/* ==========================================================================
   Sudoku site — shared styles  (clean blue / rounded aesthetic)
   ========================================================================== */
:root {
  --blue: #3f5bd6;
  --blue-dark: #2f46ac;
  --blue-soft: #eef1fb;
  --blue-softer: #f6f8fe;
  --ink: #2b3556;
  --muted: #8a93b2;
  --line: #d9def0;
  --line-strong: #9aa4cf;
  --bg: #f3f5fc;
  --white: #ffffff;
  --danger: #e2574c;
  --good: #2fa36b;
  --radius: 16px;
  --shadow: 0 6px 20px rgba(51, 66, 130, 0.08);
  --font: "Segoe UI", system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { max-width: 1040px; margin: 0 auto; padding: 0 20px; }

/* ---- Header / nav ---- */
.site-header {
  background: var(--white);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 20;
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 20px; color: var(--ink); }
.brand-mark {
  width: 34px; height: 34px; border-radius: 9px; background: var(--blue);
  color: #fff; display: grid; place-items: center; font-size: 18px; font-weight: 800;
}
.nav-links { display: flex; gap: 6px; flex-wrap: wrap; }
.nav-links a {
  padding: 8px 14px; border-radius: 999px; color: var(--ink);
  font-weight: 600; font-size: 15px;
}
.nav-links a:hover { background: var(--blue-soft); text-decoration: none; }
.nav-links a.active { background: var(--blue); color: #fff; }
.nav-toggle { display: none; background: none; border: 0; font-size: 26px; color: var(--ink); cursor: pointer; }

@media (max-width: 720px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    background: #fff; flex-direction: column; padding: 10px 20px 16px;
    border-bottom: 1px solid var(--line); gap: 4px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { border-radius: 10px; }
}

/* ---- Layout ---- */
main { padding: 26px 0 60px; }
.page-title { font-size: 30px; margin: 6px 0 4px; }
.lead { color: var(--muted); margin: 0 0 22px; font-size: 16px; }

/* ---- Game layout ---- */
.game-wrap { display: grid; grid-template-columns: minmax(0,1fr) 300px; gap: 28px; align-items: start; }
@media (max-width: 860px) { .game-wrap { grid-template-columns: 1fr; } }

@media (max-width: 860px) {
  main { padding-bottom: 150px; }
  .game-wrap { gap: 12px; }
  .game-wrap > .panel:first-child { padding: 10px; }
  .game-wrap > .panel:last-child {
    position: fixed;
    z-index: 30;
    left: 0;
    right: 0;
    bottom: 0;
    display: grid;
    grid-template-columns: minmax(120px, 0.7fr) minmax(0, 1.3fr);
    gap: 10px;
    align-items: center;
    padding: 10px max(12px, calc((100vw - 760px) / 2));
    border-radius: 18px 18px 0 0;
    border-top: 1px solid var(--line);
    box-shadow: 0 -8px 24px rgba(51, 66, 130, 0.14);
  }
  .game-wrap .pad-tools { margin: 0; gap: 6px; }
  .game-wrap .tool { border-radius: 12px; }
  .game-wrap .numpad { grid-template-columns: repeat(9, 1fr); gap: 4px; }
  .game-wrap .numpad button {
    aspect-ratio: auto;
    min-width: 0;
    height: 48px;
    border-radius: 10px;
    font-size: clamp(18px, 5vw, 26px);
  }
}

@media (max-width: 560px) {
  .container { padding-left: 12px; padding-right: 12px; }
  main { padding-top: 16px; padding-bottom: 126px; }
  .page-title { font-size: 25px; }
  .lead { margin-bottom: 14px; font-size: 14px; }
  .controls-row { gap: 7px; margin-bottom: 10px; }
  .seg button { padding: 6px 11px; }
  select.diff, .btn { padding: 8px 10px; }
  .timer { margin-left: 0; padding: 7px 10px; font-size: 16px; }
  .game-wrap > .panel:last-child {
    grid-template-columns: 1fr;
    gap: 7px;
    padding: 8px 10px max(8px, env(safe-area-inset-bottom));
  }
  .game-wrap .pad-tools { order: 2; max-width: 260px; margin: 0 auto; width: 100%; }
  .game-wrap .tool { height: 34px; aspect-ratio: auto; }
  .game-wrap .tool svg { width: 22px; height: 22px; }
  .game-wrap .tool .badge { top: -4px; right: -4px; min-width: 18px; height: 18px; font-size: 10px; }
  .game-wrap .tool .flag { top: -4px; right: -4px; font-size: 8px; }
  .game-wrap .numpad { order: 1; }
  .game-wrap .numpad button { height: 42px; border-radius: 9px; }
}

