizing: border-box; display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 10px; color: #1A1B20; text-decoration: none; flex: 1 1 auto; }
.brand-name { font-size: 19px; font-weight: 600; }
.site-nav { display: flex; align-items: center; gap: 4px; flex-wrap: wrap; }
.nav-link { height: 40px; padding: 0 14px; border-radius: 20px; display: inline-flex; align-items: center; color: #1A1B20; text-decoration: none; font-size: 15px; font-weight: 500; }
.nav-lang { padding: 0 14px 0 10px; gap: 6px; }
.nav-gh { padding: 0 16px; gap: 8px; background: #DCE2F9; color: #151B2C; }
.nav-link:hover { color: #1A1B20; }
.nav-gh:hover { color: #151B2C; }

main { display: flex; flex-direction: column; gap: 120px; padding-bottom: 96px; }

/* Hero */
.hero { max-width: 1200px; margin: 0 auto; padding: 32px 24px 0; box-sizing: border-box; width: 100%; display: flex; flex-wrap: wrap; gap: 48px; align-items: center; }
.hero-copy { flex: 1 1 440px; min-width: 0; display: flex; flex-direction: column; gap: 24px; }
.badge { align-self: flex-start; display: inline-flex; align-items: center; gap: 8px; height: 32px; padding: 0 14px 0 10px; border-radius: 16px; background: #C3EFCD; color: #0F4A22; font-size: 13px; font-weight: 500; }
.hero h1 { margin: 0; font-size: 56px; font-weight: 700; line-height: 1.08; letter-spacing: -1px; }
html:lang(zh) .hero h1 { font-size: 60px; line-height: 1.12; letter-spacing: -0.5px; }
.hero-copy p { margin: 0; font-size: 19px; line-height: 1.65; color: #44474F; max-width: 560px; }
html:lang(zh) .hero-copy p { line-height: 1.75; }
.uses { display: flex; gap: 8px; flex-wrap: wrap; }
.use { height: 32px; padding: 0 12px; border-radius: 8px; border: 1px solid #C4C6D0; box-sizing: border-box; display: inline-flex; align-items: center; font-size: 13px; color: #44474F; }
.ctas { display: flex; gap: 12px; flex-wrap: wrap; padding-top: 4px; }
.cta-main { height: 60px; padding: 0 28px 0 22px; border-radius: 30px; background: #2B5BB5; color: #FFFFFF; display: inline-flex; align-items: center; gap: 12px; text-decoration: none; font-size: 17px; font-weight: 600; }
.cta-main:hover { color: #FFFFFF; }
.cta-alt { height: 60px; padding: 0 26px; border: 1px solid #74777F; box-sizing: border-box; border-radius: 30px; display: inline-flex; align-items: center; text-decoration: none; font-size: 17px; font-weight: 500; }
.cta-note { font-size: 13px; color: #44474F; }

.hero-fan { flex: 1 1 480px; min-width: 0; position: relative; height: 440px; }
.fan-card { position: absolute; border-radius: 20px; background: #FBFCFF; padding: 10px; box-shadow: 0 12px 32px rgba(14, 47, 107, 0.16); }
.fan-card img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; border-radius: 12px; height: auto; }
.fan-card.fan-a { left: 0; top: 70px; width: 58%; transform-origin: 50% 100%; }
.fan-card.fan-c { right: 0; top: 40px; width: 54%; }
.fan-card.fan-b { left: 20%; top: 150px; width: 60%; border-radius: 22px; padding: 12px; box-shadow: 0 24px 56px rgba(14, 47, 107, 0.24); }
.fan-cap { display: flex; justify-content: space-between; padding: 8px 4px 2px; font-size: 12px; color: #44474F; }
.fan-quote { margin: 10px 4px 2px; font-size: 13px; line-height: 1.6; color: #1A1B20; }

.nudge-link { align-self: center; margin-top: -72px; display: inline-flex; align-items: center; gap: 8px; height: 44px; padding: 0 18px; border-radius: 22px; background: #FBFCFF; color: #1A1B20; text-decoration: none; font-size: 14px; font-weight: 500; }
.nudge-link:hover { color: #1A1B20; }

