/* roulang page: index */
:root {
      --primary: #C73E5D;
      --primary-glow: rgba(199, 62, 93, 0.6);
      --secondary: #0B0D17;
      --surface: #0F111A;
      --surface-alt: #131620;
      --card-bg: #1A1D2B;
      --neon-cyan: #00F0FF;
      --neon-cyan-glow: rgba(0, 240, 255, 0.4);
      --text-primary: #F0F2F5;
      --text-secondary: #CCD0DD;
      --text-muted: #8A8F9E;
      --border-subtle: rgba(199, 62, 93, 0.15);
      --border-strong: rgba(0, 240, 255, 0.25);
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 0 20px rgba(199, 62, 93, 0.2);
      --shadow-hover: 0 0 35px rgba(0, 240, 255, 0.25);
      --transition-smooth: 0.25s ease;
      --font-heading: 'PingFang SC', 'Microsoft YaHei', sans-serif;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background-color: var(--secondary);
      color: var(--text-primary);
      margin: 0;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    /* 导航流动霓虹线 */
    .nav-glow-line {
      background: linear-gradient(90deg, transparent, var(--neon-cyan), transparent);
      height: 2px;
      width: 100%;
      position: absolute;
      bottom: 0;
      left: 0;
      animation: flowLine 3s linear infinite;
      background-size: 200% 100%;
    }

    @keyframes flowLine {
      0% { background-position: 200% 0; }
      100% { background-position: -200% 0; }
    }

    .nav-link {
      position: relative;
      transition: color 0.2s;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 3px;
      background-color: var(--neon-cyan);
      transition: width 0.25s ease;
    }
    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }
    .nav-link.active {
      text-shadow: 0 0 8px #00F0FF;
      color: white;
    }

    /* 卡片hover效果 */
    .highlight-card {
      background: var(--card-bg);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-card);
      transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s;
    }
    .highlight-card:hover {
      transform: translateY(-6px);
      border-color: var(--neon-cyan);
      box-shadow: var(--shadow-hover);
    }
    .glow-line {
      width: 40px;
      height: 3px;
      background: var(--neon-cyan);
      transition: width 0.3s ease, background 0.3s;
      margin: 8px 0 12px;
    }
    .highlight-card:hover .glow-line {
      width: 80px;
      background: var(--primary);
    }

    /* 按钮样式 */
    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
      font-weight: 600;
      transition: all 0.25s ease;
      display: inline-block;
      text-align: center;
      border: none;
      cursor: pointer;
      box-shadow: 0 4px 12px rgba(199,62,93,0.3);
    }
    .btn-primary:hover {
      box-shadow: 0 0 18px var(--primary-glow);
      transform: translateY(-2px);
    }
    .btn-outline {
      border: 1.5px solid var(--neon-cyan);
      color: var(--neon-cyan);
      background: transparent;
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
      font-weight: 600;
      transition: all 0.25s ease;
      display: inline-block;
      text-align: center;
      cursor: pointer;
    }
    .btn-outline:hover {
      background: rgba(0,240,255,0.08);
      box-shadow: 0 0 12px var(--neon-cyan-glow);
    }

    /* Hero图片内发光边框 */
    .hero-image-glow {
      border-radius: 12px;
      box-shadow: 0 0 20px rgba(199,62,93,0.4), inset 0 0 20px rgba(199,62,93,0.3);
    }

    /* 方案对比卡片 */
    .compare-traditional {
      background: #1E2330;
      border: 1px solid #2A3140;
    }
    .compare-lejing {
      background: linear-gradient(145deg, #2A1A2E, #1F1B2E);
      border: 1px solid var(--primary);
      box-shadow: 0 0 20px rgba(199,62,93,0.25);
    }

    /* FAQ手风琴 */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
      padding: 1rem 0;
    }
    .faq-question {
      cursor: pointer;
      display: flex;
      align-items: center;
      font-weight: 600;
      font-size: 1.1rem;
    }
    .faq-toggle {
      color: var(--neon-cyan);
      margin-right: 1rem;
      font-weight: 700;
      width: 20px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      border-left: 3px solid transparent;
      padding-left: 1.5rem;
      margin-top: 0.5rem;
      color: var(--text-secondary);
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      border-left-color: var(--neon-cyan);
      background: rgba(0,240,255,0.02);
    }
    .faq-item.open .faq-toggle {
      color: var(--primary);
    }

    /* 输入框聚焦 */
    .input-glow:focus {
      border-color: var(--neon-cyan);
      box-shadow: 0 0 10px var(--neon-cyan-glow);
      outline: none;
    }

    /* 移动菜单 */
    .mobile-menu {
      transition: transform 0.3s ease;
      transform: translateX(100%);
      background: rgba(11,13,23,0.96);
      backdrop-filter: blur(12px);
    }
    .mobile-menu.open {
      transform: translateX(0);
    }

    @media (max-width: 768px) {
      .hero-title {
        font-size: 2.2rem;
      }
      .section-title {
        font-size: 2rem;
      }
    }

    /* 滚动动画 */
    .fade-up {
      opacity: 0;
      transform: translateY(24px);
      transition: opacity 0.6s ease, transform 0.6s ease;
    }
    .fade-up.visible {
      opacity: 1;
      transform: translateY(0);
    }