/* roulang page: index */
:root {
      --primary-bg: #0A1929;
      --accent-cyan: #00E5FF;
      --accent-orange: #FF6B35;
      --glass-bg: rgba(18, 30, 50, 0.6);
      --glass-border: rgba(255, 255, 255, 0.15);
      --text-primary: #E6F1FF;
      --text-secondary: #8892B0;
      --text-muted: #5A6A8C;
      --card-hover-bg: rgba(255, 255, 255, 0.08);
      --shadow-glow-cyan: 0 0 20px rgba(0, 229, 255, 0.3), 0 10px 30px -10px rgba(0,0,0,0.5);
      --shadow-glow-orange: 0 0 15px rgba(255, 107, 53, 0.5);
      --border-radius-card: 16px;
      --border-radius-pill: 50px;
      --border-radius-img: 12px;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-heading: 'Poppins', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --transition-smooth: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
      --sidebar-width: 90px;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--primary-bg);
      color: var(--text-primary);
      line-height: 1.6;
      display: flex;
      min-height: 100vh;
      overflow-x: hidden;
    }

    /* 左侧导航 App Shell */
    .app-sidebar {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--sidebar-width);
      height: 100vh;
      background: rgba(10, 25, 41, 0.75);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-right: 1px solid rgba(255, 255, 255, 0.08);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      padding: 2rem 0.5rem;
      z-index: 1000;
      box-shadow: 0 0 30px rgba(0, 229, 255, 0.1);
      transition: var(--transition-smooth);
    }

    .logo-area {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 0.25rem;
    }

    .logo-icon {
      width: 40px;
      height: 40px;
      background: linear-gradient(135deg, var(--accent-cyan), #0077ff);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 1.3rem;
      color: white;
      box-shadow: 0 0 15px rgba(0, 229, 255, 0.6);
      letter-spacing: 0;
      font-family: var(--font-heading);
    }

    .logo-text {
      font-size: 0.7rem;
      font-weight: 600;
      color: var(--text-primary);
      letter-spacing: 0.03em;
      text-align: center;
      line-height: 1.2;
      white-space: nowrap;
    }

    .nav-menu {
      display: flex;
      flex-direction: column;
      gap: 1.8rem;
      list-style: none;
      width: 100%;
      align-items: center;
    }

    .nav-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-decoration: none;
      color: var(--text-secondary);
      font-size: 0.7rem;
      font-weight: 500;
      gap: 0.25rem;
      transition: var(--transition-smooth);
      position: relative;
      padding: 0.5rem 0.2rem;
      width: 100%;
      text-align: center;
      border-radius: 12px;
    }

    .nav-item svg {
      width: 22px;
      height: 22px;
      stroke: currentColor;
      transition: var(--transition-smooth);
    }

    .nav-item:hover,
    .nav-item.active {
      color: var(--accent-cyan);
      background: rgba(0, 229, 255, 0.08);
    }

    .nav-item.active::before {
      content: '';
      position: absolute;
      left: 0;
      top: 8px;
      height: 28px;
      width: 3px;
      background: var(--accent-cyan);
      border-radius: 0 4px 4px 0;
      box-shadow: 0 0 10px var(--accent-cyan);
    }

    .bottom-widget {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 1.2rem;
      color: var(--text-secondary);
      font-size: 0.7rem;
    }

    .lang-switch {
      background: transparent;
      border: 1px solid rgba(255,255,255,0.2);
      color: var(--text-primary);
      padding: 0.3rem 0.7rem;
      border-radius: 20px;
      font-size: 0.7rem;
      cursor: pointer;
      transition: var(--transition-smooth);
    }

    .lang-switch:hover {
      border-color: var(--accent-cyan);
      color: var(--accent-cyan);
    }

    /* 主内容区 */
    .main-content {
      margin-left: var(--sidebar-width);
      flex: 1;
      width: calc(100% - var(--sidebar-width));
      position: relative;
    }

    /* 移动端导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 65px;
      background: rgba(10, 25, 41, 0.8);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      z-index: 999;
      align-items: center;
      justify-content: space-between;
      padding: 0 1.5rem;
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }

    .mobile-logo {
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }

    .hamburger {
      background: transparent;
      border: none;
      color: var(--text-primary);
      display: flex;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text-primary);
      transition: var(--transition-smooth);
    }

    .mobile-drawer {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(8, 20, 35, 0.95);
      backdrop-filter: blur(25px);
      -webkit-backdrop-filter: blur(25px);
      z-index: 998;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 2.5rem;
      transform: translateX(-100%);
      transition: transform 0.4s ease;
    }

