*{box-sizing:border-box;font-family:Segoe UI,Roboto,Arial,Helvetica,sans-serif}
body{margin:0;display:flex;flex-direction:column;min-height:100vh}
header{background:#1068ff;color:white;padding:12px}
header h1{margin:0 0 6px}
.note{margin:0;font-size:0.9rem;opacity:0.95}
main{padding:12px;flex:1}
.controls{display:flex;gap:18px}
.col{flex:1;background:#f6f8fb;padding:12px;border-radius:8px}
.col h2{margin-top:0}
.buttons{margin-top:8px;display:flex;gap:8px}
canvas{background:white;border:1px solid #ddd;display:block;margin-top:8px}
footer{padding:8px;font-size:0.9rem;border-top:1px solid #eee}
label{display:block;margin-top:8px}
button{padding:8px 12px;border-radius:6px;border:1px solid #ccc;background:#fff;cursor:pointer}
button:disabled{opacity:0.5;cursor:default}