/* Story: a pinned demo window whose scene follows scroll progress */
.story { position: relative; }
.js .story { height: 4600px; }
.story-pin { position: relative; display: flex; align-items: center; }
.js .story-pin { position: sticky; top: 0; height: clamp(520px, 100vh, 900px); }
.story-grid { max-width: 1200px; margin: 0 auto; padding: 24px; box-sizing: border-box; width: 100%; display: flex; gap: 40px; align-items: center; }
.story-steps { flex: 0 0 340px; max-width: 340px; display: flex; flex-direction: column; gap: 4px; }
.story-steps h2 { margin: 0 0 12px; font-size: 14px; font-weight: 600; color: #44474F; }
.step { text-align: left; border: 0; cursor: pointer; display: flex; gap: 14px; padding: 12px 14px; border-radius: 20px; background: transparent; color: #1A1B20; transition: background .3s; }
.step.story-step-on { background: #FBFCFF; }
.step-n { position: relative; width: 28px; height: 28px; flex: none; border-radius: 14px; display: flex; align-items: center; justify-content: center; font-size: 13px; font-weight: 700; background: #E1E4ED; color: #44474F; transition: background .3s, color .3s; }
.step.is-past .step-n { background: #C3EFCD; color: #0F4A22; }
.step.story-step-on .step-n { background: #2B5BB5; color: #FFFFFF; }
.step-text { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.step-title { font-size: 15px; font-weight: 600; line-height: 1.3; transition: font-size .3s; }
.step.story-step-on .step-title { font-size: 20px; }
.step-body { display: none; font-size: 14px; line-height: 1.6; color: #44474F; }
html:lang(zh) .step-body { line-height: 1.65; }
.step.story-step-on .step-body { display: inline; }
.story-bar { margin: 12px 14px 0; height: 4px; border-radius: 2px; background: #DCE2F9; overflow: hidden; }
.story-bar span { display: block; height: 4px; border-radius: 2px; background: #2B5BB5; width: 0; transition: width .2s linear; }

.story-window { flex: 1 1 auto; min-width: 0; position: relative; height: 620px; border-radius: 32px; background: #EEF1F8; box-shadow: 0 1px 2px rgba(26, 27, 32, 0.06), 0 28px 72px rgba(14, 47, 107, 0.20), inset 0 0 0 1px rgba(196, 198, 208, 0.7); overflow: hidden; }
.traffic { position: absolute; top: 0; left: 0; right: 0; height: 44px; display: flex; align-items: center; gap: 8px; padding: 0 18px; z-index: 3; }
.dot { width: 12px; height: 12px; border-radius: 6px; background: #FF5F57; }
.dot-y { background: #FEBC2E; }
.dot-g { background: #28C840; }

.scene { position: absolute; inset: 44px 0 0; box-sizing: border-box; display: flex; opacity: 0; transform: translateY(28px) scale(.98); transition: opacity .45s ease, transform .45s ease; }
.scene.is-past { transform: translateY(-28px) scale(.98); }
.scene.is-on { opacity: 1; transform: none; }
.thumb-time { position: absolute; padding: 2px 8px; border-radius: 6px; background: rgba(26, 27, 32, 0.86); color: #FFFFFF; font-weight: 600; }

/* Scene 0: paste a link */
.sc-link { padding: 28px 40px; flex-direction: column; align-items: center; justify-content: center; gap: 22px; }
.scene-title { font-size: 30px; font-weight: 600; }
.url-field { width: 100%; max-width: 640px; display: flex; align-items: center; gap: 12px; min-height: 64px; padding: 6px 6px 6px 22px; box-sizing: border-box; border-radius: 32px; background: #FBFCFF; box-shadow: inset 0 0 0 2px #2B5BB5; }
.url-text { flex: 1; min-width: 0; font-size: 16px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.url-text .caret { color: #2B5BB5; }
.preview-btn { height: 52px; padding: 0 20px; border-radius: 26px; display: inline-flex; align-items: center; font-size: 15px; font-weight: 600; white-space: nowrap; background: #DCE2F9; color: #151B2C; transition: background .3s, color .3s; }
html:lang(zh) .preview-btn { white-space: normal; }
.preview-btn.is-done { background: #0E2F6B; color: #FFFFFF; }
.drop-hint { display: inline-flex; align-items: center; gap: 8px; font-size: 14px; color: #44474F; }

