/* roulang page: index */
:root {
      --primary: #E63946;
      --primary-deep: #C62828;
      --secondary: #7B2D8E;
      --bg-dark: #0B0C10;
      --bg-card: #1A1A1A;
      --bg-card-hover: #242424;
      --text-primary: #F5F5F5;
      --text-secondary: #B0B0B0;
      --border-light: #2A2A2A;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-glow: 0 8px 24px rgba(230, 57, 70, 0.25);
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Noto Sans SC", "Helvetica Neue", system-ui, sans-serif;
      --spacing-section: 100px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-dark);
      color: var(--text-primary);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }
    .container {
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background 0.3s, height 0.3s, backdrop-filter 0.3s;
      height: 80px;
      display: flex;
      align-items: center;
      background: transparent;
    }
    .site-header.scrolled {
      background: rgba(11, 12, 16, 0.85);
      backdrop-filter: blur(12px);
      height: 64px;
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-weight: 800;
      font-size: 1.6rem;
      color: #fff;
      letter-spacing: 1px;
      display: flex;
      align-items: baseline;
      gap: 4px;
      white-space: nowrap;
    }
    .logo .logo-main {
      color: #fff;
    }
    .logo .logo-sub {
      font-size: 0.85rem;
      font-weight: 500;
      color: var(--text-secondary);
      margin-left: 2px;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-menu a {
      font-weight: 500;
      color: #ddd;
      transition: color 0.2s;
      font-size: 0.95rem;
    }
    .nav-menu a:hover {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      font-weight: 700;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      letter-spacing: 1px;
      transition: background 0.2s, transform 0.2s;
      display: inline-block;
      text-align: center;
      white-space: nowrap;
    }
    .btn-primary:hover {
      background: var(--primary-deep);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid white;
      color: white;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      transition: all 0.2s;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      border-color: var(--primary);
      background: rgba(230,57,70,0.1);
      color: var(--primary);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 26px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }
    /* 移动端导航覆盖层 */
    .mobile-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(11,12,16,0.98);
      backdrop-filter: blur(20px);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 40px;
      transform: translateY(-100%);
      transition: transform 0.4s ease;
      z-index: 999;
    }
    .mobile-nav.active {
      transform: translateY(0);
    }
    .mobile-nav a {
      font-size: 1.5rem;
      font-weight: 600;
      color: #fff;
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 20% 30%, rgba(230,57,70,0.25) 0%, var(--bg-dark) 70%);
      position: relative;
      overflow: hidden;
      padding-top: 80px;
    }
    .hero-particles {
      position: absolute;
      top:0; left:0; width:100%; height:100%;
      background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 800 600"><circle cx="100" cy="150" r="2" fill="%23E63946" opacity="0.3"/><circle cx="650" cy="400" r="3" fill="%237B2D8E" opacity="0.4"/></svg>') repeat;
      opacity: 0.2;
      animation: drift 20s linear infinite;
    }
    @keyframes drift{0%{transform:translate(0,0)}100%{transform:translate(-200px,-100px)}}
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
    }
    .hero h1 {
      font-size: clamp(2.8rem, 8vw, 5rem);
      font-weight: 900;
      line-height: 1.15;
      margin-bottom: 20px;
    }
    .hero .subtitle {
      font-size: 1.3rem;
      color: var(--text-secondary);
      margin-bottom: 36px;
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 40px;
    }
    .trust-badge {
      display: flex;
      gap: 32px;
      color: #aaa;
      font-size: 0.9rem;
    }
    /* 板块通用 */
    section {
      padding: var(--spacing-section) 0;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 800;
      margin-bottom: 16px;
      text-align: center;
    }
    .section-desc {
      color: var(--text-secondary);
      text-align: center;
      max-width: 700px;
      margin: 0 auto 48px;
    }
    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: 1fr 1fr 1fr;
      gap: 28px;
    }
    .feature-card {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      transition: all 0.25s;
    }
    .feature-card.large {
      grid-row: span 2;
      background: #1E1E1E;
    }
    .feature-card:hover {
      background: var(--bg-card-hover);
      border-color: var(--primary);
      box-shadow: var(--shadow-glow);
      transform: translateY(-4px);
    }
    .feature-icon {
      font-size: 2.4rem;
      margin-bottom: 18px;
      color: var(--primary);
    }
    .feature-card h3 {
      font-size: 1.5rem;
      margin-bottom: 12px;
    }
    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }
    .service-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--border-light);
      transition: 0.25s;
    }
    .service-card:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-glow);
      transform: translateY(-4px);
    }
    .service-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .service-body {
      padding: 24px;
    }
    .tags {
      display: flex;
      gap: 8px;
      flex-wrap: wrap;
      margin: 12px 0;
    }
    .tag {
      background: #2A2A2A;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      color: #ddd;
    }
    /* 数据墙 */
    .stats-scroll {
      display: flex;
      gap: 40px;
      overflow-x: auto;
      padding: 20px 0;
      scrollbar-width: thin;
    }
    .stat-item {
      flex: 0 0 auto;
      text-align: center;
      min-width: 160px;
    }
    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--primary);
    }
    /* 步骤 */
    .steps {
      display: flex;
      justify-content: space-between;
      gap: 24px;
    }
    .step {
      flex:1;
      text-align: center;
      padding: 28px;
      background: var(--bg-card);
      border-radius: var(--radius-card);
    }
    /* FAQ */
    .faq-item {
      background: #1E1E1E;
      border-radius: 8px;
      margin-bottom: 12px;
      overflow: hidden;
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: none;
      border:none;
      width:100%;
      text-align:left;
      color:white;
      font-size:1rem;
    }
    .faq-answer {
      max-height:0;
      overflow:hidden;
      transition:max-height 0.3s;
      padding:0 24px;
      color:#B0B0B0;
    }
    .faq-item.active .faq-answer {
      max-height:200px;
      padding-bottom:18px;
    }
    /* CTA */
    .cta-band {
      background: linear-gradient(135deg, #E63946 0%, #7B2D8E 100%);
      text-align: center;
      border-radius: 24px;
      padding: 70px 24px;
    }
    /* 页脚 */
    .site-footer {
      background: #0A0A0A;
      padding: 48px 24px;
      text-align: center;
      color: #777;
    }
    @media (max-width: 1024px) {
      .features-grid { grid-template-columns: 1fr 1fr; }
      .services-grid { grid-template-columns: 1fr; }
      .steps { flex-direction: column; }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .features-grid { grid-template-columns: 1fr; }
      .hero-actions { flex-direction: column; align-items: flex-start; }
    }