html, body { margin: 0; height: 100%; overflow: hidden; background: #0f1a2b; touch-action: none; -webkit-user-select: none; user-select: none; overscroll-behavior: none; }
canvas { display: block; }
#feel { position: fixed; right: 8px; top: 8px; background: rgba(0,0,0,.75); color: #fff; font: 12px/1.5 -apple-system, Helvetica, sans-serif; padding: 8px 10px; border-radius: 8px; width: 190px; z-index: 9; }
#feel label { display: block; margin: 4px 0; } #feel input { width: 100%; } #feel output { float: right; opacity: .8; } #feel button { margin-top: 6px; font-size: 12px; }
.back { position: fixed; left: 10px; top: 10px; color: rgba(255,255,255,.7); text-decoration: none; font: 600 13px -apple-system, Helvetica, sans-serif; z-index: 9; background: rgba(0,0,0,.3); padding: 6px 10px; border-radius: 6px; }