/* ============================================================================
   Tic Tac Toe — style.css (Game 02)
   Mobile-first, one-thumb layout. The playing screen must fit a 360 px
   viewport with zero scroll (plan §8), so everything is sized off 100dvh.
   Theme follows the site's `ai-quiz-theme` setting (resolved to
   [data-theme="dark"] / "light" by an inline script in index.html).
   ========================================================================== */

:root,
[data-theme='light'] {
  --bg-a: #e8e4f3;
  --bg-b: #d4c5e8;
  --card: #ffffff;
  --card-border: rgba(148, 163, 184, 0.35);
  --text: #1e293b;
  --muted: #64748b;
  --grid-line: #94a3b8;
  --cell: #f8fafc;
  --cell-hover: #eef2ff;
  --x: #2563eb;
  --o: #e11d48;
  --win: #10b981;
  --win-glow: rgba(16, 185, 129, 0.22);
  --primary-a: #2563eb;
  --primary-b: #4f46e5;
  --shadow: 0 10px 30px rgba(30, 27, 75, 0.12);
}

[data-theme='dark'] {
  --bg-a: #1e1b4a;
  --bg-b: #3f1229;
  --card: #1e293b;
  --card-border: rgba(148, 163, 184, 0.18);
  --text: #f1f5f9;
  --muted: #94a3b8;
  --grid-line: #475569;
  --cell: #16202f;
  --cell-hover: #1c2a3f;
  --x: #60a5fa;
  --o: #fb7185;
  --win: #34d399;
  --win-glow: rgba(52, 211, 153, 0.25);
  --primary-a: #3b82f6;
  --primary-b: #6366f1;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.45);
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font-family:
    ui-sans-serif,
    system-ui,
    -apple-system,
    'Segoe UI',
    Roboto,
    'Helvetica Neue',
    Arial,
    sans-serif;
  color: var(--text);
  background: linear-gradient(160deg, var(--bg-a), var(--bg-b)) fixed;
  -webkit-tap-highlight-color: transparent;
}

.app {
  min-height: 100vh;
  min-height: 100dvh;
  max-width: none; /* BUG-016 sweep: full-screen per owner request */
  margin: 0 auto;
  padding: 0.75rem 1rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.back-link {
  align-self: flex-start;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--muted);
  text-decoration: none;
  padding: 0.25rem 0.5rem;
  margin-left: -0.5rem;
  border-radius: 8px;
}

.back-link:hover,
.back-link:focus-visible {
  color: var(--text);
  background: var(--cell-hover);
}

/* ---- screens -------------------------------------------------------------- */

.screen {
  display: none;
  flex-direction: column;
  gap: 0.75rem;
  flex: 1;
  min-height: 0;
}

.screen--active {
  display: flex;
}

/* ---- menu ----------------------------------------------------------------- */

.menu-title {
  margin: 0.25rem 0 0;
  text-align: center;
  font-size: clamp(1.6rem, 7vw, 2.1rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.tagline {
  margin: 0;
  text-align: center;
  font-size: 0.875rem;
  color: var(--muted);
}

.card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 1rem;
  box-shadow: var(--shadow);
}

.card h2 {
  margin: 0 0 0.5rem;
  font-size: 0.8125rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.card h2 .scope {
  text-transform: none;
  letter-spacing: 0;
  font-weight: 600;
}

/* segmented controls (mode / difficulty) */

.segmented {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: 1fr;
  gap: 4px;
  background: var(--cell);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 4px;
}

.segmented button {
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  padding: 0.5rem 0.25rem;
  border-radius: 9px;
  cursor: pointer;
}

.segmented button[aria-checked='true'] {
  background: var(--card);
  color: var(--text);
  box-shadow: 0 1px 4px rgba(15, 23, 42, 0.18);
}

.row {
  margin-top: 0.75rem;
}

.row.hidden,
.hidden {
  display: none !important;
}

/* misère toggle */

.toggle-row {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  margin-top: 0.875rem;
  font-size: 0.875rem;
  cursor: pointer;
}

.toggle-row input {
  width: 1.125rem;
  height: 1.125rem;
  accent-color: var(--primary-a);
  flex-shrink: 0;
}

