/* roulang page: index */
:root {
      --primary: #0f2b4a;
      --primary-light: #1c3f5e;
      --accent: #e6a517;
      --accent-soft: #f7d44a;
      --bg-body: #f5f7fb;
      --bg-card: #ffffff;
      --text-main: #1e2b3c;
      --text-soft: #5f6b7a;
      --text-light: #f0f4fc;
      --border-light: #e2e8f0;
      --border-soft: #dce2eb;
      --shadow-sm: 0 4px 10px rgba(0,0,0,0.03), 0 2px 6px rgba(0,0,0,0.04);
      --shadow-card: 0 12px 28px rgba(0,0,0,0.05), 0 4px 12px rgba(0,0,0,0.02);
      --shadow-hover: 0 20px 32px rgba(0,0,0,0.07), 0 8px 16px rgba(0,0,0,0.04);
      --radius-md: 14px;
      --radius-lg: 20px;
      --radius-sm: 10px;
      --spacing-xs: 0.5rem;
      --spacing-sm: 1rem;
      --spacing-md: 1.75rem;
      --spacing-lg: 3rem;
      --spacing-xl: 4.5rem;
      --max-width: 1320px;
      --transition: all 0.25s ease;
      --font-sans: system-ui, -apple-system, 'Segoe UI', 'Inter', 'Roboto', 'Helvetica Neue', sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-body);
      color: var(--text-main);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input {
      font-family: inherit;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 var(--spacing-md);
    }
    /* header/nav */
    .site-header {
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-soft);
      position: sticky;
      top: 0;
      z-index: 50;
      box-shadow: 0 4px 10px rgba(0,0,0,0.02);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      padding: 0.8rem 0;
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-weight: 700;
      font-size: 1.6rem;
      letter-spacing: -0.3px;
      color: var(--primary);
    }
    .logo-icon {
      font-size: 2rem;
      color: var(--accent);
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 2.2rem;
      font-weight: 500;
      color: var(--text-main);
    }
    .nav-menu a {
      position: relative;
      padding: 0.4rem 0;
      transition: var(--transition);
      white-space: nowrap;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary);
    }
    .nav-menu a.active::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -2px;
      width: 100%;
      height: 2.5px;
      background: var(--accent);
      border-radius: 4px;
    }
    .search-cta-group {
      display: flex;
      align-items: center;
      gap: 1rem;
    }
    .search-box {
      display: flex;
      align-items: center;
      background: var(--bg-body);
      border-radius: 40px;
      padding: 0.4rem 1rem;
      border: 1px solid var(--border-light);
      transition: var(--transition);
    }
    .search-box i {
      color: var(--text-soft);
      font-size: 0.9rem;
    }
    .search-box input {
      border: none;
      background: transparent;
      padding: 0.45rem 0.5rem;
      outline: none;
      width: 140px;
      font-size: 0.9rem;
    }
    .btn-primary {
      background: var(--accent);
      color: #0a1a2b;
      font-weight: 600;
      padding: 0.6rem 1.5rem;
      border-radius: 40px;
      border: none;
      cursor: pointer;
      transition: var(--transition);
      box-shadow: 0 6px 14px rgba(230,165,23,0.25);
      white-space: nowrap;
    }
    .btn-primary:hover {
      background: #f5ba2d;
      box-shadow: 0 10px 18px rgba(230,165,23,0.35);
      transform: translateY(-1px);
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.7rem;
      color: var(--primary);
    }
    /* hero */
    .hero {
      background: linear-gradient(136deg, #0b1c2e 0%, #132b42 100%);
      color: white;
      padding: var(--spacing-xl) 0;
      position: relative;
      overflow: hidden;
    }
    .hero-bg-img {
      position: absolute;
      right: 0;
      top: 0;
      width: 50%;
      height: 100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.3;
      mask-image: linear-gradient(to left, rgba(0,0,0,0.7) 20%, transparent 90%);
      -webkit-mask-image: linear-gradient(to left, rgba(0,0,0,0.7) 20%, transparent 90%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      gap: 2.5rem;
      flex-wrap: wrap;
    }
    .hero-text {
      flex: 1 1 500px;
    }
    .hero h1 {
      font-size: clamp(2.5rem, 6vw, 3.8rem);
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1.5rem;
    }
    .hero .accent-text {
      color: var(--accent-soft);
    }
    .hero p {
      font-size: 1.2rem;
      opacity: 0.9;
      margin-bottom: 2rem;
      max-width: 500px;
    }
    .badge-group {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
      margin-top: 1.8rem;
    }
    .badge {
      background: rgba(255,255,255,0.12);
      backdrop-filter: blur(4px);
      padding: 0.5rem 1.4rem;
      border-radius: 30px;
      font-weight: 500;
      display: flex;
      align-items: center;
      gap: 0.4rem;
    }
    /* sections */
    .section {
      padding: var(--spacing-xl) 0;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 640;
      margin-bottom: 0.75rem;
      color: var(--primary);
    }
    .section-sub {
      color: var(--text-soft);
      margin-bottom: 2.8rem;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 2rem;
    }
    .card {
      background: var(--bg-card);
      border-radius: var(--radius-lg);
      padding: 1.8rem;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      border: 1px solid var(--border-light);
    }
    .card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      background: #eef3ff;
      width: 56px;
      height: 56px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 18px;
      color: var(--primary);
      font-size: 1.8rem;
      margin-bottom: 1.5rem;
    }
    .cover-img-card {
      border-radius: var(--radius-md);
      overflow: hidden;
      margin-bottom: 1.2rem;
    }
    .stats-row {
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      background: var(--primary);
      color: white;
      border-radius: var(--radius-lg);
      padding: 2rem 2.2rem;
      margin-top: 2rem;
    }
    .stat-item h3 {
      font-size: 2.3rem;
      font-weight: 700;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 1.2rem 0;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .cta-block {
      background: linear-gradient(105deg, #0f2b4a 0%, #1e3b56 100%);
      border-radius: var(--radius-lg);
      padding: 3rem 2rem;
      text-align: center;
      color: white;
    }
    .footer {
      background: #0b1a27;
      color: #ccd9e6;
      padding: 2.8rem 0;
    }
    .footer a {
      color: #b6c8dd;
    }
    @media (max-width: 1024px) {
      .nav-menu { gap: 1.5rem; }
      .search-box input { width: 100px; }
    }
    @media (max-width: 768px) {
      .hamburger { display: block; }
      .nav-menu, .search-cta-group .search-box {
        display: none;
        flex-direction: column;
        width: 100%;
      }
      .nav-menu.active-mobile {
        display: flex;
        padding: 1rem 0;
      }
      .hero-bg-img { width: 100%; opacity: 0.2; }
    }