/* roulang page: index */
:root {
      --primary-deep: #0A0E27;
      --accent-cyan: #00F0FF;
      --accent-hot: #FF4D6D;
      --text-white: #FFFFFF;
      --text-body: #B0C4DE;
      --text-muted: #7B8CA8;
      --glass-bg: rgba(255, 255, 255, 0.04);
      --glass-border: rgba(0, 240, 255, 0.15);
      --glass-bg-card: rgba(10, 14, 39, 0.6);
      --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
      --card-hover-shadow: 0 16px 48px rgba(0, 240, 255, 0.08);
      --radius-card: 16px;
      --radius-btn: 50px;
      --radius-input: 8px;
      --font-en: 'Inter', 'SF Pro Display', sans-serif;
      --font-cn: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    }

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

    body {
      background-color: var(--primary-deep);
      color: var(--text-body);
      font-family: var(--font-cn);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      overflow-x: hidden;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    /* 全局重置与辅助 */
    a {
      text-decoration: none;
      color: var(--accent-cyan);
      transition: color 0.2s;
    }

    a:hover {
      color: var(--accent-hot);
    }

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

    button, .btn {
      cursor: pointer;
      font-family: var(--font-cn);
      font-weight: 600;
      transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
      border: none;
      outline: none;
    }

    h1, h2, h3 {
      color: var(--text-white);
      font-weight: 700;
      line-height: 1.3;
    }

    h1 {
      font-size: 48px;
      font-weight: 800;
      letter-spacing: -0.5px;
    }

    h2 {
      font-size: 36px;
      display: inline-block;
      position: relative;
      margin-bottom: 48px;
    }

    h2::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -12px;
      width: 60px;
      height: 4px;
      background: var(--accent-cyan);
      border-radius: 2px;
    }

    h3 {
      font-size: 22px;
      font-weight: 600;
    }

    .section {
      padding: 100px 0;
    }

    .btn-primary {
      background: var(--accent-hot);
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-size: 16px;
      box-shadow: 0 0 20px rgba(255, 77, 109, 0.5);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    .btn-primary:hover {
      background: #E63E5C;
      box-shadow: 0 0 30px rgba(255, 77, 109, 0.8);
      transform: scale(1.03);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 12px 34px;
      border-radius: var(--radius-btn);
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    .btn-outline:hover {
      background: rgba(0, 240, 255, 0.1);
      box-shadow: 0 0 20px rgba(0, 240, 255, 0.4);
      transform: scale(1.03);
    }

    .glass-card {
      background: var(--glass-bg-card);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      box-shadow: var(--card-shadow);
      padding: 32px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10, 14, 39, 0.8);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(0, 240, 255, 0.2);
      transition: background 0.3s;
    }

    .header.scrolled {
      background: rgba(10, 14, 39, 0.95);
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 16px 0;
      max-width: 1280px;
      margin: 0 auto;
      padding-left: 32px;
      padding-right: 32px;
    }

    .logo {
      font-family: var(--font-en);
      font-weight: 800;
      font-size: 24px;
      color: var(--text-white);
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .logo-icon {
      background: linear-gradient(135deg, var(--accent-cyan), #0A0E27);
      width: 36px;
      height: 36px;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      color: white;
      font-size: 18px;
      border: 1px solid var(--accent-cyan);
    }

    .nav-links {
      display: flex;
      gap: 32px;
      list-style: none;
    }

    .nav-links a {
      color: var(--text-body);
      font-weight: 500;
      position: relative;
      padding: 4px 0;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-cyan);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-cyan);
      transition: width 0.3s;
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .nav-cta {
      background: var(--accent-hot);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-size: 14px;
      font-weight: 600;
      box-shadow: 0 0 15px rgba(255, 77, 109, 0.4);
    }

    .nav-cta:hover {
      background: #E63E5C;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
    }

    .hamburger span {
      width: 26px;
      height: 3px;
      background: var(--text-white);
      border-radius: 2px;
      transition: 0.3s;
    }

