.knapsack-layout {
  display: grid;
  grid-template-columns: minmax(220px, 0.7fr) minmax(420px, 1.3fr);
  align-items: stretch;
  gap: var(--spacing-xl);
}

.knapsack-panel {
  min-width: 0;
  padding: var(--spacing-lg);
  border: 1px solid rgba(148, 163, 184, 0.26);
  border-radius: var(--border-radius-lg);
  background: rgba(15, 23, 42, 0.82);
}

.knapsack-sum-panel {
  display: grid;
  place-items: center;
  align-content: center;
  text-align: center;
}

.knapsack-sum {
  margin: 0;
  color: var(--accent-light);
  font-size: clamp(3.5rem, 10vw, 7rem);
  font-weight: var(--font-weight-bold);
  line-height: 1;
}

.knapsack-limit {
  margin: var(--spacing-sm) 0 0;
  color: var(--text-secondary);
  font-weight: var(--font-weight-semibold);
}

.knapsack-numbers {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: var(--spacing-sm);
}

.knapsack-number {
  min-height: 4.5rem;
  padding: var(--spacing-sm);
  border: 2px solid rgba(148, 163, 184, 0.38);
  background: rgba(30, 41, 59, 0.84);
  font-size: var(--font-size-xl);
}

.knapsack-number:hover:not(:disabled),
.knapsack-number:focus-visible:not(:disabled),
.knapsack-number.is-selected {
  border-color: var(--accent-light);
  background: rgba(30, 64, 175, 0.5);
}

.knapsack-number.is-selected {
  outline: 2px solid #fef08a;
  outline-offset: 1px;
}

.knapsack-number:disabled {
  color: rgba(226, 232, 240, 0.42);
  border-color: rgba(148, 163, 184, 0.16);
  background: rgba(30, 41, 59, 0.36);
  box-shadow: none;
  cursor: not-allowed;
  transform: none;
}

@media (max-width: 800px) {
  .knapsack-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .knapsack-panel {
    padding: var(--spacing-md);
  }

  .knapsack-numbers {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}