.demo-board {
  grid-column: 1 / -1;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 10px 28px rgba(38, 32, 26, 0.08);
}

.demo-board summary {
  cursor: pointer;
  padding: 14px 16px;
  font-weight: 900;
}

.demo-board summary span {
  display: block;
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 700;
}

.demo-board-shell {
  height: min(72vh, 620px);
  min-height: 420px;
  border-top: 1px solid var(--line);
  background: #f8fbfd;
  overflow: hidden;
}

.demo-board-mount {
  width: 100%;
  height: 100%;
  touch-action: none;
}

.konva-board {
  display: grid;
  grid-template-rows: auto 1fr;
  width: 100%;
  height: 100%;
}

.board-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 10px;
  border-bottom: 1px solid var(--line);
  background: #ffffff;
}

.board-toolbar button {
  min-height: 36px;
  border: 1px solid #c8d8e1;
  border-radius: 8px;
  background: #ffffff;
  color: var(--ink);
  font: inherit;
  font-size: 0.82rem;
  font-weight: 900;
  text-transform: uppercase;
  cursor: pointer;
}

.board-toolbar button.is-active {
  border-color: #2f66b3;
  background: #2f66b3;
  color: #ffffff;
}

.board-swatches {
  display: flex;
  align-items: center;
  gap: 6px;
}

.board-swatches button {
  width: 30px;
  min-width: 30px;
  height: 30px;
  min-height: 30px;
  padding: 0;
  border-radius: 50%;
  background: var(--swatch);
}

.board-swatches button.is-active {
  outline: 3px solid #c8d8e1;
  outline-offset: 2px;
}

.board-size {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 900;
  text-transform: uppercase;
}

.board-size input {
  width: 120px;
}

.konva-host {
  width: 100%;
  height: 100%;
  background:
    linear-gradient(rgba(47, 102, 179, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(47, 102, 179, 0.07) 1px, transparent 1px),
    #ffffff;
  background-size: 32px 32px;
  touch-action: none;
  user-select: none;
}

.demo-board-fallback {
  padding: 18px;
  color: var(--muted);
  font-weight: 800;
}

@media (max-width: 720px) {
  .demo-board-shell {
    min-height: 520px;
  }

  .board-toolbar {
    gap: 6px;
  }

  .board-size {
    width: 100%;
  }
}