/* roulang page: index */
:root {
      --primary: #0B1A2F;
      --accent: #00C2D1;
      --highlight: #F59E0B;
      --bg-global: #0F172A;
      --bg-block: rgba(15,23,42,0.7);
      --card-bg: rgba(255,255,255,0.03);
      --card-border: rgba(255,255,255,0.06);
      --text-main: #E2E8F0;
      --text-muted: #94A3B8;
      --text-accent: #00C2D1;
      --font-sans: "Inter", "SF Pro Display", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "WenQuanYi Micro Hei", system-ui, sans-serif;
      --radius-xl: 24px;
      --radius-lg: 20px;
      --radius-md: 12px;
      --radius-sm: 10px;
      --shadow-glow: 0 8px 32px rgba(0,194,209,0.12);
      --transition: 0.3s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-global);
      color: var(--text-main);
      line-height: 1.7;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航悬浮胶囊 */
    .nav-capsule {
      position: fixed;
      top: 16px;
      left: 50%;
      transform: translateX(-50%);
      width: calc(100% - 32px);
      max-width: 1100px;
      background: rgba(15,23,42,0.75);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border: 1px solid rgba(255,255,255,0.06);
      border-radius: 40px;
      padding: 8px 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      z-index: 999;
      transition: var(--transition);
    }

    .logo {
      font-size: 20px;
      font-weight: 700;
      background: linear-gradient(135deg, #00C2D1 0%, #E2E8F0 80%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: 0.5px;
    }

    .nav-links {
      display: flex;
      gap: 24px;
      align-items: center;
    }

    .nav-links a {
      color: var(--text-muted);
      text-decoration: none;
      font-size: 15px;
      font-weight: 500;
      transition: color 0.2s;
      white-space: nowrap;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent);
      border-bottom: 2px solid var(--accent);
      padding-bottom: 4px;
    }

    .hamburger {
      display: none;
      background: none;
      border: none;
      color: var(--text-main);
      font-size: 24px;
      cursor: pointer;
    }

    /* 区块通用 */
    section {
      padding: 100px 0;
      position: relative;
    }

    @media (max-width: 640px) {
      section {
        padding: 64px 0;
      }
      .nav-links {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .mobile-menu {
        position: fixed;
        top: 80px;
        left: 16px;
        right: 16px;
        background: rgba(11,26,47,0.9);
        backdrop-filter: blur(24px);
        border: 1px solid rgba(255,255,255,0.08);
        border-radius: 32px;
        padding: 24px;
        display: flex;
        flex-direction: column;
        gap: 20px;
        z-index: 1000;
      }
      .mobile-menu a {
        color: var(--text-main);
        font-size: 18px;
        font-weight: 500;
        text-decoration: none;
      }
    }

    /* Hero */
    #hero {
      height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 40%, rgba(0,194,209,0.08) 0%, transparent 60%), 
                  url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-blend-mode: overlay;
      position: relative;
      overflow: hidden;
    }

    .hero-content {
      max-width: 700px;
    }

    h1 {
      font-size: clamp(36px, 6vw, 56px);
      font-weight: 700;
      line-height: 1.15;
      background: linear-gradient(to right, #00C2D1, #E2E8F0);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 20px;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
    }

    .btn-primary {
      background: linear-gradient(135deg, #00C2D1 0%, #0098A6 100%);
      color: #0B1A2F;
      font-weight: 600;
      border-radius: 12px;
      padding: 14px 32px;
      border: none;
      box-shadow: 0 0 20px rgba(0,194,209,0.3);
      text-decoration: none;
      display: inline-block;
      transition: 0.3s;
      margin-right: 16px;
    }

    .btn-primary:hover {
      box-shadow: 0 0 32px rgba(0,194,209,0.5);
      transform: scale(1.03);
    }

    .btn-ghost {
      background: transparent;
      color: var(--accent);
      border: 1px solid rgba(0,194,209,0.4);
      border-radius: 12px;
      padding: 14px 32px;
      text-decoration: none;
      font-weight: 500;
      transition: 0.3s;
    }

    .btn-ghost:hover {
      background: rgba(0,194,209,0.08);
      border-color: var(--accent);
    }

    .glass-card {
      background: rgba(255,255,255,0.03);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid rgba(255,255,255,0.06);
      border-radius: 20px;
      padding: 28px 24px;
      transition: var(--transition);
    }

    .glass-card:hover {
      border-color: rgba(0,194,209,0.3);
      box-shadow: var(--shadow-glow);
      transform: translateY(-4px);
    }

    h2 {
      font-size: clamp(28px, 4vw, 36px);
      font-weight: 600;
      margin-bottom: 20px;
      color: var(--text-main);
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    @media (max-width: 1024px) {
      .grid-3, .grid-4 {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 640px) {
      .grid-3, .grid-4 {
        grid-template-columns: 1fr;
      }
    }

    .icon-box {
      width: 48px;
      height: 48px;
      background: rgba(0,194,209,0.1);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--accent);
      font-size: 24px;
    }

    .number-highlight {
      font-size: 44px;
      font-weight: 700;
      color: var(--accent);
    }

    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.05);
      padding: 16px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      color: var(--text-main);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: 0.3s;
      color: var(--text-muted);
      font-size: 15px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 12px;
    }

    footer {
      padding: 48px 0;
      color: var(--text-muted);
      font-size: 13px;
      border-top: 1px solid rgba(255,255,255,0.05);
    }

    .cta-highlight-btn {
      background: var(--highlight);
      color: #0B1A2F;
      box-shadow: 0 0 24px rgba(245,158,11,0.4);
      border: none;
      font-weight: 700;
      padding: 16px 38px;
      border-radius: 14px;
      font-size: 18px;
    }

    .flex-between {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
    }