/* Scene 1: preview */
.sc-preview { padding: 28px 40px; flex-direction: column; align-items: center; justify-content: center; gap: 18px; }
.url-plain { width: 100%; max-width: 640px; display: flex; align-items: center; gap: 12px; min-height: 56px; padding: 6px 6px 6px 22px; box-sizing: border-box; border-radius: 28px; background: #FBFCFF; box-shadow: inset 0 0 0 1px #C4C6D0; font-size: 14px; color: #44474F; }
.url-plain span { flex: 1; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.video-card { width: 100%; max-width: 640px; border-radius: 28px; background: #FBFCFF; padding: 14px; box-sizing: border-box; display: flex; gap: 18px; flex-wrap: wrap; }
.thumb { position: relative; flex: 0 0 240px; border-radius: 16px; overflow: hidden; background: #DCE2F9; }
.thumb img { width: 100%; aspect-ratio: 16 / 10; object-fit: cover; height: auto; }
.thumb .thumb-time { right: 8px; bottom: 8px; font-size: 12px; }
.video-meta { flex: 1 1 220px; min-width: 0; display: flex; flex-direction: column; gap: 8px; padding: 4px 0; }
.video-title { font-size: 18px; font-weight: 600; line-height: 1.4; }
.video-by { font-size: 13px; color: #44474F; }
.start-btn { margin-top: auto; align-self: flex-end; height: 48px; padding: 0 22px 0 18px; border-radius: 24px; display: inline-flex; align-items: center; gap: 8px; font-size: 15px; font-weight: 600; color: #FFFFFF; background: #2B5BB5; box-shadow: none; transition: background .3s, box-shadow .3s; }
.start-btn.is-hot { background: #0E2F6B; box-shadow: 0 0 0 6px rgba(43, 91, 181, 0.25); }

/* Scene 2: screenshots */
.sc-shots { padding: 16px 28px 28px; flex-direction: column; gap: 16px; }
.shots-head { display: flex; align-items: center; gap: 12px; padding-left: 64px; }
.shots-label { flex: 1; font-size: 15px; font-weight: 600; }
.shots-count { font-size: 14px; color: #44474F; font-variant-numeric: tabular-nums; }
.shots-bar { display: flex; align-items: center; gap: 4px; height: 6px; }
.shots-bar span { height: 6px; border-radius: 3px; background: #2B5BB5; width: 0; transition: width .2s linear; }
.shots-bar span + span { flex: 1; width: auto; background: #DCE2F9; transition: none; }
.shot-grid { flex: 1; min-height: 0; display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: 10px; align-content: start; }
.shot { position: relative; border-radius: 10px; overflow: hidden; background: #DCE2F9; opacity: 0; transform: scale(.85); transition: opacity .35s ease, transform .35s cubic-bezier(.2, .8, .2, 1); }
.shot.is-on { opacity: 1; transform: none; }
.shot img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; height: auto; }
.shot span { position: absolute; left: 4px; bottom: 4px; padding: 0 5px; border-radius: 4px; background: rgba(26, 27, 32, 0.82); color: #FFFFFF; font-size: 10px; font-weight: 600; line-height: 16px; }

/* Scene 3: subtitles under the slide */
.scene-sub { padding: 16px 28px 28px; gap: 20px; }
.sub-slide { flex: 1 1 52%; min-width: 0; display: flex; flex-direction: column; gap: 10px; }
.sub-frame { position: relative; border-radius: 18px; overflow: hidden; background: #FFFFFF; box-shadow: inset 0 0 0 1px #E1E4ED; }
.sub-frame img { width: 100%; aspect-ratio: 4 / 3; object-fit: contain; height: auto; }
.sub-frame .thumb-time { left: 10px; bottom: 10px; font-size: 12px; }
.sub-cap { font-size: 13px; color: #44474F; }
.sub-list { flex: 1 1 48%; min-width: 0; border-radius: 20px; background: #FBFCFF; padding: 16px 18px; display: flex; flex-direction: column; gap: 6px; overflow: hidden; }
.sub-head { font-size: 12px; font-weight: 600; color: #44474F; padding-bottom: 6px; }
.sub-line { display: flex; gap: 10px; font-size: 14px; line-height: 1.55; opacity: 0; transform: translateY(8px); transition: opacity .3s ease, transform .3s ease; }
.sub-line.is-on { opacity: 1; transform: none; }
.sub-line b { flex: none; width: 40px; color: #2B5BB5; font-weight: 600; font-variant-numeric: tabular-nums; }

