/* ═══════════════════════════════════════════
   TrainControl — Control Grid
   ═══════════════════════════════════════════ */

.app-layout {
    flex: 1;
    display: flex;
    overflow: hidden;
    height: calc(100dvh - var(--header-h) - var(--footer-h));
}

.control-grid {
    flex: 1;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--gap-md);
    padding: var(--gap-md);
    overflow-y: auto;
    align-content: start;
}

/* ── Empty slot (drop zone) ── */
.grid-slot {
    min-height: var(--slot-min-h);
    border-radius: var(--radius-xl);
    transition: all var(--duration-med) var(--ease-out);
}

.grid-slot.empty {
    background: var(--bg-slot-empty);
    border: 2px dashed var(--border-medium);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--gap-sm);
    color: var(--text-tertiary);
}

.grid-slot.empty .drop-icon {
    font-size: 2.5rem;
    opacity: 0.35;
}

.grid-slot.empty .drop-text {
    font-size: 0.82rem;
    text-align: center;
    line-height: 1.4;
    max-width: 200px;
}

/* Drag over state */
.grid-slot.drag-over {
    border-color: var(--tc-blue);
    background: rgba(67, 89, 144, 0.06);
    box-shadow: inset 0 0 0 2px rgba(67, 89, 144, 0.15);
}

/* ── Filled slot ── */
.grid-slot.filled {
    background: var(--bg-card);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--border-card);
    box-shadow: var(--shadow-card);
    display: flex;
    flex-direction: column;
}

/* Responsive */
@media (max-width: 1100px) {
    .control-grid {
        grid-template-columns: 1fr;
    }
}