:root{--bg: #0e1116;--panel: #181d25;--line: #2a323d;--ink: #eef3f7;--dim: #93a4b3;--accent: #e0823d;--good: #4ec98a;--tile: #222c36;--tile2: #2a3744}*{box-sizing:border-box}html,body{margin:0;height:100%}body{background:radial-gradient(900px 560px at 50% -8%,#20160d,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:28px;letter-spacing:6px;font-weight:800;color:var(--accent)}.sub{margin:3px 0 0;color:var(--dim);font-size:13px}.bar{display:flex;gap:8px;justify-content:center;flex-wrap:wrap;align-items:center;margin:10px 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:6px 13px;font:600 13px system-ui;cursor:pointer}.seg button.active{background:var(--accent);color:#241000}.btn{background:var(--panel);border:1px solid var(--line);color:var(--ink);padding:7px 14px;border-radius:999px;font:700 13px system-ui;cursor:pointer}.btn:hover{border-color:var(--accent)}.btn.primary{background:var(--accent);color:#241000;border-color:var(--accent)}.scoreboard{display:flex;gap:10px;justify-content:center;margin:8px 0;flex-wrap:wrap}.readout{background:#0a0e13;border:1px solid var(--line);border-radius:8px;padding:5px 16px;font:800 22px ui-monospace,monospace;color:var(--ink);min-width:96px;text-align:center;transition:color .12s,border-color .12s}.readout span{color:var(--dim);font-size:11px;display:block;font-weight:600;letter-spacing:.5px}.readout.target{color:var(--accent)}.readout.good{color:var(--good);border-color:var(--good)}.readout.near{color:#f0c674}.stage{position:relative}.exprwrap{margin:10px 0}.expr{min-height:56px;background:#0a0e13;border:1px solid var(--line);border-radius:10px;display:flex;flex-wrap:wrap;align-items:center;gap:6px;padding:10px 12px}.placeholder{color:var(--dim);font-size:14px;font-style:italic}.etok{font:800 22px ui-monospace,monospace;line-height:1;padding:4px 2px}.etok.enum{color:var(--ink)}.etok.eop{color:var(--accent)}.etok.epar{color:var(--good);font-size:26px}.tiles{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin:14px 0}.tile{width:58px;height:58px;background:var(--tile);border:1px solid var(--line);border-radius:12px;color:var(--ink);font:800 24px ui-monospace,monospace;cursor:pointer;transition:transform .08s,background .12s,opacity .12s}.tile:hover{background:var(--tile2);border-color:var(--accent)}.tile:active{transform:translateY(2px)}.tile.used{opacity:.25;cursor:default}.ops{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;max-width:380px;margin:0 auto}.ops button{background:var(--panel);border:1px solid var(--line);color:var(--ink);padding:12px 0;border-radius:10px;font:800 20px ui-monospace,monospace;cursor:pointer}.ops button:hover{border-color:var(--accent)}.ops button[data-paren]{color:var(--good)}.ops button.erase{font:700 14px system-ui;color:var(--dim)}.controls{display:flex;align-items:center;justify-content:center;gap:12px;margin:14px 0 0}.hintcount{color:var(--dim);font-size:12px}.overlay{position:absolute;inset:-8px;display:flex;align-items:center;justify-content:center;background:#080c10d1;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 6px;font-size:24px;color:var(--accent)}.card p{margin:6px 0;color:var(--dim);font-size:14px;line-height:1.5}.card p b{color:var(--ink)}.card .row{display:flex;gap:8px;justify-content:center;margin-top:14px}.hint{text-align:center;color:var(--dim);font-size:12px;margin-top:16px;line-height:1.5}