:root {
  --accent: #0f766e;
  --accent-soft: #dff5f1;
  --ink: #16343a;
  --muted: #5c6b72;
  --line: #dce5e8;
  --paper: #f7faf9;
  --white: #ffffff;
  --shadow: 0 18px 40px rgba(28, 54, 57, 0.1);
  --radius: 14px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", Arial, Helvetica, sans-serif; line-height: 1.75; }
a { color: inherit; }
img { max-width: 100%; height: auto; display: block; }
.site-header { background: rgba(255,255,255,.96); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 10; }
.header-inner, .hero-inner, .section-inner, .footer-inner { width: min(1120px, calc(100% - 48px)); margin: 0 auto; }
.header-inner { min-height: 74px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 11px; text-decoration: none; font-size: 1.15rem; font-weight: 800; letter-spacing: .01em; }
.brand img { width: 40px; height: 40px; border-radius: 11px; }
.site-nav { display: flex; align-items: center; gap: 8px; }
.nav-link, .header-action { text-decoration: none; border-radius: 9px; padding: 8px 13px; font-size: .95rem; color: var(--muted); }
.nav-link:hover, .nav-link.is-active { color: var(--accent); background: var(--accent-soft); }
.header-action { background: var(--accent); color: #fff; font-weight: 700; margin-left: 6px; }
.menu-toggle { display: none; border: 1px solid var(--line); color: var(--ink); background: #fff; border-radius: 9px; padding: 7px 10px; }
.hero { padding: 58px 0 44px; background: linear-gradient(180deg, #fff 0%, var(--paper) 100%); }
.hero-inner { display: grid; grid-template-columns: minmax(0, .96fr) minmax(420px, 1.04fr); align-items: center; gap: 44px; }
.eyebrow { color: var(--accent); font-size: .78rem; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; margin: 0 0 14px; }
h1, h2, h3, p { margin-top: 0; }
h1 { font-size: clamp(2.3rem, 3.5vw, 3.55rem); line-height: 1.12; letter-spacing: -.02em; margin-bottom: 17px; }
.hero-lead { color: var(--muted); max-width: 58ch; font-size: 1.03rem; margin-bottom: 24px; }
.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-bottom: 24px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: 9px 17px; border-radius: 9px; text-decoration: none; font-weight: 800; border: 1px solid transparent; }
.button-primary { color: #fff; background: var(--accent); box-shadow: 0 8px 18px color-mix(in srgb, var(--accent) 24%, transparent); }
.button-secondary { color: var(--accent); background: #fff; border-color: color-mix(in srgb, var(--accent) 35%, var(--line)); }
.hero-facts { display: flex; flex-wrap: wrap; gap: 8px; color: var(--muted); font-size: .85rem; }
.hero-facts span { padding: 5px 9px; border: 1px solid var(--line); border-radius: 999px; background: #fff; }
.screen-stage { min-height: 408px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 13px; align-items: center; position: relative; padding: 22px; background: var(--accent-soft); border-radius: 22px; border: 1px solid color-mix(in srgb, var(--accent) 17%, var(--line)); box-shadow: var(--shadow); }
.screen-card { margin: 0; background: #fff; border-radius: 12px; padding: 9px 9px 8px; box-shadow: 0 9px 22px rgba(28,54,57,.12); transform: translateY(0); }
.screen-card:nth-child(2) { transform: translateY(24px); }
.screen-card:nth-child(3) { transform: translateY(-12px); }
.screen-card img { width: 100%; aspect-ratio: 3 / 5; object-fit: contain; background: #eef2f2; border-radius: 8px; }
.screen-card figcaption { color: var(--muted); font-size: .73rem; padding: 7px 2px 0; }
.stage-catalog-shelf .screen-card:nth-child(1) { transform: translateY(18px); }
.stage-catalog-shelf .screen-card:nth-child(2) { transform: translateY(-15px); }
.stage-reading-timeline { grid-template-columns: .8fr 1fr 1.05fr; }
.stage-reading-timeline .screen-card:nth-child(1) { transform: translateY(28px); }
.stage-reading-timeline .screen-card:nth-child(2) { transform: translateY(-18px); }
.stage-creator-index { grid-template-columns: .92fr 1.08fr .92fr; padding: 28px 24px; }
.stage-creator-index .screen-card:nth-child(1) { transform: translateY(18px); }
.stage-creator-index .screen-card:nth-child(2) { transform: translateY(-16px); }
.stage-creator-index .screen-card:nth-child(3) { transform: translateY(10px); }
.stage-gallery-ledger { grid-template-columns: 1fr .82fr 1fr; }
.stage-gallery-ledger .screen-card:nth-child(1) { transform: translateY(-15px); }
.stage-gallery-ledger .screen-card:nth-child(2) { transform: translateY(23px); }
.section { padding: 72px 0; }
.section.alt { background: #fff; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-heading { max-width: 720px; margin-bottom: 28px; }
