/* Stack Drop */
.stack-shell {
  width: min(100% - 2rem, 520px);
  margin: 0 auto;
}

.stack-shell .lede {
  margin-bottom: 1.1rem;
}

.stack-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.85rem;
}

.stack-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
}

.stat-pill {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
  min-width: 4.5rem;
  padding: 0.4rem 0.7rem;
  border-radius: 10px;
  background: #eef6f2;
  border: 1px solid var(--line);
}

.stat-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.stat-pill strong {
  font-size: 1.2rem;
  color: var(--ink);
  line-height: 1.1;
}

.stack-panel {
  border: none;
  box-shadow:
    0 2px 6px rgba(20, 33, 43, 0.06),
    0 14px 32px rgba(20, 33, 43, 0.12);
  padding: 0.75rem;
  background:
    linear-gradient(180deg, #e8f4ef 0%, #f7faf8 40%, #fff 100%);
}

#canvas {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 12px;
  background: linear-gradient(180deg, #d7ebe3 0%, #f3f8f6 55%, #eef2f0 100%);
  cursor: pointer;
  touch-action: manipulation;
  user-select: none;
}

.stack-hint {
  margin: 0.65rem 0 0;
  text-align: center;
  font-weight: 700;
  color: var(--ink-soft);
  font-size: 0.95rem;
}

.stack-feedback {
  min-height: 1.35rem;
  margin: 0.35rem 0 0;
  text-align: center;
  font-weight: 700;
  color: var(--accent-deep);
}

.play-board.is-celebrate {
  animation: stack-glow 750ms ease;
}

@keyframes stack-glow {
  0%,
  100% {
    box-shadow:
      0 2px 6px rgba(20, 33, 43, 0.06),
      0 14px 32px rgba(20, 33, 43, 0.12);
  }
  45% {
    box-shadow:
      0 0 0 4px rgba(240, 162, 2, 0.35),
      0 14px 34px rgba(15, 122, 106, 0.2);
  }
}

.how-to {
  margin-top: 1rem;
}

.how-to h2 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  letter-spacing: -0.03em;
  margin: 0 0 0.5rem;
}

.how-to p,
.how-to li {
  color: var(--ink-soft);
  margin: 0 0 0.45rem;
}

.how-to ul {
  margin: 0;
  padding-left: 1.15rem;
}