/* 간단한 스타일: 캔버스 중앙 배치, HUD */
:root{
    --bg: #000;
    --fg: #eaeaea;
    --accent: #6ee7b7;
}
*{box-sizing:border-box}
html,body{height:100%;margin:0}
body{
    background:var(--bg);
    color:var(--fg);
    font-family:system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
    display:flex;
    align-items:center;
    justify-content:center;
}
.wrap{width:90%;max-width:900px;text-align:center}
#gameCanvas{display:block;margin:12px auto;background:#111;border:2px solid #222;border-radius:6px}
.pixelated { image-rendering: pixelated; image-rendering: crisp-edges; }
.hud{display:flex;justify-content:space-between;color:var(--fg);font-weight:600;margin-bottom:6px}
.instructions{color:#9aa0a6;font-size:13px;margin-top:6px}
.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.game-over{color:#ff7b7b;font-weight:700}

.difficulty{margin-top:8px;color:#cbd5db;display:flex;gap:8px;justify-content:center;align-items:center}
.diff-btn{background:#222;border:3px solid #333;color:var(--fg);padding:6px 10px;border-radius:2px;cursor:pointer;font-family: 'Courier New', monospace;font-weight:700;letter-spacing:1px}
.diff-btn:hover{background:#2b2b2b}
.diff-btn.active{background:#6ee7b7;color:#022c22;border-color:#4dd7a0;box-shadow:4px 4px 0 #0b3b2a}

/* Pixel feel for HUD text */
.hud, .instructions { font-family: 'Courier New', monospace; text-shadow: 1px 1px 0 #000; }