/* ── Responsive ─────────────────────────────────────────────── */
@media (max-width: 900px) {
    .app-header {
        flex-wrap: wrap;
        gap: 0.6rem;
    }

    .stage-nav {
        order: 3;
        width: 100%;
        justify-content: center;
    }

    #svgViewport {
        grid-template-columns: 1fr;
        grid-template-rows: minmax(260px, 52vh) minmax(280px, 1fr);
    }

    #svgWorkArea {
        border-right: none;
        border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }
    #dnaCompareGrid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .app-main {
        padding: 0.75rem 0.75rem 1.5rem;
    }

    .app-header {
        padding: 0.6rem 0.75rem;
    }
}

/* ── Scrollbar style ────────────────────────────────────────── */
::-webkit-scrollbar {
    width: 5px;
    height: 5px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--surface-3);
    border-radius: 99px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-mid);
}