/* ===========================================================================
   Sudoku — layout on top of corner.css. Big 9x9 grid with bold 3x3 boxes, a
   big number pad, pencil marks, undo, hint, and an optional error check. Uses
   numbers (inherently colorblind-safe); the error check adds an underline mark,
   not color alone. Endless: every puzzle is generated fresh client-side. Sizes
   via --cell (set by fit()).
   =========================================================================== */
.sk-main { --cell: 40px; --pad-h: 52px;
  max-width: 560px; margin: 0 auto; padding: 6px clamp(10px, 3vw, 20px) 24px;
  display: flex; flex-direction: column; align-items: center; }

.sk-head { width: 100%; text-align: center; margin: 2px 0 6px; }
.sk-head h1 { font-size: clamp(1.4rem, 5.2vw, 2rem); }
.sk-head .sk-sub { color: var(--ink-soft); font-weight: 700; font-size: .92rem; margin-top: 1px; }

/* difficulty segmented control */
.sk-diff { display: inline-flex; margin: 8px 0 2px; background: var(--surface-2);
  border: 1px solid var(--line); border-radius: 999px; padding: 3px; gap: 2px; }
.sk-diff button { border: 0; background: transparent; cursor: pointer; min-height: 40px; padding: 0 16px;
  border-radius: 999px; font-family: var(--font-display); font-weight: 600; font-size: .98rem; color: var(--ink-soft); }
.sk-diff button[aria-pressed="true"] { background: var(--accent); color: var(--on-accent); }

.sk-controls { display: flex; flex-wrap: wrap; justify-content: center; gap: 6px; margin: 6px 0 2px; width: 100%; }
.sk-controls .qc-iconbtn { min-height: 44px; min-width: 0; padding: 0 12px; font-size: .84rem; gap: .32em; box-shadow: var(--shadow-soft); }
.sk-controls .qc-iconbtn[aria-pressed="true"] { background: var(--accent); color: var(--on-accent); border-color: transparent; }

.sk-msg { min-height: 1.5em; margin: 4px 0 2px; text-align: center; font-family: var(--font-display);
  font-weight: 600; font-size: 1rem; color: var(--ink); }

/* ---- grid ---- */
.sk-grid { display: grid; grid-template-columns: repeat(9, var(--cell)); grid-template-rows: repeat(9, var(--cell));
  margin: 4px auto 0; background: var(--surface);
  border: 3px solid var(--ink-soft); border-radius: 6px; overflow: hidden; }
.sk-cell { position: relative; display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--line); font-family: var(--font-display); font-weight: 600;
  font-size: calc(var(--cell) * 0.56); line-height: 1; color: var(--accent-ink);
  cursor: pointer; user-select: none; -webkit-tap-highlight-color: transparent; background: var(--surface); }
.sk-cell.box-r { border-right: 2.5px solid var(--ink-soft); }
.sk-cell.box-b { border-bottom: 2.5px solid var(--ink-soft); }
.sk-cell.given { color: var(--ink); font-weight: 700; }
.sk-cell.peer { background: var(--surface-2); }
.sk-cell.same { background: var(--accent-soft); }
.sk-cell.sel { background: color-mix(in srgb, var(--accent) 26%, var(--surface)); }
.sk-cell.sel::after { content: ""; position: absolute; inset: 0; border: 3px solid var(--accent-ink); pointer-events: none; }
.sk-cell.wrong { color: #C0392B; text-decoration: underline; text-decoration-thickness: 2px; }
@media (prefers-color-scheme: dark) { .sk-cell.wrong { color: #FF7A6B; } }
/* pencil marks */
.sk-notes { position: absolute; inset: 0; display: grid; grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(3, 1fr); padding: 1px; }
.sk-notes span { display: flex; align-items: center; justify-content: center;
  font-family: var(--font-body); font-weight: 700; font-size: calc(var(--cell) * 0.24); color: var(--ink-soft); line-height: 1; }

