/* ═══════════════════════════════════════════
   DreamAI Auto — 蓝银科技发布会风格
   ═══════════════════════════════════════════ */

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

:root {
  /* 深色区 */
  --hero-bg: #060d1b;
  --hero-bg2: #0b1628;
  --navy: #0e1a30;
  /* 浅色区 */
  --light-bg: #f4f7fb;
  --light-card: #ffffff;
  --light-border: rgba(0,0,0,.06);
  /* 强调色 */
  --accent: #4a8eff;
  --accent2: #7eb3ff;
  --silver: #c8d6e5;
  --silver-dim: rgba(200,214,229,.15);
  /* 文本 */
  --text-hero: rgba(255,255,255,.94);
  --text-hero-muted: rgba(255,255,255,.5);
  --text-dark: #1a2740;
  --text-dark-muted: #5a6a82;
  /* 通用 */
  --line-dark: rgba(255,255,255,.07);
  --line-light: rgba(0,0,0,.07);
  --radius: 16px;
  --radius-lg: 24px;
}

html { scroll-behavior: smooth; }
body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--hero-bg);
  color: var(--text-hero);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ─── 滚动淡入 ─── */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-delay-1 { transition-delay: .1s; }
.reveal-delay-2 { transition-delay: .2s; }
.reveal-delay-3 { transition-delay: .3s; }

/* ═══════════════════════════════════════════
   导航
   ═══════════════════════════════════════════ */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: 64px; display: flex; align-items: center;
  padding: 0 40px;
  border-bottom: 1px solid transparent;
  background: rgba(6,13,27,.5);
  backdrop-filter: blur(20px) saturate(1.4);
  transition: background .3s, border-color .3s;
}
nav.nav-scrolled {
  background: rgba(6,13,27,.88);
  border-bottom-color: var(--line-dark);
}
.nav-inner { max-width: 1200px; margin: 0 auto; width: 100%; display: flex; align-items: center; justify-content: space-between; }
.nav-logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.nav-logo img { width: 28px; height: 28px; object-fit: contain; }
.nav-logo-text { font-size: 15px; font-weight: 700; background: linear-gradient(90deg,var(--accent),var(--accent2)); -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent; }
.nav-links { display: flex; gap: 28px; }
.nav-links a { font-size: 13.5px; font-weight: 500; color: var(--text-hero-muted); text-decoration: none; transition: color .2s; }
.nav-links a:hover { color: var(--text-hero); }
.nav-cta {
  padding: 8px 22px; border-radius: 8px; font-size: 13.5px; font-weight: 600;
  background: rgba(74,142,255,.12); border: 1px solid rgba(74,142,255,.25);
  color: var(--accent2); text-decoration: none; transition: background .2s;
}
.nav-cta:hover { background: rgba(74,142,255,.22); }

/* ═══════════════════════════════════════════
   Hero 区域（深色 + Three.js）
   ═══════════════════════════════════════════ */
.hero-wrapper {
  position: relative;
  background:
    radial-gradient(ellipse 100% 60% at 50% 10%, rgba(74,142,255,.08) 0%, transparent 60%),
    radial-gradient(ellipse 80% 50% at 80% 0%, rgba(74,126,255,.06) 0%, transparent 50%),
    linear-gradient(180deg, var(--hero-bg) 0%, var(--hero-bg2) 100%);
  overflow: hidden;
}

.hero-video-bg {
  position: absolute; inset: 0; z-index: 0;
  width: 100%; height: 100%;
  object-fit: cover;
  pointer-events: none;
}
.hero-video-overlay {
  position: absolute; inset: 0; z-index: 1;
  background:
    radial-gradient(ellipse 60% 50% at 50% 40%, rgba(6,13,27,.5) 0%, transparent 70%),
    linear-gradient(180deg, rgba(6,13,27,.4) 0%, rgba(6,13,27,.15) 30%, rgba(6,13,27,.15) 60%, rgba(11,22,40,.8) 100%);
  pointer-events: none;
}

.hero {
  position: relative; z-index: 2;
  min-height: 100vh;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  text-align: center; padding: 120px 32px 60px;
}