/* Scene 4: AI proofreading */
.sc-ai { padding: 20px 36px 28px; flex-direction: column; gap: 16px; }
.ai-head { display: flex; align-items: center; gap: 10px; padding-left: 64px; flex-wrap: wrap; }
html:lang(zh) .ai-head { flex-wrap: nowrap; }
.ai-chip { display: inline-flex; align-items: center; gap: 6px; height: 32px; padding: 0 12px; border-radius: 8px; font-size: 13px; font-weight: 600; background: #E1E4ED; color: #44474F; transition: background .3s, color .3s; }
.sc-ai.is-clean .ai-chip { background: #C3EFCD; color: #0F4A22; }
.ai-note { font-size: 13px; color: #44474F; }
.ai-text { position: relative; border-radius: 22px; background: #FBFCFF; padding: 20px 24px; min-height: 196px; }
.ai-raw { position: absolute; inset: 20px 24px auto; margin: 0; font-size: 16px; line-height: 1.85; color: #74777F; opacity: 1; transition: opacity .5s ease; }
.ai-clean { position: relative; margin: 0; font-size: 16px; line-height: 1.85; color: #1A1B20; opacity: 0; transition: opacity .5s ease; }
.sc-ai.is-clean .ai-raw { opacity: 0; }
.sc-ai.is-clean .ai-clean { opacity: 1; }
.ai-sum { border-radius: 22px; background: #EAF0FF; padding: 18px 22px; display: flex; flex-direction: column; gap: 8px; opacity: 0; transform: translateY(16px); transition: opacity .45s ease, transform .45s cubic-bezier(.2, .8, .2, 1); }
.ai-sum.is-on { opacity: 1; transform: none; }
.ai-sum-title { display: inline-flex; align-items: center; gap: 8px; font-size: 14px; font-weight: 700; color: #0E2F6B; }
.ai-sum p { margin: 0; font-size: 15px; line-height: 1.8; }

/* Scene 5: reader */
.sc-read { inset: 0; padding: 4px 22px 0; flex-direction: column; gap: 10px; }
.read-bar { display: flex; align-items: center; gap: 12px; min-height: 60px; padding-left: 72px; }
.read-back { width: 38px; height: 38px; flex: none; border-radius: 19px; background: #E1E4ED; display: flex; align-items: center; justify-content: center; }
.read-titles { flex: 1; min-width: 0; display: flex; flex-direction: column; }
.read-crumb { font-size: 12px; color: #44474F; }
.read-title { font-size: 18px; font-weight: 500; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.read-main { flex: 1; min-height: 0; display: flex; gap: 18px; }
.demo-toc { width: 240px; flex: none; display: flex; flex-direction: column; gap: 2px; overflow: hidden; }
.toc-head { font-size: 12px; color: #44474F; padding: 4px 14px 6px; }
.toc-item { display: flex; align-items: center; gap: 8px; min-height: 36px; padding: 0 12px 0 14px; border-radius: 18px; font-size: 13px; background: transparent; color: #1A1B20; font-weight: 400; transition: background .35s, color .35s; }
.toc-item.is-active { background: #D8E2FF; color: #0E2F6B; font-weight: 600; }
.toc-item span:first-child { flex: 1; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.toc-item span + span { font-size: 11px; font-variant-numeric: tabular-nums; opacity: .8; }
.read-paper { flex: 1; min-width: 0; position: relative; border-radius: 24px 24px 0 0; background: #FBFCFF; overflow: hidden; }
.reader-body { padding: 22px 30px 40px; display: flex; flex-direction: column; gap: 14px; transform: translateY(0); transition: transform .35s cubic-bezier(.3, .7, .2, 1); }
.read-shot { position: relative; border-radius: 16px; overflow: hidden; background: #DCE2F9; padding: 0 12%; }
.read-shot img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; height: auto; }
.read-shot .thumb-time { left: 10px; bottom: 10px; font-size: 11px; }
.watch-chip { align-self: flex-start; height: 30px; padding: 0 12px 0 9px; border-radius: 15px; background: #DCE2F9; color: #151B2C; display: inline-flex; align-items: center; gap: 6px; font-size: 12px; font-weight: 600; }
.reader-body p { margin: 0; font-size: 15px; line-height: 1.9; }
.read-h { display: flex; align-items: center; gap: 10px; padding-top: 14px; }
.read-h span:first-child { flex: 1; font-size: 21px; font-weight: 600; }
.read-h span + span { font-size: 12px; color: #44474F; }

