/* roulang page: index */
:root {
      --primary: #E60012;
      --primary-dark: #CC0010;
      --secondary: #1A1A2E;
      --accent: #FFB800;
      --light-bg: #F5F5F7;
      --text-primary: #1A1A2E;
      --text-secondary: #6B7280;
      --white: #FFFFFF;
      --border-light: #E5E7EB;
      --shadow-card: 0 4px 6px -1px rgba(0,0,0,0.05), 0 2px 4px -1px rgba(0,0,0,0.03);
      --shadow-card-hover: 0 20px 25px -5px rgba(0,0,0,0.1), 0 10px 10px -5px rgba(0,0,0,0.04);
      --radius-xl: 16px;
      --radius-lg: 12px;
      --radius-pill: 50px;
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.2s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--white);
      color: var(--text-primary);
      line-height: 1.8;
      font-weight: 400;
      font-size: 18px;
      margin: 0;
      overflow-x: hidden;
    }
    h1, h2, h3, h4 {
      font-weight: 700;
    }
    h1 {
      font-size: 56px;
      line-height: 1.2;
      letter-spacing: -0.02em;
      font-weight: 800;
    }
    h2 {
      font-size: 40px;
      line-height: 1.3;
    }
    h3 {
      font-size: 24px;
      line-height: 1.4;
      font-weight: 600;
    }
    .text-body {
      font-size: 18px;
      line-height: 1.8;
      max-width: 75ch;
      color: var(--text-secondary);
    }
    .text-small {
      font-size: 14px;
      line-height: 1.6;
      font-weight: 500;
    }
    .container-custom {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    .section-space {
      margin-top: 120px;
      margin-bottom: 120px;
    }
    .btn-primary {
      background-color: var(--primary);
      color: var(--white);
      border-radius: 50px;
      padding: 14px 32px;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: background 0.2s, transform 0.15s, box-shadow 0.15s;
      text-decoration: none;
      border: none;
      cursor: pointer;
      box-shadow: 0 4px 8px rgba(230,0,18,0.25);
    }
    .btn-primary:hover {
      background-color: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 12px 20px -8px rgba(230,0,18,0.35);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      border-radius: 50px;
      padding: 12px 32px;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      transition: all 0.2s;
      text-decoration: none;
    }
    .btn-outline:hover {
      background-color: rgba(230,0,18,0.08);
      transform: translateY(-2px);
    }
    .card {
      background: var(--white);
      border-radius: var(--radius-xl);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: box-shadow 0.25s, transform 0.2s;
      height: 100%;
    }
    .card:hover {
      box-shadow: var(--shadow-card-hover);
    }
    .card-sm {
      border-radius: var(--radius-lg);
      padding: 24px;
    }
    .nav-link {
      color: rgba(255,255,255,0.9);
      font-weight: 500;
      transition: color 0.2s;
      text-decoration: none;
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .nav-active {
      color: var(--primary) !important;
      border-bottom: 2px solid var(--primary);
      padding-bottom: 4px;
    }
    .mobile-nav .nav-link {
      color: var(--text-primary);
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 16px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, margin 0.3s;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    .faq-item.active .faq-indicator {
      background-color: var(--accent);
      width: 4px;
    }
    .faq-indicator {
      width: 4px;
      height: 20px;
      background-color: var(--primary);
      margin-right: 16px;
      transition: background 0.2s;
      border-radius: 2px;
    }
    .input-underline {
      background: transparent;
      border: none;
      border-bottom: 1px solid #D1D5DB;
      padding: 12px 4px;
      width: 100%;
      font-size: 16px;
      transition: border 0.2s;
    }
    .input-underline:focus {
      outline: none;
      border-bottom: 2px solid var(--primary);
    }
    .service-card img {
      transition: transform 0.3s ease;
      height: 200px;
      object-fit: cover;
      width: 100%;
      border-radius: 12px 12px 0 0;
    }
    .service-card:hover img {
      transform: scale(1.03);
    }
    .arrow-link {
      transition: transform 0.2s;
    }
    .service-card:hover .arrow-link {
      transform: translateX(4px);
    }
    @media (max-width: 768px) {
      h1 { font-size: 40px; }
      h2 { font-size: 32px; }
      h3 { font-size: 20px; }
      .section-space {
        margin-top: 80px;
        margin-bottom: 80px;
      }
      .card {
        padding: 24px;
      }
    }
    .nav-scrolled {
      background: rgba(26,26,46,0.92) !important;
      backdrop-filter: blur(16px);
    }
    .mobile-bottom-nav {
      background: white;
      box-shadow: 0 -2px 12px rgba(0,0,0,0.08);
    }