body{margin:0;font-family:Arial;background:#111;color:#fff}
header{text-align:center;padding:10px;background:#000}
nav{display:flex;flex-wrap:wrap;background:#222}
nav button{flex:1;padding:10px;background:#333;color:#fff;border:none}
.tab{display:none;padding:15px}
canvas{background:#fff;display:block;margin:auto}
#jumpBtn{display:block;margin:15px auto;padding:15px 30px;font-size:18px}
#gameOver{text-align:center;display:none}
.calc{max-width:300px;margin:auto}
.calc input{width:100%;height:50px;font-size:24px;text-align:right}
.keys{display:grid;grid-template-columns:repeat(4,1fr);gap:5px}
.keys button{padding:20px;font-size:18px}
.clear{grid-column:span 4;background:#c33;color:#fff}