body{margin:0;padding:0;font-family:system-ui,-apple-system,Segoe UI,Arial,sans-serif;line-height:1.5}.app-shell{flex-direction:column;min-height:100vh;display:flex}.app-header{background:#fafafa;border-bottom:1px solid #ddd;flex-wrap:wrap;align-items:center;gap:1rem 1.5rem;padding:.75rem 1.5rem;display:flex}.app-title{color:inherit;font-weight:600;text-decoration:none}.app-title:hover{text-decoration:underline}.app-nav{flex-wrap:wrap;gap:.75rem 1rem;display:flex}.app-nav a{color:#06c;text-decoration:none}.app-nav a:hover{text-decoration:underline}.api-backend-toggle{cursor:pointer;align-items:center;gap:.35rem;margin-left:auto;font-size:.9rem;display:inline-flex}.app-main{flex:1;max-width:56rem;padding:1.5rem}input,button{font:inherit}input[type=text],input[type=email]{border:1px solid #ccc;border-radius:4px;padding:.4rem .5rem}button{cursor:pointer;background:#f5f5f5;border:1px solid #444;border-radius:4px;padding:.4rem .8rem}button:hover{background:#e8e8e8}pre{background:#f5f5f5;border-radius:4px;padding:1rem;overflow-x:auto}