:root{--bg: #0a1018;--panel: #16222f;--line: #294056;--ink: #eaf4fb;--dim: #8fb0c4;--accent: #2f9bb3;--ok: #62d98a;--bad: #e0654a}*{box-sizing:border-box}html,body{margin:0;height:100%}body{background:radial-gradient(900px 560px at 50% -8%,#12283a,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:600px;padding:12px 12px 26px}header{text-align:center;margin-bottom:6px}h1{margin:0;font-size:26px;letter-spacing:4px;font-weight:800;color:var(--accent)}.sub{margin:2px 0 0;color:var(--dim);font-size:13px}.bar{display:flex;gap:8px;justify-content:center;flex-wrap:wrap;align-items:center;margin:9px 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:#04222b}.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)}.status{text-align:center;min-height:20px;margin:6px 0;color:var(--dim);font-size:13px;font-weight:600}.stage{position:relative;display:flex;justify-content:center}canvas#cv{width:100%;max-width:520px;height:auto;display:block;border-radius:8px;background:#0b1019;box-shadow:0 12px 34px #0000008c;touch-action:none;cursor:pointer}.overlay{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;background:#060c14bd;border-radius:8px;backdrop-filter:blur(3px)}.overlay.hidden{display:none}.card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:22px 26px;text-align:center;max-width:360px}.card h2{margin:0 0 6px;font-size:24px;color:var(--accent)}.card p{margin:6px 0;color:var(--dim);font-size:14px}.card .row{display:flex;gap:8px;justify-content:center;margin-top:14px}.tray{display:flex;gap:10px;flex-wrap:wrap;justify-content:center;margin:14px 0 4px}.piece{background:var(--panel);border:2px solid var(--line);border-radius:10px;padding:8px;cursor:pointer;display:flex;align-items:center;justify-content:center;min-width:44px;min-height:44px}.piece:hover{border-color:var(--accent)}.piece.sel{border-color:var(--accent);box-shadow:0 0 0 2px #2f9bb359}.piece.placed{opacity:.35}.hint{text-align:center;color:var(--dim);font-size:12px;margin-top:10px;line-height:1.5}