* { margin: 0; padding: 0; box-sizing: border-box; }
  :root { --bg: #0A0F1E; --card: rgba(21,30,54,.85); --line: rgba(148,163,184,.16);
    --text: #F3F6FC; --sub: #A9BCDE; --dim: #6E84AB;
    --blue: #3B82F6; --blue2: #06B6D4; --purple: #8B5CF6; --purple2: #D946EF;
    --orange: #F97316; --orange2: #F59E0B; }
  body { font-family: "Noto Sans CJK SC","PingFang SC","Microsoft YaHei",sans-serif;
    background: var(--bg); color: var(--text); line-height: 1.6; overflow-x: hidden; }
  a { color: inherit; text-decoration: none; }
  .container { max-width: 1280px; margin: 0 auto; padding: 0 32px; }
  .bg-fixed { position: fixed; inset: 0; z-index: -1; pointer-events: none;
    background: radial-gradient(900px 600px at 10% -5%, rgba(139,92,246,.22), transparent 60%),
      radial-gradient(900px 600px at 90% 20%, rgba(59,130,246,.20), transparent 60%),
      radial-gradient(1000px 700px at 50% 100%, rgba(217,70,239,.15), transparent 60%),
      linear-gradient(180deg, #0A0F1E 0%, #1A0F30 50%, #0A0F1E 100%); }
  .bg-fixed::after { content: ""; position: absolute; inset: 0;
    background-image: linear-gradient(rgba(168,85,247,.04) 1px, transparent 1px),
      linear-gradient(90deg, rgba(168,85,247,.04) 1px, transparent 1px);
    background-size: 64px 64px;
    mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, #000 30%, transparent 100%); }
  .nav { position: fixed; top: 0; left: 0; right: 0; z-index: 100; padding: 18px 0;
    backdrop-filter: blur(20px); background: rgba(10,15,30,.7); border-bottom: 1px solid var(--line); }
  .nav-inner { display: flex; align-items: center; justify-content: space-between; }
  .logo { display: flex; align-items: center; gap: 12px; }
  .logo-mark { width: 40px; height: 40px; border-radius: 11px;
    background: linear-gradient(135deg, var(--blue), var(--purple) 60%, var(--orange));
    display: flex; align-items: center; justify-content: center; font-size: 19px; font-weight: 900; color: #fff; }
  .logo-text { font-size: 18px; font-weight: 700; letter-spacing: 1.5px; }
  .logo-text small { display: block; font-size: 10px; color: var(--dim); letter-spacing: 2px; font-weight: 400; }
  .menu { display: flex; gap: 40px; }
  .menu a { color: var(--sub); font-size: 15px; transition: color 0.2s; }
  .menu a.active, .menu a:hover { color: var(--text); }
  .nav-cta { padding: 10px 22px; border-radius: 999px;
    background: linear-gradient(135deg, var(--purple), var(--purple2)); color: #fff; font-size: 14px; font-weight: 600;
    box-shadow: 0 8px 24px rgba(139,92,246,.35); }
  .hero { padding: 200px 0 140px; text-align: center; position: relative; }
  .hero-kicker { display: inline-flex; align-items: center; gap: 12px; font-size: 13px; letter-spacing: 4px;
    color: #C4B5FD; padding: 10px 22px; border-radius: 999px;
    background: rgba(139,92,246,.12); border: 1px solid rgba(139,92,246,.3); }
  .hero-kicker .dot { width: 6px; height: 6px; border-radius: 50%; background: #C4B5FD;
    box-shadow: 0 0 12px #C4B5FD; }
  .hero h1 { margin-top: 36px; font-size: 110px; font-weight: 900; line-height: 1.05; letter-spacing: 4px; }
  .hero h1 .grad { background: linear-gradient(95deg, #EAF1FF 10%, #A5B4FC 40%, #C4B5FD 70%, #F0ABFC 100%);
    -webkit-background-clip: text; background-clip: text; color: transparent; }
  .hero h1 .ai { display: inline-block; background: linear-gradient(135deg, #C4B5FD, #F0ABFC);
    -webkit-background-clip: text; background-clip: text; color: transparent;
    text-shadow: 0 0 80px rgba(196,181,253,.4); }
  .hero-sub { margin: 32px auto 0; max-width: 800px; font-size: 22px; color: var(--sub); line-height: 1.8; }
  .hero-cta { margin-top: 56px; display: flex; gap: 18px; justify-content: center; flex-wrap: wrap; }
