/* roulang page: index */
:root {
      --primary: #E8380F;
      --primary-dark: #C92A0A;
      --secondary-dark: #1A1A2E;
      --accent-gold: #F5A623;
      --bg-light: #F9FAFB;
      --card-bg: #FFFFFF;
      --border-light: #E5E7EB;
      --text-dark: #1A1A2E;
      --text-muted: #6B7280;
      --text-light: #F9FAFB;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(232,56,15,0.12);
      --shadow-lg: 0 20px 32px rgba(0,0,0,0.08);
      --radius-xl: 24px;
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --nav-width: 280px;
      --transition: all 0.25s ease;
      --font-body: 'Noto Sans SC', 'Inter', system-ui, -apple-system, sans-serif;
      --font-number: 'Inter', 'Noto Sans SC', sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.6;
      font-size: 16px;
      display: flex;
      flex-direction: row;
      min-height: 100vh;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    button {
      font-family: inherit;
      cursor: pointer;
      border: none;
      background: none;
    }
    /* 左侧竖向导航 */
    .side-nav {
      width: var(--nav-width);
      background-color: var(--secondary-dark);
      position: fixed;
      top: 0;
      left: 0;
      height: 100vh;
      display: flex;
      flex-direction: column;
      padding: 2rem 1.5rem;
      z-index: 100;
      box-shadow: 4px 0 20px rgba(0,0,0,0.12);
      transition: transform 0.3s ease;
    }
    .nav-brand {
      display: flex;
      align-items: center;
      gap: 0.75rem;
      margin-bottom: 3rem;
    }
    .logo-icon {
      font-size: 2rem;
      color: var(--primary);
      filter: drop-shadow(0 2px 8px rgba(232,56,15,0.5));
    }
    .logo-text {
      font-size: 1.5rem;
      font-weight: 700;
      color: white;
      letter-spacing: -0.5px;
    }
    .logo-text span {
      color: var(--accent-gold);
    }
    .nav-menu {
      list-style: none;
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 0.25rem;
    }
    .nav-item {
      position: relative;
    }
    .nav-link {
      display: flex;
      align-items: center;
      padding: 0.8rem 1rem;
      color: rgba(255,255,255,0.7);
      font-weight: 500;
      border-radius: var(--radius-sm);
      transition: var(--transition);
      position: relative;
    }
    .nav-link::before {
      content: '';
      position: absolute;
      left: 0;
      top: 15%;
      height: 70%;
      width: 3px;
      background-color: transparent;
      border-radius: 2px;
      transition: width 0.2s, background-color 0.2s;
    }
    .nav-link:hover {
      color: white;
      background-color: rgba(255,255,255,0.05);
    }
    .nav-link:hover::before {
      background-color: var(--primary);
      width: 6px;
    }
    .nav-link.active {
      color: white;
      background-color: rgba(232,56,15,0.1);
    }
    .nav-link.active::before {
      background-color: var(--primary);
      width: 6px;
    }
    .nav-footer {
      margin-top: auto;
      color: rgba(255,255,255,0.5);
      font-size: 0.8rem;
      border-top: 1px solid rgba(255,255,255,0.1);
      padding-top: 1.5rem;
    }
    /* 移动端导航按钮 */
    .mobile-nav-toggle {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 1.8rem;
      cursor: pointer;
      padding: 0.5rem;
    }
    /* 主体内容区 */
    .main-content {
      margin-left: var(--nav-width);
      flex: 1;
      width: calc(100% - var(--nav-width));
      background-color: var(--bg-light);
    }
    /* 顶部移动导航栏 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background-color: var(--secondary-dark);
      z-index: 99;
      align-items: center;
      justify-content: space-between;
      padding: 0 1.5rem;
      box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    }
    .mobile-logo {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      color: white;
      font-weight: 700;
      font-size: 1.3rem;
    }
    /* 通用容器 */
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 2rem;
    }
    section {
      padding: 7rem 0;
    }
    h2 {
      font-size: 2.25rem;
      font-weight: 700;
      margin-bottom: 1.5rem;
      letter-spacing: -0.5px;
    }
    .section-subtitle {
      font-size: 1.1rem;
      color: var(--text-muted);
      max-width: 700px;
      margin-bottom: 3rem;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      padding: 0.9rem 2.2rem;
