/* roulang page: index */
:root {
      --deep-blue: #0A0E27;
      --tech-blue: #0F172A;
      --accent-cyan: #00F0FF;
      --warm-gold: #F59E0B;
      --bg-deep: #030712;
      --bg-card: rgba(15, 23, 42, 0.6);
      --border-cyan: rgba(0, 240, 255, 0.15);
      --text-primary: #F1F5F9;
      --text-secondary: #94A3B8;
      --text-muted: #64748B;
      --radius-card: 20px;
      --radius-btn: 9999px;
      --radius-input: 12px;
      --shadow-cyan: 0 0 15px rgba(0, 240, 255, 0.4);
      --glass-blur: blur(16px);
      --font-sans: 'Inter', 'Noto Sans SC', system-ui, sans-serif;
      --font-serif: 'Noto Serif SC', 'Inter', serif;
      background-color: var(--bg-deep);
      color: var(--text-primary);
      font-family: var(--font-sans);
      scroll-behavior: smooth;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      background: linear-gradient(180deg, #030712 0%, #0B1120 100%);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      color: inherit;
      text-decoration: none;
      transition: color 0.2s;
    }
    button, input {
      font-family: inherit;
    }
    .container-main {
      max-width: 1280px;
      margin: 0 auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    /* 玻璃拟态卡片 */
    .glass-card {
      background: var(--bg-card);
      backdrop-filter: var(--glass-blur);
      -webkit-backdrop-filter: var(--glass-blur);
      border: 1px solid var(--border-cyan);
      border-radius: var(--radius-card);
      box-shadow: 0 20px 25px -5px rgba(0, 240, 255, 0.08);
      transition: all 0.3s ease;
    }
    .glass-card:hover {
      border-color: rgba(0, 240, 255, 0.4);
      box-shadow: 0 25px 35px -5px rgba(0, 240, 255, 0.15);
      transform: translateY(-4px);
      background: rgba(15, 23, 42, 0.75);
    }
    /* 发光按钮 */
    .btn-glow {
      background: linear-gradient(135deg, #22D3EE 0%, #3B82F6 100%);
      border: none;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 700;
      color: #0A0E27;
      box-shadow: 0 0 20px rgba(0, 240, 255, 0.5);
      transition: all 0.3s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      letter-spacing: 0.5px;
    }
    .btn-glow:hover {
      box-shadow: 0 0 35px rgba(0, 240, 255, 0.8);
      transform: translateY(-2px);
      filter: brightness(1.1);
    }
    .btn-ghost {
      background: transparent;
      border: 1px solid var(--accent-cyan);
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      color: var(--accent-cyan);
      transition: all 0.3s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-ghost:hover {
      background: rgba(0, 240, 255, 0.1);
      box-shadow: 0 0 15px rgba(0, 240, 255, 0.3);
    }
    /* 导航频道标签激活项 */
    .nav-channel-link.active {
      color: var(--accent-cyan);
      border-bottom: 2px solid var(--accent-cyan);
      box-shadow: 0 4px 8px -2px rgba(0, 240, 255, 0.3);
    }
    .nav-channel-link:hover {
      color: var(--accent-cyan);
    }
    /* 指标数字 */
    .metric-number {
      font-family: var(--font-serif);
      font-weight: 700;
      background: linear-gradient(180deg, #00F0FF 0%, #A5F3FC 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    /* 手风琴动画 */
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.4s ease, opacity 0.3s;
      opacity: 0;
      padding: 0 20px;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      opacity: 1;
      padding: 8px 20px 20px;
    }
    .faq-icon {
      transition: transform 0.3s ease;
      display: inline-block;
      width: 24px;
      height: 24px;
      line-height: 24px;
      text-align: center;
      background: rgba(0, 240, 255, 0.1);
      border-radius: 50%;
      color: var(--accent-cyan);
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
      background: rgba(0, 240, 255, 0.25);
    }
    /* 表单发光 */
    .input-glow {
      background: rgba(15, 23, 42, 0.7);
      border: 1px solid rgba(0, 240, 255, 0.2);
      border-radius: var(--radius-input);
      padding: 14px 18px;
      width: 100%;
      color: white;
      outline: none;
      transition: 0.2s;
    }
    .input-glow:focus {
      border-color: var(--accent-cyan);
      box-shadow: 0 0 12px rgba(0, 240, 255, 0.4);
    }
    /* 动态网格背景 */
    .hero-bg {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .hero-overlay {
      background: radial-gradient(circle at 30% 40%, rgba(0,240,255,0.1) 0%, rgba(3,7,18,0.85) 80%);
    }
    /* 移动端频道横向滑动 */
    @media (max-width: 768px) {
      .nav-channels {
        overflow-x: auto;
        white-space: nowrap;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
        padding-bottom: 4px;
      }
      .nav-channels::-webkit-scrollbar {
        display: none;
      }
      .metric-number {
        font-size: 2rem;
      }
      h1 {
        font-size: 2.5rem;
      }
      h2 {
        font-size: 2rem;
      }
    }
    /* 汉堡菜单基础隐藏 */
    #mobile-menu {
      display: none;
    }
    @media (max-width: 768px) {
      #mobile-menu.open {
        display: block;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(10, 14, 39, 0.98);
        backdrop-filter: blur(20px);
        z-index: 50;
        padding: 20px;
      }
    }