/* 文字样式 */
.hero h1 .h1-top {
  color: #ffffff;
}

.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 18px; border-radius: 30px; margin-bottom: 36px;
  border: 1px solid rgba(74,142,255,.25);
  background: rgba(74,142,255,.08);
  font-size: 12px; font-weight: 600; color: var(--accent2);
  letter-spacing: .8px; text-transform: uppercase;
  animation: fadeUp .7s 0s ease both;
}
.eyebrow-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); animation: blink 2s ease infinite; }
@keyframes blink { 0%,100%{opacity:1} 50%{opacity:.25} }

.hero h1 {
  font-size: clamp(42px, 7.5vw, 84px); font-weight: 900;
  line-height: 1.1; letter-spacing: -1px;
  animation: fadeUp .8s .4s ease both;
}
.h1-top { display: block; color: var(--text-hero); }
.h1-grad {
  display: block;
  background: linear-gradient(100deg, var(--accent) 0%, var(--accent2) 40%, var(--silver) 100%);
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 0 60px rgba(74,142,255,.3));
}

.hero-sub {
  max-width: 600px; margin: 24px auto 0;
  font-size: clamp(14px, 1.8vw, 17px); color: var(--text-hero-muted); line-height: 1.7;
  animation: fadeUp .8s .8s ease both;
}

.hero-btns {
  display: flex; gap: 14px; justify-content: center; flex-wrap: wrap;
  margin-top: 44px;
  animation: fadeUp .8s 1.2s ease both;
}
.btn-primary {
  position: relative; padding: 14px 34px; border-radius: 12px;
  font-size: 15px; font-weight: 700; color: #fff; text-decoration: none;
  background: linear-gradient(135deg, var(--accent), #3a6fd8);
  overflow: hidden; transition: transform .2s, box-shadow .2s;
  box-shadow: 0 4px 30px rgba(74,142,255,.25);
  border: none; cursor: pointer;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 50px rgba(74,142,255,.35); }
.btn-secondary {
  padding: 14px 34px; border-radius: 12px;
  font-size: 15px; font-weight: 600; color: var(--silver); text-decoration: none;
  background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.1);
  transition: background .2s; cursor: pointer;
}
.btn-secondary:hover { background: rgba(255,255,255,.08); }

/* 信任标签 */
.trust-row {
  display: flex; align-items: center; justify-content: center; gap: 28px;
  margin-top: 24px; flex-wrap: wrap;
  animation: fadeUp .8s 1.6s ease both;
}
.trust-item {
  display: flex; align-items: center; gap: 6px;
  font-size: 12px; color: rgba(255,255,255,.55);
}
.trust-item svg { flex-shrink: 0; }

/* 指标行 */
.metrics {
  display: flex; justify-content: center; gap: 0; flex-wrap: wrap;
  margin-top: 80px;
  border-top: 1px solid rgba(255,255,255,.18);
  border-bottom: 1px solid rgba(255,255,255,.18);
  background: rgba(8,16,32,.35);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  animation: fadeUp .8s 2.0s ease both;
}
.metric {
  flex: 1; min-width: 140px; padding: 32px 20px; text-align: center;
  border-right: 1px solid rgba(255,255,255,.12);
}
.metric:last-child { border-right: none; }
.metric-num {
  font-size: 28px; font-weight: 800; white-space: nowrap;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent;
}
.metric-label { font-size: 12px; color: var(--text-hero-muted); margin-top: 6px; }

@keyframes fadeUp { from{opacity:0;transform:translateY(24px)} to{opacity:1;transform:translateY(0)} }

/* ═══════════════════════════════════════════
   演示视频区域（深浅过渡）
   ═══════════════════════════════════════════ */
.demo-section {
  position: relative;
  padding: 100px 32px 120px;
  background: linear-gradient(180deg, var(--hero-bg2) 0%, var(--light-bg) 100%);
  text-align: center;
}
.demo-section .section-title {
  font-size: 15px; font-weight: 600; color: var(--accent);
  letter-spacing: .5px; margin-bottom: 16px;
}
.demo-section h2 {
  font-size: clamp(24px, 3.5vw, 38px); font-weight: 800; color: var(--text-hero);
  letter-spacing: -1px; margin-bottom: 60px;
}

