*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:#f5f5f5;color:#333;min-height:100vh;display:flex;justify-content:center;padding-top:60px}#app{width:100%;max-width:500px;padding:0 16px}h1{font-size:1.5rem}.auth-container{background:#fff;border-radius:8px;padding:32px;box-shadow:0 2px 8px #0000001a}.auth-container h1{text-align:center;margin-bottom:24px}.tabs{display:flex;gap:8px;margin-bottom:20px}.tab{flex:1;padding:8px;border:1px solid #ddd;background:#f9f9f9;border-radius:4px;cursor:pointer;font-size:.9rem}.tab.active{background:#333;color:#fff;border-color:#333}#auth-form{display:flex;flex-direction:column;gap:12px}#auth-form input{padding:10px 12px;border:1px solid #ddd;border-radius:4px;font-size:.95rem}#auth-form button{padding:10px;background:#333;color:#fff;border:none;border-radius:4px;cursor:pointer;font-size:.95rem}.error{color:#d32f2f;margin-top:12px;font-size:.85rem}.todo-container{background:#fff;border-radius:8px;padding:24px;box-shadow:0 2px 8px #0000001a}header{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px}.header-right{display:flex;align-items:center;gap:12px}.user-email{font-size:.8rem;color:#888}#logout-btn{padding:6px 12px;background:none;border:1px solid #ddd;border-radius:4px;cursor:pointer;font-size:.8rem}#add-form{display:flex;gap:8px;margin-bottom:16px}#todo-input{flex:1;padding:10px 12px;border:1px solid #ddd;border-radius:4px;font-size:.95rem}#add-form button{padding:10px 16px;background:#333;color:#fff;border:none;border-radius:4px;cursor:pointer}#todo-list{list-style:none}#todo-list li{display:flex;justify-content:space-between;align-items:center;padding:10px 4px;border-bottom:1px solid #eee}#todo-list li label{display:flex;align-items:center;gap:10px;cursor:pointer}#todo-list li.completed span{text-decoration:line-through;color:#aaa}.delete-btn{background:none;border:none;font-size:1.2rem;color:#ccc;cursor:pointer;padding:0 4px}.delete-btn:hover{color:#d32f2f}