/* Scene 6: export */
.sc-export { padding: 24px 40px 32px; gap: 28px; align-items: center; justify-content: center; flex-wrap: wrap; }
.export-menu { width: 340px; padding: 8px 0; border-radius: 18px; background: #F3F4FB; box-shadow: 0 2px 6px rgba(26, 27, 32, 0.12), 0 12px 32px rgba(26, 27, 32, 0.14); display: flex; flex-direction: column; }
html:lang(zh) .export-menu { width: 320px; }
.menu-item { display: flex; align-items: center; gap: 12px; height: 48px; padding: 0 16px; font-size: 14px; background: transparent; opacity: 1; transition: background .3s, opacity .3s; }
.menu-item.is-hi { background: #DCE2F9; }
.files { width: 320px; border-radius: 24px; background: #FBFCFF; padding: 20px 22px; font-size: 13px; line-height: 2.1; box-sizing: content-box; }
.file { display: flex; align-items: center; gap: 10px; padding-left: 0; opacity: 0; transform: translateX(-8px); transition: opacity .35s ease, transform .35s ease; }
.file.is-on { opacity: 1; transform: none; }
.file.nested { padding-left: 20px; }
.file i { width: 8px; height: 8px; flex: none; border-radius: 2px; background: #2B5BB5; }
.file i.teal { background: #00596A; }
.file i.amber { background: #5B4300; }
.file span { flex: 1; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.file small { font-size: inherit; color: #74777F; }

/* Gallery */
.gallery { display: flex; flex-direction: column; gap: 28px; }
.section-intro { display: flex; flex-direction: column; gap: 12px; }
.h2 { margin: 0; font-size: 40px; font-weight: 700; line-height: 1.2; }
.lede { margin: 0; font-size: 17px; line-height: 1.7; color: #44474F; }
.gallery .lede { max-width: 720px; }
.marquee-wrap { overflow: hidden; padding: 8px 0 16px; }
.marquee { display: flex; gap: 16px; width: max-content; padding-left: 24px; }
.g-card { margin: 0; width: 280px; flex: none; border-radius: 26px; background: #FBFCFF; padding: 10px 10px 14px; box-sizing: border-box; display: flex; flex-direction: column; gap: 10px; }
.g-frame { position: relative; border-radius: 16px; overflow: hidden; background: #FFFFFF; box-shadow: inset 0 0 0 1px #E1E4ED; }
.g-frame img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; height: auto; }
.g-frame .thumb-time { left: 8px; bottom: 8px; font-size: 11px; }
.g-card figcaption { padding: 0 6px; font-size: 14px; font-weight: 600; }

/* Features */
.features { display: flex; flex-direction: column; gap: 32px; }
.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 12px; }
.feature { background: #FBFCFF; border-radius: 32px; padding: 28px; display: flex; flex-direction: column; gap: 14px; }
.f-icon { width: 56px; height: 56px; border-radius: 28px; display: flex; align-items: center; justify-content: center; }
.f-blue { background: #D6E3FF; color: #0B4FB8; }
.f-orange { background: #FFDBC9; color: #8B3A00; }
.f-yellow { background: #FCE38A; color: #5B4300; }
.f-pink { background: #FFD8EC; color: #8E1B5B; }
.f-gray { background: #E1E4ED; color: #1A1B20; }
.feature h3 { margin: 0; font-size: 20px; font-weight: 600; }
.feature p { margin: 0; font-size: 15px; line-height: 1.7; color: #44474F; }

