/* roulang page: index */
:root {
      --primary: #0B3B5E;
      --secondary: #00B4A6;
      --accent: #FF6B35;
      --bg-light: #F7F9FC;
      --bg-white: #FFFFFF;
      --bg-dark: #0A2A3F;
      --text-primary: #0B3B5E;
      --text-body: #333333;
      --text-muted: #666666;
      --text-light: #B0C4D1;
      --text-on-dark: #FFFFFF;
      --border-light: #E1E5EB;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
      --transition: all 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-body);
      margin: 0;
      padding: 0;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    a {
      color: var(--secondary);
      text-decoration: none;
      transition: var(--transition);
    }
    a:hover {
      color: #00998C;
      text-decoration: none;
    }

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

    button, .button {
      font-family: var(--font-sans);
      cursor: pointer;
    }

    h1, h2, h3, h4, h5, h6 {
      font-family: var(--font-sans);
      color: var(--text-primary);
      margin-top: 0;
      font-weight: 600;
      line-height: 1.3;
    }
    h1 { font-size: 2.5rem; font-weight: 700; }
    h2 { font-size: 2rem; font-weight: 700; }
    h3 { font-size: 1.5rem; font-weight: 600; }
    h4 { font-size: 1.2rem; font-weight: 600; }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    /* top bar */
    .top-bar-top {
      background: #0A2A3F;
      color: #CCCCCC;
      font-size: 0.85rem;
      padding: 8px 0;
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .top-bar-top .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
    }
    .top-bar-top a {
      color: #CCCCCC;
      margin-left: 1.2rem;
      transition: color 0.2s;
    }
    .top-bar-top a:hover {
      color: var(--secondary);
    }
    .top-bar-top .phone-link i {
      margin-right: 5px;
      color: var(--secondary);
    }

    /* main nav */
    .main-nav {
      background: #FFFFFF;
      padding: 0.7rem 0;
      position: sticky;
      top: 0;
      z-index: 100;
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      transition: box-shadow 0.3s;
    }
    .main-nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
    }
    .logo i {
      color: var(--secondary);
      margin-right: 10px;
      font-size: 2rem;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      color: var(--text-primary);
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      padding-bottom: 6px;
      transition: color 0.2s;
    }
    .nav-links a:after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 3px;
      background: var(--secondary);
      transition: width 0.25s;
    }
    .nav-links a:hover {
      color: var(--secondary);
    }
    .nav-links a:hover:after {
      width: 100%;
    }
    .btn-primary {
      background: var(--secondary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      border: none;
      transition: var(--transition);
      display: inline-block;
      text-align: center;
      box-shadow: 0 4px 10px rgba(0,180,166,0.25);
    }
    .btn-primary:hover {
      background: #00998C;
      color: white;
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(0,180,166,0.3);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--secondary);
      color: var(--secondary);
      padding: 10px 26px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
      display: inline-block;
    }
    .btn-outline:hover {
      background: var(--secondary);
      color: white;
      transform: translateY(-2px);
    }
    .btn-large {
      padding: 16px 40px;
      font-size: 1.1rem;
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: var(--primary);
      background: none;
      border: none;
      cursor: pointer;
    }
    @media (max-width: 1024px) {
      .nav-links {
        gap: 1.2rem;
      }
    }
    @media (max-width: 768px) {
      .hamburger {
        display: block;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 1.5rem;
        box-shadow: var(--shadow-md);
        border-radius: 0 0 12px 12px;
        gap: 1rem;
      }
      .nav-links.active {
        display: flex;
      }
    }

    /* hero */
    #hero {
      background: radial-gradient(circle at 70% 30%, #0B3B5E, #051E30);
      color: white;
      padding: 80px 0 60px;
      position: relative;
      overflow: hidden;
    }
    #hero::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 600" opacity="0.08"><path d="M0 400 Q200 300 400 450 T800 350 T1200 400" stroke="%2300B4A6" fill="none" stroke-width="2"/><path d="M0 500 Q300 400 600 550 T1200 480" stroke="%2300B4A6" fill="none" stroke-width="1.5"/></svg>') repeat;
      pointer-events: none;
    }
    .hero-content {
      display: flex;
      align-items: center;
      gap: 3rem;
      position: relative;
      z-index: 2;
    }
    .hero-text {
      flex: 0 0 55%;
    }
    .hero-text h1 {
      color: white;
      font-size: 2.8rem;
      margin-bottom: 1.2rem;
    }
    .hero-text p {
      font-size: 1.15rem;
      color: rgba(255,255,255,0.85);
      margin-bottom: 2rem;
    }
    .hero-image {
      flex: 1;
      text-align: center;
    }
    .hero-image img {
      max-height: 360px;
      border-radius: 20px;
      box-shadow: 0 20px 35px rgba(0,0,0,0.5);
      border: 2px solid rgba(255,255,255,0.15);
    }
    @media (max-width: 768px) {
      .hero-content {
        flex-direction: column;
      }
      .hero-text h1 {
        font-size: 2.2rem;
      }
    }