.section-kicker { color: var(--accent); font-size: .78rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; margin-bottom: 8px; }
h2 { font-size: clamp(1.65rem, 3vw, 2.35rem); line-height: 1.2; margin-bottom: 8px; }
.section-heading p { color: var(--muted); margin-bottom: 0; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.feature-card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 23px; min-height: 190px; }
.feature-card strong { display: block; color: var(--accent); font-size: .88rem; margin-bottom: 10px; }
.feature-card h3 { font-size: 1.08rem; margin-bottom: 8px; }
.feature-card p { color: var(--muted); font-size: .93rem; margin-bottom: 0; }
.route-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.route-card { display: flex; min-height: 154px; flex-direction: column; justify-content: space-between; text-decoration: none; background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; }
.route-card:hover { border-color: var(--accent); background: var(--accent-soft); }
.route-card span { color: var(--accent); font-weight: 800; font-size: .8rem; }
.route-card h3 { font-size: 1.08rem; margin: 13px 0 6px; }
.route-card p { color: var(--muted); font-size: .9rem; margin: 0; }
.download-band { padding: 34px 0; background: var(--accent); color: #fff; }
.download-inner { width: min(1120px, calc(100% - 48px)); margin: 0 auto; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.download-inner h2 { font-size: 1.55rem; margin-bottom: 5px; }
.download-inner p { margin: 0; color: rgba(255,255,255,.82); }
.download-band .button { background: #fff; color: var(--accent); flex: 0 0 auto; }
.subpage-hero { padding: 54px 0 34px; background: #fff; border-bottom: 1px solid var(--line); }
.subpage-hero h1 { font-size: clamp(2rem, 4vw, 3.2rem); margin-bottom: 12px; }
.subpage-hero p { color: var(--muted); max-width: 68ch; margin-bottom: 0; }
.prose-grid { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(250px, .75fr); gap: 34px; align-items: start; }
.prose { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 30px; }
.prose h2 { font-size: 1.45rem; margin-top: 28px; }
.prose h2:first-child { margin-top: 0; }
.prose h3 { font-size: 1.05rem; margin-top: 21px; margin-bottom: 6px; }
.prose p, .prose li { color: #52636b; }
.prose ul, .prose ol { padding-left: 22px; }
.side-note { position: sticky; top: 102px; border-left: 3px solid var(--accent); background: var(--accent-soft); padding: 20px 21px; border-radius: 0 var(--radius) var(--radius) 0; }
.side-note strong { display: block; margin-bottom: 6px; }
.side-note p { color: #50636a; margin-bottom: 0; font-size: .92rem; }
.faq-list { display: grid; gap: 10px; }
details { background: #fff; border: 1px solid var(--line); border-radius: 11px; padding: 0 18px; }
summary { cursor: pointer; list-style: none; padding: 17px 30px 17px 0; position: relative; font-weight: 800; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; color: var(--accent); position: absolute; right: 2px; top: 15px; font-size: 1.3rem; }
details[open] summary::after { content: "−"; }
details p { color: var(--muted); margin: 0 0 17px; padding-right: 16px; }
.site-footer { padding: 28px 0; background: #18373d; color: #d7e6e5; text-align: center; }
.site-footer p { margin: 0; font-size: .82rem; }
.site-footer .copyright { margin-top: 5px; color: #a9c1c0; }
@media (max-width: 880px) {
  .header-inner, .hero-inner, .section-inner, .footer-inner, .download-inner { width: min(100% - 32px, 680px); }
  .menu-toggle { display: inline-flex; }
  .site-nav { display: none; position: absolute; top: 74px; left: 0; right: 0; padding: 12px 16px 16px; background: #fff; border-bottom: 1px solid var(--line); flex-direction: column; align-items: stretch; }
  .site-nav.is-open { display: flex; }
  .nav-link, .header-action { text-align: center; margin: 0; }
  .hero { padding: 38px 0 20px; }
  .hero-inner { grid-template-columns: 1fr; gap: 30px; }
  .hero-copy { order: 1; }
  .hero-media { order: 2; }
  .screen-stage { min-height: 340px; padding: 15px; gap: 8px; }
  .feature-grid, .route-grid { grid-template-columns: 1fr; }
  .prose-grid { grid-template-columns: 1fr; }
  .side-note { position: static; }
  .download-inner { flex-direction: column; align-items: flex-start; }
}
@media (max-width: 480px) {
  .header-inner, .hero-inner, .section-inner, .footer-inner, .download-inner { width: min(100% - 24px, 680px); }
  h1 { font-size: 2.35rem; }
  .hero-facts span { font-size: .78rem; }
  .screen-stage { border-radius: 16px; min-height: 278px; }
  .screen-card { padding: 6px; border-radius: 9px; }
  .screen-card figcaption { font-size: .63rem; }
  .prose { padding: 21px 18px; }
}