    .mobile-drawer.open {
      transform: translateX(0);
    }

    .mobile-drawer a {
      font-size: 1.8rem;
      font-weight: 600;
      color: var(--text-primary);
      text-decoration: none;
      transition: var(--transition-smooth);
    }

    .mobile-drawer a:hover {
      color: var(--accent-cyan);
    }

    /* 通用容器 */
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 2rem;
    }

    section {
      padding: 6rem 0;
      position: relative;
    }

    /* 按钮 */
    .btn-glow {
      background: linear-gradient(135deg, #FF6B35, #FF8C42);
      color: white;
      font-weight: 600;
      padding: 0.8rem 2.2rem;
      border-radius: var(--border-radius-pill);
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border: none;
      cursor: pointer;
      box-shadow: 0 0 15px rgba(255, 107, 53, 0.5);
      transition: var(--transition-smooth);
      letter-spacing: 0.02em;
      font-size: 1rem;
    }

    .btn-glow:hover {
      transform: translateY(-2px);
      box-shadow: 0 0 25px rgba(255, 107, 53, 0.8), 0 10px 20px rgba(0,0,0,0.4);
      background: linear-gradient(135deg, #FF7B4A, #FF9B5A);
    }

    .btn-outline-glow {
      background: transparent;
      border: 2px solid var(--accent-cyan);
      color: var(--accent-cyan);
      font-weight: 600;
      padding: 0.8rem 2.2rem;
      border-radius: var(--border-radius-pill);
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      transition: var(--transition-smooth);
      letter-spacing: 0.02em;
    }

    .btn-outline-glow:hover {
      background: rgba(0, 229, 255, 0.1);
      box-shadow: 0 0 15px rgba(0, 229, 255, 0.4);
      transform: translateY(-2px);
    }

    /* 玻璃卡片 */
    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(15px);
      -webkit-backdrop-filter: blur(15px);
      border: 1px solid var(--glass-border);
      border-radius: var(--border-radius-card);
      padding: 2rem;
      transition: var(--transition-smooth);
    }

    .glass-card:hover {
      background: var(--card-hover-bg);
      border-color: rgba(0, 229, 255, 0.4);
      box-shadow: 0 0 30px rgba(0, 229, 255, 0.2);
      transform: translateY(-8px);
    }

    /* Hero */
    .hero-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.9fr;
      gap: 3rem;
      align-items: center;
      min-height: 90vh;
    }

    .hero-title {
      font-family: var(--font-heading);
      font-size: clamp(2.8rem, 6vw, 4.5rem);
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.15;
      margin-bottom: 1.5rem;
      color: white;
    }

    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 2.5rem;
      max-width: 550px;
    }

    .data-panel {
      background: rgba(18, 30, 50, 0.55);
      backdrop-filter: blur(20px);
      border: 1px solid rgba(255,255,255,0.2);
      border-radius: 24px;
      padding: 2rem;
      box-shadow: 0 20px 40px rgba(0,0,0,0.6);
    }

    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }

    /* 案例瀑布流 */
    .masonry-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.5rem;
    }

    .masonry-item {
      border-radius: var(--border-radius-img);
      overflow: hidden;
      position: relative;
      background: #0f1a2b;
      transition: var(--transition-smooth);
    }

    .masonry-item img {
      width: 100%;
      display: block;
      object-fit: cover;
      transition: transform 0.4s ease;
    }

    .masonry-item:hover img {
      transform: scale(1.05);
    }

    /* 方案对比表 */
    .compare-table {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
    }

    /* 表单 */
    .contact-form input, .contact-form textarea {
      background: rgba(255, 255, 255, 0.05);
      border: 1px solid rgba(255, 255, 255, 0.2);
      border-radius: var(--border-radius-pill);
      padding: 0.9rem 1.5rem;
      color: var(--text-primary);
      width: 100%;
      margin-bottom: 1rem;
      transition: var(--transition-smooth);
    }

    .contact-form input:focus, .contact-form textarea:focus {
      border-color: var(--accent-cyan);
      box-shadow: 0 0 10px rgba(0, 229, 255, 0.3);
      outline: none;
    }

    footer {
      background: #05101c;
      padding: 4rem 0 2rem;
      border-top: 1px solid rgba(0,229,255,0.2);
    }

    @media (max-width: 992px) {
      .app-sidebar {
        display: none;
      }
      .mobile-header {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 65px;
      }
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .highlights-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .masonry-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .compare-table {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 640px) {
      .highlights-grid, .masonry-grid {
        grid-template-columns: 1fr;
      }
    }