/* roulang page: index */
:root {
      --primary: #1B3A5C;
      --primary-dark: #152E4A;
      --accent: #C8A96E;
      --accent-dark: #B3934F;
      --bg: #F7F5F0;
      --bg-dark: #0F1F2E;
      --text-primary: #2C2416;
      --text-secondary: #6B6255;
      --text-light: #A69F94;
      --border-light: #E4DFD5;
      --card-bg: #FFFFFF;
      --radius-card: 8px;
      --radius-btn: 6px;
      --shadow-card: 0 2px 12px rgba(27, 58, 92, 0.06);
      --shadow-card-hover: 0 8px 28px rgba(27, 58, 92, 0.12);
      --shadow-btn: 0 4px 10px rgba(27, 58, 92, 0.08);
      --shadow-btn-hover: 0 8px 18px rgba(27, 58, 92, 0.15);
      --transition-smooth: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }

    * {
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
      scroll-padding-top: 80px;
    }

    body {
      margin: 0;
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", system-ui, sans-serif;
      background-color: var(--bg);
      color: var(--text-primary);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

    a {
      color: inherit;
      text-decoration: none;
    }

    button, input, textarea {
      font-family: inherit;
    }

    .container-custom {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    @media (min-width: 640px) {
      .container-custom {
        padding-left: 24px;
        padding-right: 24px;
      }
    }
    @media (min-width: 1024px) {
      .container-custom {
        padding-left: 32px;
        padding-right: 32px;
      }
    }

    .top-bar {
      background-color: #EFECE6;
      font-size: 0.8rem;
      height: 38px;
    }

    .nav-blur {
      background-color: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(27, 58, 92, 0.05);
    }

    .nav-link {
      position: relative;
      font-weight: 500;
      padding-bottom: 4px;
      transition: color var(--transition-smooth);
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background-color: var(--accent);
      transition: width var(--transition-smooth);
    }
    .nav-link:hover::after,
    .nav-link-active::after {
      width: 100%;
    }
    .nav-link-active {
      color: var(--primary);
    }

    .hero-overlay {
      background: linear-gradient(90deg, rgba(27,58,92,0.75) 0%, rgba(15,31,46,0.45) 60%, rgba(15,31,46,0.1) 100%);
    }

    .btn-primary {
      background-color: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 500;
      box-shadow: var(--shadow-btn);
      transition: all var(--transition-smooth);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background-color: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: var(--shadow-btn-hover);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-btn);
      padding: 11px 27px;
      font-weight: 500;
      transition: all var(--transition-smooth);
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background-color: var(--primary);
      color: white;
    }

    .card-service {
      background-color: var(--card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      padding: 28px;
      transition: all var(--transition-smooth);
      display: flex;
      flex-direction: column;
      border-top: 3px solid transparent;
    }
    .card-service:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-3px);
      border-top-color: var(--accent);
    }

    .card-case {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: all var(--transition-smooth);
    }
    .card-case:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    .card-case:hover img {
      transform: scale(1.04);
    }
    .card-case img {
      transition: transform 0.4s ease;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      background-color: #FAF9F6;
      padding: 18px 20px;
      font-weight: 600;
      font-size: 1.05rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      transition: background-color 0.2s;
    }
    .faq-question:hover {
      background-color: #F3F1EB;
    }
    .faq-answer {
      padding: 0 20px;
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s ease;
      background-color: white;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      padding: 16px 20px;
      max-height: 300px;
    }
    .faq-icon {
      transition: transform 0.3s ease;
      color: var(--accent);
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    .input-field {
      background-color: #F0EDE6;
      border: none;
      border-bottom: 2px solid transparent;
      padding: 14px 16px;
      border-radius: 6px 6px 0 0;
      width: 100%;
      transition: all 0.2s;
      font-size: 1rem;
      color: var(--text-primary);
    }
    .input-field:focus {
      outline: none;
      border-bottom-color: var(--accent);
      background-color: #EDE9E0;
    }
    .input-field::placeholder {
      color: #B7AFA2;
    }

    .footer-dark {
      background-color: var(--bg-dark);
      color: #D1D5DB;
    }
    .footer-dark a:hover {
      color: var(--accent);
    }

    .number-highlight {
      color: var(--primary);
    }
    .accent-line {
      height: 2px;
      background-color: var(--accent);
      width: 60px;
      margin: 16px 0;
    }

    @media (max-width: 768px) {
      .mobile-menu {
        display: none;
        position: fixed;
        top: 0;
        right: 0;
        width: 75%;
        max-width: 320px;
        height: 100vh;
        background-color: var(--bg-dark);
        z-index: 50;
        flex-direction: column;
        padding: 80px 24px 30px;
        box-shadow: -10px 0 30px rgba(0,0,0,0.2);
        transform: translateX(100%);
        transition: transform 0.3s ease;
      }
      .mobile-menu.open {
        display: flex;
        transform: translateX(0);
      }
      .mobile-menu a {
        color: white;
        font-size: 1.1rem;
        padding: 14px 0;
        border-bottom: 1px solid rgba(255,255,255,0.1);
        display: block;
        font-weight: 500;
      }
    }