/* Just Sudoku — shared page chrome (colors, lang-switch, footer) matches the rest of the
   itkama.de site (see ../index.html, ../privacy/index.html): same --bg/--fg/--muted/--accent/
   --line variables and dark-mode values. The board itself needs a few extra roles the marketing
   pages don't (selection/peer/conflict highlighting) — those get their own --game-* variables
   below, taken from the Android app's ui/theme/Theme.kt fallback palette for exact parity with
   the app's board colors.

   --game-numpad-inactive-bg/-fg (the number pad's default, not-held-not-exhausted look) is its
   own pair rather than reusing --game-secondary-container/--game-surface-variant (the board's
   same-value/peer highlight colors): the two concerns happen to share values in this default
   palette, but a custom palette (see [data-theme="purple"] below) may reasonably want the number
   pad's resting color to differ from either board highlight, so they're decoupled from the start. */
:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #5a5a5a;
  --accent: #3060c0;
  --line: #dddddd;

  --game-primary: #3D5AFE;
  --game-on-primary: #ffffff;
  --game-primary-container: #DCE1FF;
  --game-on-primary-container: #00105C;
  --game-primary-fixed-dim: #5C6BC0;
  --game-secondary-container: #A6F2E4;
  --game-error: #BA1A1A;
  --game-error-container: #FFDAD6;
  --game-surface-variant: #E1E2EC;
  --game-outline-variant: #C4C6D0;
  --game-numpad-inactive-bg: #A6F2E4;
  --game-numpad-inactive-fg: #00201C;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --fg: #f0f0f0;
    --muted: #a8a8a8;
    --accent: #8ab4ff;
    --line: #333333;

    --game-primary: #8C9EFF;
    --game-on-primary: #001A6B;
    --game-primary-container: #1A2F66;
    --game-on-primary-container: #DCE1FF;
    --game-secondary-container: #163F3A;
    --game-error: #FFB4AB;
    --game-error-container: #93000A;
    --game-surface-variant: #2A3350;
    --game-outline-variant: #3A3A3C;
    --game-numpad-inactive-bg: #163F3A;
    --game-numpad-inactive-fg: #A6F2E4;
  }
}

/* A custom palette (as opposed to the default above, which follows the system light/dark
   setting): a fixed, self-contained look regardless of prefers-color-scheme, picked via the
   palette button. :root[data-theme="purple"] outranks both blocks above on specificity alone
   (an attribute selector on :root beats a bare :root), so this reliably wins no matter what the
   system theme is or where this rule sits in the file. */
:root[data-theme="purple"] {
  color-scheme: dark;
  --bg: #000000;
  --fg: #ffffff;
  --muted: #9c8bb5;
  --accent: #aa90fe;
  --line: #3a2a56;

  --game-primary: #aa90fe;
  --game-on-primary: #1a0f2e;
  --game-primary-container: #aa90fe;
  --game-on-primary-container: #1a0f2e;
  --game-primary-fixed-dim: #aa90fe;
  --game-secondary-container: #5b2c94;
  --game-error: #ffb4ab;
  --game-error-container: #93000a;
  --game-surface-variant: #31184f;
  /* Same hue as the selected-cell color (per request), but at reduced opacity — full-strength
     against a black background made even a 1px line read as loud/high-contrast, not actually
     thicker (the app's own grid lines are the same 1dp/3dp, just a neutral gray instead of an
     accent color). This keeps the lilac tint without it fighting for attention. */
  --game-outline-variant: rgba(170, 144, 254, 0.35);
  --game-numpad-inactive-bg: #31184f;
  --game-numpad-inactive-fg: #aa90fe;
}

