/* 光合AI 官网 · tokens 见 docs/DESIGN.md */
:root {
  --ink: #101820;
  --ink-2: #18232E;
  --gold: #E8B84B;
  --gold-soft: rgba(232, 184, 75, 0.15);
  --leaf: #7FB069;
  --text: #E9EDF0;
  --text-muted: #9AA7B0;
  --line: #2A3742;
  --font-heading: 'Noto Serif SC', 'Source Han Serif SC', 'Songti SC', 'STSong', serif;
  --font-body: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
}

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

body {
  background: var(--ink);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
}

h1, h2, h3 { font-family: var(--font-heading); font-weight: 600; line-height: 1.35; }
h1 { font-size: 44px; }
h2 { font-size: 30px; }
h3 { font-size: 20px; }
a { color: var(--gold); text-decoration: none; }
a:hover { text-decoration: underline; }
em.gold { font-style: normal; color: var(--gold); }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* ===== 页头 ===== */
.site-header {
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0;
  background: rgba(16, 24, 32, 0.92);
  backdrop-filter: blur(8px);
  z-index: 10;
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand {
  font-family: var(--font-heading);
  font-size: 22px; color: var(--text);
  display: flex; align-items: center; gap: 10px;
}
.brand a { display: flex; align-items: center; gap: 10px; }
.brand img { height: 34px; width: auto; display: block; }
.brand b { color: var(--gold); font-weight: 600; }
.site-nav a { color: var(--text-muted); margin-left: 24px; font-size: 14px; }
.site-nav a:hover { color: var(--gold); text-decoration: none; }
.site-nav a.on { color: var(--gold); }

/* ===== Hero ===== */
.hero .wrap {
  display: flex; align-items: center; gap: 64px;
  padding-top: 96px; padding-bottom: 96px;
}
.hero-copy { flex: 1; }
.hero-copy .tagline {
  display: inline-block;
  border: 1px solid var(--gold);
  color: var(--gold);
  border-radius: 999px;
  padding: 4px 16px;
  font-size: 14px;
  margin-bottom: 24px;
}
.hero-copy h1 { margin-bottom: 24px; }
.hero-copy .sub { color: var(--text-muted); max-width: 32em; margin-bottom: 40px; }
.btn {
  display: inline-block;
  background: var(--gold);
  color: var(--ink);
  font-weight: 600;
  padding: 12px 32px;
  border-radius: 999px;
}
.btn:hover { text-decoration: none; filter: brightness(1.08); }
.btn-ghost {
  display: inline-block;
  border: 1px solid var(--line);
  color: var(--text);
  padding: 11px 32px;
  border-radius: 999px;
  margin-left: 12px;
}
.btn-ghost:hover { text-decoration: none; border-color: var(--gold); color: var(--gold); }
.hero-note { font-size: 14px; color: var(--text-muted); margin-top: 16px; }
.hero-crumbs { font-size: 14px; color: var(--gold); letter-spacing: 2px; margin-bottom: 16px; }
.hero-crumbs span { color: var(--text-muted); margin: 0 8px; }
.pills { margin-top: 24px; }
.pills span {
  display: inline-block;
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 16px;
  font-size: 13px;
  color: var(--text-muted);
  margin: 0 8px 8px 0;
}

/* Hero 右侧产品信息卡 */
.hero-card {
  flex: 0 0 320px;
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 32px;
}
.hero-card .label {
  font-size: 12px; letter-spacing: 4px; color: var(--gold);
  margin-bottom: 24px;
}
.hero-card .film-frame { width: 150px; margin: 0 auto 24px; }
.hero-card .film-frame .ratio { font-size: 26px; }
.hero-card dl { margin: 0; }
.hero-card .row {
  display: flex; justify-content: space-between; align-items: baseline;
  border-top: 1px solid var(--line);
  padding: 12px 0;
  font-size: 14px;
}
.hero-card .row dt { color: var(--text-muted); }
.hero-card .row dd { margin: 0; font-weight: 600; text-align: right; }

