:root {
   --primary: #4f46e5;
   --primary-dark: #4338ca;
   --bg: #f8fafc;
   --card: #ffffff;
   --text: #1e293b;
   --muted: #64748b;
   --border: #e2e8f0;
 }

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

 html {
   scroll-behavior: smooth;
 }

 body {
   font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
   background: var(--bg);
   color: var(--text);
   line-height: 1.6;
 }

 .container {
   max-width: 960px;
   margin: 0 auto;
   padding: 0 20px;
 }

 .site-header {
   background: rgba(255, 255, 255, 0.9);
   backdrop-filter: blur(10px);
   border-bottom: 1px solid var(--border);
   position: sticky;
   top: 0;
   z-index: 10;
 }

 .header-inner {
   display: flex;
   align-items: center;
   justify-content: space-between;
   height: 64px;
 }

 .brand {
   display: flex;
   align-items: center;
   gap: 10px;
 }

 .brand-icon {
   width: 36px;
   height: 36px;
   border-radius: 10px;
 }

 .brand-name {
   font-size: 20px;
   font-weight: 700;
 }

 .nav {
   display: flex;
   gap: 24px;
 }

 .nav a {
   color: var(--muted);
   text-decoration: none;
   font-size: 15px;
 }

 .nav a:hover {
   color: var(--primary);
 }

 .hero {
   padding: 72px 0 56px;
 }

 .hero-inner {
   display: grid;
   grid-template-columns: 1.2fr 0.8fr;
   gap: 40px;
   align-items: center;
 }

 .eyebrow {
   color: var(--primary);
   font-weight: 600;
   letter-spacing: 1px;
   margin-bottom: 12px;
 }

 h1 {
   font-size: 42px;
   line-height: 1.2;
   letter-spacing: 0;
   margin-bottom: 16px;
 }

 .hero-desc {
   color: var(--muted);
   font-size: 17px;
   margin-bottom: 28px;
 }

 .hero-actions {
   display: flex;
   gap: 12px;
   flex-wrap: wrap;
 }

 .btn {
   display: inline-block;
   padding: 12px 24px;
   border-radius: 10px;
   text-decoration: none;
   font-size: 15px;
   font-weight: 600;
   border: 1px solid transparent;
   cursor: pointer;
 }

 .btn-primary {
   background: var(--primary);
   color: #fff;
 }

 .btn-primary:hover {
   background: var(--primary-dark);
 }

 .btn-ghost {
   background: var(--card);
   border-color: var(--border);
   color: var(--text);
 }

 .hero-visual {
   display: flex;
   justify-content: center;
 }

 .hero-icon {
   width: 180px;
   height: 180px;
   border-radius: 36px;
   box-shadow: 0 20px 50px rgba(79, 70, 229, 0.18);
 }

 .features {
   padding: 56px 0;
 }

 .features h2,
 .download h2 {
   font-size: 30px;
   text-align: center;
   margin-bottom: 32px;
 }

 .feature-grid {
   display: grid;
   grid-template-columns: repeat(3, 1fr);
   gap: 16px;
 }

 .feature-card {
   background: var(--card);
   border: 1px solid var(--border);
   border-radius: 12px;
   padding: 20px;
 }

 .feature-card h3 {
   font-size: 17px;
   margin-bottom: 8px;
 }

 .feature-card p {
   color: var(--muted);
   font-size: 14px;
 }

 .download {
   padding: 56px 0;
 }

 .download-desc {
   text-align: center;
   color: var(--muted);
   margin-bottom: 28px;
 }

 .download-grid {
   display: grid;
   grid-template-columns: repeat(2, 1fr);
   gap: 16px;
 }

 .download-card {
   background: var(--card);
   border: 1px solid var(--border);
   border-radius: 12px;
   padding: 24px;
   text-align: center;
 }

 .download-card h3 {
   margin-bottom: 6px;
 }

 .download-card p {
   color: var(--muted);
   font-size: 14px;
   margin-bottom: 16px;
 }

 .site-footer {
   border-top: 1px solid var(--border);
   padding: 24px 0;
   text-align: center;
   color: var(--muted);
 }

 .footer-small {
   font-size: 12px;
   margin-top: 4px;
 }

 @media (max-width: 720px) {
   .hero-inner {
     grid-template-columns: 1fr;
     text-align: center;
   }

   .hero-actions {
     justify-content: center;
   }

   h1 {
     font-size: 32px;
   }

   .hero-icon {
     width: 140px;
     height: 140px;
   }

   .feature-grid,
   .download-grid {
     grid-template-columns: 1fr;
   }
 }