/* roulang page: index */
:root {
      --primary: #1E2A38;
      --accent: #F18F01;
      --bg: #F5F6F8;
      --card: #FFFFFF;
      --dark-bg: #0F172A;
      --text: #1E293B;
      --text-light: #64748B;
      --border: rgba(255,255,255,0.1);
      --glass-bg: rgba(15,23,42,0.85);
      --shadow-sm: 0 4px 24px rgba(0,0,0,0.06);
      --shadow-md: 0 12px 32px rgba(0,0,0,0.12);
      --radius: 16px;
      --transition: all 0.25s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --content-width: 1200px;
      --sidebar-width: 240px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      display: flex;
      min-height: 100vh;
      -webkit-font-smoothing: antialiased;
    }

    /* 左侧导航 App Shell */
    .app-sidebar {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--sidebar-width);
      height: 100vh;
      background: var(--glass-bg);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-right: 1px solid var(--border);
      display: flex;
      flex-direction: column;
      padding: 2rem 1.5rem;
      z-index: 100;
      transition: var(--transition);
    }

    .logo-area {
      margin-bottom: 3rem;
      display: flex;
      align-items: center;
      gap: 0.75rem;
    }

    .logo-icon {
      width: 36px;
      height: 36px;
      background: var(--accent);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 700;
      font-size: 1.2rem;
      transform: rotate(0deg);
    }

    .logo-text {
      font-size: 1.25rem;
      font-weight: 700;
      color: white;
      letter-spacing: 0.5px;
    }
    .logo-text span {
      color: var(--accent);
    }

    .nav-menu {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 0.5rem;
    }

    .nav-menu a {
      display: block;
      color: #cbd5e1;
      text-decoration: none;
      padding: 0.75rem 1rem;
      border-left: 3px solid transparent;
      border-radius: 0 8px 8px 0;
      transition: var(--transition);
      font-weight: 500;
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: white;
      background: rgba(255,255,255,0.05);
    }
    .nav-menu a:hover {
      border-left-color: var(--accent);
      color: var(--accent);
    }
    .nav-menu a.active {
      border-left-color: var(--accent);
      color: var(--accent);
      font-weight: 600;
    }

    /* 移动端顶部栏 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 60px;
      background: var(--dark-bg);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      z-index: 99;
      align-items: center;
      justify-content: space-between;
      padding: 0 1.5rem;
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    .mobile-logo {
      color: white;
      font-weight: 700;
      font-size: 1.2rem;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .hamburger {
      display: flex;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: white;
      border-radius: 2px;
      transition: var(--transition);
    }
    #menu-toggle {
      display: none;
    }
    #menu-toggle:checked ~ .mobile-drawer {
      transform: translateX(0);
    }
    .mobile-drawer {
      position: fixed;
      top: 60px;
      left: 0;
      width: 100%;
      height: calc(100vh - 60px);
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      transform: translateX(-100%);
      transition: transform 0.3s ease;
      z-index: 98;
      padding: 2rem;
      display: flex;
      flex-direction: column;
      gap: 1rem;
    }
    .mobile-drawer a {
      color: #e2e8f0;
      font-size: 1.2rem;
      padding: 0.75rem;
      border-left: 3px solid transparent;
      text-decoration: none;
    }
    .mobile-drawer a:hover {
      color: var(--accent);
      border-left-color: var(--accent);
    }

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

    .container {
      max-width: var(--content-width);
      margin: 0 auto;
      padding: 0 2rem;
    }

    section {
      padding: 5rem 0;
    }

    /* 按钮 */
    .btn {
      display: inline-block;
      padding: 0.85rem 2.2rem;
      border-radius: 40px;
      font-weight: 600;
      text-decoration: none;
      transition: var(--transition);
      cursor: pointer;
      border: none;
      font-size: 1rem;
      letter-spacing: 0.3px;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      box-shadow: 0 4px 12px rgba(241,143,1,0.3);
    }
    .btn-primary:hover {
      box-shadow: 0 0 20px rgba(241,143,1,0.7);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid white;
      color: white;
    }
    .btn-outline:hover {
      border-color: var(--accent);
      color: var(--accent);
      box-shadow: 0 0 12px rgba(241,143,1,0.3);
    }
    .btn-ghost {
      color: var(--accent);
      font-weight: 600;
      padding: 0.5rem 0;
      border-bottom: 1px solid transparent;
    }
    .btn-ghost:hover {
      border-bottom-color: var(--accent);
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #1E2A38 0%, #0F172A 100%);
      color: white;
      display: flex;
      align-items: center;
      min-height: 90vh;
      padding: 6rem 0 4rem;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 3rem;
      align-items: center;
    }
    .hero h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 1.5rem;
    }
    .hero .sub {
      font-size: 1.15rem;
      color: #cbd5e1;
      margin-bottom: 2rem;
    }
    .hero-buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .hero-image {
      background-color: #2d3a4a;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: 24px;
      height: 380px;
      position: relative;
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .hero-image::after {
      content: "";
      position: absolute;
      inset: 0;
      background: rgba(30,42,56,0.25);
      backdrop-filter: blur(0px);
    }
    .image-placeholder-icon {
      position: absolute;
      z-index: 2;
      opacity: 0.6;
      font-size: 4rem;
      color: white;
    }

