style.css

:root{--gap:8px;--pad:10px}
body{font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial; padding:var(--pad); margin:0; background:#fbfbfb; color:#111}
h1{font-size:18px;margin:0 0 8px}
.controls{display:flex;flex-direction:column;gap:var(--gap);max-width:980px;margin-bottom:12px}
.row{display:flex;gap:8px;flex-wrap:wrap;align-items:center}
label{font-size:13px}
input[type="number"], select, button, input[type="file"]{padding:6px;border-radius:8px;border:1px solid #ccc}
button{background:#fff;cursor:pointer}
canvas{border:1px solid #bbb;background:#fff;touch-action:none}
.small{font-size:12px;color:#444}
.status{font-size:13px;color:#222;margin-left:6px}
.controls .group{display:flex;gap:6px;flex-wrap:wrap}
.footer{font-size:12px;color:#666;margin-top:8px}
#modeIndicator{font-weight:bold;padding:2px 6px;border-radius:6px;}
@media (max-width:520px){
  .row{gap:6px}
  canvas{width:92vw;height:92vw}
}