/* roulang page: index */
:root {
      --bs-primary: #D4A843;
      --bs-primary-hover: #B88A2E;
      --bs-dark: #1E1E1E;
      --bs-body-bg: #F8F9FA;
      --bs-border-radius: 0.75rem;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", system-ui, -apple-system, sans-serif;
      --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.06);
      --shadow-hover: 0 12px 28px rgba(0, 0, 0, 0.12);
      --text-primary: #1E1E1E;
      --text-secondary: #4B4B4B;
      --border-light: #E9ECEF;
      --transition: all 0.2s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bs-body-bg);
      color: var(--text-primary);
      line-height: 1.7;
      font-size: 1rem;
      scroll-behavior: smooth;
      margin: 0;
      padding: 0;
    }

    h1, h2, h3, h4, h5, h6 {
      font-weight: 700;
      line-height: 1.3;
    }

    h1 {
      font-size: 2.5rem;
      letter-spacing: -0.02em;
      margin-bottom: 1rem;
    }

    h2 {
      font-size: 1.8rem;
      font-weight: 600;
      margin-bottom: 1.5rem;
    }

    h3 {
      font-size: 1.25rem;
      font-weight: 600;
    }

    a {
      color: var(--bs-primary);
      text-decoration: none;
      transition: var(--transition);
    }

    a:hover {
      color: var(--bs-primary-hover);
    }

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

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

    /* 按钮系统 */
    .btn-primary {
      background: linear-gradient(135deg, #D4A843 0%, #C69C3A 100%);
      border: none;
      border-radius: 30px;
      padding: 0.75rem 2.2rem;
      font-weight: 600;
      color: white;
      transition: var(--transition);
      box-shadow: 0 4px 12px rgba(212, 168, 67, 0.3);
      letter-spacing: 0.3px;
    }

    .btn-primary:hover, .btn-primary:focus {
      background: var(--bs-primary-hover);
      box-shadow: 0 8px 20px rgba(184, 138, 46, 0.4);
      color: white;
      transform: translateY(-2px);
    }

    .btn-outline-primary {
      border: 2px solid var(--bs-primary);
      background: transparent;
      color: var(--bs-primary);
      border-radius: 30px;
      padding: 0.65rem 2rem;
      font-weight: 600;
      transition: var(--transition);
    }

    .btn-outline-primary:hover {
      background: rgba(212, 168, 67, 0.08);
      border-color: var(--bs-primary-hover);
      color: var(--bs-primary-hover);
      transform: translateY(-2px);
    }

    /* 导航栏卡片化 */
    .navbar {
      background: rgba(255, 255, 255, 0.9);
      backdrop-filter: blur(8px);
      box-shadow: var(--shadow-sm);
      border-radius: 0 0 20px 20px;
      padding: 0.8rem 1.5rem;
      margin: 0 auto;
      max-width: 1300px;
      top: 10px;
      left: 0;
      right: 0;
      position: fixed;
      z-index: 1030;
      transition: var(--transition);
    }

    .navbar-brand {
      font-weight: 700;
      font-size: 1.5rem;
      letter-spacing: 1px;
      color: var(--bs-dark) !important;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }

    .navbar-brand i {
      color: var(--bs-primary);
      font-size: 1.8rem;
    }

    .nav-link {
      color: var(--text-secondary) !important;
      font-weight: 500;
      margin: 0 0.3rem;
      padding: 0.6rem 1rem !important;
      border-radius: 30px;
      transition: var(--transition);
      background: transparent;
    }

    .nav-link:hover, .nav-link.active {
      background: rgba(212, 168, 67, 0.1);
      color: var(--bs-primary) !important;
    }

    .navbar-toggler {
      border: none;
      box-shadow: none;
    }

    .navbar-toggler:focus {
      box-shadow: none;
    }

    /* 移动端菜单全屏卡片 */
    @media (max-width: 991px) {
      .navbar-collapse {
        background: white;
        border-radius: 24px;
        box-shadow: var(--shadow-hover);
        padding: 2rem 1.5rem;
        margin-top: 1rem;
        position: absolute;
        top: 70px;
        left: 10px;
        right: 10px;
        z-index: 1040;
      }
    }

    /* Hero */
    .hero {
      background: linear-gradient(rgba(30, 30, 30, 0.75), rgba(30, 30, 30, 0.7)), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 90vh;
      display: flex;
      align-items: center;
      color: white;
      border-radius: 0 0 60px 60px;
      margin-top: 70px;
      text-align: center;
      position: relative;
    }

    .hero h1 {
      font-size: 3.2rem;
      font-weight: 700;
      text-shadow: 0 4px 12px rgba(0,0,0,0.5);
      line-height: 1.2;
    }

    .hero .lead {
      font-size: 1.25rem;
      opacity: 0.9;
      margin-bottom: 2rem;
    }

    /* 通用卡片 */
    .card-custom {
      background: white;
      border-radius: 20px;
      box-shadow: var(--shadow-sm);
      border: none;
      transition: var(--transition);
      height: 100%;
    }

    .card-custom:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    .section-title {
      position: relative;
      margin-bottom: 2.5rem;
      font-weight: 700;
    }

    .section-title:after {
      content: '';
      display: block;
      width: 60px;
      height: 4px;
      background: var(--bs-primary);
      margin-top: 0.75rem;
      border-radius: 4px;
    }

    .dark-bg {
      background-color: var(--bs-dark);
      color: white;
      border-radius: 60px 60px 0 0;
    }

    .accordion-button:not(.collapsed) {
      background-color: rgba(212, 168, 67, 0.08);
      color: var(--bs-dark);
      box-shadow: none;
    }

    .accordion-button:focus {
      border-color: var(--bs-primary);
      box-shadow: 0 0 0 0.2rem rgba(212,168,67,0.25);
    }

    .accordion-item {
      border: 1px solid var(--border-light);
      border-radius: 16px !important;
      margin-bottom: 1rem;
      overflow: hidden;
    }

    .footer {
      background: #1E1E1E;
      color: #ccc;
      padding: 3rem 0 1.5rem;
    }

    .footer a {
      color: #aaa;
    }

    .footer a:hover {
      color: var(--bs-primary);
    }

    .back-to-top {
      position: fixed;
      bottom: 30px;
      right: 30px;
      background: var(--bs-primary);
      color: white;
      border-radius: 50%;
      width: 48px;
      height: 48px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.4rem;
      box-shadow: 0 6px 18px rgba(0,0,0,0.2);
      transition: 0.3s;
      z-index: 99;
      border: none;
    }

    .back-to-top:hover {
      background: var(--bs-primary-hover);
      transform: rotate(90deg);
    }

    @media (max-width: 768px) {
      h1 { font-size: 2rem; }
      .hero h1 { font-size: 2.2rem; }
      .navbar { border-radius: 0 0 16px 16px; }
    }