/* roulang page: index */
:root {
      --primary-purple: #7B2FBE;
      --neon-cyan: #00F0FF;
      --deep-bg: #0D0B1A;
      --card-bg: rgba(30, 28, 46, 0.85);
      --card-solid: #1E1C2E;
      --text-light: #E8E6F0;
      --text-muted: #A9A5C0;
      --accent-orange: #FF6B35;
      --gold: #C9A96E;
      --white: #FFFFFF;
      --border-radius: 12px;
      --btn-radius: 6px;
      --shadow-glow: 0 8px 24px rgba(123, 47, 190, 0.35);
      --font-heading: 'Segoe UI', 'Roboto', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      --font-body: 'Inter', 'Segoe UI', 'Roboto', system-ui, -apple-system, sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-body);
      background-color: var(--deep-bg);
      color: var(--text-light);
      line-height: 1.8;
      letter-spacing: 0.5px;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4, .h1, .h2, .h3 {
      font-family: var(--font-heading);
      font-weight: 700;
      letter-spacing: 1px;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }
    /* 导航栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(13, 11, 26, 0.8);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(123, 47, 190, 0.4);
      transition: background 0.3s ease;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--white);
      text-decoration: none;
      letter-spacing: 2px;
    }
    .logo i {
      color: var(--neon-cyan);
      font-size: 2.2rem;
    }
    .logo span {
      background: linear-gradient(135deg, var(--primary-purple), var(--neon-cyan));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .desktop-nav {
      display: flex;
      gap: 28px;
      align-items: center;
    }
    .desktop-nav a {
      color: var(--text-muted);
      text-decoration: none;
      font-weight: 600;
      font-size: 1rem;
      transition: color 0.2s, text-shadow 0.2s;
      position: relative;
    }
    .desktop-nav a:hover,
    .desktop-nav a.active {
      color: var(--neon-cyan);
      text-shadow: 0 0 8px rgba(0,240,255,0.5);
    }
    .menu-toggle {
      background: none;
      border: none;
      color: var(--neon-cyan);
      font-size: 2rem;
      cursor: pointer;
      display: none;
    }
    /* 移动端底部导航 */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background: rgba(20, 16, 36, 0.95);
      backdrop-filter: blur(20px);
      border-top: 1px solid var(--primary-purple);
      z-index: 99;
      justify-content: space-around;
      padding: 8px 0 12px;
    }
    .mobile-bottom-nav a {
      color: var(--text-muted);
      text-align: center;
      font-size: 0.8rem;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
      text-decoration: none;
      font-weight: 500;
    }
    .mobile-bottom-nav a i {
      font-size: 1.4rem;
    }
    .mobile-bottom-nav a.active {
      color: var(--neon-cyan);
    }
    /* 板块通用 */
    section {
      padding: 90px 0;
      scroll-margin-top: 70px;
    }
    .section-title {
      font-size: 2.6rem;
      font-weight: 800;
      margin-bottom: 1.2rem;
      background: linear-gradient(135deg, #C084FC, var(--neon-cyan));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      text-align: center;
    }
    .section-subtitle {
      color: var(--text-muted);
      text-align: center;
      max-width: 700px;
      margin: 0 auto 3rem auto;
      font-size: 1.2rem;
    }
    /* 按钮 */
    .btn-primary {
      background: linear-gradient(135deg, var(--primary-purple), #a855f7);
      border: none;
      color: white;
      padding: 14px 32px;
      border-radius: var(--btn-radius);
      font-weight: 700;
      letter-spacing: 1px;
      transition: all 0.25s;
      display: inline-block;
      text-decoration: none;
      box-shadow: 0 6px 18px rgba(123,47,190,0.5);
    }
    .btn-primary:hover {
      filter: brightness(1.15);
      transform: translateY(-2px);
      box-shadow: 0 12px 28px rgba(0,240,255,0.3);
      color: white;
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--neon-cyan);
      color: var(--neon-cyan);
      padding: 12px 28px;
      border-radius: var(--btn-radius);
      font-weight: 700;
      transition: 0.25s;
      text-decoration: none;
      display: inline-block;
    }
    .btn-outline:hover {
      background: rgba(0,240,255,0.1);
      box-shadow: 0 0 16px var(--neon-cyan);
      color: white;
    }
    /* 卡片样式 */
    .feature-card, .service-card {
      background: var(--card-bg);
      border: 1px solid rgba(123,47,190,0.5);
      border-radius: var(--border-radius);
      padding: 28px 20px;
      transition: all 0.3s ease;
      backdrop-filter: blur(4px);
    }
    .feature-card:hover, .service-card:hover {
      border-color: var(--neon-cyan);
      box-shadow: var(--shadow-glow);
      transform: translateY(-5px);
    }
    /* 移动端菜单覆盖层 */
    .mobile-overlay {
      display: none;
      position: fixed;
      top: 70px;
      left: 0;
      width: 100%;
      height: calc(100% - 70px);
      background: rgba(13,11,26,0.98);
      z-index: 99;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
    }
    .mobile-overlay a {
      font-size: 1.8rem;
      color: var(--text-light);
      text-decoration: none;
    }
    @media (max-width: 1024px) {
      .desktop-nav { display: none; }
      .menu-toggle { display: block; }
      .mobile-bottom-nav { display: flex; }
      section { padding: 70px 0; }
    }