  .btn { padding: 18px 40px; border-radius: 999px; font-size: 15px; font-weight: 600;
    display: inline-flex; align-items: center; gap: 8px; transition: all 0.25s; }
  .btn-primary { background: linear-gradient(135deg, var(--purple), var(--purple2));
    color: #fff; box-shadow: 0 14px 36px rgba(139,92,246,.45); }
  .btn-primary:hover { transform: translateY(-2px); box-shadow: 0 20px 50px rgba(139,92,246,.6); }
  .btn-ghost { background: rgba(148,163,184,.08); color: var(--text); border: 1px solid var(--line); }
  .section { padding: 120px 0; }
  .section-head { text-align: center; margin-bottom: 80px; }
  .section-kicker { font-size: 13px; letter-spacing: 4px; color: #C4B5FD;
    display: inline-flex; align-items: center; gap: 12px; }
  .section-kicker::before, .section-kicker::after { content: ""; width: 30px; height: 1px;
    background: rgba(139,92,246,.3); }
  .section-title { margin-top: 18px; font-size: 52px; font-weight: 900; letter-spacing: 2px; line-height: 1.2; }
  .section-sub { margin-top: 18px; color: var(--sub); font-size: 18px; }
  /* 产品能力 */
  .ai-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }
  .ai-card { position: relative; padding: 44px 40px; border-radius: 24px; overflow: hidden;
    background: linear-gradient(180deg, rgba(30,20,60,.7), rgba(15,12,30,.7));
    border: 1px solid rgba(139,92,246,.18);
    transition: transform 0.4s, border-color 0.4s; }
  .ai-card:hover { transform: translateY(-6px); border-color: rgba(139,92,246,.5); }
  .ai-card::before { content: ""; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: linear-gradient(90deg, var(--c1), var(--c2)); }
  .ai-card::after { content: ""; position: absolute; top: -120px; right: -120px;
    width: 280px; height: 280px; border-radius: 50%;
    background: radial-gradient(circle, var(--glow), transparent 70%); }
  .ai-card > * { position: relative; z-index: 1; }
  .ai-card .num { position: absolute; top: 28px; right: 36px;
    font-size: 64px; font-weight: 900; -webkit-text-stroke: 1.2px rgba(148,163,184,.2);
    color: transparent; line-height: 1; font-family: Arial; }
  .ai-card .ic { width: 76px; height: 76px; border-radius: 20px;
    display: flex; align-items: center; justify-content: center;
    background: linear-gradient(135deg, var(--c1), var(--c2));
    box-shadow: 0 14px 36px var(--shadow); }
  .ai-card .ic svg { width: 38px; height: 38px; }
  .ai-card h3 { margin-top: 26px; font-size: 30px; font-weight: 800; letter-spacing: 1.5px; }
  .ai-card .sub { margin-top: 8px; color: var(--vc); font-size: 16px; letter-spacing: 1px; }
  .ai-card p { margin-top: 22px; color: var(--sub); font-size: 15px; line-height: 1.85; }
  .ai-card ul { margin-top: 22px; list-style: none; display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
  .ai-card ul li { font-size: 13px; padding: 8px 14px; border-radius: 10px;
    color: var(--sub); border: 1px solid var(--line); background: rgba(148,163,184,.04);
    display: flex; align-items: center; gap: 8px; }
  .ai-card ul li::before { content: "✓"; color: var(--vc); font-weight: 700; font-family: Arial; }
  /* 演示对话框 */
  .demo { margin-top: 80px; padding: 60px 50px; border-radius: 28px;
    background: linear-gradient(135deg, rgba(139,92,246,.10), rgba(59,130,246,.10));
    border: 1px solid rgba(139,92,246,.2); }
  @media (max-width: 600px) {
    .demo { margin-top: 20px; }
  }
  .demo-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
  .demo-left h3 { font-size: 38px; font-weight: 900; letter-spacing: 2px; line-height: 1.3; }
  .demo-left h3 .grad { background: linear-gradient(95deg, #A5B4FC, #C4B5FD 50%, #F0ABFC);
