/* roulang page: index */
:root {
      --bg-primary: #1A1A1A;
      --bg-card: #242424;
      --accent-neon: #FF4C2E;
      --accent-hover: #E63E1E;
      --text-primary: #F5F5F0;
      --text-secondary: #A0A0A0;
      --border-light: rgba(255, 255, 255, 0.05);
      --nav-width: 72px;
      --border-radius-card: 8px;
      --border-radius-btn: 4px;
      --transition-fast: 0.25s ease;
      --spacing-lg: 120px;
      --spacing-md: 80px;
      --container-max: 1200px;
    }
    
    * {
      box-sizing: border-box;
    }
    
    body {
      margin: 0;
      background-color: var(--bg-primary);
      font-family: 'Inter', '苹方', 'PingFang SC', system-ui, -apple-system, sans-serif;
      color: var(--text-primary);
      line-height: 1.6;
      font-size: 16px;
      display: flex;
      min-height: 100vh;
      background: var(--bg-primary);
    }
    
    /* 左侧导航 App Shell */
    .app-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--nav-width);
      height: 100vh;
      background: #141414;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 24px 0;
      border-right: 1px solid var(--border-light);
      z-index: 40;
      transition: transform 0.3s ease;
    }
    
    .nav-logo {
      font-family: 'Impact', '思源黑体 Heavy', 'Arial Black', sans-serif;
      font-weight: 900;
      font-size: 20px;
      line-height: 1.1;
      letter-spacing: -0.02em;
      color: var(--text-primary);
      writing-mode: vertical-rl;
      text-orientation: mixed;
      margin-bottom: 48px;
      cursor: pointer;
      user-select: none;
    }
    .nav-logo span {
      color: var(--accent-neon);
    }
    
    .nav-links {
      display: flex;
      flex-direction: column;
      gap: 28px;
      flex: 1;
      align-items: center;
    }
    
    .nav-item {
      width: 44px;
      height: 44px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--text-secondary);
      font-size: 20px;
      position: relative;
      transition: color var(--transition-fast);
      border-radius: 8px;
    }
    .nav-item:hover, .nav-item.active {
      color: var(--accent-neon);
    }
    .nav-item::after {
      content: '';
      position: absolute;
      right: -10px;
      top: 50%;
      transform: translateY(-50%);
      width: 2px;
      height: 0%;
      background: var(--accent-neon);
      transition: height 0.2s ease;
    }
    .nav-item:hover::after {
      height: 60%;
    }
    
    .nav-bottom {
      display: flex;
      flex-direction: column;
      gap: 20px;
      color: var(--text-secondary);
      font-size: 16px;
      margin-top: auto;
    }
    
    /* 主内容区 */
    .main-content {
      margin-left: var(--nav-width);
      flex: 1;
      width: calc(100% - var(--nav-width));
      max-width: 100%;
    }
    
    .container-custom {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* 板块间距 */
    section {
      padding: var(--spacing-lg) 0;
    }
    
    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: #141414;
      padding: 16px 20px;
      z-index: 45;
      align-items: center;
      justify-content: space-between;
      border-bottom: 1px solid var(--border-light);
    }
    .mobile-logo {
      font-family: 'Impact', '思源黑体 Heavy', sans-serif;
      font-size: 24px;
      letter-spacing: -0.02em;
      color: var(--text-primary);
    }
    .hamburger {
      font-size: 24px;
      color: var(--text-primary);
      background: none;
      border: none;
    }
    .mobile-drawer {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: #1A1A1A;
      z-index: 50;
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 32px;
      transform: translateX(-100%);
      transition: transform 0.3s ease;
    }
    .mobile-drawer.open {
      transform: translateX(0);
    }
    .mobile-drawer a {
      font-size: 24px;
      color: var(--text-primary);
      text-decoration: none;
      font-weight: 600;
    }
    .mobile-drawer a:hover {
      color: var(--accent-neon);
    }
    .close-drawer {
      position: absolute;
      top: 20px;
      right: 20px;
      background: none;
      border: none;
      color: var(--text-primary);
      font-size: 28px;
    }
    
    /* 基础元素 */
    h1, h2, h3 {
      font-family: 'Impact', '思源黑体 Heavy', 'Arial Black', sans-serif;
      letter-spacing: -0.02em;
      line-height: 1.1;
      color: var(--text-primary);
    }
    h1 { font-size: 64px; }
    h2 { font-size: 48px; }
    h3 { font-size: 28px; }
    
