/* roulang page: index */
:root {
      --primary-dark: #1a1a1a;
      --primary-purple: #7c3aed;
      --accent-orange: #f97316;
      --accent-green: #10b981;
      --bg-soft: #fafaf9;
      --white: #ffffff;
      --text-body: #334155;
      --text-heading: #0f172a;
      --text-light: #f1f5f9;
      --border-light: #e2e8f0;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 28px rgba(0,0,0,0.06);
      --shadow-lg: 0 12px 32px rgba(0,0,0,0.08);
      --radius-card: 16px;
      --radius-btn: 12px;
      --radius-input: 10px;
      --section-gap: 6rem;
      --container-max: 1280px;
      --font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-mono: "SF Mono", "Menlo", monospace;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: var(--font-family);
      background-color: var(--bg-soft);
      color: var(--text-body);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    a, button, input, select, textarea {
      font-family: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 1.5rem;
    }
    /* 导航 */
    .nav {
      position: sticky;
      top: 0;
      z-index: 60;
      background: rgba(255, 255, 255, 0.94);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid var(--border-light);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 0.4rem;
      font-weight: 700;
      font-size: 1.35rem;
      letter-spacing: -0.5px;
      color: var(--text-heading);
      text-decoration: none;
    }
    .logo-icon {
      font-size: 1.7rem;
      filter: drop-shadow(0 2px 4px rgba(124,58,237,0.25));
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 2.5rem;
      list-style: none;
    }
    .nav-menu a {
      text-decoration: none;
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-heading);
      transition: color 0.2s;
      position: relative;
    }
    .nav-menu a:hover {
      color: var(--primary-purple);
    }
    .nav-cta {
      background-color: var(--primary-purple);
      color: white;
      padding: 0.3rem 1.3rem;
      border-radius: 30px;
      text-decoration: none;
      font-weight: 600;
      font-size: 0.9rem;
      transition: background 0.2s, box-shadow 0.2s;
    }
    .nav-cta:hover {
      background-color: #6d28d9;
      box-shadow: 0 8px 18px rgba(124,58,237,0.3);
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 2rem;
      cursor: pointer;
    }
    .mobile-menu {
      display: none;
      flex-direction: column;
      background: white;
      padding: 2rem 1.5rem;
      border-top: 1px solid var(--border-light);
    }
    .mobile-menu.show {
      display: flex;
    }
    /* Hero */
    .hero {
      background: var(--primary-dark);
      color: var(--text-light);
      padding: 4rem 0 5rem;
      position: relative;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      isolation: isolate;
    }
    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(26,26,26,0.7);
      backdrop-filter: blur(1px);
      z-index: 1;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      flex-direction: column;
      align-items: flex-start;
      max-width: 800px;
    }
    .hero h1 {
      font-size: 3.5rem;
      font-weight: 800;
      line-height: 1.1;
      letter-spacing: -0.02em;
      color: white;
      margin-bottom: 1.2rem;
    }
    .hero .sub-head {
      font-size: 1.2rem;
      max-width: 600px;
      margin-bottom: 2rem;
      color: #e2e8f0;
    }
    .hero-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
    }
    .btn-purple {
      background: var(--primary-purple);
      color: white;
      padding: 0.8rem 2rem;
      border-radius: var(--radius-btn);
      text-decoration: none;
      font-weight: 600;
      border: none;
      display: inline-block;
      transition: all 0.25s cubic-bezier(0.4,0,0.2,1);
    }
    .btn-purple:hover {
      filter: brightness(1.15);
      box-shadow: var(--shadow-lg);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--primary-purple);
      color: var(--primary-purple);
      padding: 0.8rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: 0.25s ease;
    }
    .btn-outline:hover {
      background: rgba(124,58,237,0.05);
    }
    .hero-stats {
      display: flex;
      gap: 2rem;
      margin-top: 2.5rem;
      flex-wrap: wrap;
    }
    .stat {
      background: rgba(255,255,255,0.08);
      backdrop-filter: blur(10px);
      border: 1px solid rgba(255,255,255,0.12);
      border-radius: 16px;
      padding: 0.8rem 1.3rem;
    }
    .stat-val {
      font-family: var(--font-mono);
      font-size: 1.8rem;
      font-weight: 700;
      color: white;
    }
    .stat-label {
      font-size: 0.8rem;
      color: #cbd5e1;
    }
    /* sections */
    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      margin-bottom: 3rem;
      color: var(--text-heading);
    }
    section {
      padding: var(--section-gap) 0;
    }
    /* Dashboard */
    .dashboard-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 1.25rem;
    }
    .metric-card {
      background: rgba(26,26,26,0.92);
      backdrop-filter: blur(14px);
      border: 1px solid rgba(255,255,255,0.08);
      border-radius: 20px;
      padding: 1.2rem;
      color: white;
      font-family: var(--font-mono);
    }
    .metric-val {
      font-size: 2rem;
      font-weight: 700;
    }
    .arrow-up { color: var(--accent-green); }
    .arrow-down {color: var(--accent-orange);}
    /* services grid */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 2rem;
    }
    .service-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 1.8rem;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
    }
    .service-icon {
      width: 56px;
      height: 56px;
      background: #f3f0ff;
      color: var(--primary-purple);
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 14px;
      font-size: 1.8rem;
      margin-bottom: 1.5rem;
    }
    .service-card h3 {
      font-size: 1.25rem;
    }
    .learn-more {
      color: var(--primary-purple);
      font-weight: 600;
      text-decoration: none;
    }
    /* comparison */
    .comp-row {
      display: flex;
      gap: 3rem;
    }
    .comp-left, .comp-right {
      flex:1;
      background: white;
      padding: 2rem;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
    }
    .vs {
      font-weight: 800;
      color: var(--primary-purple);
    }
    /* faq */
    .faq-item {
      background: white;
      border-bottom: 1px solid var(--border-light);
      padding: 1rem 0;
      cursor: pointer;
    }
    .faq-q {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
    }
    .faq-a {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
    }
    .faq-item.open .faq-a {
      max-height: 200px;
    }
    /* CTA */
    .cta {
      background: var(--primary-dark);
      color: white;
    }
    .form-group input, .form-group textarea {
      width:100%;
      padding:0.85rem;
      border-radius:10px;
      border:1px solid var(--border-light);
    }
    /* footer */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      background: #f1f5f9;
    }
    @media(max-width:1024px){
      .dashboard-grid{grid-template-columns: repeat(2,1fr);}
      .services-grid{grid-template-columns: repeat(2,1fr);}
      .comp-row{flex-direction: column;}
    }
    @media(max-width:768px){
      .hero h1{font-size:2.2rem;}
      .section-title{font-size:1.75rem;}
      .services-grid,.dashboard-grid{grid-template-columns:1fr;}
      .nav-menu{display:none;}
      .hamburger{display:block;}
      .footer-grid{grid-template-columns:1fr;}
      .comp-row{flex-direction:column;}
    }