      font-weight: 600;
      border-radius: var(--radius-sm);
      transition: all 0.2s;
      background: white;
      color: var(--text-dark);
      box-shadow: var(--shadow-sm);
    }
    .btn-primary {
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
      color: white;
      border: none;
      box-shadow: 0 8px 18px rgba(232,56,15,0.3);
    }
    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 12px 24px rgba(232,56,15,0.4);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .badge {
      background: rgba(245,166,35,0.15);
      color: #b27a1a;
      font-weight: 600;
      padding: 0.25rem 1rem;
      border-radius: 20px;
      font-size: 0.85rem;
    }
    .data-badge {
      font-family: var(--font-number);
      font-weight: 800;
      font-size: 2.2rem;
      color: var(--accent-gold);
    }
    /* Hero */
    .hero {
      background: linear-gradient(135deg, #1A1A2E 0%, #16213E 100%);
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
      color: white;
      padding: 6rem 0;
      position: relative;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    .hero h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 1.5rem;
    }
    .hero .subtitle {
      font-size: 1.2rem;
      opacity: 0.9;
      margin-bottom: 2rem;
    }
    .stats-row {
      display: flex;
      gap: 2rem;
      margin-top: 2.5rem;
      flex-wrap: wrap;
    }
    .stat-item {
      background: rgba(255,255,255,0.08);
      backdrop-filter: blur(8px);
      border-radius: var(--radius-lg);
      padding: 1.2rem 1.8rem;
      text-align: center;
    }
    .hero-visual {
      display: flex;
      justify-content: center;
      align-items: center;
    }
    /* 卡片网格 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }
    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-xl);
      padding: 2rem;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      transition: var(--transition);
      position: relative;
      overflow: hidden;
    }
    .feature-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .feature-card::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 4px;
      background: linear-gradient(90deg, var(--primary), var(--accent-gold));
      transform: scaleX(0);
      transition: transform 0.3s;
      transform-origin: left;
    }
    .feature-card:hover::after {
      transform: scaleX(1);
    }
    .card-icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 1.5rem;
      transition: transform 0.3s;
    }
    .feature-card:hover .card-icon {
      transform: rotate(5deg);
    }
    /* 证言卡片 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 2rem;
    }
    .testimonial-card {
      background: var(--card-bg);
      border-radius: var(--radius-xl);
      padding: 2rem;
      box-shadow: var(--shadow-sm);
      border-left: 6px solid var(--primary);
    }
    /* FAQ */
    .faq-item {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      margin-bottom: 1rem;
      border: 1px solid var(--border-light);
      overflow: hidden;
    }
    .faq-question {
      width: 100%;
      padding: 1.2rem 1.8rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      background: transparent;
      font-size: 1.1rem;
    }
    .faq-answer {
      padding: 0 1.8rem 1.2rem;
      color: var(--text-muted);
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .faq-item.active {
      border-left: 5px solid var(--primary);
    }
    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, var(--primary), var(--primary-dark));
      color: white;
      border-radius: var(--radius-xl);
      margin: 4rem auto;
      padding: 4rem 2rem;
    }
    footer {
      background: var(--secondary-dark);
      color: rgba(255,255,255,0.8);
      padding: 4rem 0 2rem;
    }
    @media (max-width: 1024px) {
      .cards-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .side-nav { transform: translateX(-100%); }
      .side-nav.open { transform: translateX(0); }
      .mobile-header, .mobile-nav-toggle { display: flex; }
      .main-content { margin-left: 0; width: 100%; }
      .hero-grid { grid-template-columns: 1fr; }
      .hero h1 { font-size: 2rem; }
      section { padding: 5rem 0; }
      .cards-grid, .testimonial-grid { grid-template-columns: 1fr; }
      .container { padding: 0 1.5rem; }
    }