.video-stage {
  max-width: 900px; margin: 0 auto;
  border-radius: var(--radius-lg);
  overflow: hidden; position: relative;
  background: rgba(10,20,40,.6);
  border: 1px solid rgba(74,142,255,.15);
  box-shadow:
    0 0 80px rgba(74,142,255,.1),
    0 20px 80px rgba(0,0,0,.4),
    inset 0 1px 0 rgba(255,255,255,.05);
  transition: transform .4s cubic-bezier(.22,.61,.36,1), box-shadow .3s;
  will-change: transform;
}
.video-stage:hover {
  box-shadow:
    0 0 120px rgba(74,142,255,.15),
    0 30px 100px rgba(0,0,0,.5),
    inset 0 1px 0 rgba(255,255,255,.05);
}
.video-stage video {
  display: block; width: 100%; border-radius: var(--radius-lg);
}
.video-overlay {
  position: absolute; bottom: 16px; right: 16px;
  display: flex; gap: 8px;
}
.video-overlay button {
  padding: 8px 16px; border-radius: 8px;
  font-size: 12px; font-weight: 600; border: none; cursor: pointer;
  background: rgba(0,0,0,.6); color: #fff;
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,.1);
  transition: background .2s;
}
.video-overlay button:hover { background: rgba(0,0,0,.8); }

/* ═══════════════════════════════════════════
   浅色内容区域（通用）
   ═══════════════════════════════════════════ */
.light-section {
  background: var(--light-bg);
  color: var(--text-dark);
  padding: 100px 32px;
}
.light-section .section-tag {
  font-size: 12px; font-weight: 700; color: var(--accent);
  letter-spacing: 1.2px; text-transform: uppercase; margin-bottom: 14px;
}
.light-section h2 {
  font-size: clamp(28px, 4vw, 46px); font-weight: 800;
  letter-spacing: -1.5px; line-height: 1.1; color: var(--text-dark);
}
.light-section .section-lead {
  font-size: 16px; color: var(--text-dark-muted);
  margin-top: 12px; max-width: 520px; line-height: 1.65;
}
.section-inner { max-width: 1200px; margin: 0 auto; }

/* ═══════════════════════════════════════════
   功能卡片（浅色）
   ═══════════════════════════════════════════ */
.features-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 20px;
  margin-top: 64px;
}
.f-card {
  padding: 36px; border-radius: var(--radius-lg);
  border: 1px solid var(--light-border);
  background: var(--light-card);
  box-shadow: 0 2px 12px rgba(0,0,0,.04);
  transition: border-color .3s, box-shadow .3s, transform .3s;
}
.f-card:hover {
  border-color: rgba(74,142,255,.2);
  box-shadow: 0 8px 40px rgba(74,142,255,.08);
  transform: translateY(-4px);
}
.f-card.large { grid-column: 1 / -1; display: flex; gap: 48px; align-items: center; }
.f-card-content { flex: 1; }
.f-card-visual { flex: 1.2; }
.f-icon { font-size: 32px; margin-bottom: 18px; }
.f-title { font-size: 19px; font-weight: 700; margin-bottom: 10px; color: var(--text-dark); }
.f-desc { font-size: 14px; color: var(--text-dark-muted); line-height: 1.7; }

/* Mock UI（功能大卡内）*/
.mock-ui {
  background: var(--navy); border: 1px solid rgba(255,255,255,.08);
  border-radius: 14px; overflow: hidden;
}
.mock-bar {
  padding: 12px 16px; border-bottom: 1px solid rgba(255,255,255,.06);
  display: flex; align-items: center; gap: 7px;
}
.d { width: 10px; height: 10px; border-radius: 50%; }
.dr { background: #ff5f57; } .dy { background: #ffbd2e; } .dg { background: #28ca41; }
.mock-bar-title { font-size: 12px; color: rgba(255,255,255,.4); margin-left: 4px; }
.mock-body { padding: 20px 16px; }
.mock-row {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 12px; border-radius: 9px; margin-bottom: 8px;
  background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.06);
}
.mock-row:last-child { margin-bottom: 0; }
.dot-s { width: 7px; height: 7px; border-radius: 50%; flex-shrink: 0; }
.dot-done { background: #34d399; }
.dot-run  { background: var(--accent); animation: blink 1.5s infinite; }
.dot-wait { background: rgba(255,255,255,.18); }
.mock-row-text { flex: 1; font-size: 12px; font-weight: 500; color: rgba(255,255,255,.75); }
.mock-row-badge { font-size: 10px; font-weight: 700; padding: 3px 8px; border-radius: 6px; }
.badge-done { background: rgba(52,211,153,.12); color: #34d399; }
.badge-run  { background: rgba(74,142,255,.12); color: var(--accent); }
.badge-wait { background: rgba(255,255,255,.06); color: rgba(255,255,255,.35); }

