/* SudokuPuzz.com – site styles.
   Layout: graph-paper desk; a white sheet holds the content, the menu sits in a side column on wide screens and below the content on phones. */
:root{
  --paper:#e9edf2; --sheet:#fbfcfd; --ink:#1b2430; --lead:#5a6573; --rule:#c6ced8; --strong:#1b2430;
  --pen:#1f46c8; --mark:#ffe37d; --peer:#e2e8f1; --same:#c9d7fa; --error:#c2352c; --tint:#eef2f8;
  --display:"Bricolage Grotesque",ui-sans-serif,system-ui,sans-serif;
  --body:"Figtree",ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;
  --hand:"Kalam","Comic Sans MS","Bradley Hand",cursive;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --paper:#11151b; --sheet:#1a2029; --ink:#e5eaf0; --lead:#94a0ae; --rule:#2e3743; --strong:#c8d2dd;
  --pen:#93b2ff; --mark:#574b12; --peer:#222b37; --same:#2a3c66; --error:#ff7c72; --tint:#202733; color-scheme:dark}}
:root[data-theme="dark"]{
  --paper:#11151b; --sheet:#1a2029; --ink:#e5eaf0; --lead:#94a0ae; --rule:#2e3743; --strong:#c8d2dd;
  --pen:#93b2ff; --mark:#574b12; --peer:#222b37; --same:#2a3c66; --error:#ff7c72; --tint:#202733; color-scheme:dark}

*{box-sizing:border-box}
[hidden]{display:none!important}
html{-webkit-text-size-adjust:100%}
body{margin:0;background-color:var(--paper);color:var(--ink);font:17px/1.65 var(--body);
  background-image:linear-gradient(color-mix(in srgb,var(--rule) 45%,transparent) 1px,transparent 1px),
    linear-gradient(90deg,color-mix(in srgb,var(--rule) 45%,transparent) 1px,transparent 1px);
  background-size:24px 24px}
img{max-width:100%;height:auto}
a{color:var(--pen);text-underline-offset:.15em}
a:hover{text-decoration-thickness:2px}
:focus-visible{outline:3px solid var(--pen);outline-offset:2px}
.wrap{max-width:1140px;margin:0 auto;padding-inline:16px}

/* Header */
.top{padding-block:18px 12px}
.top .wrap{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px 24px}
.logo{font:800 clamp(1.7rem,4vw,2.3rem)/1 var(--display);letter-spacing:-.03em;text-decoration:none;color:var(--ink)}
.logo span{color:var(--pen);font-family:var(--hand);font-weight:700;letter-spacing:0;margin-left:2px}
.langs{display:flex;flex-wrap:wrap;gap:6px;margin:0;padding:0;list-style:none}
.langs a{display:flex;align-items:center;gap:6px;padding:4px 9px;border:1px solid var(--rule);border-radius:999px;background:var(--sheet);
  font-size:.82rem;font-weight:600;text-decoration:none;color:var(--lead)}
.langs a:hover{color:var(--ink);border-color:var(--strong)}
.langs a[aria-current]{background:var(--ink);color:var(--sheet);border-color:var(--ink)}
.langs img{width:16px;height:11px;border-radius:2px}
.logo{margin-right:auto}
.menu-jump{display:none;place-items:center;width:42px;height:42px;border:1px solid var(--rule);border-radius:10px;background:var(--sheet);color:var(--ink)}
.menu-jump svg{width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round}
.menu-jump:hover{border-color:var(--strong)}
@media (max-width:900px){.menu-jump{display:grid}}
@media (max-width:640px){.top .wrap{gap:10px}.langpick summary{height:42px;padding:0 12px}}
@media (max-width:420px){.lp-label{display:none}.logo{font-size:1.6rem}}

/* Page grid */
.layout{display:grid;grid-template-columns:minmax(0,1fr) 250px;gap:28px;align-items:start;padding-block:8px 40px}
@media (max-width:900px){.layout{grid-template-columns:minmax(0,1fr)}}
.sheet{background:var(--sheet);border:1px solid var(--rule);border-radius:14px;padding:clamp(20px,4vw,44px);min-width:0;
  box-shadow:0 18px 40px -30px color-mix(in srgb,var(--ink) 50%,transparent)}

