/* roulang page: index */
:root {
      --primary: #0A7BFF;
      --primary-glow: rgba(10, 123, 255, 0.5);
      --accent: #FF6A00;
      --accent-glow: rgba(255, 106, 0, 0.45);
      --success: #00D68F;
      --bg-deep: #0B1120;
      --bg-card: #111B2F;
      --glass-bg: rgba(17, 27, 47, 0.7);
      --glass-border: rgba(255, 255, 255, 0.08);
      --text-primary: #E8ECF1;
      --text-secondary: #8A95AA;
      --text-muted: #6B7A90;
      --radius-lg: 20px;
      --radius-md: 16px;
      --radius-sm: 12px;
      --radius-btn: 10px;
      --shadow-glass: 0 8px 32px rgba(0, 0, 0, 0.45);
      --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.35);
      --font-sans: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --transition-smooth: 0.25s cubic-bezier(0.2, 0.0, 0, 1.0);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      display: block;
      max-width: 100%;
      height: auto;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition-smooth);
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: transparent;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: all var(--transition-smooth);
      font-weight: 600;
      white-space: nowrap;
    }
    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }

    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: transparent;
      backdrop-filter: blur(0px);
      transition: background 0.3s, backdrop-filter 0.3s, box-shadow 0.3s;
      border-bottom: 1px solid transparent;
    }
    .nav.scrolled {
      background: rgba(11, 17, 32, 0.88);
      backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.06);
      box-shadow: 0 8px 20px rgba(0,0,0,0.25);
    }
    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 1.4rem;
      letter-spacing: -0.3px;
      color: white;
    }
    .logo svg {
      width: 32px;
      height: 32px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      font-weight: 500;
      color: var(--text-secondary);
    }
    .nav-links a {
      position: relative;
      padding: 6px 0;
      font-size: 0.95rem;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: white;
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -4px;
      width: 100%;
      height: 3px;
      background: var(--accent);
      border-radius: 3px;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 600;
      box-shadow: 0 0 14px var(--primary-glow);
      border: 1px solid rgba(255,255,255,0.15);
    }
    .btn-primary:hover {
      background: #1a88ff;
      box-shadow: 0 0 22px var(--primary-glow);
      transform: scale(1.03);
    }
    .btn-ghost {
      background: transparent;
      border: 1.5px solid white;
      color: white;
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 600;
    }
    .btn-ghost:hover {
      background: rgba(255,255,255,0.06);
    }
    .btn-large {
      background: var(--accent);
      color: white;
      padding: 18px 42px;
      font-size: 1.1rem;
      border-radius: 12px;
      box-shadow: 0 0 20px var(--accent-glow);
      animation: pulse-glow 2.2s infinite;
      font-weight: 700;
    }
    @keyframes pulse-glow {
      0% { box-shadow: 0 0 12px var(--accent-glow); }
      50% { box-shadow: 0 0 28px var(--accent), 0 0 40px var(--accent-glow); }
      100% { box-shadow: 0 0 12px var(--accent-glow); }
    }
    .btn-large:hover {
      background: #ff7b1a;
      transform: scale(1.02);
    }

    /* 汉堡菜单 */
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      cursor: pointer;
    }
    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: white;
      border-radius: 2px;
      transition: 0.3s;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 80%;
      max-width: 320px;
      height: 100vh;
      background: rgba(11,17,32,0.96);
      backdrop-filter: blur(24px);
      padding: 24px;
      display: flex;
      flex-direction: column;
      gap: 28px;
      transition: right 0.35s ease;
      z-index: 999;
      border-left: 1px solid rgba(255,255,255,0.08);
    }
    .mobile-menu.open {
      right: 0;
    }
    .mobile-menu a {
      font-size: 1.2rem;
      font-weight: 500;
      color: var(--text-secondary);
    }

    /* 区块通用 */
    section {
      padding: 90px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }
    .section-sub {
      color: var(--text-secondary);
      max-width: 680px;
      margin: 0 auto 48px;
      font-size: 1.1rem;
    }

    /* Hero */
    .hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 40%, #13203b 0%, #0B1120 85%);
      position: relative;
      overflow: hidden;
    }
    .hero::before {
      content: '';
      position: absolute;
      width: 100%;
      height: 100%;
      background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 200" opacity="0.08"><path d="M30 50 L170 50 L170 150 L30 150 Z" fill="none" stroke="white" stroke-width="1.2"/><circle cx="100" cy="100" r="40" fill="none" stroke="white" stroke-width="0.8"/></svg>');
      background-size: 220px;
      opacity: 0.25;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
      position: relative;
      z-index: 2;
    }
    .hero h1 {
      font-size: 3.2rem;
      font-weight: 700;
      line-height: 1.25;
      letter-spacing: -0.5px;
      margin-bottom: 20px;
    }
    .hero p {
      font-size: 1.2rem;
      color: var(--text-secondary);
      max-width: 480px;
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      background: rgba(17,27,47,0.6);
      backdrop-filter: blur(12px);
      border-radius: 24px;
      border: 1px solid var(--glass-border);
      overflow: hidden;
      box-shadow: var(--shadow-glass);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      display: block;
    }

    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-md);
      padding: 28px;
      transition: all 0.3s;
      box-shadow: var(--shadow-glass);
    }
    .glass-card:hover {
      transform: translateY(-6px);
      border-color: rgba(255,255,255,0.18);
      box-shadow: 0 16px 40px rgba(0,0,0,0.5);
    }
    .icon-accent {
      color: var(--accent);
      font-size: 2rem;
      margin-bottom: 20px;
    }
    .number-highlight {
      font-size: 2.6rem;
      font-weight: 800;
      color: var(--accent);
      line-height: 1.2;
    }
    .case-card {
      background: rgba(17,27,47,0.8);
      border-radius: var(--radius-md);
      padding: 24px;
      border: 1px solid rgba(255,255,255,0.05);
    }
    .img-placeholder {
      background: #1a2540;
      border-radius: 12px;
      aspect-ratio: 16 / 9;
      overflow: hidden;
      margin-bottom: 16px;
    }
    .img-placeholder img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    .faq-question {
      width: 100%;
      background: transparent;
      padding: 20px 0;
      font-size: 1.1rem;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      color: white;
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-secondary);
      padding-left: 8px;
    }
    .faq-answer.open {
      max-height: 200px;
      padding-bottom: 16px;
    }

    footer {
      background: #0a0f1a;
      padding: 60px 0 30px;
      color: var(--text-muted);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2,1fr); }
      .hero-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links, .nav .btn-primary { display: none; }
      .hamburger { display: flex; }
      .grid-3 { grid-template-columns: 1fr; }
      .hero h1 { font-size: 2.3rem; }
      .footer-grid { grid-template-columns: 1fr; }
    }