/* roulang page: index */
:root {
      --bg-deep: #0A0E17;
      --card-bg: #141A24;
      --card-bg-alt: #1A1F2B;
      --accent-cyan: #00F0FF;
      --accent-red: #FF3A2F;
      --text-primary: #E8ECF1;
      --text-secondary: #8A919F;
      --text-muted: #5A606A;
      --border-color: #3A404A;
      --border-light: #2A303A;
      --radius-sm: 4px;
      --radius-md: 8px;
      --radius-pill: 50px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.4);
      --shadow-glow-cyan: 0 0 20px rgba(0,240,255,0.6);
      --transition-smooth: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg-deep);
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    .inter-font {
      font-family: "Inter", "SF Pro Display", sans-serif;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }
    /* 导航栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(10, 14, 23, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(58, 64, 74, 0.6);
      z-index: 100;
      padding: 8px 0;
      transition: background 0.3s;
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 15px;
      position: relative;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--accent-cyan);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 6px;
      text-decoration: none;
      white-space: nowrap;
    }
    .logo i {
      font-size: 1.6rem;
      color: var(--accent-cyan);
    }
    .search-box {
      flex: 1;
      max-width: 360px;
      min-width: 200px;
      position: relative;
      margin: 0 20px;
    }
    .search-box input {
      width: 100%;
      background: #1A1F2B;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-pill);
      padding: 12px 20px 12px 45px;
      color: var(--text-primary);
      font-size: 0.95rem;
      transition: var(--transition-smooth);
      outline: none;
    }
    .search-box input::placeholder {
      color: var(--text-secondary);
      font-weight: 400;
    }
    .search-box input:focus {
      border-color: var(--accent-cyan);
      box-shadow: 0 0 15px rgba(0,240,255,0.2);
    }
    .search-icon {
      position: absolute;
      left: 18px;
      top: 50%;
      transform: translateY(-50%);
      color: var(--text-secondary);
      font-size: 1.1rem;
      pointer-events: none;
    }
    .nav-links {
      display: flex;
      gap: 25px;
      align-items: center;
    }
    .nav-links a {
      color: var(--text-secondary);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      white-space: nowrap;
    }
    .nav-links a:hover {
      color: var(--accent-cyan);
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: var(--text-primary);
      cursor: pointer;
      background: none;
      border: none;
    }
    @media (max-width: 1024px) {
      .search-box {
        max-width: 250px;
        margin: 0 10px;
      }
      .nav-links {
        gap: 15px;
      }
    }
    @media (max-width: 768px) {
      .header-inner {
        flex-wrap: wrap;
      }
      .logo {
        order: 1;
        flex: 1;
      }
      .hamburger {
        display: block;
        order: 2;
      }
      .search-box {
        order: 3;
        width: 100%;
        max-width: 100%;
        margin: 8px 0 0;
      }
      .nav-links {
        display: none;
        order: 4;
        width: 100%;
        flex-direction: column;
        background: rgba(20, 26, 36, 0.95);
        backdrop-filter: blur(12px);
        padding: 15px 20px;
        border-radius: var(--radius-md);
        margin-top: 8px;
        border: 1px solid var(--border-light);
      }
      .nav-links.active {
        display: flex;
      }
    }
    /* 通用区块 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 640px) {
      section {
        padding: 80px 0;
      }
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 600;
      letter-spacing: -0.5px;
      margin-bottom: 15px;
      color: var(--text-primary);
    }
    @media (max-width: 640px) {
      .section-title {
        font-size: 1.8rem;
      }
    }
    .section-lead {
      color: var(--text-secondary);
      font-size: 1.1rem;
      max-width: 700px;
      margin-bottom: 40px;
    }
    /* Hero */
    #hero {
      padding: 140px 0 100px;
      background: radial-gradient(circle at 30% 40%, rgba(0,240,255,0.08) 0%, transparent 50%);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 50px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-left h1 {
      font-size: 3.5rem;
      font-weight: 700;
      letter-spacing: -1px;
      line-height: 1.1;
      margin-bottom: 20px;
      color: white;
    }
    .hero-left .sub {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 30px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-cyan);
      color: #0A0E17;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      text-decoration: none;
      transition: var(--transition-smooth);
      border: none;
      display: inline-block;
      font-size: 1rem;
      letter-spacing: 0.5px;
    }
    .btn-primary:hover {
      box-shadow: var(--shadow-glow-cyan);
      color: #0A0E17;
      background: #33f5ff;
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      transition: var(--transition-smooth);
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .btn-outline:hover {
      background: var(--accent-cyan);
      color: #0A0E17;
    }
    .hero-right {
      flex: 1;
      min-height: 400px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: var(--radius-md);
      position: relative;
      box-shadow: var(--shadow-card);
    }
    .hero-right::after {
      content: '';
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 20% 20%, transparent 30%, #0A0E17 100%);
      border-radius: inherit;
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero-left h1 {
        font-size: 2.5rem;
      }
      .hero-right {
        width: 100%;
        min-height: 280px;
      }
    }
    /* 亮点 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
      margin-top: 30px;
    }
    .stat-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      padding: 35px 25px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-light);
