/*
 * ChessTracker styles.
 *
 * The board is a square CSS grid sized against both viewport dimensions so it
 * always fits without scrolling, on a phone held in either orientation.
 */

:root {
  --bg: #302e2b;
  --panel: #262421;
  --panel-raised: #3a3835;
  --border: #46443f;
  --text: #f1f0ee;
  --text-dim: #a7a29a;
  --accent: #81b64c;
  --accent-dark: #6a9a3c;
  --warn: #e0a03c;
  --danger: #d4593f;

  --sq-light: #eeeed2;
  --sq-dark: #769656;
  --sq-highlight: rgba(247, 236, 91, 0.55);
  --sq-select: rgba(247, 236, 91, 0.7);
  --sq-preview: rgba(224, 160, 60, 0.75);

  --radius: 10px;
  --board-size: min(92vw, calc(100vh - 320px), 560px);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial,
    sans-serif;
  font-size: 15px;
  line-height: 1.45;
  padding: 0 16px 24px;
  -webkit-text-size-adjust: 100%;
}

h1,
h2 {
  margin: 0;
  font-weight: 600;
}

/* ------------------------------------------------------------------ header */

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  max-width: 1040px;
  margin: 0 auto;
  padding: 16px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  font-size: 34px;
  line-height: 1;
  color: var(--accent);
}

.app-header h1 {
  font-size: 20px;
  letter-spacing: 0.2px;
}

.tagline {
  margin: 2px 0 0;
  color: var(--text-dim);
  font-size: 13px;
}

.header-actions {
  display: flex;
  gap: 8px;
}

/* ------------------------------------------------------------------ layout */

.layout {
  max-width: 1040px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: auto minmax(240px, 300px);
  gap: 20px;
  align-items: start;
  justify-content: center;
}

.board-panel {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: var(--board-size);
}

/* ------------------------------------------------------------ player strip */

.player-strip {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 34px;
  padding: 4px 10px;
  background: var(--panel);
  border: 1px solid transparent;
  border-radius: var(--radius);
}

.player-strip.to-move {
  border-color: var(--accent);
}

.player-id {
  display: flex;
  align-items: center;
  gap: 7px;
  font-weight: 600;
  font-size: 14px;
  white-space: nowrap;
}

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 1px solid #15140f;
}

.dot.white {
  background: #f7f6f3;
}

.dot.black {
  background: #3f3d39;
  border-color: #6e6b64;
}

.captured {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1px;
  flex: 1;
  min-width: 0;
  overflow: hidden;
}

.taken {
  font-size: 19px;
  line-height: 1;
  /* Overlap the glyphs slightly so a full set still fits on a phone. */
  margin-right: -5px;
}

.taken.white {
  color: #f7f6f3;
  text-shadow: 0 0 1px #14130f, 0 0 1px #14130f;
}

.taken.black {
  color: #6f6b64;
}

.lead {
  font-size: 13px;
  font-weight: 700;
  color: var(--accent);
  white-space: nowrap;
}

/* ------------------------------------------------------------------- board */

.board-wrap {
  position: relative;
  width: var(--board-size);
  height: var(--board-size);
}

.board {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  grid-template-rows: repeat(8, 1fr);
  width: 100%;
  height: 100%;
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 8px 26px rgba(0, 0, 0, 0.45);
  touch-action: manipulation;
}

.sq {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.sq.light {
  background: var(--sq-light);
}

.sq.dark {
  background: var(--sq-dark);
}

.sq:focus-visible {
  outline: 3px solid #4a9de0;
  outline-offset: -3px;
  z-index: 3;
}

.piece {
  font-size: calc(var(--board-size) / 8 * 0.82);
  line-height: 1;
  pointer-events: none;
  position: relative;
  z-index: 2;
  /* Nudge the glyphs onto the visual centre of the square. */
  transform: translateY(-2%);
}

.piece.white {
  color: #fff;
  text-shadow: 0 0 1px #1d1c19, 0 1px 1px #1d1c19, 1px 0 1px #1d1c19, 0 -1px 1px #1d1c19,
    -1px 0 1px #1d1c19, 0 2px 3px rgba(0, 0, 0, 0.35);
}