/* Privacy */
.grow { border-radius: 48px; background: #2B5BB5; color: #FFFFFF; padding: 56px; box-sizing: border-box; display: flex; flex-wrap: wrap; gap: 40px; align-items: center; }
.privacy-copy { flex: 1 1 420px; min-width: 0; display: flex; flex-direction: column; gap: 16px; }
.privacy-copy p { margin: 0; font-size: 17px; line-height: 1.7; color: #D8E2FF; }
.privacy-list { flex: 1 1 320px; min-width: 0; display: flex; flex-direction: column; gap: 2px; }
.privacy-row { display: flex; align-items: center; gap: 14px; padding: 18px 20px; border-radius: 6px; background: #3D6CC4; }
.privacy-row:first-child { border-radius: 24px 24px 6px 6px; }
.privacy-row:last-child { border-radius: 6px 6px 24px 24px; }
.privacy-row span:first-of-type { flex: 1; font-size: 16px; font-weight: 600; }
.privacy-row span + span { font-size: 13px; color: #D8E2FF; }

/* Download */
.download { display: flex; flex-direction: column; gap: 28px; }
.tab-row { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.seg { display: flex; gap: 2px; }
.seg button { border: 0; cursor: pointer; font-weight: 600; background: #E3E6EF; color: #1A1B20; border-radius: 8px; transition: background .25s, color .25s, border-radius .25s; }
.seg button:first-child { border-radius: var(--r) 8px 8px var(--r); }
.seg button:last-child { border-radius: 8px var(--r) var(--r) 8px; }
.seg button[aria-selected="true"] { background: #2B5BB5; color: #FFFFFF; border-radius: var(--r); }
.seg-platform { --r: 26px; flex: 0 1 560px; }
.seg-platform button { flex: 1; min-width: 0; height: 52px; font-size: 16px; }
.seg-cli { --r: 20px; flex-wrap: wrap; }
.seg-cli button { height: 40px; padding: 0 16px; font-size: 14px; }
.detected { display: inline-flex; align-items: center; gap: 6px; font-size: 14px; color: #44474F; }
.panel { display: flex; flex-direction: column; gap: 2px; }
.tile { background: #FBFCFF; display: flex; align-items: center; flex-wrap: wrap; }
.tile-top { border-radius: 32px 32px 8px 8px; padding: 28px 32px; gap: 20px; }
.tile-bottom { border-radius: 8px 8px 32px 32px; padding: 20px 20px 20px 32px; gap: 16px; }
.tile-top.tight { padding: 24px 20px 24px 32px; gap: 16px; }
.tile-bottom.roomy { padding: 28px 32px; gap: 20px; }
.tile-label { flex: 1 1 280px; min-width: 0; display: flex; flex-direction: column; gap: 4px; }
.tile-label.narrow { flex-basis: 260px; }
.tile-label strong { font-size: 20px; font-weight: 600; }
.tile-label span { font-size: 15px; color: #44474F; }
.tile-hint { flex: 1 1 260px; font-size: 15px; color: #44474F; }
.dl-btn { height: 56px; padding: 0 26px 0 20px; border-radius: 28px; background: #2B5BB5; color: #FFFFFF; display: inline-flex; align-items: center; gap: 10px; text-decoration: none; font-size: 16px; font-weight: 600; }
.dl-btn:hover { color: #FFFFFF; }
.cmd { flex: 1 1 420px; min-width: 0; display: flex; align-items: center; gap: 8px; height: 52px; padding: 0 6px 0 18px; border-radius: 26px; background: #EEF1F8; font-size: 14px; box-sizing: border-box; }
.cmd .prompt { color: #2B5BB5; font-weight: 600; }
.cmd code { flex: 1; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; font: inherit; }
.copy { height: 40px; flex: none; padding: 0 14px; border: 0; border-radius: 20px; background: #DCE2F9; color: #151B2C; font-size: 13px; font-weight: 600; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif; cursor: pointer; }
.dl-note { display: flex; align-items: flex-start; gap: 10px; font-size: 14px; color: #44474F; padding: 0 8px; }
.dl-note svg { flex: none; margin-top: 2px; }

