styles.css

:root{
  --bg:#0f1221; --panel:#161a2e; --accent:#7bd3ff; --ok:#59e38b; --bad:#ff6b6b; --ink:#eef3ff; --muted:#a7b0d0;
}
html,body{margin:0;padding:0;background:var(--bg);color:var(--ink);font-family:system-ui,-apple-system,Segoe UI,Roboto,Inter,Arial,sans-serif}
.wrap{max-width:920px;margin:0 auto;padding:16px 16px 64px}
header{display:flex;gap:12px;align-items:center;justify-content:space-between;margin:8px 0 16px}
.brand{font-weight:700;letter-spacing:.3px}
.pill{background:var(--panel);border:1px solid #2a2f50;border-radius:999px;padding:8px 12px;font-size:14px;color:var(--muted)}
.grid{display:grid;gap:12px}
.levels{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.card{background:var(--panel);border:1px solid #242947;border-radius:12px;padding:14px;display:flex;flex-direction:column;gap:8px}
.card h3{margin:0 0 4px;font-size:18px}
.lock{color:var(--muted);font-size:14px}
button{background:transparent;border:1px solid var(--accent);color:var(--accent);padding:10px 14px;border-radius:10px;font-weight:600;cursor:pointer}
button:hover{background:rgba(123,211,255,.08)}
.ghost{opacity:.65}
.smallbtn{font-size:12px;padding:6px 10px}
.hud{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin:10px 0 16px}
.hearts span{display:inline-block;width:18px;height:18px;border-radius:50%;background:var(--ok);margin-right:6px}
.hearts span.off{background:#3a3f66}
.bar{height:10px;background:#2a2f50;border-radius:999px;overflow:hidden;flex:1}
.fill{height:100%;width:0;background:linear-gradient(90deg,var(--accent),#9df7c9)}
.note{font-size:13px;color:var(--muted)}
.panel{background:var(--panel);border:1px solid #242947;border-radius:12px;padding:14px}
.qcode{white-space:pre-wrap;background:#11142a;border:1px dashed #2a2f50;border-radius:8px;padding:8px;margin-top:8px;color:#cfe3ff;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}
.options{display:grid;gap:10px;margin-top:12px}
.options button{justify-content:flex-start}
.good{outline:2px solid var(--ok)}
.bad{outline:2px solid var(--bad)}
.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}
.spacer{flex:1}
.tag{font-size:12px;border:1px solid #2a2f50;border-radius:999px;padding:4px 8px;color:var(--muted)}
.toast{position:fixed;left:50%;transform:translateX(-50%);bottom:24px;background:#0b0e1e;border:1px solid #1e2340;padding:10px 14px;border-radius:10px;color:var(--ink);opacity:0;transition:opacity .25s,transform .25s;pointer-events:none}
.toast.show{opacity:1;transform:translate(-50%,0)}
.drag-wrap{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:12px}
.bucket,.tile{border:1px dashed #39406c;border-radius:10px;padding:10px;background:#10142a}
.bucket{min-height:48px}
.tile{cursor:grab}
.bucket.correct{border-color:var(--ok)}
.bucket.wrong{border-color:var(--bad)}
.review li{margin:6px 0}
a.link{color:var(--accent);text-decoration:none}
.small{font-size:12px;color:var(--muted)}