/* 签名元素：9:16 竖屏胶片帧 */
.film-frame {
  flex: 0 0 auto;
  width: 216px; aspect-ratio: 9 / 16;
  border: 1px solid var(--gold);
  border-radius: 12px;
  background:
    /* 两侧齿孔 */
    repeating-linear-gradient(to bottom, transparent 0 14px, var(--gold-soft) 14px 26px) 8px 0 / 8px 100% no-repeat,
    repeating-linear-gradient(to bottom, transparent 0 14px, var(--gold-soft) 14px 26px) calc(100% - 8px) 0 / 8px 100% no-repeat,
    linear-gradient(160deg, var(--ink-2) 30%, #1F2E3A 70%);
  position: relative;
  display: flex; align-items: center; justify-content: center;
}
.film-frame .ratio {
  font-family: var(--font-heading);
  font-size: 36px; color: var(--gold);
}
.film-frame .ai-mark {
  position: absolute; right: 24px; bottom: 16px;
  font-size: 12px; color: var(--text-muted);
  border: 1px solid var(--line);
  padding: 1px 8px; border-radius: 4px;
}

/* ===== 区块 ===== */
.section { padding: 64px 0; border-top: 1px solid var(--line); }
.section h2 { margin-bottom: 40px; }
.section h2 small {
  display: block; font-family: var(--font-body);
  font-size: 14px; font-weight: 400; color: var(--text-muted); margin-top: 8px;
}

.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 24px; }
.card {
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 24px;
}
.card h3 { color: var(--gold); margin-bottom: 8px; }
.card .tag {
  display: inline-block;
  font-size: 12px; color: var(--leaf);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 2px 10px;
  margin-bottom: 10px;
}
.card p { color: var(--text-muted); font-size: 14px; }

/* 服务流程 */
.steps { display: flex; flex-wrap: wrap; gap: 16px; counter-reset: step; }
.step {
  flex: 1 1 160px;
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 24px 16px;
  counter-increment: step;
}
.step::before {
  content: "0" counter(step);
  font-family: var(--font-heading);
  color: var(--gold); font-size: 24px; display: block; margin-bottom: 8px;
}
.step b { display: block; margin-bottom: 4px; }
.step span { font-size: 14px; color: var(--text-muted); }

/* 应用场景 */
.scenes { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 24px; }
.scene {
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 24px;
  text-align: center;
}
.scene .film-frame { width: 130px; margin: 0 auto 20px; border-color: var(--line); }
.scene video {
  width: 100%; max-width: 200px; aspect-ratio: 9 / 16;
  object-fit: cover; display: block;
  margin: 0 auto 20px;
  border: 1px solid var(--line); border-radius: 12px;
  transition: border-color 0.25s ease;
}
.scene:hover video { border-color: var(--gold); }
.scene video { cursor: pointer; }

/* 视频灯箱 */
.video-modal {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(16, 24, 32, 0.75);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  display: flex; align-items: center; justify-content: center;
}
.video-modal video {
  max-height: 86vh; max-width: 92vw;
  border-radius: 12px;
  border: 1px solid var(--gold);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.6);
}
.video-modal .close {
  position: absolute; top: 16px; right: 28px;
  background: none; border: none;
  font-size: 44px; line-height: 1; color: var(--text);
  cursor: pointer;
}
.video-modal .close:hover { color: var(--gold); }
.scene .film-frame .shot {
  font-size: 13px; color: var(--gold); letter-spacing: 1px;
}
.scene h3 { margin-bottom: 8px; }
.scene p { color: var(--text-muted); font-size: 14px; text-align: left; }

/* 创作课程 */
.course-bar {
  margin-top: 24px;
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 24px;
  display: flex; flex-wrap: wrap; align-items: center;
  gap: 16px 40px;
}
.course-bar .item b { display: block; font-size: 13px; color: var(--text-muted); font-weight: 400; }
.course-bar .item span { font-size: 15px; font-weight: 600; }
.course-bar .btn { margin-left: auto; }
@media (max-width: 760px) { .course-bar .btn { margin-left: 0; } }

/* 合规承诺 */
.pledges { list-style: none; display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 16px 40px; }
.pledges li { padding-left: 28px; position: relative; color: var(--text-muted); }
.pledges li::before {
  content: "✓";
  position: absolute; left: 0;
  color: var(--leaf); font-weight: 700;
}
.pledges li b { color: var(--text); }

