/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --primary: #4E6EF2;
      --primary-glow: rgba(78, 110, 242, 0.5);
      --secondary: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --bg-deep: #0A0E1A;
      --bg-card: #141929;
      --glass-bg: rgba(255, 255, 255, 0.04);
      --glass-border: rgba(255, 255, 255, 0.06);
      --text-main: #E8ECF1;
      --text-muted: #86909C;
      --text-white: #FFFFFF;
      --radius-card: 16px;
      --radius-btn: 12px;
      --radius-tag: 8px;
      --radius-capsule: 24px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4), 0 0 0 1px rgba(255,255,255,0.06) inset;
      --shadow-btn: 0 0 20px rgba(78,110,242,0.4);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --max-width: 1200px;
      --section-gap: 100px;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    html {
      scroll-behavior: smooth;
      background-color: var(--bg-deep);
    }
    
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-main);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
      background-image: radial-gradient(circle at 30% 10%, rgba(78,110,242,0.08) 0%, transparent 45%);
    }
    
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* 标题层级 */
    h1 {
      font-size: 48px;
      line-height: 1.2;
      font-weight: 700;
      color: var(--text-white);
    }
    h2 {
      font-size: 36px;
      line-height: 1.3;
      font-weight: 600;
      color: var(--text-white);
      margin-bottom: 16px;
    }
    h3 {
      font-size: 20px;
      line-height: 1.4;
      font-weight: 600;
      color: var(--text-white);
    }
    p {
      color: var(--text-muted);
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }
    
    /* 按钮基础 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: all 0.25s ease;
      border: none;
      background: transparent;
      color: var(--text-white);
    }
    .btn-primary {
      background: var(--primary);
      box-shadow: var(--shadow-btn);
      color: white;
    }
    .btn-primary:hover {
      background: #3f5bda;
      box-shadow: 0 0 28px rgba(78,110,242,0.7);
      transform: translateY(-2px);
    }
    .btn-outline {
      border: 1px solid rgba(255,255,255,0.25);
      background: transparent;
    }
    .btn-outline:hover {
      border-color: var(--primary);
      background: rgba(78,110,242,0.1);
      transform: translateY(-2px);
    }
    
    /* 导航 */
    .nav-bar {
      position: fixed;
      top: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10, 14, 26, 0.7);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(255,255,255,0.06);
      transition: background 0.3s ease;
    }
    .nav-bar.scrolled {
      background: rgba(10, 14, 26, 0.95);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--text-white);
      letter-spacing: -0.5px;
      display: flex;
      align-items: baseline;
      gap: 6px;
    }
    .logo span {
      color: var(--primary);
      font-weight: 300;
      font-size: 18px;
      opacity: 0.9;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: rgba(255,255,255,0.75);
      transition: color 0.2s;
      position: relative;
      padding: 4px 0;
    }
    .nav-links a:hover, .nav-links a.active {
      color: white;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s;
    }
    .nav-links a:hover::after, .nav-links a.active::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      font-size: 24px;
      color: white;
      background: none;
      border: none;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: rgba(10,14,26,0.96);
      backdrop-filter: blur(20px);
      flex-direction: column;
      padding: 24px;
      gap: 20px;
      border-bottom: 1px solid rgba(255,255,255,0.06);
      z-index: 999;
    }
    .mobile-menu a {
      color: white;
      font-size: 18px;
      font-weight: 500;
    }
    
    /* 板块间距 */
    section {
      padding: var(--section-gap) 0;
    }
    
    /* Hero */
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
      min-height: 90vh;
      padding-top: 100px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-left h1 {
      margin-bottom: 20px;
    }
    .hero-left .subtitle {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .hero-glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      border-radius: 24px;
      padding: 40px;
      box-shadow: var(--shadow-card);
      width: 100%;
      max-width: 500px;
      transform: rotate(1deg);
      transition: transform 0.3s;
    }
    .hero-glass-card:hover {
      transform: rotate(0deg) scale(1.01);
    }
    .hero-glass-card img {
      border-radius: 16px;
      opacity: 0.9;
    }
    