/* Given as a standard Material Design "palette generator" set (primary/dark primary/light
   primary + text-on-primary, accent, primary/secondary text, divider) rather than mapped to
   this app's specific roles directly — a dark theme (black background) rather than the light
   look the generator's colors were originally calibrated for, so "primary/secondary text" and
   "divider" (light-background values) are replaced with dark-theme equivalents instead of used
   as-is, and entered-digit text uses light primary rather than dark primary (illegible on black).
   Grid lines use a translucent primary rather than a flat divider gray or the full-strength
   accent — the same "brand-hued but low-opacity" fix Purple's grid lines needed. The same-value/
   peer/number-pad dark backgrounds are shades of the given *accent* (#e040fb) — a distinctly
   more purple-leaning look than [data-theme="berry"] below, which re-derives those same three
   from *primary* instead for a berrier, less purple feel; keeping both since they read as
   genuinely different themes, not just variations. Conflict/error color is the same dark-theme
   red as Purple/Berry, for the same reason: staying universally recognizable as "wrong" rather
   than reinterpreted into the theme's own hue. */
:root[data-theme="pink"] {
  color-scheme: dark;
  --bg: #000000;
  --fg: #ffffff;
  --muted: #b3919f;
  --accent: #e040fb;
  --line: #4a2f42;

  --game-primary: #e91e63;
  --game-on-primary: #ffffff;
  --game-primary-container: #f8bbd0;
  --game-on-primary-container: #212121;
  --game-primary-fixed-dim: #f8bbd0;
  --game-secondary-container: #6a1b7a;
  --game-error: #ffb4ab;
  --game-error-container: #93000a;
  --game-surface-variant: #3d1a35;
  --game-outline-variant: rgba(233, 30, 99, 0.3);
  --game-numpad-inactive-bg: #3d1a35;
  --game-numpad-inactive-fg: #f8bbd0;
}

/* Same given brand colors and dark (black) background as Pink above, but the same-value/peer/
   number-pad dark backgrounds are shades of *primary* here instead of the given accent — every
   dark surface stays a shade of the same berry-pink rather than mixing in Pink's more
   purple-leaning accent undertone. --accent itself is unchanged (still used for the
   language-switch highlight), just not the source for these three derived shades. Different
   enough from Pink in practice to keep as its own separate theme rather than a variant. */
:root[data-theme="berry"] {
  color-scheme: dark;
  --bg: #000000;
  --fg: #ffffff;
  --muted: #b8899e;
  --accent: #e040fb;
  --line: #4a1f30;

  --game-primary: #e91e63;
  --game-on-primary: #ffffff;
  --game-primary-container: #f8bbd0;
  --game-on-primary-container: #212121;
  --game-primary-fixed-dim: #f8bbd0;
  --game-secondary-container: #8c1245;
  --game-error: #ffb4ab;
  --game-error-container: #93000a;
  --game-surface-variant: #3a0f22;
  --game-outline-variant: rgba(233, 30, 99, 0.3);
  --game-numpad-inactive-bg: #3a0f22;
  --game-numpad-inactive-fg: #f8bbd0;
}

/* Built from a single given base color (#52c4b7) with everything else derived from it, following
   Purple's structure: the base itself carries every "bright" role (held digit, selected cell,
   entered-digit text, number-pad text, accent), and the two board highlights plus the divider and
   secondary-text tones are the same hue at progressively lower lightness. Kept the derived
   lightness steps far enough apart that same-value (#1c5f58) can't be confused with the
   peer row/column tint (#10322f) — the mistake that once made a highlighted row read as one solid
   block in the Android app. Dark text on the base (not white): the base is light enough that
   white on it lands around 2:1 contrast, while this dark teal reaches ~7:1. Grid lines are the
   translucent base again, so they composite over whatever cell tint is underneath and stay
   visible on all of them. Conflict/error red is the shared dark-theme red as in Purple/Berry —
   deliberately not derived from the base, so "wrong" stays universally recognizable. */
:root[data-theme="turquoise"] {
  color-scheme: dark;
  --bg: #000000;
  --fg: #ffffff;
  --muted: #8bb1ae;
  --accent: #52c4b7;
  --line: #234340;