    /* sections */
    section {
      padding: 80px 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 3rem;
    }
    .section-title h2 {
      color: var(--primary);
    }
    .section-title p {
      color: var(--text-muted);
      max-width: 700px;
      margin: 0 auto;
    }

    /* features cards */
    .feature-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      border-left: 5px solid var(--secondary);
      transition: var(--transition);
      margin-bottom: 30px;
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
      border-left-width: 6px;
    }
    .feature-card h4 {
      margin-bottom: 8px;
    }
    .metric {
      font-weight: 700;
      color: var(--accent);
      margin-top: 12px;
      font-size: 1.1rem;
    }

    /* alternating rows */
    .alt-row {
      display: flex;
      align-items: center;
      gap: 2.5rem;
      margin-bottom: 60px;
    }
    .alt-row.reverse {
      flex-direction: row-reverse;
    }
    .alt-img img {
      border-radius: 16px;
      box-shadow: var(--shadow-sm);
      width: 100%;
    }
    .tag {
      background: #E8F4F3;
      color: var(--primary);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      margin-right: 6px;
    }
    @media (max-width: 768px) {
      .alt-row, .alt-row.reverse {
        flex-direction: column;
      }
    }

    /* scenario cards */
    .scene-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      margin-bottom: 30px;
    }
    .scene-img {
      height: 180px;
      overflow: hidden;
    }
    .scene-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s;
    }
    .scene-card:hover .scene-img img {
      transform: scale(1.06);
    }
    .scene-card:hover {
      box-shadow: var(--shadow-md);
    }
    .scene-body {
      padding: 20px;
    }

    /* case logos */
    .logo-wall img {
      filter: grayscale(100%) opacity(0.65);
      transition: var(--transition);
      max-height: 50px;
      margin: 15px;
    }
    .logo-wall img:hover {
      filter: grayscale(0%) opacity(1);
    }

    /* pricing */
    .pricing-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      text-align: center;
      position: relative;
      transition: var(--transition);
    }
    .pricing-card.featured {
      border: 2px solid var(--secondary);
      background: #F0FAF9;
    }
    .badge {
      background: var(--accent);
      color: white;
      padding: 6px 18px;
      border-radius: 20px;
      font-size: 0.8rem;
      position: absolute;
      top: -12px;
      left: 50%;
      transform: translateX(-50%);
    }
    .price {
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--primary);
    }

    /* faq */
    .accordion-title {
      background: #F7F9FC;
      border-radius: 8px;
      padding: 16px 20px;
      font-weight: 600;
      transition: background 0.2s;
    }
    .accordion-title:hover {
      background: #E8F4F3;
    }
    .accordion-item.is-active .accordion-title {
      color: var(--secondary);
      border-left: 4px solid var(--secondary);
    }

    /* cta banner */
    .cta-banner {
      background: #0A2A3F;
      color: white;
      padding: 70px 0;
      text-align: center;
      position: relative;
    }

    /* footer */
    .footer {
      background: #0A2A3F;
      color: #B0C4D1;
      padding: 60px 0 20px;
    }
    .footer a {
      color: #B0C4D1;
    }
    .footer a:hover {
      color: var(--secondary);
    }
    .social-icons i {
      font-size: 1.4rem;
      margin-right: 14px;
      border: 1px solid #B0C4D1;
      padding: 8px;
      border-radius: 50%;
      transition: 0.2s;
    }
    .social-icons i:hover {
      background: var(--secondary);
      border-color: var(--secondary);
      color: white;
    }

    @media (max-width: 640px) {
      section { padding: 50px 0; }
      h1 { font-size: 2rem; }
      .btn-large { padding: 14px 30px; }
    }