*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:#1a1a1a;background:#f5f6f8}.app-layout{display:flex;flex-direction:column;min-height:100vh}.app-layout>header{padding:.75rem 1.25rem;background:#1f2937;color:#fff}.app-body{display:flex;flex:1}.app-body>nav{width:220px;flex-shrink:0;background:#fff;border-right:1px solid #e2e2e2;padding:1rem 0}.app-body>nav ul{list-style:none;margin:0;padding:0}.app-body>nav a{display:block;padding:.6rem 1.25rem;color:#374151;text-decoration:none}.app-body>nav a.active{background:#eef2ff;color:#4338ca;font-weight:600}.app-body>main{flex:1;padding:1.5rem}