.panel {
  background: var(--white); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 18px;
}

.controls-row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin-bottom: 16px; }
.seg { display: inline-flex; background: var(--blue-soft); border-radius: 999px; padding: 4px; gap: 2px; }
.seg button {
  border: 0; background: transparent; color: var(--ink); font-weight: 600;
  padding: 7px 14px; border-radius: 999px; cursor: pointer; font-size: 14px;
}
.seg button.active { background: var(--blue); color: #fff; }

select.diff, .btn {
  border: 1px solid var(--line); background: #fff; color: var(--ink);
  font-weight: 600; padding: 9px 14px; border-radius: 12px; cursor: pointer; font-size: 14px;
  font-family: var(--font);
}
.btn.primary { background: var(--blue); color: #fff; border-color: var(--blue); }
.btn.primary:hover { background: var(--blue-dark); }
.btn:hover { background: var(--blue-soft); }

.timer {
  margin-left: auto; display: inline-flex; align-items: center; gap: 8px;
  font-variant-numeric: tabular-nums; font-weight: 700; font-size: 18px; color: var(--ink);
  background: var(--blue-soft); padding: 8px 14px; border-radius: 12px;
}
.timer .pause-btn { background: none; border: 0; cursor: pointer; color: var(--blue); font-size: 16px; padding: 0; line-height: 1; }

/* ---- Board ---- */
.board {
  width: min(100%, 540px); aspect-ratio: 1/1; margin: 0 auto;
  display: grid; grid-template-columns: repeat(9, 1fr); grid-template-rows: repeat(9, 1fr);
  background: var(--line-strong); border: 3px solid var(--line-strong); border-radius: 12px; overflow: hidden;
  gap: 1px; user-select: none; position: relative;
}
.cell {
  background: #fff; display: flex; align-items: center; justify-content: center;
  font-size: clamp(18px, 4.4vw, 30px); font-weight: 600; color: var(--blue);
  cursor: pointer; position: relative;
}
.cell.given { color: var(--ink); font-weight: 700; }
/* thicker 3x3 separators */
.cell.bt { box-shadow: inset 0 2px 0 var(--line-strong); }
.cell.bl { box-shadow: inset 2px 0 0 var(--line-strong); }
.cell.bt.bl { box-shadow: inset 2px 0 0 var(--line-strong), inset 0 2px 0 var(--line-strong); }
.cell.selected { background: #dfe6fb; }
.cell.peer { background: var(--blue-softer); }
.cell.same { background: #d3ddf9; }
.cell.conflict { color: var(--danger); background: #fde8e6; }
.cell.hinted { animation: pop .5s ease; background: #dff3e8; }
@keyframes pop { 0%{transform:scale(1);} 40%{transform:scale(1.15);} 100%{transform:scale(1);} }

.notes { display: grid; grid-template-columns: repeat(3,1fr); grid-template-rows: repeat(3,1fr);
  width: 100%; height: 100%; font-size: clamp(8px, 1.6vw, 11px); color: var(--muted); font-weight: 600; }
.notes span { display: grid; place-items: center; }

/* killer cage overlay */
.cage-sum { position: absolute; top: 2px; left: 3px; font-size: clamp(7px,1.5vw,10px);
  font-weight: 700; color: var(--blue-dark); line-height: 1; }
.cell.cage-t { border-top: 1px dashed var(--line-strong); }
.cell.cage-l { border-left: 1px dashed var(--line-strong); }

/* ---- Number pad (matches screenshot) ---- */
.pad-tools { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-bottom: 12px; }
.tool {
  aspect-ratio: 1/1; border: 0; border-radius: 18px; background: var(--blue-soft);
  color: var(--blue); display: grid; place-items: center; cursor: pointer; position: relative;
  transition: background .15s;
}
.tool:hover { background: #e3e8fb; }
.tool svg { width: 42%; height: 42%; }
.tool .badge {
  position: absolute; top: -6px; right: -6px; min-width: 22px; height: 22px; padding: 0 6px;
  background: var(--blue); color: #fff; border-radius: 999px; font-size: 12px; font-weight: 700;
  display: grid; place-items: center;
}
.tool .flag {
  position: absolute; top: -8px; right: -8px; background: var(--muted); color: #fff;
  font-size: 10px; font-weight: 800; padding: 2px 6px; border-radius: 8px; letter-spacing: .5px;
}
.tool.on .flag { background: var(--good); }
.tool.on { background: #d3ddf9; }

