/* roulang page: index */
/* ----- 设计变量 ----- */
    :root {
      --primary-deep: #0B0C0E;
      --surface-gray: #1A1C20;
      --highlight-lime: #C5FB00;
      --text-primary: #E5E7EB;
      --text-secondary: #9CA3AF;
      --text-tertiary: #6B7280;
      --border-subtle: rgba(255, 255, 255, 0.04);
      --border-medium: rgba(229, 231, 235, 0.08);
      --radius-card: 12px;
      --radius-pill: 40px;
      --radius-button: 6px;
      --shadow-glow: 0 8px 30px rgba(197, 251, 0, 0.08);
      --transition: 0.25s ease;
      --container-width: 1280px;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      background-color: var(--primary-deep);
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      color: var(--text-primary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: transparent;
    }

    .container {
      max-width: var(--container-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* ----- 悬浮胶囊导航 ----- */
    .nav-capsule {
      position: fixed;
      top: 24px;
      left: 50%;
      transform: translateX(-50%);
      width: auto;
      max-width: 95%;
      background: rgba(15, 17, 20, 0.75);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border: 1px solid var(--border-medium);
      border-radius: var(--radius-pill);
      padding: 8px 28px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      z-index: 999;
      transition: background 0.3s;
    }

    .logo {
      font-weight: 700;
      font-size: 1.4rem;
      letter-spacing: -0.02em;
      color: var(--text-primary);
      display: flex;
      align-items: center;
      gap: 6px;
      white-space: nowrap;
    }
    .logo i {
      color: var(--highlight-lime);
      font-size: 1.8rem;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      margin-left: 40px;
    }

    .nav-links a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
      white-space: nowrap;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--highlight-lime);
      transition: width 0.25s ease;
      border-radius: 2px;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--highlight-lime);
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .menu-toggle {
      display: none;
      font-size: 1.6rem;
      color: var(--text-primary);
      margin-left: 20px;
      background: transparent;
      border: none;
    }

    /* 移动端抽屉菜单 */
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(11, 12, 14, 0.96);
      backdrop-filter: blur(25px);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 36px;
      z-index: 1000;
      transform: translateX(100%);
      transition: transform 0.3s ease;
    }
    .mobile-menu.open {
      transform: translateX(0);
    }
    .mobile-menu a {
      font-size: 1.8rem;
      font-weight: 600;
      color: var(--text-primary);
    }
    .mobile-menu .close-btn {
      position: absolute;
      top: 30px;
      right: 30px;
      font-size: 2.2rem;
      color: var(--text-secondary);
    }

    /* ----- 通用板块 ----- */
    section {
      padding: 100px 0;
      position: relative;
    }

    .section-label {
      display: inline-block;
      color: var(--highlight-lime);
      font-weight: 600;
      font-size: 0.9rem;
      letter-spacing: 0.5px;
      margin-bottom: 12px;
      text-transform: uppercase;
    }

    h2 {
      font-size: 2.8rem;
      font-weight: 700;
      letter-spacing: -0.02em;
      line-height: 1.2;
      margin-bottom: 20px;
    }

    .text-secondary {
      color: var(--text-secondary);
      font-size: 1.1rem;
      max-width: 700px;
    }

    .btn-primary {
      background: var(--highlight-lime);
      color: #0B0C0E;
      font-weight: 700;
      padding: 14px 32px;
      border-radius: var(--radius-button);
      display: inline-flex;
      align-items: center;
      gap: 8px;
      transition: background 0.2s, box-shadow 0.2s;
      font-size: 1rem;
    }
    .btn-primary:hover {
      background: #d9ff4d;
      box-shadow: 0 8px 22px rgba(197, 251, 0, 0.3);
    }

    .btn-ghost {
      border: 1px solid var(--text-secondary);
      color: var(--text-primary);
      padding: 12px 30px;
      border-radius: var(--radius-button);
      font-weight: 500;
      transition: border-color 0.2s, color 0.2s;
    }
    .btn-ghost:hover {
      border-color: var(--highlight-lime);
      color: var(--highlight-lime);
    }

    /* ----- Hero 首屏 ----- */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center 30%;
      position: relative;
      padding-top: 100px;
    }
    .hero::after {
      content: '';
      position: absolute;
      top: 0; left: 0; right: 0; bottom: 0;
      background: linear-gradient(90deg, rgba(11,12,14,0.92) 40%, rgba(11,12,14,0.4) 100%);
    }
    .hero .container {
      position: relative;
      z-index: 2;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .hero-title {
      font-size: 3.8rem;
      font-weight: 800;
      line-height: 1.1;
      letter-spacing: -0.02em;
    }
    .hero-highlight {
      color: var(--highlight-lime);
    }
    .hero-desc {
      margin: 24px 0 32px;
      font-size: 1.2rem;
      color: var(--text-secondary);
      max-width: 480px;
    }
    .hero-visual {
      display: flex;
      justify-content: center;
    }
    .hero-visual img {
      max-height: 420px;
      width: auto;
      filter: drop-shadow(0 20px 30px rgba(0,0,0,0.6));
    }

    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
      margin-top: 48px;
    }
    .card {
      background: var(--surface-gray);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      transition: transform 0.25s, box-shadow 0.25s, border-color 0.2s;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-glow);
      border-color: rgba(197, 251, 0, 0.2);
    }
    .card-icon {
      font-size: 2.4rem;
      color: var(--highlight-lime);
      margin-bottom: 20px;
    }
    .card h3 {
      font-size: 1.5rem;
      margin-bottom: 12px;
    }

    /* 图文交错区块 */
    .feature-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 80px;
      align-items: center;
      margin-top: 60px;
    }
    .feature-img img {
      border-radius: 16px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
    }

    /* 数据区域 */
    .stats-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      margin-top: 40px;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-size: 3.2rem;
      font-weight: 700;
      color: var(--highlight-lime);
      font-feature-settings: "tnum";
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
      margin-top: 40px;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-medium);
      padding: 18px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      margin-top: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    /* CTA 深色区块 */
    .cta-dark {
      background: #0B0C0E;
      text-align: center;
      border-top: 1px solid var(--highlight-lime);
    }

    footer {
      background: var(--surface-gray);
      padding: 60px 0 30px;
      color: var(--text-secondary);
    }

    @media (max-width: 1024px) {
      .hero .container { grid-template-columns: 1fr; }
      .feature-row { grid-template-columns: 1fr; gap: 40px; }
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      h2 { font-size: 2.2rem; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .menu-toggle { display: block; }
      section { padding: 70px 0; }
      .grid-3, .faq-grid { grid-template-columns: 1fr; }
    }