    .btn-primary {
      background: var(--accent-neon);
      color: #fff;
      border: none;
      padding: 14px 32px;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: background var(--transition-fast), transform var(--transition-fast);
      display: inline-block;
      text-decoration: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: scale(1.03);
      color: #fff;
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent-neon);
      color: var(--accent-neon);
      padding: 14px 32px;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
      transition: background var(--transition-fast);
      display: inline-block;
      text-decoration: none;
    }
    .btn-outline:hover {
      background: rgba(255,76,46,0.08);
      color: var(--accent-neon);
    }
    
    .card {
      background: var(--bg-card);
      border-radius: var(--border-radius-card);
      padding: 28px;
      border: 1px solid var(--border-light);
      transition: transform var(--transition-fast), border-bottom var(--transition-fast);
      position: relative;
      overflow: hidden;
    }
    .card:hover {
      transform: translateY(-4px);
      border-bottom: 3px solid var(--accent-neon);
    }
    
    /* Hero 双栏 */
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-left {
      flex: 0 0 55%;
    }
    .hero-right {
      flex: 0 0 45%;
      position: relative;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 420px;
      border-radius: 12px;
      overflow: hidden;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: rgba(26,26,26,0.65);
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .speed-lines {
      width: 100%;
      height: 100%;
      position: relative;
      overflow: hidden;
    }
    .line {
      position: absolute;
      height: 2px;
      background: rgba(255,76,46,0.7);
      animation: moveRight 2s linear infinite;
    }
    @keyframes moveRight {
      0% { transform: translateX(-100%); }
      100% { transform: translateX(100%); }
    }
    
    /* 优势网格 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .icon-circle {
      font-size: 40px;
      color: var(--accent-neon);
      margin-bottom: 16px;
      transition: transform 0.2s;
    }
    .card:hover .icon-circle {
      transform: rotate(8deg);
    }
    
    /* 案例瀑布流 */
    .services-waterfall {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--bg-card);
      border-radius: var(--border-radius-card);
      overflow: hidden;
      transition: all var(--transition-fast);
      border: 1px solid var(--border-light);
    }
    .service-card:nth-child(odd) {
      transform: translateY(-20px);
    }
    .service-card:hover {
      transform: translateY(-8px);
      border-bottom: 3px solid var(--accent-neon);
    }
    .service-img {
      width: 100%;
      height: 180px;
      object-fit: cover;
    }
    .tag {
      background: var(--accent-neon);
      color: white;
      font-size: 12px;
      padding: 4px 10px;
      border-radius: 12px;
      display: inline-block;
      margin: 8px 0;
    }
    
    /* 方案对比 */
    .compare-container {
      display: flex;
      align-items: center;
      gap: 0;
    }
    .compare-left, .compare-right {
      flex: 1;
      background: var(--bg-card);
      padding: 32px;
      border-radius: 12px;
    }
    .vs-divider {
      width: 10%;
      display: flex;
      flex-direction: column;
      align-items: center;
      font-weight: bold;
      font-size: 24px;
      color: var(--accent-neon);
    }
    .feature-item i {
      margin-right: 8px;
    }
    
    /* 横向数字墙 */
    .data-scroll {
      display: flex;
      gap: 48px;
      overflow-x: auto;
      padding: 24px 0;
      scrollbar-width: thin;
    }
    .data-item {
      flex: 0 0 auto;
      text-align: center;
    }
    .big-number {
      font-size: 56px;
      font-weight: 900;
      color: var(--accent-neon);
    }
    
    /* FAQ */
    .accordion-title {
      font-size: 18px;
      background: var(--bg-card);
      border: none;
      color: var(--text-primary);
      padding: 20px;
      border-left: 3px solid transparent;
      transition: 0.2s;
    }
    .accordion-item.is-active .accordion-title {
      border-left-color: var(--accent-neon);
    }
    
    /* CTA */
    .cta-section {
      background: #141414;
      padding: 80px 0;
    }
    
    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .social-icons i {
      font-size: 20px;
      margin-right: 16px;
      color: var(--text-secondary);
      transition: color 0.2s;
    }
    .social-icons i:hover {
      color: var(--accent-neon);
    }
    
    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
      }
      .advantages-grid, .services-waterfall {
        grid-template-columns: repeat(2, 1fr);
      }
      .service-card:nth-child(odd) {
        transform: translateY(0);
      }
    }
    
    @media (max-width: 768px) {
      .app-nav {
        display: none;
      }
      .mobile-header {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 70px;
      }
      h1 { font-size: 42px; }
      h2 { font-size: 36px; }
      .advantages-grid, .services-waterfall {
        grid-template-columns: 1fr;
      }
      .compare-container {
        flex-direction: column;
      }
      .vs-divider {
        width: 100%;
        flex-direction: row;
        margin: 20px 0;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      section {
        padding: var(--spacing-md) 0;
      }
    }