body{margin:0}*{box-sizing:border-box;margin:0;padding:0}body{background:#f4f4f4;font-family:Arial,sans-serif}.container{background:#fff;border-radius:12px;max-width:700px;margin:50px auto;padding:30px;box-shadow:0 0 20px #0000001a}h1{text-align:center;color:#333;margin-bottom:20px}form{gap:10px;display:flex}input{border:1px solid #ddd;border-radius:8px;flex:1;padding:12px}button{cursor:pointer;color:#fff;border:none;border-radius:8px;padding:12px 18px}form button{background:#007bff}ul{margin-top:20px;list-style:none}li{background:#fafafa;border-radius:8px;justify-content:space-between;align-items:center;margin-bottom:10px;padding:15px;display:flex}span{cursor:pointer}.completed{color:gray;text-decoration:line-through}.edit{background:#28a745;margin-right:5px}.delete{background:#dc3545}@media (width<=600px){form{flex-direction:column}li{flex-direction:column;gap:10px}}