:root{--bg:#0f1115;--panel:#171a21;--ink:#e7e9ee;--muted:#9aa3b2;--accent:#7c3aed;--border:#262b36}*{box-sizing:border-box}body,html{margin:0;padding:0;background:var(--bg);color:var(--ink)}body{font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif}.shell-header{position:-webkit-sticky;position:sticky;top:0;z-index:10;display:flex;align-items:center;gap:12px;flex-wrap:wrap;padding:10px 14px;background:var(--panel);border-bottom:1px solid var(--border)}.brand{font-weight:700;letter-spacing:.02em}.timer{font-feature-settings:"tnum";font-variant-numeric:tabular-nums;font-weight:600;color:var(--accent)}.spacer{flex:1 1}.btn{background:transparent;color:var(--ink);border:1px solid var(--border);border-radius:8px;padding:6px 10px;font-size:13px;cursor:pointer}.btn.primary,.btn:hover{border-color:var(--accent)}.btn.primary{background:var(--accent);color:#fff}.btn:disabled{opacity:.5;cursor:not-allowed}.version-nav{display:flex;align-items:center;gap:6px;font-size:13px;color:var(--muted)}.canvas-wrap{max-width:760px;margin:0 auto;padding:16px}.canvas-frame{width:100%;border:1px solid var(--border);border-radius:12px;background:#fff;display:block}.about{max-width:760px;margin:0 auto;padding:0 16px 40px;color:var(--muted);font-size:14px;line-height:1.6}.about h2{color:var(--ink);font-size:16px}.modal-backdrop{position:fixed;inset:0;background:rgba(0,0,0,.6);display:flex;align-items:center;justify-content:center;padding:16px;z-index:100}.modal{background:var(--panel);border:1px solid var(--border);border-radius:14px;width:100%;max-width:440px;padding:18px}.modal h3{margin:0 0 4px}.modal .target{color:var(--muted);font-size:13px;margin-bottom:10px;word-break:break-all}.modal textarea{width:100%;min-height:96px;background:var(--bg);color:var(--ink);border:1px solid var(--border);border-radius:8px;padding:10px;font:inherit;resize:vertical}.modal .row{display:flex;gap:8px;justify-content:flex-end;margin-top:12px}.toast{position:fixed;bottom:18px;left:50%;transform:translateX(-50%);background:var(--panel);border:1px solid var(--border);color:var(--ink);padding:10px 14px;border-radius:10px;z-index:200;font-size:14px}.building{color:var(--accent);font-size:13px;display:inline-flex;align-items:center;gap:6px}.spinner{width:12px;height:12px;border:2px solid var(--border);border-top-color:var(--accent);border-radius:50%;animation:spin .8s linear infinite;display:inline-block}@keyframes spin{to{transform:rotate(1turn)}}