.numpad { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.numpad button {
  aspect-ratio: 1/1; border: 0; border-radius: 18px; background: var(--blue-soft);
  color: var(--blue); font-size: clamp(24px, 6vw, 34px); font-weight: 600; cursor: pointer;
  transition: background .12s, transform .05s;
}
.numpad button:hover { background: #e3e8fb; }
.numpad button:active { transform: scale(.96); }
.numpad button.selected { background: #cdd8f7; }
.numpad button.done { background: #e7f4ee; color: var(--good); }

/* ---- Win banner ---- */
.win {
  margin-top: 14px; text-align: center; background: #e7f4ee; color: var(--good);
  border-radius: 12px; padding: 14px; font-weight: 700; display: none;
}
.win.show { display: block; }
.daily-meta { margin-top: 12px; text-align: center; color: var(--muted); font-size: 14px; }
.share-btn { margin-left: 8px; border: 0; border-radius: 8px; padding: 6px 10px; background: var(--blue); color: #fff; cursor: pointer; font-weight: 700; }

/* ---- Generic content ---- */
.content { background: #fff; border-radius: var(--radius); box-shadow: var(--shadow); padding: 26px 30px; }
.content h2 { margin-top: 26px; }
.content h2:first-child { margin-top: 0; }
.content ul, .content ol { padding-left: 22px; }
.content li { margin: 6px 0; }
.callout { background: var(--blue-soft); border-radius: 12px; padding: 14px 18px; margin: 18px 0; }

/* ---- Printable ---- */
.print-controls { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; margin-bottom: 20px; }
.sheet { background: #fff; border-radius: var(--radius); box-shadow: var(--shadow); padding: 24px; margin-bottom: 24px; }
.print-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 26px; }
@media (max-width: 640px) { .print-grid { grid-template-columns: 1fr; } }
.mini-board { width: 100%; max-width: 300px; aspect-ratio: 1/1; margin: 8px auto 0;
  display: grid; grid-template-columns: repeat(9,1fr); grid-template-rows: repeat(9,1fr);
  border: 2px solid #333; gap: 0; }
.mini-board .mc { border: 0.5px solid #bbb; display: grid; place-items: center; font-size: 15px; color: #111; }
.mini-board .mc.bt { border-top: 1.5px solid #333; }
.mini-board .mc.bl { border-left: 1.5px solid #333; }
.puzzle-label { font-weight: 700; text-align: center; margin-bottom: 4px; }

footer.site-footer { border-top: 1px solid var(--line); background: #fff; padding: 22px 0; color: var(--muted); font-size: 14px; }
footer.site-footer .container { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; }

@media print {
  .site-header, .site-footer, .print-controls, .no-print { display: none !important; }
  body { background: #fff; }
  .sheet { box-shadow: none; page-break-after: always; padding: 0; }
  .answers-sheet { page-break-before: always; }
}

/* solver grid */
.solver-board { width: min(100%, 460px); aspect-ratio:1/1; margin: 0 auto;
  display:grid; grid-template-columns:repeat(9,1fr); grid-template-rows:repeat(9,1fr);
  border:3px solid var(--line-strong); gap:1px; background:var(--line-strong); border-radius:10px; overflow:hidden; }
.solver-board input {
  border:0; text-align:center; font-size:clamp(16px,4vw,26px); font-weight:600; color:var(--blue);
  background:#fff; width:100%; height:100%; padding:0; -moz-appearance:textfield;
}
.solver-board input::-webkit-outer-spin-button, .solver-board input::-webkit-inner-spin-button { -webkit-appearance:none; }
.solver-board input:focus { outline:2px solid var(--blue); outline-offset:-2px; background:#eef1fb; }
.solver-board input.bt { box-shadow: inset 0 2px 0 var(--line-strong); }
.solver-board input.bl { box-shadow: inset 2px 0 0 var(--line-strong); }
.solver-board input.solved { color: var(--good); }
.solver-msg { text-align:center; margin-top:14px; font-weight:700; min-height:22px; }
.solver-msg.err { color: var(--danger); }
.solver-msg.ok { color: var(--good); }