  --game-primary: #52c4b7;
  --game-on-primary: #0d2b28;
  --game-primary-container: #52c4b7;
  --game-on-primary-container: #0d2b28;
  --game-primary-fixed-dim: #52c4b7;
  --game-secondary-container: #1c5f58;
  --game-error: #ffb4ab;
  --game-error-container: #93000a;
  --game-surface-variant: #10322f;
  --game-outline-variant: rgba(82, 196, 183, 0.3);
  --game-numpad-inactive-bg: #10322f;
  --game-numpad-inactive-fg: #52c4b7;
}

* { box-sizing: border-box; }

/* .screen and .dialog-overlay below each set their own `display`, which — at equal CSS
   specificity — would otherwise silently override the `hidden` attribute's native
   `display: none` and leave a "hidden" screen/dialog visible on top of everything else. */
[hidden] { display: none !important; }

html, body {
  height: 100%; /* fallback for browsers without dvh support (still fine, just the old bug) */
  height: 100dvh;
  /* 100% (and old-style 100vh) means the *largest possible* viewport on mobile Safari/Chrome —
     with the address bar collapsed — not the currently-visible one. With the address bar shown
     (the common case right after loading), that made the page a bit taller than what's actually
     visible, pushing the number pad's second row below the fold. 100dvh ("dynamic viewport
     height") tracks the real, current viewport instead. */

  /* Kills the iOS/Android rubber-band bounce past the edges of the page. The layout below is
     built to exactly fill the viewport (flex column, footer/lang-switch at their natural size,
     #app taking the rest) so there's normally nothing to scroll in the first place — this just
     also removes the elastic overscroll glow some browsers still show even then. */
  overscroll-behavior-y: none;
  /* The app never intentionally scrolls sideways — a stray sub-pixel rounding overflow anywhere
     (e.g. splitting the number pad's row width across 5 buttons) is enough for mobile browsers to
     allow a slight horizontal pan/scroll otherwise, which throws off centering just enough to
     notice without any content actually being cut off. This forecloses that regardless of cause. */
  overflow-x: hidden;
}

body {
  margin: 0;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

button {
  font-family: inherit;
  border: none;
  cursor: pointer;
  background: none;
  color: inherit;
}
button:disabled { opacity: 0.4; cursor: default; }

/* Icon buttons (header actions + toolbar) hold a single inline SVG each — same stroke style
   throughout (line icons, no emoji/glyph mix) so they read as one consistent set. */
.game-header button svg, .toolbar button svg {
  width: 22px;
  height: 22px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  display: block;
}

/* body is a flex column filling the exact viewport height: lang-switch and the footer keep
   their natural size, #app takes whatever's left — nothing left over to scroll. */
.lang-switch {
  flex: 0 0 auto;
  text-align: right;
  font-size: 0.9rem;
  padding: 1rem 1rem 0;
}
.lang-switch button {
  background: none;
  border: none;
  color: var(--muted);
  font: inherit;
  cursor: pointer;
  padding: 0.2rem 0.4rem;
}
.lang-switch button:hover,
.lang-switch button[aria-current="true"] { color: var(--accent); }

.site-footer {
  flex: 0 0 auto;
  margin: 0.5rem auto 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
  text-align: center;
  font-size: 0.9rem;
  color: var(--muted);
  max-width: 480px;
  width: 100%;
}
.site-footer a { color: var(--muted); }

#app {
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  flex-direction: column;
}

.screen {
  flex: 1 1 auto;
  min-height: 0;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 16px;
  /* Safety valve only: the layout is sized to fit without scrolling, but on a genuinely too-short
     viewport this lets content still reach rather than getting silently clipped. */
  overflow-y: auto;
}