/* Content typography */
.prose{max-width:none}
.prose>*{margin-block:0 1em}
.prose h1{font:800 clamp(2rem,5vw,2.9rem)/1.05 var(--display);letter-spacing:-.03em;margin-bottom:.5em;text-wrap:balance}
.prose h2{font:700 1.5rem/1.2 var(--display);margin-top:1.6em;margin-bottom:.4em;text-wrap:balance}
.prose h3,.prose .sub{font:700 1.15rem/1.3 var(--display);margin-top:1.4em;margin-bottom:.3em}
.prose p,.prose ul,.prose ol{max-width:68ch}
.prose ul,.prose ol{padding-left:1.25em}
.prose li{margin-block:.25em}
.prose li::marker{color:var(--lead)}
.prose .lead{font-size:1.12rem;color:var(--lead)}
.prose hr{border:0;border-top:1px solid var(--rule);margin-block:2em}
.prose .figure{float:right;margin:0 0 1em 1.25em;max-width:min(45%,260px)}
.prose .figure-l{float:left;margin:0 1.25em 1em 0;max-width:min(40%,220px)}
.prose .clear{clear:both}
@media (max-width:560px){.prose .figure,.prose .figure-l{float:none;margin:0 0 1em;max-width:100%}}

.levels{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:10px;list-style:none;padding:0!important;max-width:none!important}
.levels a{display:block;padding:14px 16px;border:1.5px solid var(--rule);border-radius:12px;background:var(--sheet);text-decoration:none;color:var(--ink);font-weight:700;font-family:var(--display)}
.levels a:hover{border-color:var(--strong)}
.levels small{display:block;font:500 .78rem var(--body);color:var(--lead)}

.callout{background:var(--tint);border-radius:12px;padding:16px 20px;max-width:68ch}
.callout>*{margin:0}
.callout>*+*{margin-top:.4em}
.webmaster-note{margin-top:2.2em}
.more-games{border:1.5px dashed var(--rule);border-radius:12px;padding:12px 18px;font-weight:600;max-width:68ch}

.phones{font-size:.9rem;color:var(--lead)}
.phones b{color:var(--ink)}
.shots{display:grid;grid-template-columns:repeat(auto-fill,minmax(130px,1fr));gap:12px;max-width:620px}
.shots img{border:1px solid var(--rule);border-radius:6px;display:block}
.dl-btn{display:inline-block;font-weight:700;padding:10px 18px;border-radius:10px;background:var(--ink);color:var(--sheet)!important;text-decoration:none}

.code-box{width:100%;min-height:11em;font:13px/1.45 ui-monospace,SFMono-Regular,Menlo,monospace;padding:12px;border:1px solid var(--rule);border-radius:10px;background:var(--tint);color:var(--ink);resize:vertical}

/* Forms (contact, newsletter) */
.form{display:grid;gap:14px;max-width:480px}
.form label,.form .lbl{display:grid;gap:4px;font-weight:600;font-size:.95rem}
.form input[type=text],.form input:not([type]),.form input[type=email],.form textarea{font:inherit;font-weight:400;padding:10px 12px;border:1px solid var(--rule);border-radius:10px;background:var(--sheet);color:var(--ink);width:100%}
.form textarea{min-height:9em}
.form .radios{display:flex;gap:18px;font-weight:400}
.form .radios label{display:flex;align-items:center;gap:6px;font-weight:400}
.btn,.form input[type=submit]{font:inherit;font-weight:700;border:1.5px solid var(--strong);background:var(--ink);color:var(--sheet);border-radius:10px;padding:10px 18px;cursor:pointer;justify-self:start}
.btn:hover,.form input[type=submit]:hover{background:var(--pen);border-color:var(--pen)}

