:root{--bg: #0d1413;--panel: #15201e;--line: #28403b;--ink: #eef6f3;--dim: #8fb0a8;--accent: #4a9c8a;--good: #5be0b8;--bad: #ff8a99;--rung: #1c2b28;--rung-done: #2f6b5d}*{box-sizing:border-box}html,body{margin:0;height:100%}body{background:radial-gradient(900px 560px at 50% -8%,#14211f,var(--bg));color:var(--ink);font-family:system-ui,-apple-system,Segoe UI,sans-serif;display:flex;justify-content:center;-webkit-user-select:none;user-select:none}#app{width:100%;max-width:540px;padding:12px 12px 26px}header{text-align:center;margin-bottom:6px}h1{margin:0;font-size:27px;letter-spacing:5px;font-weight:800;color:var(--accent)}.sub{margin:4px 0 0;color:var(--dim);font-size:13px}.bar{display:flex;gap:8px;justify-content:center;flex-wrap:wrap;align-items:center;margin:12px 0}.seg{display:inline-flex;background:var(--panel);border:1px solid var(--line);border-radius:999px;overflow:hidden}.seg button{background:none;border:none;color:var(--dim);padding:7px 16px;font:600 13px system-ui;cursor:pointer}.seg button.active{background:var(--accent);color:#052019}.select{background:var(--panel);border:1px solid var(--line);color:var(--ink);padding:7px 12px;border-radius:999px;font:600 13px system-ui;cursor:pointer}.btn{background:var(--panel);border:1px solid var(--line);color:var(--ink);padding:8px 16px;border-radius:999px;font:700 13px system-ui;cursor:pointer}.btn:hover{border-color:var(--accent)}.btn.primary{background:var(--accent);color:#052019;border-color:var(--accent)}.scoreboard{display:flex;gap:10px;justify-content:center;margin:8px 0}.readout{background:#07100e;border:1px solid var(--line);border-radius:8px;padding:5px 16px;font:800 18px ui-monospace,monospace;color:var(--accent);min-width:78px;text-align:center}.readout span{color:var(--dim);font-size:10px;display:block;font-weight:600;letter-spacing:.5px}.stage{position:relative;margin:10px 0}.ladder{display:flex;gap:5px;align-items:stretch;height:18px;padding:4px;background:#07100e;border:1px solid var(--line);border-radius:10px}.rung{flex:1;background:var(--rung);border-radius:4px;transition:background .25s,box-shadow .25s}.rung.done{background:var(--rung-done)}.rung.active{background:var(--accent);box-shadow:0 0 8px var(--accent)}.quiz{text-align:center;margin-top:18px}.prompt{font-size:clamp(18px,5.4vw,24px);font-weight:800;line-height:1.25;min-height:60px;display:flex;align-items:center;justify-content:center}.region-tag{color:var(--dim);font-size:12px;letter-spacing:1px;text-transform:uppercase;margin:2px 0 14px}.choices{display:grid;grid-template-columns:1fr 1fr;gap:10px;max-width:460px;margin:0 auto}.choice{background:var(--panel);border:1px solid var(--line);color:var(--ink);padding:16px 10px;border-radius:10px;font:700 16px system-ui;cursor:pointer;transition:transform .08s,border-color .15s}.choice:hover:not(:disabled){border-color:var(--accent)}.choice:active:not(:disabled){transform:scale(.97)}.choice:disabled{cursor:default;opacity:.9}.choice.correct{background:var(--good);color:#052019;border-color:var(--good)}.choice.wrong{background:#4a1f28;color:var(--bad);border-color:var(--bad)}.feedback{min-height:24px;margin-top:16px;font-size:15px;font-weight:600}.feedback .good{color:var(--good)}.feedback .bad{color:var(--bad)}.overlay{position:absolute;inset:-6px;display:flex;align-items:center;justify-content:center;background:#060c0bdb;border-radius:12px;backdrop-filter:blur(3px);z-index:5}.overlay.hidden{display:none}.card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:22px 26px;text-align:center;max-width:340px}.card h2{margin:0 0 8px;font-size:23px;color:var(--accent)}.card p{margin:6px 0;color:var(--ink);font-size:15px}.card .row{display:flex;gap:8px;justify-content:center;margin-top:16px}.hint{text-align:center;color:var(--dim);font-size:12px;margin-top:22px;line-height:1.6}.hint b{color:var(--ink)}