.piece.black {
  color: #2b2926;
  text-shadow: 0 0 1px rgba(255, 255, 255, 0.35), 0 2px 3px rgba(0, 0, 0, 0.3);
}

/* Backstop for the pawn glyph alongside the U+FE0E text-presentation
   selector in app.js: naming a font with real chess-symbol coverage keeps
   WebKit from substituting its colour emoji pawn, which ignores the
   colour/text-shadow above. */
.piece-p {
  font-family: 'Apple Symbols', -apple-system, BlinkMacSystemFont, 'Segoe UI Symbol', 'Segoe UI',
    Roboto, 'Helvetica Neue', Arial, sans-serif;
}

/* Rank numbers go top-left, file letters bottom-right, so the corner square
   can carry both without them colliding. */
.coord {
  position: absolute;
  font-size: 10px;
  font-weight: 700;
  opacity: 0.7;
  pointer-events: none;
  z-index: 1;
}

.coord-rank {
  inset: 2px auto auto 3px;
}

.coord-file {
  inset: auto 3px 1px auto;
}

.sq.light .coord {
  color: var(--sq-dark);
}

.sq.dark .coord {
  color: var(--sq-light);
}

body.hide-coords .coord {
  display: none;
}

/* Highlights ---------------------------------------------------------- */

.sq.last-from::before,
.sq.last-to::before,
.sq.selected::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--sq-highlight);
  z-index: 0;
}

.sq.selected::before {
  background: var(--sq-select);
}

.sq.in-check::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(
    circle at center,
    rgba(212, 89, 63, 0.95) 12%,
    rgba(212, 89, 63, 0.55) 48%,
    transparent 72%
  );
  z-index: 0;
}

/* A dot for a quiet move, a ring for a capture — the chess.com convention. */
.sq.target::after {
  content: '';
  position: absolute;
  width: 30%;
  height: 30%;
  border-radius: 50%;
  background: rgba(20, 20, 18, 0.28);
  z-index: 1;
}

.sq.target-capture::after {
  content: '';
  position: absolute;
  inset: 0;
  border: 6px solid rgba(20, 20, 18, 0.28);
  border-radius: 50%;
  z-index: 1;
}

.sq.target.preview::after,
.sq.target-capture.preview::after {
  background: rgba(224, 160, 60, 0.55);
}

.sq.target-capture.preview::after {
  background: none;
  border-color: var(--sq-preview);
}

.sq.target:hover::after,
.sq.target-capture:hover::after {
  background: rgba(20, 20, 18, 0.4);
}

.sq.target-capture:hover::after {
  background: none;
  border-color: rgba(20, 20, 18, 0.45);
}

/* Game-over overlay ---------------------------------------------------- */

.board-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(20, 19, 16, 0.72);
  border-radius: 6px;
  z-index: 5;
}

/* `display: flex` above outranks the browser's [hidden] rule, so restate it. */
.board-overlay[hidden] {
  display: none;
}

.overlay-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  text-align: center;
  max-width: 80%;
}

.overlay-text {
  margin: 0 0 14px;
  font-size: 17px;
  font-weight: 600;
}

/* -------------------------------------------------------------- side panel */

.side-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.status-card,
.moves-card,
.nav-card,
.tools-card,
.farboard-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
}

.status-line {
  margin: 0;
  font-size: 16px;
  font-weight: 600;
}

.status-line.check {
  color: var(--warn);
}

.status-line.over {
  color: var(--accent);
}

.hint {
  margin: 6px 0 0;
  font-size: 13px;
  color: var(--text-dim);
}

.hint.preview {
  color: var(--warn);
}

.moves-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 6px;
}

.moves-head h2 {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-dim);
}

.move-count {
  font-size: 12px;
  color: var(--text-dim);
}

.move-list {
  list-style: none;
  margin: 0;
  padding: 0;
  max-height: 320px;
  overflow-y: auto;
  font-variant-numeric: tabular-nums;
}

.move-row {
  display: grid;
  grid-template-columns: 34px 1fr 1fr;
  align-items: center;
  gap: 2px;
  border-radius: 5px;
}