/* --- Difficulty screen --- */
#screen-difficulty { justify-content: center; gap: 12px; }
#screen-difficulty h1 { margin-bottom: 24px; }
.difficulty-list { display: flex; flex-direction: column; gap: 12px; width: 100%; max-width: 280px; }
.difficulty-button {
  padding: 14px;
  border-radius: 8px;
  background: var(--game-primary);
  color: var(--game-on-primary);
  font-size: 1.05rem;
}

/* --- Game screen ---
   A CSS Grid with named areas so portrait and landscape can reflow the exact same 4 elements
   (header/board/toolbar/numpad) without touching the HTML or JS at all — just which areas go
   where, and how many columns/rows there are. */
#screen-game {
  display: grid;
  grid-template-areas: "header" "board" "toolbar" "numpad";
  grid-template-columns: 1fr;
  grid-template-rows: auto auto auto auto;
  align-items: stretch;
  gap: 12px;
  max-width: 480px;
  margin: 0 auto;
  width: 100%;
}

.game-header {
  grid-area: header;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  font-size: 1.1rem;
}
.game-header .header-actions { display: flex; gap: 8px; }
.game-header button, .toolbar button { padding: 6px; border-radius: 8px; }

.board {
  grid-area: board;
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  grid-template-rows: repeat(9, 1fr);
  width: 100%;
  aspect-ratio: 1;
  border: 2px solid var(--fg);
  outline: none;
  touch-action: none;
}

.cell {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  border-right: 1px solid var(--game-outline-variant);
  border-bottom: 1px solid var(--game-outline-variant);
  cursor: pointer;
  user-select: none;
  /* A muted, always-the-same-tone-in-both-themes accent for user-entered digits (distinct from
     a given clue's plain --fg text below), matching the app's `primaryFixedDim` role. */
  color: var(--game-primary-fixed-dim);
}
.cell.box-right { border-right: 3px solid var(--fg); }
.cell.box-bottom { border-bottom: 3px solid var(--fg); }

/* Background priority (mutually exclusive, applied in this order by app.js):
   selected > conflict > same-value > peer > plain. Text-color priority is separate and only
   these three rules affect it, later ones winning ties: selected, then given (must beat
   selected — you can select a given cell), then conflict-text (must beat everything). */
.cell.peer { background: var(--game-surface-variant); }
.cell.same-value { background: var(--game-secondary-container); }
.cell.selected { background: var(--game-primary-container); color: var(--game-on-primary-container); }
.cell.given { font-weight: 700; color: var(--fg); }
.cell.conflict { background: var(--game-error-container); }
.cell.conflict-text { color: var(--game-error); }

.pencil-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(3, 1fr);
  width: 100%;
  height: 100%;
  padding: 2px;
}
.pencil-grid span {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.55rem;
  color: var(--fg);
}

.toolbar {
  grid-area: toolbar;
  display: flex;
  justify-content: space-around;
  width: 100%;
}
.toolbar button.active { background: var(--game-primary-container); color: var(--game-on-primary-container); }

/* Flexbox + wrap + centered justify-content (not CSS grid): this way, when the trailing row of
   digits has fewer than a full row's worth, it centers itself automatically instead of
   left-aligning with a lopsided gap — no JS layout math needed. 5 columns in portrait (bigger,
   easier-to-tap buttons); 3 in landscape, in its own dedicated right-hand column — mirroring the
   Android app's own portrait/landscape split. */
.number-pad {
  grid-area: numpad;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-content: center;
  gap: 4px;
  width: 100%;
}
.digit-button {
  flex: 0 0 auto;
  aspect-ratio: 1;
  border-radius: 8px;
  font-size: 1.1rem;
  background: var(--game-numpad-inactive-bg);
  color: var(--game-numpad-inactive-fg);
  touch-action: none;
}
.digit-button.exhausted { opacity: 0.4; }
.digit-button.held { background: var(--game-primary); color: var(--game-on-primary); opacity: 1; }

@media (orientation: portrait) {
  .digit-button { flex-basis: calc((100% - 4 * 4px) / 5); }
}

