.app-shell {
  display: flex;
  width: 100%;
  height: 100vh;
  overflow: hidden;
  background: var(--bg);
}

.workspace {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow: hidden;
  position: relative;
}

.workspace-content {
  flex: 1;
  overflow-y: auto;
  padding: 2.5rem;
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 1.5rem;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.5rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.5rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
}

.col-span-4 { grid-column: span 4 / span 4; }
.col-span-8 { grid-column: span 8 / span 8; }
.col-span-12 { grid-column: span 12 / span 12; }

.stack-3 > * + * { margin-top: 0.75rem; }
.stack-4 > * + * { margin-top: 1rem; }
.stack-6 > * + * { margin-top: 1.5rem; }
.stack-8 > * + * { margin-top: 2rem; }

@media (max-width: 1280px) {
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 1024px) {
  .workspace-content { padding: 1.25rem; }
  .grid-12 { grid-template-columns: 1fr; }
  .col-span-4, .col-span-8, .col-span-12 { grid-column: auto; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}