/* roulang page: index */
:root {
      --primary: #E63946;
      --primary-hover: #C1121F;
      --secondary: #1D1D2E;
      --accent: #F4A261;
      --bg-light: #F8F9FA;
      --bg-dark: #16161F;
      --text-dark: #1D1D2E;
      --text-mid: #4A4A5A;
      --text-light: #6C6C7C;
      --text-white: #FFFFFF;
      --text-off-white: #E0E0E0;
      --border-light: rgba(0,0,0,0.06);
      --border-dark: rgba(255,255,255,0.08);
      --glass-bg: rgba(22,22,31,0.75);
      --glass-border: rgba(255,255,255,0.1);
      --card-shadow-light: 0 4px 20px rgba(0,0,0,0.06);
      --card-shadow-dark: 0 4px 24px rgba(0,0,0,0.25);
      --radius-lg: 12px;
      --radius-md: 8px;
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
      --font-data: 'DIN Alternate', 'Bebas Neue', 'Oswald', sans-serif;
    }
    
    * {
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-body);
      color: var(--text-dark);
      background-color: var(--bg-light);
      line-height: 1.75;
      margin: 0;
      overflow-x: hidden;
    }
    
    h1, h2, h3, h4 {
      font-family: var(--font-heading);
      font-weight: 700;
      letter-spacing: -0.02em;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    .container {
      max-width: 1200px;
      padding-left: 20px;
      padding-right: 20px;
    }
    
    /* 导航栏 */
    .navbar {
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid var(--glass-border);
      padding: 16px 0;
      transition: background 0.3s, box-shadow 0.3s;
      z-index: 1030;
    }
    
    .navbar.scrolled {
      background: #16161F;
      box-shadow: 0 2px 20px rgba(0,0,0,0.3);
    }
    
    .navbar-brand {
      font-family: var(--font-heading);
      font-size: 24px;
      font-weight: 700;
      color: #F4A261 !important;
      letter-spacing: -0.01em;
    }
    
    .nav-link {
      color: #B0B0C0 !important;
      font-weight: 500;
      margin: 0 8px;
      position: relative;
      transition: color 0.2s;
    }
    
    .nav-link:hover, .nav-link.active {
      color: #F4A261 !important;
    }
    
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -8px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
    }
    
    .btn-primary-custom {
      background: var(--primary);
      border: none;
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-md);
      font-weight: 600;
      transition: all 0.3s ease;
      box-shadow: 0 4px 14px rgba(230,57,70,0.35);
    }
    
    .btn-primary-custom:hover {
      background: var(--primary-hover);
      color: white;
      box-shadow: 0 6px 18px rgba(230,57,70,0.5);
      transform: translateY(-1px);
    }
    
    .btn-outline-custom {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
      padding: 10px 28px;
      border-radius: var(--radius-md);
      font-weight: 600;
      transition: all 0.3s ease;
    }
    
    .btn-outline-custom:hover {
      background: var(--primary);
      color: white;
    }
    
    .btn-glass {
      background: rgba(255,255,255,0.1);
      backdrop-filter: blur(10px);
      border: 1px solid rgba(255,255,255,0.2);
      color: white;
      padding: 10px 28px;
      border-radius: var(--radius-md);
      font-weight: 600;
      transition: 0.3s;
    }
    
    .btn-glass:hover {
      background: rgba(255,255,255,0.2);
      color: white;
    }
    
    /* Hero */
    .hero {
      height: 100vh;
      min-height: 700px;
      background: url('/assets/images/backpic/back-1.webp') no-repeat center center/cover;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
    }
    
    .hero-overlay {
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background: linear-gradient(180deg, rgba(22,22,31,0.6) 0%, rgba(22,22,31,0.85) 100%);
      z-index: 1;
    }
    
    .hero-content {
      position: relative;
      z-index: 2;
      text-align: center;
      max-width: 800px;
    }
    
    .hero h1 {
      font-size: 56px;
      line-height: 1.15;
      font-weight: 800;
      margin-bottom: 24px;
      color: white;
    }
    
    .hero .lead {
      font-size: 20px;
      color: #E0E0E0;
      margin-bottom: 40px;
    }
    
    .scroll-indicator {
      position: absolute;
      bottom: 30px;
      left: 50%;
      transform: translateX(-50%);
      z-index: 2;
      color: rgba(255,255,255,0.7);
      font-size: 14px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 6px;
    }
    
    /* 板块间距 */
    section {
      padding: 120px 0;
    }
    
    .bg-dark-section {
      background: var(--bg-dark);
      color: white;
    }
    
    .bg-light-section {
      background: var(--bg-light);
    }
    
    .section-title {
      font-size: 38px;
      margin-bottom: 16px;
      font-weight: 700;
    }
    
    .section-subtitle {
      color: var(--text-mid);
      font-size: 18px;
      margin-bottom: 56px;
    }
    
    .bg-dark-section .section-subtitle {
      color: #B0B0C0;
    }
    
    /* 卡片 */
    .feature-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--card-shadow-light);
      transition: transform 0.3s, box-shadow 0.3s;
      height: 100%;
    }
    
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: 0 12px 30px rgba(0,0,0,0.12);
    }
    
    .bg-dark-section .feature-card {
      background: rgba(255,255,255,0.04);
      color: white;
      box-shadow: var(--card-shadow-dark);
    }
    
    .icon-circle {
      width: 60px;
      height: 60px;
      background: rgba(230,57,70,0.1);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 26px;
      margin-bottom: 20px;
    }
    
    /* 案例卡片 */
    .case-card {
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--card-shadow-light);
      transition: transform 0.3s;
    }
    
    .case-card:hover {
      transform: scale(1.02);
    }
    
    .case-img {
      height: 200px;
      object-fit: cover;
    }
    
    /* 手风琴 */
    .accordion-button {
      font-weight: 600;
      font-size: 18px;
      background: rgba(0,0,0,0.02);
      border: none;
      padding: 18px 24px;
    }
    
    .bg-dark-section .accordion-button {
      background: rgba(255,255,255,0.03);
      color: white;
    }
    
    .accordion-button:not(.collapsed) {
      background: rgba(230,57,70,0.05);
      color: var(--primary);
      box-shadow: none;
    }
    
    .accordion-body {
      padding: 20px 24px;
      line-height: 1.9;
    }
    
    /* 页脚 */
    footer {
      background: #0f0f15;
      color: #B0B0C0;
      padding: 60px 0 30px;
    }
    
    footer a {
      color: #B0B0C0;
    }
    
    footer a:hover {
      color: var(--accent);
    }
    
    @media (max-width: 768px) {
      .hero h1 {
        font-size: 36px;
      }
      .section-title {
        font-size: 30px;
      }
      section {
        padding: 80px 0;
      }
      .navbar-brand {
        font-size: 20px;
      }
    }