    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .mobile-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        height: 100vh;
        background: rgba(10, 14, 39, 0.98);
        backdrop-filter: blur(24px);
        flex-direction: column;
        padding: 40px;
        gap: 32px;
        transition: right 0.4s ease;
        z-index: 1001;
        display: flex;
      }
      .mobile-menu.active {
        right: 0;
      }
      .mobile-menu a {
        color: var(--text-white);
        font-size: 20px;
        border-bottom: 1px solid rgba(255,255,255,0.1);
        padding-bottom: 12px;
      }
    }

    /* Hero */
    .hero {
      padding: 180px 0 100px;
      display: flex;
      align-items: center;
      gap: 60px;
    }

    .hero-left {
      flex: 0 0 60%;
    }

    .hero-right {
      flex: 0 0 35%;
      position: relative;
    }

    .hero-img {
      width: 100%;
      border-radius: 24px;
      object-fit: cover;
      box-shadow: 0 0 40px rgba(0, 240, 255, 0.3);
      border: 1px solid rgba(0,240,255,0.3);
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-body);
      margin: 24px 0 32px;
    }

    .hero-actions {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    /* 亮点网格 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }

    .feature-card {
      transition: transform 0.3s, border-color 0.3s, box-shadow 0.3s;
    }

    .feature-card:hover {
      transform: translateY(-8px);
      border-color: rgba(0, 240, 255, 0.4);
      box-shadow: var(--card-hover-shadow);
    }

    .feature-icon {
      font-size: 32px;
      color: var(--accent-cyan);
      margin-bottom: 20px;
    }

    /* 瀑布流 */
    .waterfall {
      column-count: 3;
      column-gap: 24px;
    }

    .waterfall-item {
      break-inside: avoid;
      margin-bottom: 24px;
      overflow: hidden;
    }

    .waterfall-img {
      width: 100%;
      border-radius: 16px 16px 0 0;
      object-fit: cover;
    }

    .waterfall-content {
      padding: 24px;
    }

    .tag {
      background: rgba(0,240,255,0.1);
      border: 1px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      margin-right: 8px;
    }

    /* 方案对比 */
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }

    .plan-card {
      position: relative;
    }

    .recommend-badge {
      position: absolute;
      top: -14px;
      right: 24px;
      background: var(--accent-hot);
      color: white;
      padding: 4px 16px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
    }

    .feature-list {
      list-style: none;
      margin: 24px 0;
    }

    .feature-list li {
      margin-bottom: 14px;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    /* 数据条 */
    .trust-strip {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
      gap: 30px;
    }

    .trust-number {
      font-family: var(--font-en);
      font-size: 42px;
      font-weight: 700;
      color: var(--accent-cyan);
    }

    /* FAQ */
    .faq-item {
      margin-bottom: 16px;
      cursor: pointer;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      color: var(--text-white);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--text-body);
    }

    .faq-item.active .faq-answer {
      max-height: 300px;
      padding-top: 16px;
    }

    .faq-item.active .arrow {
      transform: rotate(180deg);
    }

    .arrow {
      transition: 0.3s;
      color: var(--accent-cyan);
    }

    /* 最终CTA */
    .cta-banner {
      background: radial-gradient(circle at center, #0A0E27, rgba(0,240,255,0.1));
      padding: 100px 0;
      text-align: center;
    }

    /* Footer */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      padding: 60px 0;
      border-top: 1px solid rgba(255,255,255,0.05);
    }

    .copyright {
      text-align: center;
      padding: 24px 0;
      color: var(--text-muted);
      border-top: 1px solid rgba(255,255,255,0.05);
    }

    @media (max-width: 1024px) {
      .hero {
        flex-direction: column;
      }
      .features-grid {
        grid-template-columns: 1fr 1fr;
      }
      .waterfall {
        column-count: 2;
      }
    }

    @media (max-width: 768px) {
      h1 {
        font-size: 32px;
      }
      h2 {
        font-size: 26px;
      }
      .section {
        padding: 60px 0;
      }
      .features-grid,
      .compare-grid {
        grid-template-columns: 1fr;
      }
      .waterfall {
        column-count: 1;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .hero {
        padding-top: 120px;
      }
    }