/* ═══════════════════════════════════════════
   模型区（浅色）
   ═══════════════════════════════════════════ */
.models-grid {
  display: flex; flex-wrap: wrap; gap: 10px; margin-top: 56px;
}
.model-pill {
  padding: 12px 22px; border-radius: 30px;
  border: 1px solid var(--light-border);
  background: var(--light-card);
  font-size: 13px; font-weight: 500; color: var(--text-dark);
  display: flex; align-items: center; gap: 8px;
  box-shadow: 0 1px 4px rgba(0,0,0,.04);
  transition: border-color .2s, box-shadow .2s, transform .2s;
}
.model-pill:hover {
  border-color: rgba(74,142,255,.2);
  box-shadow: 0 4px 20px rgba(74,142,255,.08);
  transform: translateY(-2px);
}
.pill-dot { width: 7px; height: 7px; border-radius: 50%; flex-shrink: 0; }
.pill-new { background: #34d399; }
.pill-fast { background: #fbbf24; }
.pill-pro { background: var(--accent); }
.pill-std { background: #94a3b8; }
.pill-label { font-size: 10px; color: var(--text-dark-muted); }

/* ═══════════════════════════════════════════
   使用步骤区（深色回归）
   ═══════════════════════════════════════════ */
.dark-section {
  background: linear-gradient(180deg, var(--hero-bg2) 0%, var(--navy) 100%);
  color: var(--text-hero);
  padding: 100px 32px;
}
.dark-section .section-tag {
  font-size: 12px; font-weight: 700; color: var(--accent2);
  letter-spacing: 1.2px; text-transform: uppercase; margin-bottom: 14px;
}
.dark-section h2 {
  font-size: clamp(28px, 4vw, 46px); font-weight: 800;
  letter-spacing: -1.5px; color: var(--text-hero);
}
.dark-section .section-lead {
  font-size: 16px; color: var(--text-hero-muted);
  margin-top: 12px; max-width: 480px; line-height: 1.65;
}

.steps-grid {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 0; margin-top: 64px; position: relative;
}
.steps-grid::before {
  content: ''; position: absolute; top: 32px; left: 8%; right: 8%;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(74,142,255,.2) 20%, rgba(74,142,255,.2) 80%, transparent);
}
.step-item { text-align: center; padding: 0 16px; position: relative; }
.step-circle {
  width: 64px; height: 64px; border-radius: 50%;
  margin: 0 auto 20px;
  display: flex; align-items: center; justify-content: center;
  font-size: 22px;
  background: var(--hero-bg); border: 1px solid rgba(74,142,255,.2);
  position: relative; z-index: 1;
  transition: border-color .3s, box-shadow .3s;
}
.step-item:hover .step-circle {
  border-color: rgba(74,142,255,.5);
  box-shadow: 0 0 30px rgba(74,142,255,.15);
}
.step-label { font-size: 14px; font-weight: 700; margin-bottom: 8px; }
.step-note { font-size: 12px; color: var(--text-hero-muted); line-height: 1.6; }

/* ═══════════════════════════════════════════
   授权方案（浅色）
   ═══════════════════════════════════════════ */
.plans-grid {
  display: grid; grid-template-columns: repeat(5, 1fr);
  gap: 14px; margin-top: 56px;
}
.p-card {
  padding: 30px 24px; border-radius: var(--radius-lg);
  border: 1px solid var(--light-border);
  background: var(--light-card);
  position: relative;
  box-shadow: 0 2px 12px rgba(0,0,0,.04);
  transition: border-color .3s, transform .3s, box-shadow .3s;
}
.p-card:hover {
  border-color: rgba(74,142,255,.18);
  transform: translateY(-4px);
  box-shadow: 0 8px 40px rgba(74,142,255,.08);
}
.p-card.hot {
  border-color: rgba(74,142,255,.3);
  background: linear-gradient(135deg, rgba(74,142,255,.04), rgba(126,179,255,.06));
}
.p-card.hot::after {
  content: '\u63A8\u8350'; position: absolute; top: -1px; right: 20px;
  padding: 4px 12px; border-radius: 0 0 8px 8px;
  background: linear-gradient(135deg, var(--accent), #3a6fd8);
  font-size: 10px; font-weight: 800; color: #fff; letter-spacing: .5px;
}
.p-name { font-size: 16px; font-weight: 800; margin-bottom: 4px; color: var(--text-dark); }
.p-dur { font-size: 12px; color: var(--text-dark-muted); margin-bottom: 22px; }
.p-feats { list-style: none; display: flex; flex-direction: column; gap: 9px; }
.p-feats li {
  font-size: 13px; color: var(--text-dark-muted);
  display: flex; align-items: center; gap: 8px;
}
.p-feats li::before { content: '\2014'; color: var(--accent); font-weight: 600; }
.p-btn {
  display: block; text-align: center; margin-top: 24px;
  padding: 11px; border-radius: 9px; font-size: 13px; font-weight: 600;
  text-decoration: none; transition: .2s;
  border: 1px solid var(--light-border); color: var(--text-dark); background: transparent;
}
.p-btn:hover { background: rgba(74,142,255,.06); border-color: rgba(74,142,255,.2); }
.p-btn.hot-btn { background: linear-gradient(135deg, var(--accent), #3a6fd8); border: none; color: #fff; }
.p-btn.hot-btn:hover { opacity: .88; }

