/* roulang page: index */
:root {
      --bg-deep: #0A0E17;
      --bg-card: #1A1F2E;
      --bg-card-alt: #252B3A;
      --primary: #6C3CFC;
      --primary-hover: #7B4FFF;
      --accent: #00F0FF;
      --text-primary: #FFFFFF;
      --text-secondary: #B0B8C1;
      --text-muted: #6B7280;
      --border-subtle: rgba(108, 60, 252, 0.15);
      --border-active: rgba(108, 60, 252, 0.5);
      --shadow-glow: 0 0 20px rgba(108, 60, 252, 0.3);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-sans: 'Inter', 'Noto Sans SC', sans-serif;
      --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
      --transition: 0.3s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-secondary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: var(--font-sans);
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(10, 14, 23, 0.85);
      backdrop-filter: blur(12px);
      z-index: 999;
      border-bottom: 1px solid rgba(108, 60, 252, 0.3);
      transition: var(--transition);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 1.5rem;
      color: #FFFFFF;
      letter-spacing: 1px;
    }
    .logo-icon {
      width: 28px;
      height: 28px;
      background: linear-gradient(135deg, #6C3CFC, #00F0FF);
      border-radius: 6px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #0A0E17;
      font-weight: 800;
      font-size: 1rem;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: var(--text-secondary);
      font-weight: 500;
      position: relative;
      padding: 4px 0;
      transition: color var(--transition);
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background var(--transition), box-shadow var(--transition);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 0 18px rgba(108, 60, 252, 0.7);
    }
    .btn-ghost {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background var(--transition);
    }
    .btn-ghost:hover {
      background: rgba(108, 60, 252, 0.1);
      color: white;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 25px;
      height: 3px;
      background: var(--text-secondary);
      border-radius: 4px;
      transition: var(--transition);
    }
    /* 英雄区 */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, rgba(10,14,23,0.92) 0%, rgba(10,14,23,0.7) 60%);
    }
    .hero-content {
      position: relative;
      max-width: 700px;
    }
    .hero h1 {
      font-size: clamp(3rem, 8vw, 5rem);
      font-weight: 800;
      background: linear-gradient(135deg, #6C3CFC, #00F0FF);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 1.3rem;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 550px;
    }
    .hero-btns {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    /* 通用版块 */
    section {
      padding: 120px 0;
    }
    .section-title {
      font-size: 2.4rem;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 16px;
    }
    .section-sub {
      color: var(--text-muted);
      max-width: 600px;
      margin-bottom: 48px;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 28px;
      border: 1px solid var(--border-subtle);
      transition: all var(--transition);
    }
    .card:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-glow);
      transform: translateY(-4px);
    }
    .icon-box {
      width: 48px;
      height: 48px;
      background: rgba(108, 60, 252, 0.15);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--accent);
      font-size: 1.6rem;
    }
    /* 服务非对称区 */
    .features-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .feature-wide {
      grid-column: span 2;
    }
    .service-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
    }
    .tag {
      background: var(--bg-card);
      padding: 8px 18px;
      border-radius: 20px;
      border: 1px solid var(--border-subtle);
      color: var(--text-secondary);
      transition: var(--transition);
    }
    .tag:hover {
      border-color: var(--accent);
      color: white;
    }
    .data-numbers {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    .big-number {
      font-family: var(--font-mono);
      font-size: clamp(2.5rem, 5vw, 4rem);
      font-weight: 700;
      color: var(--accent);
    }
    .case-row {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 16px;
    }
    .case-card {
      flex: 0 0 380px;
      background: var(--bg-card);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--border-subtle);
    }
    .case-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .faq-item {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      margin-bottom: 12px;
      border: 1px solid var(--border-subtle);
      transition: var(--transition);
    }
    .faq-question {
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      color: white;
      cursor: pointer;
    }
    .faq-answer {
      padding: 0 24px 20px;
      color: var(--text-secondary);
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .cta-block {
      background: radial-gradient(circle at center, #6C3CFC, #0A0E17);
      text-align: center;
      padding: 100px 0;
    }
    .footer {
      background: #0A0E17;
      padding: 60px 0 30px;
      border-top: 1px solid rgba(108, 60, 252, 0.2);
    }
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .data-numbers { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-content { text-align: center; }
      .grid-3, .features-grid { grid-template-columns: 1fr; }
      .feature-wide { grid-column: span 1; }
      .data-numbers { grid-template-columns: 1fr; }
    }