*{box-sizing:border-box}body{margin:0}header{min-height:72px;padding:12px 24px;display:flex;align-items:center;gap:24px;border-bottom:4px solid #193d57;background:#fffbea;color:#193d57}header strong{letter-spacing:2px;border-left:8px solid #54cc52;padding-left:12px}button{font:inherit;background:#54cc52;color:#193d57;padding:12px 20px;cursor:pointer}button:disabled{opacity:.5;cursor:wait}#next{margin-left:auto}#status{margin:0;padding:0 24px;color:#ad3833;background:#fffbea}#status:not(:empty){padding:12px 24px}#welcome{min-height:calc(100dvh - 72px);padding:9vh 7vw;background:linear-gradient(90deg,#fffbeaf2 0 38%,#fffbea00 78%),url('/school-bg.png') center/cover;image-rendering:pixelated}#welcome small{background:#193d57;color:#fffbea;padding:10px 14px;display:inline-block}h1{font-size:clamp(30px,5vw,64px);line-height:1.55;color:#193d57;text-shadow:3px 3px #fffbea;letter-spacing:-1px}#welcome p{line-height:1.9;max-width:530px}iframe{display:block;width:100%;height:calc(100dvh - 72px);border:0;background:#29b0ff}[hidden]{display:none!important}@media(max-width:600px){header{gap:10px;padding:10px 12px;flex-wrap:wrap}header strong{font-size:12px}#progress{font-size:12px}#next{padding:8px;font-size:12px}#welcome{padding:7vh 6vw;background:linear-gradient(#fffbeae8,#fffbea66),url('/school-bg.png') center/cover}iframe{height:calc(100dvh - 104px)}}
/* Keep one scrolling game viewport, even when the toolbar wraps on a phone. */
iframe#game{height:calc(100dvh - var(--shell-top,72px))}
@media(max-width:600px){
  body>header{gap:8px;padding:8px 12px;min-height:60px}
  body>header strong{font-size:11px;letter-spacing:0}
  #progress{margin-left:auto;font-size:11px}
  #next{flex-basis:100%;min-height:44px;margin:0}
  #welcome{padding:32px 20px;min-height:calc(100dvh - var(--shell-top,72px))}
  #welcome h1{font-size:clamp(25px,7vw,36px)}
  #welcome small{font-size:11px;line-height:1.8}
  #welcome button{display:block;width:100%;margin:16px 0 0;min-height:48px}
  #status:not(:empty){font-size:12px;line-height:1.6;padding:8px 12px}
}