/* ═══════════════════════════════════════════
   CTA 区域（深色收尾）
   ═══════════════════════════════════════════ */
.cta-section {
  padding: 120px 32px 160px; text-align: center;
  background: linear-gradient(180deg, var(--light-bg) 0%, var(--hero-bg2) 40%, var(--hero-bg) 100%);
  color: var(--text-hero);
  position: relative;
}
.cta-glow {
  position: absolute; top: 55%; left: 50%; transform: translate(-50%,-50%);
  width: 600px; height: 300px; border-radius: 50%;
  background: radial-gradient(ellipse, rgba(74,142,255,.1) 0%, transparent 70%);
  pointer-events: none;
}
.cta-inner { position: relative; }
.cta-inner h2 {
  font-size: clamp(32px, 5vw, 58px); font-weight: 900;
  letter-spacing: -2px; line-height: 1.05; margin-bottom: 20px;
}
.cta-inner p { font-size: 16px; color: var(--text-hero-muted); margin-bottom: 40px; }
.cta-contact {
  display: inline-flex; align-items: center; gap: 12px;
  padding: 16px 40px; border-radius: 14px; font-size: 16px; font-weight: 700;
  background: linear-gradient(135deg, var(--accent), #3a6fd8);
  color: #fff; text-decoration: none;
  box-shadow: 0 4px 60px rgba(74,142,255,.25);
  transition: transform .2s, box-shadow .2s;
}
.cta-contact:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 60px rgba(74,142,255,.35);
}
.cta-grad {
  background: linear-gradient(135deg, var(--accent), var(--accent2), var(--silver));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}

/* ═══════════════════════════════════════════
   Footer
   ═══════════════════════════════════════════ */
footer {
  border-top: 1px solid var(--line-dark);
  padding: 28px 40px;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 12px;
  background: var(--hero-bg);
}
.footer-logo { display: flex; align-items: center; gap: 8px; text-decoration: none; }
.footer-logo img { width: 22px; height: 22px; object-fit: contain; }
.footer-logo span {
  font-size: 13px; font-weight: 700;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent;
}
footer small { font-size: 12px; color: rgba(255,255,255,.2); }

/* ═══════════════════════════════════════════
   分割线
   ═══════════════════════════════════════════ */
.divider-light { max-width: 1200px; margin: 0 auto; height: 1px; background: var(--line-light); }
.divider-dark { max-width: 1200px; margin: 0 auto; height: 1px; background: var(--line-dark); }

/* ═══════════════════════════════════════════
   响应式
   ═══════════════════════════════════════════ */
@media (max-width: 900px) {
  nav { padding: 0 20px; }
  .nav-links { display: none; }
  .features-grid { grid-template-columns: 1fr; }
  .f-card.large { flex-direction: column; }
  .plans-grid { grid-template-columns: 1fr 1fr; }
  .steps-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .steps-grid::before { display: none; }
  footer { padding: 24px 20px; }
  .video-stage { margin: 0 8px; }
}
@media (max-width: 600px) {
  .plans-grid { grid-template-columns: 1fr; }
  .metrics { flex-direction: column; }
  .metric { border-right: none; border-bottom: 1px solid var(--line-dark); }
  .metric:last-child { border-bottom: none; }
  .steps-grid { grid-template-columns: 1fr; }
}