/* roulang page: index */
:root {
      --bg-deep: #0A0E17;
      --surface-dark: #141A24;
      --border-muted: #2A3040;
      --energy-red: #FF4D2E;
      --energy-red-hover: #FF6B52;
      --victory-green: #00E5A0;
      --text-primary: #FFFFFF;
      --text-secondary: #B0B8C5;
      --text-muted: #5A6270;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Roboto', sans-serif;
      --font-mono: 'Inter', 'Roboto', monospace;
      --shadow-card: 0 8px 24px rgba(0,0,0,0.5);
      --shadow-glow: 0 12px 32px rgba(255,77,46,0.15);
      --radius-sm: 4px;
      --transition-base: all 0.25s ease;
      --container-width: 1280px;
      --nav-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      background-color: var(--bg-deep);
      color: var(--text-secondary);
      font-family: var(--font-sans);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    .container {
      max-width: var(--container-width);
      margin: 0 auto;
      padding: 0 40px;
    }
    h1, h2, h3, .h2, .h3 {
      color: var(--text-primary);
      font-weight: 700;
      letter-spacing: -0.02em;
    }
    a {
      color: inherit;
      text-decoration: none;
      transition: var(--transition-base);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: var(--transition-base);
      font-weight: 600;
      white-space: nowrap;
    }
    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: var(--bg-deep);
      border-bottom: 1px solid var(--border-muted);
      z-index: 1000;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 1.6rem;
      font-weight: 800;
      color: var(--text-primary);
      letter-spacing: -0.01em;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--energy-red);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      padding: 8px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--energy-red);
      transition: width 0.2s ease;
    }
    .nav-links a:hover {
      color: var(--text-primary);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--energy-red);
      color: #FFFFFF;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 700;
      box-shadow: 0 4px 12px rgba(255,77,46,0.3);
      border: none;
    }
    .btn-primary:hover {
      background: var(--energy-red-hover);
      transform: translateY(-2px);
      box-shadow: var(--shadow-glow);
    }
    .btn-outline {
      background: transparent;
      color: #FFFFFF;
      border: 1px solid var(--border-muted);
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
    }
    .btn-outline:hover {
      border-color: #FFFFFF;
      transform: translateY(-2px);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text-primary);
      transition: var(--transition-base);
    }
    /* 移动端导航 */
    @media (max-width: 768px) {
      .container {
        padding: 0 20px;
      }
      .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70%;
        max-width: 320px;
        height: 100vh;
        background: var(--surface-dark);
        flex-direction: column;
        justify-content: center;
        gap: 40px;
        transition: right 0.3s ease;
        box-shadow: -8px 0 24px rgba(0,0,0,0.6);
        z-index: 999;
      }
      .nav-links.active {
        right: 0;
      }
      .hamburger {
        display: flex;
      }
      .nav-links .btn-primary {
        width: fit-content;
      }
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      margin-top: var(--nav-height);
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 30% 40%, rgba(10,14,23,0.7) 0%, #0A0E17 95%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
    }
    .hero-tag {
      font-size: 0.9rem;
      font-weight: 600;
      color: var(--energy-red);
      letter-spacing: 0.08em;
      text-transform: uppercase;
      margin-bottom: 16px;
    }
    .hero h1 {
      font-size: 3.5rem;
      line-height: 1.1;
      margin-bottom: 24px;
      font-weight: 800;
    }
    .hero-desc {
      font-size: 1.2rem;
      color: var(--text-secondary);
      max-width: 580px;
      margin-bottom: 36px;
    }
    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    @media (max-width: 768px) {
      .hero h1 {
        font-size: 2.2rem;
      }
      .hero-desc {
        font-size: 1rem;
      }
    }
    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2.4rem;
      margin-bottom: 20px;
      font-weight: 700;
    }
    .section-sub {
      color: var(--text-muted);
      margin-bottom: 56px;
      font-size: 1.1rem;
    }
    /* 痛点/方案网格 */
    .grid-2col {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 40px;
      align-items: center;
    }
    .pain-point {
      background: var(--surface-dark);
      border-left: 4px solid var(--energy-red);
      padding: 28px;
      border-radius: var(--radius-sm);
      margin-bottom: 24px;
      transition: var(--transition-base);
    }
    .pain-point:hover {
      box-shadow: var(--shadow-glow);
    }
    .pain-point h3 {
      font-size: 1.5rem;
      margin-bottom: 10px;
    }
    /* 数据卡片 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
      margin-top: 40px;
    }
    .stat-card {
      background: var(--surface-dark);
      padding: 36px 24px;
      border-radius: var(--radius-sm);
      border-top: 3px solid var(--victory-green);
      text-align: center;
      transition: var(--transition-base);
    }
    .stat-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-glow);
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 3rem;
      font-weight: 700;
      color: #FFFFFF;
      display: flex;
      align-items: baseline;
      justify-content: center;
      gap: 4px;
    }
    .stat-label {
      color: var(--text-muted);
      margin-top: 12px;
    }
    /* 证言卡片 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }
    .testimonial {
      background: var(--surface-dark);
      padding: 32px;
      border-radius: var(--radius-sm);
      display: flex;
      gap: 20px;
      border-left: 3px solid var(--energy-red);
    }
    .testimonial img {
      width: 60px;
      height: 60px;
      border-radius: 50%;
      object-fit: cover;
    }
    .stars {
      color: var(--victory-green);
      letter-spacing: 2px;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-muted);
      padding: 24px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      align-items: center;
      gap: 16px;
      font-weight: 700;
      font-size: 1.2rem;
      color: #FFFFFF;
      transition: var(--transition-base);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      padding-left: 40px;
      margin-top: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 16px;
    }
    .faq-item.active .faq-question {
      color: var(--energy-red);
    }
    /* CTA */
    .cta-section {
      background: var(--surface-dark);
      text-align: center;
      border-radius: var(--radius-sm);
      padding: 80px 40px;
      margin: 60px 0;
      border: 1px solid var(--border-muted);
    }
    /* 页脚 */
    .site-footer {
      border-top: 3px solid var(--energy-red);
      padding: 40px 0;
      text-align: center;
      color: var(--text-muted);
      font-size: 0.9rem;
    }
    @media (max-width: 1024px) {
      .grid-2col, .testimonial-grid {
        grid-template-columns: 1fr;
      }
      .stats-grid {
        grid-template-columns: 1fr;
      }
    }