.train-layout {
  display: grid;
  grid-template-columns: minmax(230px, 310px) minmax(0, 1fr);
  gap: 18px;
  max-width: 1220px;
  margin: 0 auto;
  align-items: start;
}

.train-panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 18px;
  background: linear-gradient(160deg, rgba(255, 209, 184, 0.95), rgba(255, 253, 245, 0.9));
}

.hint {
  margin-bottom: 0;
  color: #405363;
  font-size: 1.08rem;
  font-weight: 850;
  line-height: 1.55;
}

.train-stage {
  padding: 18px;
  background: rgba(255, 253, 245, 0.78);
}

.engine {
  display: inline-flex;
  align-items: center;
  min-height: 54px;
  margin-bottom: 16px;
  padding: 0 22px;
  border-radius: 18px;
  background: #263238;
  color: #fffdf5;
  font-weight: 950;
  box-shadow: 0 10px 22px rgba(71, 85, 105, 0.16);
}

.train-track {
  display: grid;
  grid-template-columns: repeat(var(--columns), minmax(58px, 1fr));
  gap: 10px;
  min-height: 88px;
  margin-bottom: 18px;
}

.carriage,
.number-piece {
  display: grid;
  min-height: 70px;
  place-items: center;
  border: 3px solid rgba(255, 255, 255, 0.78);
  border-radius: 22px;
  background: var(--car-color, #ffe089);
  color: #263238;
  cursor: pointer;
  font-size: clamp(1.35rem, 4vw, 2.4rem);
  font-weight: 950;
  box-shadow: 0 12px 22px rgba(71, 85, 105, 0.14);
  touch-action: none;
  user-select: none;
}

.carriage.is-selected,
.number-piece.is-selected {
  outline: 5px solid rgba(77, 163, 199, 0.36);
}

.carriage.is-empty {
  border-style: dashed;
  background: rgba(255, 255, 255, 0.54);
  color: #607282;
}

.carriage.is-dragging {
  opacity: 0.55;
}

.number-depot {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.number-depot:empty {
  display: none;
}

.number-piece {
  width: 76px;
}

@media (max-width: 820px) {
  .train-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 540px) {
  .train-stage {
    padding: 12px;
  }

  .train-track {
    grid-template-columns: repeat(5, minmax(52px, 1fr));
  }

  .carriage,
  .number-piece {
    min-height: 62px;
    border-radius: 18px;
  }
}