    -webkit-background-clip: text; background-clip: text; color: transparent; }
  .demo-left p { margin-top: 24px; color: var(--sub); font-size: 16px; line-height: 1.9; }
  .demo-left ul { margin-top: 28px; list-style: none; }
  .demo-left li { padding: 12px 0; color: var(--text); font-size: 15px;
    display: flex; align-items: center; gap: 12px; border-bottom: 1px solid var(--line); }
  .demo-left li::before { content: "▸"; color: #C4B5FD; }
  .demo-right { padding: 32px; border-radius: 20px;
    background: rgba(10,15,30,.7); border: 1px solid rgba(139,92,246,.2);
    height: 460px; display: flex; flex-direction: column; gap: 16px; }
  .chat-bubble { max-width: 80%; padding: 14px 20px; border-radius: 18px;
    font-size: 14px; line-height: 1.6; }
  .chat-user { background: rgba(59,130,246,.18); color: var(--text);
    border: 1px solid rgba(59,130,246,.3); align-self: flex-end;
    border-bottom-right-radius: 4px; }
  .chat-ai { background: linear-gradient(135deg, rgba(139,92,246,.18), rgba(217,70,239,.18));
    color: var(--text); border: 1px solid rgba(139,92,246,.3);
    align-self: flex-start; border-bottom-left-radius: 4px; }
  .chat-ai .typing { display: inline-block; width: 6px; height: 6px; border-radius: 50%;
    background: #C4B5FD; margin-right: 4px; animation: blink 1.4s infinite both; }
  .chat-ai .typing:nth-child(2) { animation-delay: .2s; }
  .chat-ai .typing:nth-child(3) { animation-delay: .4s; }
  @keyframes blink { 0%,80%,100% { opacity: 0; } 40% { opacity: 1; } }
  .demo-header { display: flex; align-items: center; gap: 10px; padding-bottom: 16px;
    border-bottom: 1px solid var(--line); margin-bottom: 8px; }
  .demo-header .av { width: 36px; height: 36px; border-radius: 50%;
    background: linear-gradient(135deg, var(--purple), var(--purple2));
    display: flex; align-items: center; justify-content: center; font-size: 14px; font-weight: 900; color: #fff; }
  .demo-header .meta small { display: block; color: var(--dim); font-size: 11px; }
  /* 数据 */
  .stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-top: 80px; }
  .stat { padding: 32px 24px; border-radius: 20px;
    background: var(--card); border: 1px solid var(--line); text-align: center; }
  .stat .v { font-size: 56px; font-weight: 900; letter-spacing: 1px;
    background: linear-gradient(135deg, #C4B5FD, #F0ABFC);
    -webkit-background-clip: text; background-clip: text; color: transparent; font-family: Arial; }
  .stat .l { margin-top: 8px; color: var(--sub); font-size: 14px; letter-spacing: 2px; }
  .footer { margin-top: 120px; padding: 60px 0 40px; border-top: 1px solid var(--line); background: rgba(5,9,16,.6); }
  .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 60px; }
  .footer h5 { font-size: 14px; color: var(--text); margin-bottom: 18px; letter-spacing: 2px; }
  .footer ul { list-style: none; }
  .footer li { margin-bottom: 10px; }
  .footer a { color: var(--sub); font-size: 14px; }
  .footer-bottom { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--line);
    display: flex; justify-content: space-between; color: var(--dim); font-size: 12px; letter-spacing: 1.5px; }
  /* 主题色 */
  .c-blue   { --c1: var(--blue);   --c2: var(--blue2);   --vc: #7DB8FF; --glow: rgba(59,130,246,.15);  --shadow: rgba(59,130,246,.3); }
  .c-purple { --c1: var(--purple); --c2: var(--purple2); --vc: #C4B5FD; --glow: rgba(139,92,246,.18);  --shadow: rgba(139,92,246,.35); }
  .c-orange { --c1: var(--orange); --c2: var(--orange2); --vc: #FDBA74; --glow: rgba(249,115,22,.14);  --shadow: rgba(249,115,22,.3); }
  .c-pink   { --c1: #EC4899;      --c2: var(--purple2); --vc: #F0ABFC; --glow: rgba(236,72,153,.16);  --shadow: rgba(236,72,153,.32); }