/* roulang page: index */
:root {
      --bg-deep: #0A0E27;
      --gradient-bg: linear-gradient(135deg, #0A0E27 0%, #1E1B4B 50%, #0A0E27 100%);
      --glass-bg: rgba(30, 27, 75, 0.45);
      --glass-border: rgba(124, 58, 237, 0.25);
      --glass-hover-bg: rgba(124, 58, 237, 0.15);
      --glass-hover-border: rgba(124, 58, 237, 0.5);
      --primary: #7C3AED;
      --primary-light: #8B5CF6;
      --accent: #06B6D4;
      --accent-light: #22D3EE;
      --text-main: #E2E8F0;
      --text-dim: #94A3B8;
      --text-white: #FFFFFF;
      --success: #10B981;
      --radius-card: 16px;
      --radius-btn: 12px;
      --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(124, 58, 237, 0.15);
      --shadow-hover: 0 8px 32px rgba(124, 58, 237, 0.25), 0 0 0 1px rgba(124, 58, 237, 0.4);
      --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }

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

    body {
      font-family: 'Inter', 'Noto Sans SC', system-ui, sans-serif;
      background: var(--bg-deep);
      background-image: var(--gradient-bg);
      color: var(--text-main);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }

    /* 导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(10, 14, 39, 0.85);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(124, 58, 237, 0.2);
      transition: var(--transition);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      padding: 0.75rem 1.5rem;
      max-width: 1200px;
      margin: 0 auto;
    }

    .logo {
      font-size: 1.6rem;
      font-weight: 800;
      color: var(--text-white);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .logo i {
      color: var(--primary-light);
      font-size: 1.8rem;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 1.8rem;
      flex-wrap: wrap;
    }

    .nav-link {
      font-weight: 500;
      color: var(--text-dim);
      position: relative;
      padding: 0.25rem 0;
      transition: color 0.2s;
    }
    .nav-link:hover,
    .nav-link.active {
      color: var(--accent);
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }
    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }

    .search-trigger {
      color: var(--text-dim);
      font-size: 1.2rem;
      margin-left: 0.5rem;
      background: none;
      border: none;
    }
    .search-trigger:hover {
      color: var(--accent);
    }
    .search-box {
      display: none;
      position: absolute;
      right: 1.5rem;
      top: 70px;
      background: rgba(10,14,39,0.95);
      backdrop-filter: blur(20px);
      padding: 0.75rem 1rem;
      border-radius: 40px;
      border: 1px solid var(--glass-border);
    }
    .search-box.active {
      display: flex;
      align-items: center;
    }
    .search-box input {
      background: transparent;
      border: none;
      color: white;
      padding: 0.3rem 0.5rem;
      width: 180px;
    }
    .search-box input:focus {
      outline: none;
    }

    .hot-tags {
      display: flex;
      gap: 0.5rem;
      margin-left: 1rem;
    }
    .tag {
      background: rgba(124,58,237,0.2);
      color: var(--accent);
      font-size: 0.75rem;
      padding: 0.2rem 0.75rem;
      border-radius: 20px;
      font-weight: 500;
    }

    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: white;
      background: none;
      border: none;
    }

    @media (max-width: 768px) {
      .nav-menu {
        display: none;
        width: 100%;
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
        background: rgba(10,14,39,0.9);
        backdrop-filter: blur(20px);
        padding: 1.5rem;
        margin-top: 1rem;
        border-radius: 20px;
      }
      .nav-menu.open {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .hot-tags {
        margin-left: 0;
        margin-top: 0.5rem;
      }
    }

    /* 区块通用 */
    section {
      padding: 5rem 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 3rem 0;
      }
    }

    .section-title {
      font-size: clamp(1.8rem, 3.5vw, 2.5rem);
      font-weight: 700;
      letter-spacing: -0.01em;
      color: var(--text-white);
      margin-bottom: 2.5rem;
      text-align: center;
      position: relative;
    }
    .section-title::after {
      content: '';
      display: block;
      width: 50px;
      height: 3px;
      background: var(--primary);
      margin: 0.75rem auto 0;
    }

    /* 按钮 */
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 0.875rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      letter-spacing: 0.02em;
      box-shadow: 0 0 20px rgba(124, 58, 237, 0.5);
      transition: var(--transition);
      display: inline-block;
    }
    .btn-primary:hover {
      background: var(--primary-light);
      box-shadow: 0 0 30px rgba(124, 58, 237, 0.8);
      transform: scale(1.03);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent);
      color: var(--accent);
      padding: 0.875rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
      display: inline-block;
    }
    .btn-outline:hover {
      background: rgba(6, 182, 212, 0.1);
      border-color: var(--accent-light);
    }

    /* 卡片 */
    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(12px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      padding: 2rem;
    }
    .glass-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      background: var(--glass-hover-bg);
      border-color: var(--glass-hover-border);
    }

    /* Hero */
    .hero {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 2rem;
      flex-wrap: wrap;
    }
    .hero-content {
      flex: 1 1 400px;
    }
    .hero h1 {
      font-size: clamp(2.5rem, 5vw, 4rem);
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.15;
      color: white;
      margin-bottom: 1.25rem;
    }
    .hero .sub {
      font-size: 1.2rem;
      color: var(--text-dim);
      margin-bottom: 2rem;
    }
    .hero-buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1 1 400px;
      position: relative;
      border-radius: 24px;
      overflow: hidden;
      box-shadow: 0 0 30px rgba(124,58,237,0.4);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }

    /* 栅格 */
    .grid-2, .grid-3, .grid-4 {
      display: grid;
      gap: 2rem;
    }
    .grid-2 { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: repeat(3, 1fr); }
    .grid-4 { grid-template-columns: repeat(4, 1fr); }

    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    }

    .icon-box {
      font-size: 2.5rem;
      color: var(--primary-light);
      margin-bottom: 1rem;
    }

    .service-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      border-radius: 16px 16px 0 0;
    }

    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--success);
      font-variant-numeric: tabular-nums;
    }

    .testimonial-card {
      display: flex;
      gap: 1rem;
      align-items: flex-start;
      border-left: 4px solid var(--primary);
      padding-left: 1.5rem;
    }
    .avatar {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: rgba(124,58,237,0.3);
      border: 2px solid var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
    }

    .faq-item {
      border-bottom: 1px solid rgba(124,58,237,0.2);
      padding: 1.2rem 0;
    }
    .faq-question {
      font-weight: 700;
      color: white;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-dim);
    }
    .faq-answer.open {
      max-height: 200px;
      margin-top: 0.8rem;
    }

    .cta-section {
      text-align: center;
      background: radial-gradient(circle at center, rgba(124,58,237,0.2) 0%, transparent 70%);
    }

    footer {
      background: #0A0E27;
      border-top: 1px solid rgba(124,58,237,0.3);
      padding: 2rem 0;
    }