body,html{margin:0;padding:0;font-family:"Helvetica, Arial, sans-serif";color:#333}a{text-decoration:none;color:white}a:hover{color:#217dbb}header,footer{background-color:#3498db;color:white;padding:1rem;text-align:center}main{padding:2rem}.container{max-width:1200px;margin:0 auto;padding:1rem}.button{background-color:#2ecc71;border:none;color:white;padding:0.5rem 1rem;cursor:pointer;transition:background-color 0.3s ease}.button:hover{background-color:#25a25a}