.move-row:nth-child(odd) {
  background: rgba(255, 255, 255, 0.03);
}

.move-number {
  color: var(--text-dim);
  font-size: 13px;
  padding-left: 4px;
}

.move {
  appearance: none;
  background: none;
  border: 0;
  border-radius: 5px;
  color: var(--text);
  font: inherit;
  font-size: 14px;
  text-align: left;
  padding: 4px 6px;
  cursor: pointer;
}

.move:hover {
  background: var(--panel-raised);
}

.move.current {
  background: var(--accent-dark);
  color: #fff;
  font-weight: 600;
}

.move.future {
  color: var(--text-dim);
  font-style: italic;
}

.empty-moves {
  margin: 4px 0 0;
  font-size: 13px;
  color: var(--text-dim);
}

/* ---------------------------------------------------------------- controls */

.nav-card {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px;
}

.btn {
  appearance: none;
  background: var(--panel-raised);
  border: 1px solid var(--border);
  border-radius: 7px;
  color: var(--text);
  font: inherit;
  font-size: 14px;
  padding: 8px 12px;
  cursor: pointer;
  transition: background 0.12s ease, border-color 0.12s ease;
}

.btn:hover:not(:disabled) {
  background: #4a4744;
}

.btn:disabled {
  opacity: 0.4;
  cursor: default;
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent-dark);
  color: #1b2a10;
  font-weight: 600;
}

.btn-primary:hover:not(:disabled) {
  background: var(--accent-dark);
}

.btn.nav {
  padding: 8px 0;
  text-align: center;
}

.btn.nav.wide {
  grid-column: 1 / -1;
}

.btn.small {
  font-size: 13px;
  padding: 6px 10px;
}

.tools-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-dim);
  cursor: pointer;
}

.toggle input {
  width: 16px;
  height: 16px;
  accent-color: var(--accent);
  cursor: pointer;
}

.tool-buttons {
  display: flex;
  gap: 6px;
}

.tool-buttons .btn {
  flex: 1;
}

.tool-feedback {
  margin: 0;
  min-height: 16px;
  font-size: 12px;
  color: var(--accent);
}

.farboard-title {
  margin: 0;
  font-size: 14px;
  font-weight: 600;
}

.farboard-text {
  margin: 4px 0 0;
  font-size: 13px;
  color: var(--text-dim);
}

.farboard-card a,
.app-footer a {
  color: var(--accent);
  font-weight: 600;
}

/* --------------------------------------------------------------- promotion */

.promotion-backdrop {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(15, 14, 12, 0.7);
  z-index: 20;
}

.promotion-backdrop[hidden] {
  display: none;
}

.promotion-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  text-align: center;
}

.promotion-card p {
  margin: 0 0 12px;
  font-weight: 600;
}

.promotion-choices {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}

.promotion-choice {
  appearance: none;
  width: 62px;
  height: 62px;
  background: var(--sq-light);
  border: 2px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.promotion-choice:hover,
.promotion-choice:focus-visible {
  border-color: var(--accent);
  outline: none;
}

.promotion-choice .piece {
  font-size: 44px;
}

/* ------------------------------------------------------------------ footer */

.app-footer {
  max-width: 1040px;
  margin: 24px auto 0;
  color: var(--text-dim);
  font-size: 12px;
  text-align: center;
}

.app-footer p {
  margin: 0;
}

.app-footer p + p {
  margin-top: 6px;
}

/* ------------------------------------------------------------- responsive */

@media (max-width: 860px) {
  :root {
    --board-size: min(94vw, calc(100vh - 260px), 520px);
  }

  .layout {
    grid-template-columns: minmax(0, 1fr);
    justify-items: center;
  }

  .side-panel {
    width: min(94vw, 520px);
  }

  .move-list {
    max-height: 200px;
  }
}

@media (max-width: 420px) {
  body {
    padding: 0 10px 20px;
  }

  :root {
    --board-size: min(96vw, calc(100vh - 250px));
  }

  .app-header {
    padding: 12px 0;
  }

  .tagline {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
  }
}