/* roulang page: index */
:root {
      --primary: #1A56DB;
      --primary-hover: #1A47C4;
      --accent: #F97316;
      --accent-hover: #EA580C;
      --dark-bg: #0F172A;
      --text-main: #0F172A;
      --text-secondary: #475569;
      --white: #FFFFFF;
      --bg-light: #F8FAFC;
      --border-light: #E2E8F0;
      --success: #10B981;
      --danger: #EF4444;
      --bs-primary: #1A56DB;
      --bs-primary-rgb: 26, 86, 219;
      --bs-border-radius: 8px;
      --bs-card-border-radius: 12px;
      --shadow-sm: 0 4px 12px rgba(15, 23, 42, 0.06);
      --shadow-lg: 0 12px 28px rgba(15, 23, 42, 0.10);
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-english: 'Inter', var(--font-sans);
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      color: var(--text-main);
      background-color: var(--white);
      line-height: 1.7;
      margin: 0;
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4, .english-number {
      font-family: var(--font-english);
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container-xl {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
    }
    /* 导航区 */
    #nav {
      position: sticky;
      top: 0;
      z-index: 1020;
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      transition: all 0.2s ease;
    }
    .brand-row {
      background: var(--white);
      padding: 8px 0;
      border-bottom: 1px solid var(--border-light);
    }
    .brand-text {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
    }
    .brand-text i {
      color: var(--accent);
      margin-right: 8px;
      font-size: 1.8rem;
    }
    .quick-contact {
      font-size: 0.9rem;
      color: var(--text-secondary);
      display: flex;
      align-items: center;
      gap: 20px;
    }
    .quick-contact i {
      color: var(--primary);
      margin-right: 4px;
    }
    .channel-row .nav-link {
      font-weight: 500;
      color: var(--text-secondary);
      padding: 12px 16px;
      border-bottom: 3px solid transparent;
      transition: all 0.2s;
      font-size: 0.95rem;
    }
    .channel-row .nav-link:hover,
    .channel-row .nav-link.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .navbar-toggler {
      border: none;
      color: var(--primary);
    }
    .navbar-toggler:focus {
      box-shadow: none;
    }
    @media (max-width: 992px) {
      .channel-row .navbar-collapse {
        background: rgba(255,255,255,0.95);
        backdrop-filter: blur(12px);
        padding: 12px;
        border-radius: 12px;
        margin-top: 8px;
      }
      .channel-row .nav-link {
        border-bottom: none;
        padding: 10px 12px;
      }
    }
    /* Hero */
    #hero {
      background: linear-gradient(135deg, #F8FAFC 0%, #E2E8F0 100%);
      position: relative;
      overflow: hidden;
      padding: 60px 0;
    }
    #hero::after {
      content: "";
      position: absolute;
      right: -100px;
      top: -80px;
      width: 400px;
      height: 400px;
      background: radial-gradient(circle, rgba(249,115,22,0.25) 0%, rgba(249,115,22,0) 70%);
      border-radius: 50%;
      z-index: 0;
    }
    .hero-content {
      position: relative;
      z-index: 2;
    }
    .hero-title {
      font-size: 2.75rem;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--text-main);
      margin-bottom: 1.2rem;
    }
    .hero-subtitle {
      font-size: 1.1rem;
      color: var(--text-secondary);
      max-width: 500px;
      margin-bottom: 2rem;
    }
    .btn-primary-custom {
      background: var(--primary);
      border: none;
      color: white;
      border-radius: 8px;
      padding: 12px 28px;
      font-weight: 600;
      transition: 0.2s ease;
    }
    .btn-primary-custom:hover {
      background: var(--primary-hover);
      transform: scale(1.02);
      color: white;
    }
    .btn-outline-primary-custom {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      border-radius: 8px;
      padding: 12px 28px;
      font-weight: 600;
      transition: 0.2s ease;
    }
    .btn-outline-primary-custom:hover {
      background: var(--primary);
      color: white;
    }
    .hero-illustration {
      position: relative;
      z-index: 2;
      animation: float 6s ease-in-out infinite;
    }
    @keyframes float {
      0% { transform: translateY(0px); }
      50% { transform: translateY(-12px); }
      100% { transform: translateY(0px); }
    }
    /* 亮点卡片 */
    .highlight-card {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: 12px;
      padding: 24px;
      transition: all 0.2s ease;
      box-shadow: var(--shadow-sm);
    }
    .highlight-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
    }
    .icon-circle {
      width: 56px;
      height: 56px;
      background: var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 24px;
      margin-bottom: 16px;
      transition: 0.2s;
    }
    .highlight-card:hover .icon-circle {
      background: var(--accent);
      box-shadow: 0 0 16px rgba(249,115,22,0.5);
    }
    /* 案例瀑布 */
    .case-card {
      border-radius: 12px;
      overflow: hidden;
      background: white;
      border: 1px solid var(--border-light);
      box-shadow: var(--shadow-sm);
      transition: 0.2s;
      margin-bottom: 20px;
      break-inside: avoid;
    }
    .case-card:hover {
      transform: translateY(-3px);
      box-shadow: var(--shadow-lg);
    }
    .case-img-wrap {
      position: relative;
      overflow: hidden;
    }
    .case-img-wrap img {
      transition: 0.3s ease;
    }
    .case-card:hover .case-img-wrap img {
      transform: scale(1.03);
      filter: brightness(1.05);
    }
    .case-tag {
      position: absolute;
      top: 12px;
      left: 12px;
      background: rgba(249,115,22,0.9);
      color: white;
      padding: 4px 12px;
      border-radius: 6px;
      font-size: 0.8rem;
      font-weight: 600;
    }
    .case-body {
      padding: 20px;
    }
    /* 方案对比 */
    .compare-traditional {
      background: #F1F5F9;
      border-radius: 12px;
      padding: 24px;
    }
    .compare-thunder {
      background: #EBF0FF;
      border-radius: 12px;
      padding: 24px;
      border: 1px solid #BFDBFE;
    }
    .compare-row {
      display: flex;
      justify-content: space-between;
      padding: 10px 0;
      border-bottom: 1px solid var(--border-light);
    }
    .mark-bad {
      color: var(--danger);
      font-weight: 600;
    }
    .mark-good {
      color: var(--success);
      font-weight: 600;
    }
    /* FAQ */
    .accordion-button:not(.collapsed) {
      background-color: #F0F4FF;
      color: var(--primary);
      font-weight: 600;
    }
    .accordion-button:focus {
      box-shadow: none;
      border-color: var(--primary);
    }
    .faq-icon {
      color: var(--accent);
      margin-right: 12px;
      transition: transform 0.2s;
    }
    .accordion-button:not(.collapsed) .faq-icon {
      transform: rotate(45deg);
    }
    /* CTA */
    #contact {
      background: var(--dark-bg);
      color: white;
    }
    .btn-accent {
      background: var(--accent);
      border: none;
      color: white;
      border-radius: 8px;
      padding: 14px 32px;
      font-weight: 600;
      transition: 0.2s;
    }
    .btn-accent:hover {
      background: var(--accent-hover);
      box-shadow: 0 8px 18px rgba(249,115,22,0.4);
      color: white;
    }
    .form-control {
      border-radius: 8px;
      border: 1px solid var(--border-light);
      padding: 12px;
    }
    /* Footer */
    footer a {
      color: #CBD5E1;
      transition: color 0.2s;
    }
    footer a:hover {
      color: white;
    }
    @media (max-width: 576px) {
      .hero-title {
        font-size: 2rem;
      }
    }