/* series scoreboard */

.scoreboard {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 0.5rem;
  text-align: center;
}

.score {
  background: var(--cell);
  border-radius: 12px;
  padding: 0.625rem 0.25rem;
}

.score .num {
  display: block;
  font-size: 1.375rem;
  font-weight: 800;
  line-height: 1.1;
}

.score .label {
  font-size: 0.75rem;
  color: var(--muted);
}

.score--x .num {
  color: var(--x);
}

.score--o .num {
  color: var(--o);
}

.scoreboard-actions {
  margin-top: 0.625rem;
  display: flex;
  justify-content: flex-end;
}

/* buttons */

button.primary {
  border: 0;
  border-radius: 14px;
  padding: 0.875rem 1rem;
  font: inherit;
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, var(--primary-a), var(--primary-b));
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.35);
  transition:
    transform 0.12s ease,
    box-shadow 0.12s ease,
    filter 0.12s ease;
}

button.primary:hover:not(:disabled) {
  filter: brightness(1.06);
}

button.primary:active:not(:disabled) {
  transform: scale(0.98);
}

button.primary:disabled {
  opacity: 0.55;
  cursor: default;
  box-shadow: none;
}

button.ghost {
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 0.625rem 0.875rem;
  font: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text);
  background: var(--card);
  cursor: pointer;
}

button.ghost:hover:not(:disabled),
button.ghost:focus-visible {
  background: var(--cell-hover);
}

button.ghost:disabled {
  opacity: 0.5;
  cursor: default;
}

button:focus-visible,
a:focus-visible,
.cell:focus-visible {
  outline: 3px solid var(--primary-a);
  outline-offset: 2px;
}

/* ---- playing screen --------------------------------------------------------- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.topbar .ghost {
  padding: 0.4rem 0.75rem;
}

.mini-series {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--muted);
  background: var(--card);
  border: 1px solid var(--card-border);
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  white-space: nowrap;
}

.turn {
  text-align: center;
  font-size: 1.0625rem;
  font-weight: 800;
  min-height: 1.6em;
}

.turn[data-mark='X'] {
  color: var(--x);
}

.turn[data-mark='O'] {
  color: var(--o);
}

.badge {
  align-self: center;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--muted);
  background: var(--card);
  border: 1px dashed var(--grid-line);
  border-radius: 999px;
  padding: 0.3rem 0.75rem;
}

/* the board: grid lines come from the container background showing through
   the gaps, so the whole board is exactly one visual table */

.board-wrap {
  position: relative;
  flex: 1;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 5px;
  padding: 5px;
  background: var(--grid-line);
  border-radius: 18px;
  /* fit narrow phones and short landscape viewports alike */
  width: min(100%, 58vh);
  width: min(100%, 58vh, 58dvh);
  max-width: none; /* scales with the screen (full-screen treatment) */
  aspect-ratio: 1;
}

.cell {
  position: relative;
  border: 0;
  padding: 0;
  aspect-ratio: 1;
  border-radius: 13px;
  background: var(--cell);
  cursor: pointer;
  color: inherit;
  transition: background 0.12s ease;
}

.cell:not(:disabled):hover {
  background: var(--cell-hover);
}

.cell:disabled {
  cursor: default;
}

.cell svg {
  position: absolute;
  top: 21%;
  left: 21%;
  width: 58%;
  height: 58%;
  overflow: visible;
}

.cell .stroke {
  fill: none;
  stroke: currentColor;
  stroke-width: 11;
  stroke-linecap: round;
}

.cell[data-mark='X'] {
  color: var(--x);
}

.cell[data-mark='O'] {
  color: var(--o);
}

/* draw-in animation for marks. The resting state is the FULL mark; the
   animation lives on a temporary .cell--animating class that game.js removes
   after ~600ms, so a mark is always visible in the end even if animations
   never run or their clock is frozen (backgrounded webviews). */

.cell--animating .stroke {
  stroke-dasharray: 80;
  animation: draw-in 0.22s ease-out backwards;
}

.cell--animating .s2 {
  animation-delay: 0.14s;
}

@keyframes draw-in {
  from {
    stroke-dashoffset: 80;
  }
  to {
    stroke-dashoffset: 0;
  }
}

