*{margin:0;padding:0;box-sizing:border-box}:root{--green: #4CAF50;--green-light: #E8F5E9;--red: #F44336;--red-light: #FFEBEE;--orange: #FF9800;--orange-light: #FFF3E0;--blue: #2196F3;--gray: #9E9E9E;--gray-light: #F5F5F5;--dark: #212121;--white: #FFFFFF}body{font-family:Segoe UI,system-ui,-apple-system,sans-serif;font-size:18px;color:var(--dark);background:var(--gray-light);line-height:1.5}button{cursor:pointer;border:none;border-radius:8px;font-size:18px;font-weight:600;padding:14px 28px;transition:opacity .2s,transform .1s}button:active{transform:scale(.97)}button:disabled{opacity:.5;cursor:not-allowed}input{font-size:20px;padding:14px 18px;border:2px solid #ccc;border-radius:8px;outline:none;width:100%;transition:border-color .2s}input:focus{border-color:var(--blue)}.container{max-width:100%;margin:0 auto;padding:20px}h1{font-size:28px;font-weight:700}h2{font-size:22px;font-weight:600}@media(max-width:768px){.container{padding:12px}h1{font-size:22px}h2{font-size:18px}button{padding:12px 20px;font-size:16px}input{font-size:16px;padding:12px 14px}}