:root{--green:#2e5e4e;--green-light:#4c9a7c;--bg:#f5f7f4;--card:#fff;--ink:#1a2420;--muted:#7a857f;--line:#e3e8e4;--correct:#2f8f5b;--wrong:#c0564f}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}body,html{margin:0;padding:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Noto Sans TC,Roboto,sans-serif;font-size:16px;-webkit-text-size-adjust:100%}.wrap{max-width:520px;margin:0 auto;padding:16px;min-height:100vh;display:flex;flex-direction:column}.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:20px}.btn{display:block;width:100%;border:none;border-radius:12px;padding:14px 16px;font-size:16px;font-weight:600;cursor:pointer;background:var(--green);color:#fff}.btn:disabled{opacity:.5}.btn-ghost{background:transparent;color:var(--green);border:1px solid var(--green)}.opt{display:block;width:100%;text-align:left;border:1.5px solid var(--line);background:#fff;border-radius:12px;padding:14px 16px;margin-bottom:10px;font-size:16px;color:var(--ink);cursor:pointer}.opt.sel{border-color:var(--green);background:#eef5f1}.opt.correct{border-color:var(--correct);background:#e7f5ec}.opt.wrong{border-color:var(--wrong);background:#fbeceb}.muted{color:var(--muted)}.center{text-align:center}.bar{height:6px;background:var(--line);border-radius:6px;overflow:hidden}.bar>span{display:block;height:100%;background:var(--green-light);transition:width .25s ease}.pill{display:inline-block;font-size:12px;padding:3px 10px;border-radius:999px;background:#eef5f1;color:var(--green);font-weight:600}