      transition: var(--transition-smooth);
      text-align: center;
    }
    .stat-card:hover {
      border-color: var(--accent-cyan);
      transform: translateY(-4px);
      box-shadow: 0 12px 30px rgba(0,240,255,0.15);
    }
    .stat-number {
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent-cyan);
      font-family: "Inter", sans-serif;
    }
    .stat-title {
      font-size: 1.1rem;
      font-weight: 600;
      margin: 10px 0 5px;
    }
    .stat-desc {
      color: var(--text-secondary);
      font-size: 0.9rem;
    }
    @media (max-width: 768px) {
      .highlights-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 案例瀑布流 */
    .waterfall {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
      margin-top: 30px;
    }
    .case-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-light);
      transition: var(--transition-smooth);
      display: flex;
      flex-direction: column;
    }
    .case-card:hover {
      border-color: var(--accent-cyan);
      transform: translateY(-4px);
      box-shadow: 0 15px 30px rgba(0,240,255,0.2);
    }
    .case-img {
      position: relative;
      overflow: hidden;
      height: 220px;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s ease;
    }
    .case-card:hover .case-img img {
      transform: scale(1.05);
    }
    .case-overlay {
      position: absolute;
      inset: 0;
      background: rgba(10,14,23,0.7);
      display: flex;
      align-items: center;
      justify-content: center;
      opacity: 0;
      transition: 0.3s;
      color: white;
      font-weight: 600;
    }
    .case-card:hover .case-overlay {
      opacity: 1;
    }
    .case-tag {
      position: absolute;
      top: 12px;
      right: 12px;
      background: var(--accent-red);
      color: white;
      padding: 4px 12px;
      border-radius: 2px;
      font-size: 0.8rem;
      font-weight: 600;
      z-index: 2;
    }
    .case-content {
      padding: 20px;
    }
    .case-content h3 {
      font-size: 1.3rem;
      font-weight: 600;
    }
    .case-content p {
      color: var(--text-secondary);
      font-size: 0.9rem;
      margin: 8px 0 0;
    }
    @media (max-width: 640px) {
      .waterfall {
        grid-template-columns: 1fr;
      }
    }
    /* 对比表 */
    .compare-container {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-light);
      margin-top: 25px;
    }
    .compare-row {
      display: flex;
    }
    .compare-col {
      flex: 1;
      padding: 20px;
    }
    .compare-header {
      background: #141A24;
      font-weight: 700;
      font-size: 1.2rem;
      border-bottom: 1px solid var(--border-light);
    }
    .compare-item {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 14px 0;
      border-bottom: 1px solid var(--border-light);
    }
    .compare-item:last-child {
      border-bottom: none;
    }
    .strikethrough {
      color: var(--text-muted);
      text-decoration: line-through;
    }
    .advantage {
      color: var(--accent-cyan);
      font-weight: 600;
    }
    .advantage i {
      margin-right: 6px;
      color: var(--accent-cyan);
    }
    @media (max-width: 640px) {
      .compare-row {
        flex-direction: column;
      }
    }
    /* FAQ */
    .faq-list {
      margin-top: 25px;
    }
    .faq-item {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      border: 1px solid var(--border-light);
    }
    .faq-question {
      padding: 18px 24px;
      display: flex;
      align-items: center;
      gap: 12px;
      cursor: pointer;
      font-weight: 600;
      color: var(--text-primary);
      transition: 0.2s;
    }
    .faq-question i {
      color: var(--accent-cyan);
      transition: transform 0.3s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      background: #1A1F2B;
      padding: 0 24px;
      color: var(--text-secondary);
      transition: max-height 0.4s ease, padding 0.3s;
    }
    .faq-item.active .faq-answer {
      max-height: 180px;
      padding: 20px 24px;
    }
    .faq-item.active .faq-question i {
      transform: rotate(180deg);
      color: var(--accent-red);
    }
    /* CTA */
    .cta-banner {
      background: #0A0E17;
      background-image: radial-gradient(circle at 30% 30%, rgba(0,240,255,0.08) 0%, transparent 70%);
      text-align: center;
      padding: 80px 20px;
      border-top: 1px solid var(--border-light);
      border-bottom: 1px solid var(--border-light);
    }
    .btn-cta {
      background: var(--accent-red);
      color: white;
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-sm);
      font-size: 1.1rem;
      transition: 0.3s;
      display: inline-block;
      margin-top: 25px;
      text-decoration: none;
    }
    .btn-cta:hover {
      background: #FF5A52;
      transform: scale(1.05);
      color: white;
    }
    /* Footer */
    .site-footer {
      background: #080B12;
      padding: 50px 0 25px;
      border-top: 1px solid var(--accent-cyan);
      color: var(--text-secondary);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
      margin-bottom: 30px;
    }
    .footer-logo {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--accent-cyan);
    }
    .footer-links a {
      display: block;
      color: var(--text-secondary);
      margin: 6px 0;
      text-decoration: none;
    }
    .footer-links a:hover {
      color: var(--accent-cyan);
    }
    .social-icons i {
      font-size: 1.4rem;
      margin-right: 15px;
      color: var(--text-secondary);
      transition: 0.2s;
    }
    .copyright {
      text-align: center;
      padding-top: 20px;
      border-top: 1px solid var(--border-light);
      font-size: 0.9rem;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 480px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }
   .fade-up {
      opacity: 0;
      transform: translateY(25px);
      transition: opacity 0.6s ease, transform 0.6s ease;
    }
    .fade-up.visible {
      opacity: 1;
      transform: translateY(0);
    }