/* Ads and legacy embeds stay contained */
.ad{max-width:100%;overflow:hidden;margin-block:1.4em;text-align:center;clear:both}
.ad-top{margin:0 auto;max-width:728px;overflow:hidden}
.ad-float{float:right;margin:0 0 1em 1.5em;max-width:100%;overflow:hidden}
@media (max-width:640px){.ad-float{float:none;margin:1em 0}}
.embed{max-width:100%;overflow-x:auto;margin-block:1.4em}
.embed iframe{max-width:100%;border:0}

/* Side menu */
.side{position:sticky;top:16px;display:grid;gap:18px}
@media (max-width:900px){.side{position:static}}
.side nav{background:var(--sheet);border:1px solid var(--rule);border-radius:14px;padding:16px 8px}
.side h2{margin:0 12px 8px;font:600 .72rem/1 var(--body);text-transform:uppercase;letter-spacing:.12em;color:var(--lead)}
.side ul{list-style:none;margin:0 0 10px;padding:0}
.side ul+h2{margin-top:14px}
.side a{display:block;padding:6px 12px;border-radius:8px;text-decoration:none;color:var(--ink);font-weight:500;font-size:.95rem;line-height:1.35}
.side a:hover{background:var(--tint)}
.side a[aria-current]{background:var(--mark);font-weight:700}
.side .em{font-style:italic}

footer.foot{padding-block:22px 28px;color:var(--lead);font-size:.9rem;text-align:center}