/* CLI */
.cli { display: flex; flex-wrap: wrap; gap: 48px; align-items: center; }
.cli-copy { flex: 1 1 340px; min-width: 0; display: flex; flex-direction: column; gap: 16px; }
.cmd-cli { flex: none; height: auto; min-height: 52px; padding: 6px 6px 6px 18px; background: #FBFCFF; font-size: 13px; }
.cmd-cli code { overflow-x: auto; text-overflow: clip; }
.guide-link { align-self: flex-start; height: 44px; display: inline-flex; align-items: center; gap: 6px; text-decoration: none; font-size: 15px; font-weight: 600; }
.term { flex: 1 1 520px; min-width: 0; border-radius: 28px; background: #1B1D22; box-shadow: 0 24px 60px rgba(14, 18, 30, 0.28), inset 0 0 0 1px rgba(255, 255, 255, 0.06); overflow: hidden; }
.term-bar { height: 48px; display: flex; align-items: center; gap: 8px; padding: 0 18px; background: #23262C; }
.term-title { flex: 1; text-align: center; font-size: 13px; color: #8E9099; }
.term-spacer { width: 52px; }
.term-body { padding: 22px 26px 26px; min-height: 300px; box-sizing: border-box; font-size: 14px; line-height: 1.9; color: #E2E2E9; }
.term-cmd { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.t-dir { color: #8FD9A0; }
.t-prompt { color: #ADC6FF; font-weight: 600; }
.t-bin { color: #ADC6FF; }
.t-arg { color: #FFB59A; }
.term-body .caret { color: #ADC6FF; }
.t-line { display: flex; gap: 10px; white-space: nowrap; overflow: hidden; }
.t-line b { width: 1em; flex: none; font-weight: 600; }
.t-line span { overflow: hidden; text-overflow: ellipsis; }
.t-step b { color: #ADC6FF; }
.t-step span { color: #C4C6D0; }
.t-ok b { color: #8FD9A0; }
.t-ok span { color: #E2E2E9; }
.t-dim b, .t-dim span { color: #8E9099; }

/* Footer */
.site-footer { border-top: 1px solid #C4C6D0; }
.footer-inner { max-width: 1200px; margin: 0 auto; padding: 32px 24px 48px; box-sizing: border-box; display: flex; flex-wrap: wrap; gap: 16px 32px; align-items: center; font-size: 14px; color: #44474F; }
.footer-brand { display: flex; align-items: center; gap: 8px; color: #1A1B20; font-weight: 600; }
.footer-gap { flex: 1; }

/* 404 */
.lost { max-width: 1200px; margin: 0 auto; padding: 72px 24px 96px; box-sizing: border-box; display: flex; flex-direction: column; align-items: flex-start; gap: 24px; }
.lost h1 { margin: 0; font-size: 56px; font-weight: 700; line-height: 1.08; letter-spacing: -1px; }
.lost p { margin: 0; font-size: 19px; line-height: 1.65; color: #44474F; }

/* Design breakpoints -------------------------------------------------------- */

@media (max-width: 900px) {
  .story-grid { flex-direction: column !important; gap: 12px !important; padding: 12px 16px !important; }
  .story-steps { flex: none !important; max-width: none !important; width: 100%; }
  .story-steps h2 { display: none; }
  .story-step-idle { display: none !important; }
  .story-step-on { padding: 10px 12px !important; }
  .story-window { width: 100%; height: min(480px, calc(100svh - 210px)) !important; border-radius: 24px !important; }
  .demo-toc { display: none !important; }
  .hero-fan { height: 300px !important; }
  .scene-pad { padding: 16px !important; gap: 14px !important; }
  .thumb { flex-basis: 100% !important; }
  .shot-grid { grid-template-columns: repeat(4, minmax(0, 1fr)) !important; gap: 6px !important; }
  .scene-sub { flex-direction: column !important; padding: 12px 16px !important; gap: 10px !important; }
  .reader-body { padding: 16px !important; }
  .export-menu { display: none !important; }
}

@media (max-width: 640px) {
  .nav-more { display: none !important; }
  .hero h1 { font-size: 36px !important; letter-spacing: 0 !important; }
  html:lang(zh) .hero h1 { font-size: 38px !important; }
  .h2 { font-size: 28px !important; }
  main { gap: 72px !important; }
  .grow { padding: 32px 22px !important; }
  .story-step-on > span:last-child > span:first-child { font-size: 17px !important; }
  .scene-title { font-size: 22px !important; }
  .hero-copy p { font-size: 17px !important; }
  .lost h1 { font-size: 36px; letter-spacing: 0; }
}