    /* 核心亮点网格 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .feature-card {
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      border: 1px solid transparent;
    }
    .feature-card:hover {
      transform: translateY(-8px);
      border-color: rgba(78,110,242,0.3);
      box-shadow: 0 16px 40px rgba(0,0,0,0.6), 0 0 0 1px var(--primary-glow) inset;
    }
    .feature-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .feature-card h3 {
      margin-bottom: 8px;
    }
    
    /* 案例瀑布流 */
    .cases-masonry {
      display: columns;
      columns: 2;
      column-gap: 20px;
      margin-top: 40px;
    }
    .case-card {
      break-inside: avoid;
      margin-bottom: 20px;
      background: var(--glass-bg);
      backdrop-filter: blur(16px);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
    }
    .case-card:hover {
      transform: translateY(-6px);
      box-shadow: 0 20px 40px rgba(0,0,0,0.6), 0 0 0 1px var(--primary-glow);
    }
    .case-img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    .case-content {
      padding: 20px;
    }
    .case-tags {
      display: flex;
      gap: 8px;
      margin: 12px 0;
    }
    .tag {
      background: rgba(78,110,242,0.2);
      color: var(--primary);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 500;
    }
    
    /* 方案对比 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .pricing-card {
      background: var(--glass-bg);
      backdrop-filter: blur(16px);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      border: 1px solid rgba(255,255,255,0.04);
      transition: all 0.3s;
      display: flex;
      flex-direction: column;
    }
    .pricing-card.recommended {
      border: 1px solid var(--primary);
      box-shadow: 0 0 24px rgba(78,110,242,0.25);
      position: relative;
    }
    .badge-recommend {
      position: absolute;
      top: 16px;
      right: 16px;
      background: var(--secondary);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
    }
    .price {
      font-size: 28px;
      font-weight: 700;
      color: white;
      margin: 16px 0;
    }
    .feature-list {
      list-style: none;
      margin: 24px 0;
      flex: 1;
    }
    .feature-list li {
      padding: 8px 0;
      color: var(--text-muted);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .feature-list i.fa-check {
      color: var(--secondary);
    }
    .feature-list i.fa-times {
      color: var(--text-muted);
      opacity: 0.5;
    }
    
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 40px auto 0;
    }
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.06);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 500;
      font-size: 20px;
      color: white;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-in-out;
      color: var(--text-muted);
      padding-left: 0;
      margin-top: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 16px;
      padding-left: 16px;
      border-left: 3px solid var(--primary);
    }
    
    /* CTA 横幅 */
    .cta-banner {
      background: linear-gradient(135deg, #0A0E1A 0%, #141E3A 100%);
      text-align: center;
      padding: 80px 24px;
      border-radius: 24px;
      margin: 0 24px;
    }
    .cta-btn-large {
      padding: 16px 48px;
      font-size: 18px;
      font-weight: 600;
      margin-top: 24px;
    }
    
    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      padding: 60px 0 40px;
      border-top: 1px solid rgba(255,255,255,0.05);
    }
    .copyright {
      text-align: center;
      padding: 24px 0;
      font-size: 12px;
      color: var(--text-muted);
      border-top: 1px solid rgba(255,255,255,0.03);
    }
    
    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid { flex-direction: column; text-align: center; }
      .hero-left .subtitle { max-width: 100%; }
      .features-grid { grid-template-columns: repeat(2,1fr); }
      .pricing-grid { grid-template-columns: 1fr; max-width: 500px; margin-left: auto; margin-right: auto; }
    }
    @media (max-width: 768px) {
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
      .nav-links { display: none; }
      .hamburger { display: block; }
      .features-grid { grid-template-columns: 1fr; }
      .cases-masonry { columns: 1; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero-glass-card { transform: rotate(0); }
    }
    @media (min-width: 769px) {
      .mobile-menu { display: none !important; }
    }