:root{color-scheme:dark;font-family:system-ui,-apple-system,sans-serif;background:#0e1923;color:#edf4fa}
*{box-sizing:border-box}body{margin:0;min-height:100vh}.wrap{max-width:690px;margin:5vh auto;padding:2rem}h1{font-size:clamp(1.7rem,4vw,2.5rem)}p{line-height:1.65;color:#c4d3dd}.back,a{color:#9fd4ff}form{display:grid;gap:.8rem;margin-top:2rem}label{font-weight:600}input{font:inherit;padding:.9rem 1rem;border:1px solid #668098;border-radius:.5rem;background:#142536;color:white;width:100%}input:focus{outline:3px solid #9fd4ff}button{font:inherit;font-weight:700;background:#a8dfc7;color:#092016;border:0;border-radius:.5rem;padding:1rem;cursor:pointer;margin-top:.5rem}button:disabled{opacity:.65;cursor:default}#result{min-height:2.5rem;font-weight:600}.foot{border-top:1px solid #334d60;margin-top:2.5rem;padding-top:1rem}