/* circle circumference (2πr = 182) needs a longer dash than the x strokes */
.cell--animating[data-mark='O'] .stroke {
  stroke-dasharray: 183;
  animation: draw-in-o 0.3s ease-out backwards;
}

@keyframes draw-in-o {
  from {
    stroke-dashoffset: 183;
  }
  to {
    stroke-dashoffset: 0;
  }
}

/* winning line highlight: winning marks pop, the rest recede */

.cell--win {
  background: var(--win-glow);
  animation: win-pulse 0.9s ease-in-out 2;
}

.cell--win[data-mark='X'],
.cell--win[data-mark='O'] {
  color: var(--win);
}

.cell--dim {
  opacity: 0.4;
}

@keyframes win-pulse {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.06);
  }
}

/* deal-in of the cleared board between rounds */

.board--deal {
  animation: deal 0.35s ease-out;
}

@keyframes deal {
  from {
    opacity: 0.2;
    transform: scale(0.96);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@media (prefers-reduced-motion: reduce) {
  .cell--animating .stroke,
  .cell--win,
  .board--deal,
  .overlay--in .overlay-card {
    animation: none;
  }

  button.primary,
  button.ghost,
  .cell {
    transition: none;
  }
}

/* ---- round-end overlay ------------------------------------------------------- */

.overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem;
  border-radius: 18px;
  /* Fallback first: without color-mix the scrim must still be visible. */
  background: rgba(15, 23, 42, 0.55);
  background: color-mix(in srgb, var(--bg-a) 55%, transparent);
  -webkit-backdrop-filter: blur(3px);
  backdrop-filter: blur(3px);
}

.overlay-card {
  width: 100%;
  max-width: 19rem;
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 1.25rem 1rem;
  text-align: center;
}

.overlay--in .overlay-card {
  animation: pop 0.25s ease-out;
}

@keyframes pop {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.overlay-emoji {
  font-size: 2rem;
  line-height: 1;
}

.overlay-title {
  margin: 0.375rem 0 0.25rem;
  font-size: 1.5rem;
  font-weight: 800;
}

.overlay-title[data-mark='X'] {
  color: var(--x);
}

.overlay-title[data-mark='O'] {
  color: var(--o);
}

.overlay-sub {
  margin: 0 0 1rem;
  font-size: 0.875rem;
  color: var(--muted);
}

.overlay-actions {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.overlay-actions .ghost-row {
  display: flex;
  gap: 0.5rem;
}

.overlay-actions .ghost-row > button {
  flex: 1;
}

/* ---- toast ---------------------------------------------------------------------- */

.toast {
  position: fixed;
  left: 50%;
  bottom: 1.25rem;
  transform: translate(-50%, 200%);
  /* parked fully out of sight — the % translate resolves against the content
     box, so the padded pill otherwise peeks above the bottom edge */
  opacity: 0;
  background: var(--text);
  color: var(--card);
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 0.5rem 0.9rem;
  border-radius: 999px;
  transition:
    transform 0.25s ease,
    opacity 0.25s ease;
  pointer-events: none;
  z-index: 10;
}

.toast--in {
  transform: translate(-50%, 0);
  opacity: 1;
}

/* ---- small viewports --------------------------------------------------------------- */

@media (max-height: 560px) {
  .app {
    gap: 0.5rem;
  }

  .menu-title {
    font-size: 1.4rem;
  }

  .card {
    padding: 0.75rem;
  }

  .board {
    width: min(100%, 52vh);
    width: min(100%, 52vh, 52dvh);
  }
}

/* AI "thinking" pulse (suggestion 02 item 1): a faint settle on the cell the
   computer is about to take (Medium/Hard only) — feedback that a move is
   being decided, not a hint; it resolves into the mark on its own. */
.cell--think {
  animation: cell-think 1s ease-in-out infinite;
}

@keyframes cell-think {
  0%,
  100% {
    box-shadow: inset 0 0 0 2px rgb(255 255 255 / 0.08);
  }
  50% {
    box-shadow: inset 0 0 0 3px rgb(255 255 255 / 0.22);
  }
}

@media (prefers-reduced-motion: reduce) {
  .cell--think {
    animation: none;
  }
}