:root{
    --panel:#fff; --bg:#f6f7fb; --ink:#111; --muted:#666; --border:#d9d9d9; --accent:#0b73c8;
    --radius:12px; --pad:12px; --gap:8px; --input-h:34px;
  }
  *{box-sizing:border-box;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif}

  /* Responsive layout: full-width page; wrap when narrow */
  body{
    margin:0;
    background:var(--bg);
    color:var(--ink);
    padding:16px;
  }
  .wrap{
    display:flex;
    gap:16px;
    align-items:flex-start;
    flex-wrap:wrap;       /* stacks on small screens */
    width:100%;
    max-width:none;
  }
  .left-col, .right-col{ flex:0 0 auto; }
  .panel{
    width:300px; max-width:300px;
    background:var(--panel); border:1px solid var(--border); border-radius:var(--radius);
    padding:var(--pad); box-shadow:0 1px 4px rgba(0,0,0,.06);
  }
  @media (max-width: 680px){
    .wrap{ justify-content:center; }
    .left-col, .right-col{
      width:100%;
      flex-basis:100%;
      display:flex;
      flex-direction:column;
      align-items:center;
      gap:16px;
    }
    .panel{
      width:100%;
      max-width:300px;   /* keep “classic” 300px panels, centered */
      margin:0 auto;
    }
  }

  h2{margin:0 0 8px;font-size:16px}

  .controls{display:grid;gap:var(--gap);grid-template-columns:repeat(2,minmax(0,1fr))}
  .row{display:contents}
  .field{display:flex;flex-direction:column;gap:4px;min-width:0}
  label{color:var(--muted);font-size:12px;line-height:1}
  input,select,button{
    width:100%;min-width:0;height:var(--input-h);
    padding:0 10px;font-size:13px;line-height:var(--input-h);
    border:1px solid var(--border);border-radius:8px;background:#fff;outline:none
  }
  input:focus,select:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(11,115,200,.12)}
  .calc[readonly]{background:#f3f4f6;color:#555;border-color:#e5e7eb}

  .grid-wrap{display:flex;flex-direction:column;gap:8px}
  .grid-canvas{display:block;width:100%;height:auto;border:1px solid var(--border);border-radius:8px;background:#fff}
  .legend{font-size:12px;color:#6b7280;display:flex;justify-content:space-between}
  .hint{font-size:12px;color:#777;margin-top:6px}

  .actions{display:flex;gap:8px;align-items:center}
  .btn{height:var(--input-h);padding:0 12px;border-radius:8px;border:1px solid var(--border);background:#fff;cursor:pointer}
  .btn.primary{background:var(--accent);color:#fff;border:none}
  .btn:disabled{opacity:.6;cursor:not-allowed}

  .list{display:flex;flex-direction:column;gap:6px;max-height:160px;overflow:auto}
  .hs-item{display:grid;grid-template-columns:1fr auto auto;gap:6px;align-items:center;border:1px solid #e5e7eb;border-radius:8px;padding:6px 8px;background:#fafafa}
  .pill{font-size:11px;color:#555;background:#eef2ff;border:1px solid #dbeafe;padding:2px 6px;border-radius:999px}
  .del{background:#fff;border:1px solid #e5e7eb;border-radius:6px;padding:2px 8px;cursor:pointer}
  .del:hover{background:#fee2e2;border-color:#fecaca}

  .small{font-size:12px;color:#6b7280}
  .note{font-size:12px;color:#b91c1c;margin-top:6px}

  .chart{display:none;margin-top:8px;border:1px solid var(--border);border-radius:8px}
  .chart.pick{outline:2px dashed #0b73c8; outline-offset:3px}
  .vis-legend{display:flex;justify-content:space-between;font-size:12px;color:#555;margin-top:4px}
  .key{display:inline-flex;align-items:center;gap:6px}
  .swatch{width:12px;height:12px;border-radius:2px;display:inline-block}

  table{width:100%;border-collapse:collapse;font-size:12px}
  th,td{padding:6px 6px;border-bottom:1px solid #e5e7eb;text-align:right;white-space:nowrap}
  th:first-child,td:first-child{text-align:center}
  thead th{position:sticky;top:0;background:#fafafa;z-index:1}
  .tbl-wrap{max-height:220px;overflow:auto;border:1px solid var(--border);border-radius:8px}