*{box-sizing:border-box;margin:0;padding:0}body{font-family:system-ui,-apple-system,sans-serif;line-height:1.5;color:#333;background-color:#f5f5f5;min-height:100vh}.todo-container{max-width:600px;margin:0 auto;padding:20px}h1{margin-bottom:1rem;font-size:2rem}.todo-form{margin-bottom:20px}.input-group{display:flex;gap:10px}.input-group input{flex:1;padding:8px;border:1px solid #ccc;border-radius:4px;font-size:16px}.input-group button{padding:8px 16px;background-color:#06c;color:#fff;border:none;border-radius:4px;cursor:pointer;font-family:inherit}.input-group button:disabled{background-color:#ccc;cursor:not-allowed}.error-message{color:#dc3545;margin:10px 0;padding:10px;background-color:#ffe6e6;border-radius:4px}.loading{text-align:center;color:#666;margin:20px 0}.todo-list{list-style:none;padding:0;margin:0}.todo-item{padding:10px;background-color:#fff;border:1px solid #ddd;margin-bottom:5px;border-radius:4px}