/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --primary-dark: #0F3B4B;
      --accent: #E8A317;
      --bg-light: #F8FAFB;
      --card-bg: #FFFFFF;
      --text-main: #2C3E50;
      --text-secondary: #5A6C7D;
      --border-color: #E0E6EB;
      --footer-bg: #1A2F3A;
      --footer-text: #B0BEC5;
      --shadow-card: 0 2px 16px rgba(26, 95, 122, 0.08);
      --shadow-hover: 0 8px 30px rgba(26, 95, 122, 0.15);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --transition-base: all 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.7;
      margin: 0;
      padding: 0;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      color: var(--primary);
      text-decoration: none;
      transition: var(--transition-base);
    }
    a:hover {
      color: var(--accent);
    }

    /* 导航栏 */
    .navbar {
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(10px);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      height: 64px;
      padding: 0 1.5rem;
    }
    .navbar-brand {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--primary) !important;
      letter-spacing: 1px;
      white-space: nowrap;
    }
    .navbar .nav-link {
      font-size: 1rem;
      color: var(--text-main) !important;
      margin: 0 0.25rem;
      padding: 0.5rem 0.75rem;
      border-bottom: 2px solid transparent;
      transition: var(--transition-base);
      font-weight: 500;
    }
    .navbar .nav-link:hover,
    .navbar .nav-link.active {
      color: var(--primary) !important;
      border-bottom-color: var(--primary);
    }
    .navbar-toggler {
      border: none;
      color: var(--primary);
    }
    .navbar-toggler-icon {
      background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='%231A5F7A' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
    }

    @media (max-width: 991.98px) {
      .navbar-collapse {
        background: white;
        padding: 1rem;
        border-radius: 12px;
        box-shadow: 0 8px 24px rgba(0,0,0,0.08);
        margin-top: 0.5rem;
      }
    }

    /* 容器 */
    .container-custom {
      max-width: 1140px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 区块间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }

    /* Hero */
    #hero {
      position: relative;
      min-height: 85vh;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      display: flex;
      align-items: center;
      color: white;
      overflow: hidden;
    }
    #hero::before {
      content: '';
      position: absolute;
      top: 0; left: 0; right: 0; bottom: 0;
      background: linear-gradient(135deg, rgba(15, 59, 75, 0.8) 0%, rgba(26, 95, 122, 0.65) 100%);
      z-index: 1;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
    }
    .hero-title {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 1.5rem;
    }
    .hero-subtitle {
      font-size: 1.25rem;
      margin-bottom: 2rem;
      opacity: 0.9;
    }
    .btn-primary-custom {
      background: var(--primary);
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      color: white;
      box-shadow: 0 4px 12px rgba(26,95,122,0.2);
      transition: var(--transition-base);
    }
    .btn-primary-custom:hover {
      background: #124b61;
      filter: brightness(1.05);
      color: white;
    }
    .btn-outline-custom {
      background: transparent;
      border: 2px solid white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      color: white;
      transition: var(--transition-base);
    }
    .btn-outline-custom:hover {
      background: rgba(255,255,255,0.15);
      color: white;
    }
    @media (max-width: 768px) {
      .hero-title {
        font-size: 2.2rem;
      }
      #hero {
        min-height: 70vh;
      }
    }

    /* 卡片通用 */
    .card-custom {
      background: var(--card-bg);
      border: none;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      padding: 28px 24px;
      transition: var(--transition-base);
      height: 100%;
    }
    .card-custom:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      width: 48px;
      height: 48px;
      background: var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 1.3rem;
      margin-bottom: 1.2rem;
    }

    /* 数据条 */
    .data-strip {
      background: var(--primary-dark);
      color: white;
      padding: 60px 0;
    }
    .data-number {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }
    .data-label {
      color: rgba(255,255,255,0.7);
      font-size: 1rem;
    }

    /* 服务卡片混合布局 */
    .service-card-wide {
      background: #f0f4f7;
      border-radius: var(--radius-card);
      padding: 32px;
      margin-bottom: 1.5rem;
    }

    /* 案例交替 */
    .case-block {
      margin-bottom: 3rem;
    }
    .case-img {
      border-radius: 12px;
      overflow: hidden;
    }

    /* FAQ */
    .accordion-button {
      font-weight: 600;
      background: white;
      border: 1px solid var(--border-color);
      border-radius: 8px !important;
      padding: 16px 20px;
      color: var(--text-main);
    }
    .accordion-button:not(.collapsed) {
      background: rgba(26,95,122,0.04);
      border-color: var(--primary);
      color: var(--primary);
      box-shadow: none;
    }
    .accordion-body {
      padding: 16px 20px;
      color: var(--text-secondary);
      line-height: 1.8;
    }

    /* 表单 */
    .form-control {
      border: 1px solid var(--border-color);
      border-radius: var(--radius-input);
      padding: 12px 16px;
      height: 48px;
    }
    .form-control:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(26,95,122,0.15);
    }
    .btn-submit {
      background: var(--primary);
      color: white;
      font-weight: 600;
      padding: 12px 24px;
      border-radius: var(--radius-btn);
      border: none;
    }

    /* 页脚 */
    footer {
      background: var(--footer-bg);
      color: var(--footer-text);
      padding: 50px 0 20px;
    }
    footer a {
      color: #cfd8dc;
    }
    footer a:hover {
      color: var(--accent);
    }
    .copyright {
      background: #152732;
      padding: 15px 0;
      font-size: 0.9rem;
    }