    /* 板块标题 */
    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      margin-bottom: 0.5rem;
      color: var(--primary);
    }
    .section-sub {
      font-size: 1.1rem;
      color: #64748b;
      margin-bottom: 2.5rem;
    }

    /* 服务卡片 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 1.5rem;
    }
    .service-card {
      background: var(--card);
      padding: 2rem;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 1px solid #f1f5f9;
      display: flex;
      flex-direction: column;
      gap: 1rem;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    .icon-circle {
      width: 48px;
      height: 48px;
      background: rgba(241,143,1,0.1);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent);
      font-size: 1.8rem;
    }
    .service-card h3 {
      font-size: 1.4rem;
      font-weight: 600;
    }
    .service-card p {
      color: #475569;
      font-size: 0.95rem;
    }

    /* 数据 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.5rem;
      background: #f8fafc;
      padding: 2.5rem;
      border-radius: 24px;
    }
    .stat-item h4 {
      font-size: 2.4rem;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }
    .stat-item p {
      color: #334155;
      font-weight: 500;
    }

    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.5rem;
    }
    .case-card {
      background: white;
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
    }
    .case-img {
      height: 180px;
      background-color: #e0e4e8;
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .case-img.cover1 { background-image: url('/assets/images/coverpic/cover-1.webp'); }
    .case-img.cover2 { background-image: url('/assets/images/coverpic/cover-2.webp'); }
    .case-img.cover3 { background-image: url('/assets/images/coverpic/cover-3.webp'); }
    .case-content {
      padding: 1.5rem;
    }

    /* 解决方案 */
    .solution-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2.5rem;
      align-items: center;
    }
    .solution-image {
      background: #e0e4e8 url('/assets/images/backpic/back-2.webp') center/cover;
      height: 320px;
      border-radius: 20px;
    }

    /* FAQ */
    .faq-list {
      display: flex;
      flex-direction: column;
      gap: 0.8rem;
    }
    .faq-item {
      background: white;
      border-radius: 12px;
      padding: 0.8rem 1.5rem;
      box-shadow: 0 2px 8px rgba(0,0,0,0.03);
      border-left: 4px solid var(--accent);
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: #475569;
      margin-top: 0;
    }
    .faq-item.open .faq-answer {
      max-height: 150px;
      margin-top: 0.8rem;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: var(--dark-bg);
      text-align: center;
      padding: 5rem 1rem;
      color: white;
    }
    .cta-banner h2 {
      font-size: 2.2rem;
      margin-bottom: 1rem;
    }

    /* 页脚 */
    .footer {
      background: #1E2A38;
      color: #cbd5e1;
      padding: 3rem 0 1.5rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
    }
    .footer a {
      color: #94a3b8;
      text-decoration: none;
    }
    .footer a:hover { color: var(--accent); }
    .copyright {
      border-top: 1px solid #334155;
      margin-top: 2rem;
      padding-top: 1.5rem;
      text-align: center;
      font-size: 0.85rem;
      color: #64748b;
    }

    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .hero-image { height: 280px; }
      .cases-grid { grid-template-columns: repeat(2,1fr); }
    }

    @media (max-width: 768px) {
      .app-sidebar { display: none; }
      .mobile-header { display: flex; }
      .main-content { margin-left: 0; width: 100%; }
      .container { padding: 0 1.5rem; }
      .hero { min-height: auto; padding: 5rem 0 2rem; }
      .hero h1 { font-size: 2rem; }
      .cards-grid, .cases-grid, .stats-grid, .solution-row, .footer-grid {
        grid-template-columns: 1fr;
      }
      .stats-grid { grid-template-columns: 1fr 1fr; }
      .section-title { font-size: 1.8rem; }
    }