/* ---------- Sudoku game ---------- */
.sudoku{container-type:inline-size;margin-block:1.2em 1.8em}
.sp-grid{display:grid;gap:14px;grid-template-areas:"status" "board" "tools" "pad" "setup"}
@container (min-width:640px){
  .sp-grid{grid-template-columns:minmax(0,1.45fr) minmax(220px,1fr);column-gap:28px;
    grid-template-areas:"board status" "board pad" "board tools" "board setup" "board .";align-items:start}
}
.sp-status{grid-area:status;display:flex;flex-wrap:wrap;gap:4px 14px;align-items:baseline;font-variant-numeric:tabular-nums}
.sp-lvl{font:700 1.25rem/1.2 var(--display)}
.sp-meta{color:var(--lead);font-size:.92rem}
.sp-clock{font-weight:600;color:var(--ink)}
.sp-boardwrap{grid-area:board;position:relative;container-type:inline-size}
.sp-board{display:grid;grid-template-columns:repeat(9,1fr);aspect-ratio:1;max-width:100%;background:var(--sheet);
  border:2.5px solid var(--strong);border-radius:6px;overflow:hidden;touch-action:manipulation;user-select:none;-webkit-user-select:none;
  box-shadow:0 14px 34px -22px color-mix(in srgb,var(--ink) 50%,transparent)}
.sp-cell{position:relative;border:0;border-right:1px solid var(--rule);border-bottom:1px solid var(--rule);background:transparent;padding:0;
  display:grid;place-items:center;cursor:pointer;font:600 6.4cqi/1 var(--display);color:var(--ink);-webkit-tap-highlight-color:transparent}
.sp-cell:nth-child(9n){border-right:0}
.sp-cell:nth-child(n+73){border-bottom:0}
.sp-cell.br{border-right:2px solid var(--strong)}
.sp-cell.bb{border-bottom:2px solid var(--strong)}
.sp-cell.peer{background:var(--peer)}
.sp-cell.same{background:var(--same)}
.sp-cell.sel{background:var(--mark)}
.sp-cell.user{font:700 7.2cqi/1 var(--hand);color:var(--pen);padding-top:.6cqi}
.sp-cell.conflict,.sp-cell.wrong{color:var(--error)}
.sp-cell.wrong::after{content:"";position:absolute;inset:18%;border:2px solid var(--error);border-radius:50%;opacity:.55}
.sp-cell:focus-visible{outline-offset:-3px}
.sp-notes{display:grid;grid-template-columns:repeat(3,1fr);width:100%;height:100%;padding:.4cqi}
.sp-notes span{display:grid;place-items:center;font:400 2.5cqi/1 var(--hand);color:var(--lead)}
.sp-notes span.hit{color:var(--pen);font-weight:700}
.sp-solved{position:absolute;inset:0;display:grid;place-items:center;border-radius:6px;background:color-mix(in srgb,var(--sheet) 84%,transparent);backdrop-filter:blur(2px)}
.sp-solved .card{text-align:center;padding:20px}
.sp-solved strong{display:block;font:800 clamp(2rem,10cqi,3.4rem)/1 var(--display);letter-spacing:-.03em}
.sp-solved strong em{font:700 1em var(--hand);color:var(--pen);font-style:normal}
.sp-solved p{margin:10px 0 16px;color:var(--lead);font-variant-numeric:tabular-nums}
@media (prefers-reduced-motion:no-preference){.sp-solved .card{animation:sp-pop .45s cubic-bezier(.2,1.4,.4,1)}@keyframes sp-pop{from{transform:scale(.85);opacity:0}}}
.sp-tools{grid-area:tools;display:grid;grid-template-columns:repeat(5,1fr);gap:4px}
.sp-tool{display:flex;flex-direction:column;align-items:center;gap:2px;padding:8px 2px;border:0;background:transparent;border-radius:10px;cursor:pointer;
  color:var(--lead);font:500 .78rem/1.2 var(--body)}
.sp-tool svg{width:24px;height:24px;stroke:var(--ink);fill:none;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
.sp-tool:hover{background:var(--tint);color:var(--ink)}
.sp-tool[aria-pressed="true"]{background:var(--ink);color:var(--sheet)}
.sp-tool[aria-pressed="true"] svg{stroke:var(--sheet)}
.sp-notestate{font-size:.66rem;text-transform:uppercase;letter-spacing:.08em}
.sp-pad{grid-area:pad;display:grid;grid-template-columns:repeat(9,1fr);gap:4px}
@container (min-width:640px){.sp-pad{grid-template-columns:repeat(3,1fr);gap:8px}}
.sp-key{position:relative;aspect-ratio:.85;border:1px solid var(--rule);background:var(--sheet);border-radius:9px;cursor:pointer;
  font:700 clamp(1.2rem,5cqi,1.8rem)/1 var(--display);color:var(--ink);transition:transform .08s}
@container (min-width:640px){.sp-key{aspect-ratio:1.25;font-size:1.7rem}}
.sp-key small{position:absolute;left:0;right:0;bottom:3px;font:500 .64rem var(--body);color:var(--lead);font-variant-numeric:tabular-nums}
@container (min-width:640px){.sp-key small{left:auto;right:7px;bottom:5px}}
.sp-key:hover{border-color:var(--strong)}
.sp-key:active{transform:scale(.95)}
.sp-key.done{opacity:.3}
.notes-on .sp-key{font-family:var(--hand);color:var(--pen)}
.sp-setup{grid-area:setup;display:grid;gap:10px}
.sp-setup h3{margin:0;font:600 .72rem/1 var(--body);text-transform:uppercase;letter-spacing:.1em;color:var(--lead)}
.sp-levels{display:grid;grid-template-columns:repeat(4,1fr);border:1px solid var(--rule);border-radius:10px;padding:3px;background:var(--sheet)}
.sp-levels button{border:0;background:transparent;border-radius:7px;padding:9px 2px;cursor:pointer;font:600 .85rem var(--body);color:var(--lead);min-width:0;overflow:hidden;text-overflow:ellipsis}
.sp-levels button:hover{color:var(--ink)}
.sp-levels button.on{background:var(--ink);color:var(--sheet)}
.sp-setup .btn{background:transparent;color:var(--ink)}
.sp-setup .btn:hover{background:var(--ink);color:var(--sheet);border-color:var(--ink)}
.sp-keys{margin:0;font-size:.8rem;color:var(--lead)}
@media (hover:none){.sp-keys{display:none}}

