body { margin:0; font-family:Arial,Helvetica,sans-serif; background:#f0e68c; }
#game-container { position:relative; width:800px; margin:auto; }
canvas { display:block; background:#add8e6; }
#ui-overlay { position:absolute; top:10px; left:10px; color:#fff; font-size:1.2em; text-shadow:0 0 2px #000; }
#screens > div { position:absolute; inset:0; background:rgba(0,0,0,0.7); color:#fff; text-align:center; padding-top:20%; display:none; }
#screens > div.visible { display:block; }
button { margin:10px; padding:10px 20px; font-size:1em; cursor:pointer; }