.container{max-width:600px;margin:0 auto;padding:20px}h1{font-size:24px;margin-bottom:10px}.form{display:flex;margin-bottom:20px}input[type=text]{flex:1;padding:8px;font-size:16px}button{padding:8px 16px;font-size:16px;background-color:#2196f3;color:#fff;border:none;cursor:pointer}.user-list{margin-bottom:20px}.user-item{display:flex;align-items:center;justify-content:space-between;margin-bottom:10px}h2{font-size:18px;margin:0}.button-group button{margin-left:10px}.actions button{margin-right:10px}@media screen and (max-width: 600px){input[type=text],button{font-size:14px}h1{font-size:20px}h2{font-size:16px}}