* { box-sizing: border-box; }

:root {
  --board-size: min(88vw, 560px);
}

html {
  /* reserve scrollbar space so its appearance never shifts the board */
  scrollbar-gutter: stable;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  background: #edebe9;
  color: #4d4d4d;
  font-family: "Noto Sans", "Segoe UI", system-ui, sans-serif;
}

main {
  /* horizontal centering only: vertical `auto` recentered the layout when
     the analysis graph appeared/disappeared, moving the board under
     chessground's cached bounds and breaking click targets */
  margin: 0 auto;
  display: flex;
  gap: 24px;
  padding: 24px;
  flex-wrap: wrap;
  justify-content: center;
}

/* the eval bar and board never wrap apart */
.play-area {
  display: flex;
  gap: 24px;
}

.board-col {
  position: relative;
}

.eval-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  /* keep the bar level with the board despite the action row above it */
  padding-top: 40px;
}

.board-actions {
  width: var(--board-size);
  height: 32px;
  margin-bottom: 8px;
}

#eval-bar {
  width: 16px;
  height: var(--board-size);
  background: #403d39; /* black's share, from the top */
  border-radius: 3px;
  overflow: hidden;
  position: relative;
  box-shadow: inset 0 0 2px rgba(0, 0, 0, 0.4);
}

#eval-white {
  position: absolute;
  bottom: 0;
  width: 100%;
  height: 50%;
  background: #fff;
  transition: height 0.6s ease;
}

#eval-num {
  font-size: 0.7rem;
  font-weight: 600;
  color: #6f6c66;
  min-height: 1em;
}

#board {
  width: var(--board-size);
  height: var(--board-size);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.18);
}

#analysis {
  margin-top: 12px;
  width: var(--board-size);
}

#analysis.hidden {
  display: none;
}

#graph {
  display: block;
  width: 100%;
  height: 90px;
  background: #403d39; /* black's share, like the eval bar */
  border-radius: 6px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.18);
  cursor: pointer;
}

#analysis-summary {
  margin: 6px 0 0;
  font-size: 0.8rem;
  color: #6f6c66;
  min-height: 1em;
}

.panel {
  width: 260px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

h1 {
  margin: 0;
  font-size: 1.3rem;
  color: #333;
}

#status {
  margin: 0;
  min-height: 1.4em;
  font-weight: 600;
  color: #629924;
}

#status.error {
  color: #df5353;
}

button:focus-visible,
select:focus-visible,
input:focus-visible,
a:focus-visible {
  outline: 2px solid #629924;
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  #eval-white {
    transition: none;
  }
}

.controls {
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: #fff;
  border: 1px solid #d9d9d9;
  border-radius: 6px;
  padding: 12px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.controls label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 0.85rem;
}

.controls select,
.controls input[type="range"] {
  width: 100%;
}

.controls select {
  background: #fff;
  color: #4d4d4d;
  border: 1px solid #ccc;
  border-radius: 4px;
  padding: 4px;
}

.buttons {
  display: flex;
  gap: 8px;
}

.buttons button {
  flex: 1;
  padding: 6px 4px;
  background: #f7f6f5;
  color: #4d4d4d;
  border: 1px solid #ccc;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.85rem;
}

.buttons button:hover:not(:disabled) {
  background: #629924;
  border-color: #629924;
  color: #fff;
}

.buttons button:disabled {
  opacity: 0.4;
  cursor: default;
}

#moves {
  margin: 0;
  padding: 12px;
  background: #fff;
  border: 1px solid #d9d9d9;
  border-radius: 6px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
  list-style: none;
  overflow-y: auto;
  max-height: 320px;
  font-size: 0.9rem;
  flex: 1;
}

#moves li {
  display: flex;
  gap: 12px;
  padding: 2px 0;
}

#moves .num {
  color: #a0a0a0;
  width: 2em;
  text-align: right;
}

#moves .san {
  width: 4.5em;
  color: #333;
}

#moves.analysed .san {
  cursor: pointer;
  border-radius: 3px;
}

#moves.analysed .san:hover {
  background: rgba(98, 153, 36, 0.12);
}

#moves .san.current {
  background: rgba(98, 153, 36, 0.22);
}

/* narrow screens: shrink the board so it fits beside the eval bar
   (16px bar + 8px gap + 12px padding each side = 48px, plus 16px for the
   scrollbar gutter — 100vw includes the scrollbar the gutter reserves) */
@media (max-width: 740px) {
  :root {
    --board-size: min(calc(100vw - 64px), 560px);
  }

  main {
    gap: 12px;
    padding: 12px;
  }

  .play-area {
    gap: 8px;
  }

  .panel {
    width: 100%;
    max-width: 560px;
  }
}

#pgn-input {
  padding: 6px 8px;
  background: #fff;
  border: 1px solid #d9d9d9;
  border-radius: 6px;
  font-size: 0.8rem;
  color: #4d4d4d;
}

#pgn-input.invalid {
  border-color: #df5353;
  outline: 1px solid #df5353;
}

.panel-links {
  margin: 0;
  font-size: 0.8rem;
  text-align: right;
}

.panel-links a {
  color: #629924;
}

#promo-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.6);
  z-index: 10;
}

#promo-overlay.hidden {
  display: none;
}

.promo-box {
  display: flex;
  gap: 8px;
  background: #fff;
  border: 1px solid #d9d9d9;
  padding: 14px;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
}

.promo-box button {
  font-size: 2.4rem;
  line-height: 1;
  width: 64px;
  height: 64px;
  background: #f7f6f5;
  color: #333;
  border: 1px solid #ccc;
  border-radius: 6px;
  cursor: pointer;
}

.promo-box button:hover {
  background: #629924;
  color: #fff;
}