.more-games p{margin:0}
.btn.ghost{background:transparent;color:var(--ink)}
.btn.ghost:hover{background:var(--ink);color:var(--sheet);border-color:var(--ink)}

/* ---------- Sudoku solver ---------- */
.solver{container-type:inline-size;max-width:520px;margin-block:1.2em 2em;display:grid;gap:14px}
.sv-board{display:grid;grid-template-columns:repeat(9,1fr);aspect-ratio:1;background:var(--sheet);border:2.5px solid var(--strong);border-radius:6px;overflow:hidden}
.sv-cell{min-width:0;width:100%;height:100%;border:0;border-right:1px solid var(--rule);border-bottom:1px solid var(--rule);background:transparent;
  text-align:center;font:600 6.4cqi/1 var(--display);color:var(--ink);padding:0;border-radius:0;caret-color:var(--pen)}
.sv-cell:nth-child(9n){border-right:0}
.sv-cell:nth-child(n+73){border-bottom:0}
.sv-cell.br{border-right:2px solid var(--strong)}
.sv-cell.bb{border-bottom:2px solid var(--strong)}
.sv-cell:focus{outline:none;background:var(--mark)}
.sv-cell.solved{font:700 7.2cqi/1 var(--hand);color:var(--pen)}
.sv-cell.bad{color:var(--error);background:color-mix(in srgb,var(--error) 12%,transparent)}
.sv-actions{display:flex;flex-wrap:wrap;gap:8px}
.sv-msg{margin:0;color:var(--lead);min-height:1.6em}

/* Language picker */
.langpick{position:relative}
.langpick summary{list-style:none;cursor:pointer;display:flex;align-items:center;gap:8px;padding:6px 12px;border:1px solid var(--rule);border-radius:999px;background:var(--sheet);font-weight:600;font-size:.9rem}
.langpick summary::-webkit-details-marker{display:none}
.langpick summary::after{content:"";width:7px;height:7px;border-right:2px solid var(--lead);border-bottom:2px solid var(--lead);transform:rotate(45deg) translateY(-2px);margin-left:2px}
.langpick[open] summary::after{transform:rotate(-135deg) translateY(-1px)}
.langpick summary img{width:18px;height:12px;border-radius:2px;object-fit:cover}
.langpick nav{position:absolute;right:0;top:calc(100% + 6px);z-index:10;background:var(--sheet);border:1px solid var(--rule);border-radius:12px;padding:8px;
  box-shadow:0 16px 36px -18px color-mix(in srgb,var(--ink) 55%,transparent);width:min(320px,calc(100vw - 32px))}
.langpick .langs{display:grid;grid-template-columns:1fr 1fr;gap:2px}
.langpick .langs a{border:0;border-radius:8px;background:transparent;padding:7px 10px;font-size:.9rem}
.langpick .langs a:hover{background:var(--tint)}
.langpick .langs img{width:18px;height:12px;object-fit:cover}
.langpick .langs a[aria-current]{background:var(--tint);color:var(--ink);font-weight:700}
@media (max-width:640px){.top .wrap{position:relative}.langpick{position:static}.langpick nav{left:16px;right:16px;width:auto;top:calc(100% + 4px)}}

/* Long labels (e.g. Greek, Hungarian) must never widen the game */
.sp-grid{grid-template-columns:minmax(0,1fr)}
.sp-tool{min-width:0;overflow-wrap:break-word;hyphens:auto;text-align:center}
.sp-levels button{min-width:0}
.sp-tool{font-size:.72rem}
@container (min-width:640px){.sp-tool{font-size:.78rem}}
.sp-setup .btn{white-space:normal}
@container (max-width:479px){
  .sp-levels{grid-template-columns:repeat(2,1fr);gap:3px}
  .sp-tools{gap:2px}
  .sp-tool{font-size:.7rem;padding-inline:0}
}
@media (max-width:420px){.sheet{padding:20px 14px}}
@container (max-width:479px){.sp-key{aspect-ratio:auto;height:clamp(44px,13cqi,56px);padding-bottom:10px}.sp-key small{bottom:2px}}