/* ---- number pad ---- */
.sk-pad { display: grid; grid-template-columns: repeat(9, 1fr); gap: 5px; width: 100%; max-width: 460px; margin: 12px auto 0; }
.sk-pad button { height: var(--pad-h); min-width: 0; border: 1px solid var(--line); border-radius: 10px;
  background: var(--surface-2); color: var(--ink); font-family: var(--font-display); font-weight: 700;
  font-size: clamp(1.1rem, calc(var(--pad-h) * 0.5), 1.6rem); cursor: pointer; -webkit-tap-highlight-color: transparent; }
.sk-pad button:active { transform: translateY(2px); }
.sk-pad button.done { color: var(--line); pointer-events: none; }

.sk-tools { display: flex; justify-content: center; gap: 8px; width: 100%; max-width: 460px; margin: 8px auto 0; flex-wrap: wrap; }
.sk-tools .qc-iconbtn { min-height: 46px; padding: 0 14px; font-size: .9rem; gap: .32em; flex: 1 1 0; justify-content: center; }
.sk-tools .qc-iconbtn[aria-pressed="true"] { background: var(--accent); color: var(--on-accent); border-color: transparent; }

/* ---- result ---- */
.sk-result { display: none; width: 100%; max-width: 460px; margin: 12px 0 2px; padding: 14px 16px;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); text-align: center; }
body.sk.is-done .sk-result { display: block; }
body.sk.is-done .sk-pad, body.sk.is-done .sk-tools { display: none; }
.sk-result h2 { font-size: 1.3rem; margin-bottom: .2em; }
.sk-result .streakline { color: var(--ink-soft); font-weight: 700; margin-top: 4px; }
.sk-result-actions { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: 14px; }

@media (max-width: 460px) {
  .sk-controls .lbl, .sk-tools .lbl { display: none; }
  .sk-controls .qc-iconbtn { padding: 0 13px; font-size: 1.15rem; }
  .sk-tools .qc-iconbtn { padding: 0; font-size: 1.2rem; }
  .sk-diff button { padding: 0 11px; font-size: .88rem; }
}

/* ---- print: a clean black-and-white puzzle to solve on paper ---- */
@media print {
  .qc-nav, .qc-foot, .sk-diff, .sk-controls, .sk-msg, .sk-pad, .sk-tools, .sk-result, .sk-sub, .qc-sr, .qc-modal-overlay { display: none !important; }
  html, body, .sk-main { background: #fff !important; color: #000 !important; }
  .sk-main { --cell: 48px !important; max-width: none; padding: 0; }
  .sk-head { margin: 0 0 10px; }
  .sk-head h1 { color: #000 !important; }
  .sk-grid { border: 3px solid #000 !important; background: #fff !important; margin: 10px auto; }
  .sk-cell { background: #fff !important; color: #000 !important; border: 1px solid #999 !important; }
  .sk-cell.box-r { border-right: 2.5px solid #000 !important; }
  .sk-cell.box-b { border-bottom: 2.5px solid #000 !important; }
  .sk-cell.given { font-weight: 800 !important; }
  .sk-cell:not(.given) { color: #444 !important; }               /* your entries a touch lighter */
  .sk-cell.peer, .sk-cell.same, .sk-cell.sel { background: #fff !important; }
  .sk-cell.sel::after { display: none !important; }
  .sk-cell.wrong { color: #000 !important; text-decoration: none !important; }
  .sk-notes span { color: #666 !important; }
  /* on a "with my numbers" printout, lightly shade the cells you filled in so
     they're easy to tell from the printed givens (force it to actually print) */
  body:not(.print-blank) .sk-cell.filled {
    background: #e6e6e6 !important;
    -webkit-print-color-adjust: exact !important; print-color-adjust: exact !important;
  }
  /* "Blank puzzle": print only the givens, not the player's own numbers/notes */
  body.print-blank .sk-cell:not(.given) { color: transparent !important; }
  body.print-blank .sk-cell .sk-notes { display: none !important; }
}