/* 联系商务 */
.contact-box {
  background: var(--ink-2);
  border: 1px solid var(--gold-soft);
  border-radius: 12px;
  padding: 40px;
  text-align: center;
}
.contact-box p { color: var(--text-muted); margin: 16px auto 24px; max-width: 36em; }

/* ===== 页脚 ===== */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 40px 0 64px;
  margin-top: 64px;
  font-size: 14px; color: var(--text-muted);
}
.site-footer .links { margin-bottom: 16px; }
.site-footer .links a { margin-right: 24px; color: var(--text-muted); }
.site-footer .links a:hover { color: var(--gold); }
.site-footer p { margin-bottom: 4px; }
.site-footer a { color: var(--text-muted); }

/* ===== 法务长文页（协议/隐私/公示）===== */
.prose { max-width: 760px; margin: 0 auto; padding: 64px 24px; line-height: 1.8; }
.prose h1 { font-size: 32px; margin-bottom: 8px; }
.prose .meta { color: var(--text-muted); font-size: 14px; margin-bottom: 40px; }
.prose h2 { font-size: 20px; margin: 40px 0 16px; color: var(--gold); }
.prose h3 { font-size: 17px; margin: 24px 0 8px; }
.prose p, .prose li { color: var(--text); margin-bottom: 12px; }
.prose ul, .prose ol { padding-left: 24px; margin-bottom: 16px; }
.prose table { border-collapse: collapse; width: 100%; margin: 16px 0; font-size: 14px; }
.prose th, .prose td { border: 1px solid var(--line); padding: 8px 12px; text-align: left; }
.prose th { background: var(--ink-2); }
.prose .notice {
  background: var(--ink-2);
  border-left: 3px solid var(--gold);
  padding: 16px 24px;
  border-radius: 0 12px 12px 0;
  margin: 24px 0;
  color: var(--text-muted);
  font-size: 14px;
}

/* ===== Hover 交互 ===== */
.card, .step, .scene, .hero-card, .contact-box, .course-bar, .pills span,
.btn, .btn-ghost, .site-nav a, .site-footer .links a,
.brand img, .pledges li, .prose table td, .prose .notice {
  transition: all 0.25s ease;
}
.pledges li::before { transition: transform 0.25s ease; }
.scene .film-frame { transition: border-color 0.25s ease; }

.card:hover, .step:hover, .scene:hover, .hero-card:hover {
  transform: translateY(-4px);
  border-color: rgba(232, 184, 75, 0.45);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.35);
}
.scene:hover .film-frame { border-color: var(--gold); }
.contact-box:hover, .course-bar:hover { border-color: rgba(232, 184, 75, 0.45); }

.btn:hover { transform: translateY(-2px); box-shadow: 0 8px 20px rgba(232, 184, 75, 0.25); }
.btn-ghost:hover { transform: translateY(-2px); }
.pills span:hover { border-color: var(--gold); color: var(--gold); transform: translateY(-2px); }

.site-nav a { position: relative; }
.site-nav a::after {
  content: ""; position: absolute; left: 0; bottom: -6px;
  width: 0; height: 1px; background: var(--gold);
  transition: width 0.25s ease;
}
.site-nav a:hover::after { width: 100%; }

.brand:hover img { transform: rotate(60deg); }

.pledges li:hover { color: var(--text); }
.pledges li:hover::before { transform: scale(1.3); }

.prose table tr:hover td { background: var(--ink-2); }
.prose .notice:hover { border-left-width: 6px; }

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}

/* ===== 响应式 ===== */
@media (max-width: 760px) {
  h1 { font-size: 32px; }
  h2 { font-size: 24px; }
  .hero .wrap { flex-direction: column-reverse; gap: 40px; padding-top: 64px; padding-bottom: 64px; }
  .film-frame { width: 160px; }
  .site-nav { flex: 1; overflow-x: auto; white-space: nowrap; text-align: right; margin-left: 16px; }
  .site-nav a { margin-left: 14px; font-size: 13px; }
  .site-nav .hide-m { display: none; }
}