.shell { background: var(--color-bg); display: flex; flex-direction: column; padding-top: 64px; }
.main { flex: 1; padding: 16px; max-width: 1100px; margin: 0 auto; width: 100%; display: flex; flex-direction: column; gap: 16px; }
@media (min-width: 640px) {
  .main { padding: 32px; gap: 24px; }
}