/* All landscape overrides live in this one block, deliberately placed after every base rule
   above rather than scattered next to what each one modifies: a media query does not raise a
   rule's priority over a later rule of equal selector specificity, so an earlier landscape-only
   `.toolbar { justify-content: center }` was silently overridden right back to the base
   `.toolbar { justify-content: space-around }` declared further down the file — the layout kept
   looking like the un-overridden default no matter what the media query said. Keeping every
   landscape rule below all the rules it touches makes that class of bug impossible here. */
@media (orientation: landscape) {
  /* Three columns: board left, the toolbar ("functions") in a narrow middle column, number pad
     right — each with its own dedicated space instead of the toolbar/number pad previously
     sharing one column (which is also what made board-height vs. right-column-height so hard to
     keep in sync). The header (title/timer/reset/share/close) spans the full width up top instead,
     since it's page-level chrome rather than an in-game action. --board-size/--digit-size are
     still computed by app.js (updateLandscapeLayout) from the real measured space, the same way
     the Android app's BoxWithConstraints does — the values below only matter as a same-frame
     fallback, before JS has run once. */
  #screen-game {
    grid-template-areas: "header header header" "board toolbar numpad";
    grid-template-columns: var(--board-size, min(60vmin, 420px)) 84px 1fr;
    grid-template-rows: auto 1fr;
    max-width: 1000px;
  }
  #board {
    width: var(--board-size, min(60vmin, 420px));
    height: var(--board-size, min(60vmin, 420px));
    aspect-ratio: unset;
  }
  .toolbar {
    flex-direction: column;
    justify-content: center;
    gap: 12px;
  }
  .game-header button svg, .toolbar button svg { width: 26px; height: 26px; }
  /* Same JS-measured sizing as #board above and for the same reason: a width-only flex-basis
     doesn't know how much vertical room is actually available, so a 3-wide row could end up
     taller than the space it has to fit in. --digit-size is capped by both the available width
     and height (app.js), mirroring the app's own NumberPad.kt exactly. */
  .digit-button {
    flex-basis: var(--digit-size, calc((100% - 2 * 4px) / 3));
    width: var(--digit-size, auto);
    height: var(--digit-size, auto);
    aspect-ratio: unset;
  }
}

.dialog-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}
.dialog {
  background: var(--bg);
  color: var(--fg);
  border-radius: 12px;
  padding: 24px;
  max-width: 320px;
  width: 100%;
  text-align: center;
}
.dialog p { color: var(--muted); }
.dialog button {
  margin: 16px 4px 0;
  padding: 10px 20px;
  border-radius: 8px;
  background: var(--game-primary);
  color: var(--game-on-primary);
}
.dialog button.secondary {
  background: none;
  color: var(--muted);
  border: 1px solid var(--line);
}

/* Higher-specificity selector (.dialog button.theme-option, not just .theme-option) so this
   reliably wins over the plain ".dialog button" rule above regardless of source order — see the
   landscape-layout comment further up for why that's not something to leave to chance here. */
.dialog button.theme-option {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  margin: 8px 0 0;
  padding: 10px 14px;
  border-radius: 8px;
  background: none;
  border: 1px solid var(--line);
  color: var(--fg);
  text-align: left;
  font-size: 0.95rem;
}
.dialog button.theme-option.active { border-color: var(--game-primary); border-width: 2px; }
.theme-swatch {
  flex: 0 0 auto;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 1px solid rgba(128, 128, 128, 0.4);
}

.update-banner {
  position: fixed;
  left: 50%;
  bottom: 16px;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 12px;
  max-width: calc(100% - 32px);
  padding: 10px 10px 10px 16px;
  border-radius: 8px;
  background: var(--game-primary);
  color: var(--game-on-primary);
  font-size: 0.9rem;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.35);
  z-index: 10;
}
.update-banner button {
  flex: 0 0 auto;
  padding: 6px 14px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.25);
  font-weight: 600;
}