/* roulang page: index */
:root {
      --primary-deep: #1E2D2F;
      --accent-gold: #D4A843;
      --electric-cyan: #00B4B4;
      --bg-warm: #FAF8F5;
      --white: #FFFFFF;
      --light-cyan-bg: #F0F6F6;
      --border-light: #E5E0DA;
      --text-muted: #5A6A6C;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.10);
      --border-radius-lg: 16px;
      --border-radius-md: 10px;
      --border-radius-pill: 30px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      --font-numbers: "Inter", "Segoe UI", system-ui;
      --transition-base: 0.25s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--primary-deep);
      line-height: 1.75;
      margin: 0;
      padding-left: 240px;
      transition: padding-left 0.3s;
    }
    h1, h2, h3, h4 {
      font-weight: 600;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    /* 左侧竖向导航 */
    .vertical-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: 240px;
      height: 100vh;
      background-color: var(--primary-deep);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      padding: 2rem 1.5rem;
      z-index: 1040;
      box-shadow: 2px 0 12px rgba(0,0,0,0.15);
      transition: transform 0.3s;
    }
    .nav-brand {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--accent-gold);
      letter-spacing: 1px;
      margin-bottom: 2.5rem;
    }
    .nav-link {
      color: #CCCCCC;
      font-weight: 500;
      padding: 0.6rem 0;
      display: block;
      transition: color 0.2s, transform 0.2s;
      border-left: 3px solid transparent;
      padding-left: 0.5rem;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--accent-gold);
      border-left-color: var(--accent-gold);
      transform: translateX(4px);
    }
    .nav-contact {
      color: #AAAAAA;
      font-size: 0.85rem;
      margin-top: 2rem;
      border-top: 1px solid rgba(255,255,255,0.2);
      padding-top: 1.5rem;
    }
    /* 移动端顶部导航 */
    .mobile-nav {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background-color: var(--primary-deep);
      z-index: 1050;
      align-items: center;
      padding: 0 1.25rem;
    }
    .navbar-toggler {
      border: none;
      color: white;
      font-size: 1.5rem;
    }
    .offcanvas {
      background-color: var(--primary-deep);
      color: white;
    }
    .offcanvas .nav-link {
      color: #ddd;
      font-size: 1.2rem;
      padding: 1rem;
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    /* 主内容区 */
    .main-content {
      padding: 0;
    }
    section {
      padding: 100px 0;
    }
    .container-custom {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 2rem;
    }
    h2 {
      font-size: 2rem;
      font-weight: 600;
      margin-bottom: 2.5rem;
      position: relative;
      display: inline-block;
    }
    h2::after {
      content: '';
      display: block;
      width: 40px;
      height: 4px;
      background-color: var(--accent-gold);
      margin-top: 8px;
      border-radius: 2px;
    }
    .btn-primary-custom {
      background-color: var(--accent-gold);
      border: none;
      color: white;
      font-weight: 600;
      padding: 0.8rem 2.2rem;
      border-radius: var(--border-radius-pill);
      transition: all var(--transition-base);
      box-shadow: 0 4px 12px rgba(212,168,67,0.3);
    }
    .btn-primary-custom:hover {
      background-color: #B89030;
      box-shadow: 0 0 20px rgba(212,168,67,0.5);
      color: white;
    }
    .btn-outline-cyan {
      border: 2px solid var(--electric-cyan);
      color: var(--electric-cyan);
      background: transparent;
      font-weight: 600;
      padding: 0.7rem 2rem;
      border-radius: var(--border-radius-pill);
      transition: all var(--transition-base);
    }
    .btn-outline-cyan:hover {
      background-color: rgba(0,180,180,0.1);
      color: var(--electric-cyan);
    }
    .card-custom {
      background: var(--white);
      border-radius: var(--border-radius-lg);
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      border: none;
      height: 100%;
    }
    .card-custom:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    /* Hero */
    #hero {
      background: linear-gradient(135deg, #1E2D2F 0%, #0F1A1B 100%);
      color: white;
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    .hero-overlay {
      position: absolute;
      top:0; left:0; width:100%; height:100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.1;
    }
    /* 数据徽章 */
    .stat-badge {
      text-align: center;
      padding: 2rem 1rem;
    }
    .stat-number {
      font-family: var(--font-numbers);
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--accent-gold);
      line-height: 1.2;
    }
    .stat-label {
      color: rgba(255,255,255,0.85);
      font-size: 0.9rem;
      margin-top: 0.5rem;
    }
    .stat-line {
      width: 20px;
      height: 3px;
      background: var(--electric-cyan);
      margin: 0.8rem auto 0;
    }
    /* FAQ手风琴 */
    .accordion-button {
      font-weight: 600;
      font-size: 1.1rem;
      color: var(--primary-deep);
      background-color: var(--white);
      border-bottom: 1px solid var(--border-light);
      box-shadow: none;
      padding: 1.2rem 1.5rem;
      transition: 0.3s;
    }
    .accordion-button:not(.collapsed) {
      background-color: var(--light-cyan-bg);
      color: var(--primary-deep);
      box-shadow: none;
      border-left: 4px solid var(--accent-gold);
    }
    .accordion-body {
      background-color: var(--light-cyan-bg);
      padding: 1.2rem 1.8rem;
      color: #2C3E3F;
    }
    .footer-link {
      color: #AAAAAA;
      transition: color 0.2s;
    }
    .footer-link:hover {
      color: var(--accent-gold);
    }
    @media (max-width: 991.98px) {
      body {
        padding-left: 0;
      }
      .vertical-nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
      }
      section {
        padding: 60px 0;
      }
      h2 {
        font-size: 1.8rem;
      }
      .stat-number {
        font-size: 2.2rem;
      }
      #hero h1 {
        font-size: 2.2rem;
      }
    }
    @media (max-width: 575.98px) {
      .btn-primary-custom, .btn-outline-cyan {
        width: 100%;
        margin-bottom: 0.5rem;
      }
      .stat-badge {
        padding: 1rem;
      }
    }