.app {
    display: grid;
    grid-template-columns: var(--sidebar-w) 1fr;
    grid-template-rows: var(--topbar-h) 1fr;
    grid-template-areas:
        "brand topbar"
        "sidebar main";
    height: 100vh;
    height: 100dvh;
}

.app[data-sidebar="collapsed"] {
    grid-template-columns: 0 1fr;
}

/* ---------- Topbar ---------- */

.brand {
    grid-area: brand;
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    padding: 0 var(--sp-3);
    background: var(--surface-2);
    border-right: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    min-width: 0;
}

.app[data-sidebar="collapsed"] .brand {
    border-right: 0;
    padding: 0;
    background: transparent;
}

.brand__title {
    font-size: var(--fs-md);
    font-weight: 700;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.app[data-sidebar="collapsed"] .brand__title {
    display: none;
}

.topbar {
    grid-area: topbar;
    display: flex;
    align-items: center;
    gap: var(--sp-3);
    padding: 0 var(--sp-4);
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    min-width: 0;
}

.topbar__spacer {
    flex: 1;
    min-width: 0;
}

.topbar__actions {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    flex-shrink: 0;
}

/* ---------- Sidebar ---------- */

.sidebar {
    grid-area: sidebar;
    position: relative;
    display: flex;
    flex-direction: column;
    min-height: 0;
    background: var(--surface-2);
    border-right: 1px solid var(--border);
    overflow: hidden;
}

/* Tirador de ancho: invisible en reposo, se pinta al pasar por encima o al
   recibir foco. Vive dentro de la sidebar, pegado a su borde derecho. */
.sidebar__resizer {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    width: 7px;
    cursor: col-resize;
    background: transparent;
    touch-action: none;
    z-index: 3;
}

.sidebar__resizer::after {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    right: 0;
    width: 2px;
    background: var(--brand);
    opacity: 0;
    transition: opacity 0.12s ease;
}

.sidebar__resizer:hover::after,
.sidebar__resizer:focus-visible::after,
body.is-resizing .sidebar__resizer::after {
    opacity: 1;
}

.sidebar__resizer:focus-visible {
    outline: none;
}

/* Durante el arrastre: nada de selección de texto ni cursores cambiantes. */
body.is-resizing {
    user-select: none;
    cursor: col-resize;
}

body.is-resizing * {
    cursor: col-resize !important;
}

.app[data-sidebar="collapsed"] .sidebar {
    display: none;
}

/* Colapsada o en modo drawer el ancho no se ajusta a mano. */
.app[data-sidebar="collapsed"] .sidebar__resizer {
    display: none;
}

.sidebar__tools {
    padding: var(--sp-3);
    display: flex;
    flex-direction: column;
    gap: var(--sp-2);
    border-bottom: 1px solid var(--border);
}

.sidebar__meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--sp-2);
    font-size: var(--fs-xs);
    color: var(--text-muted);
}

.sidebar__scroll {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    overflow-x: hidden;
}

/* ---------- Main ---------- */

.main {
    grid-area: main;
    min-width: 0;
    min-height: 0;
    overflow-y: auto;
    background: var(--bg);
    padding: var(--sp-5);
    scroll-behavior: smooth;
}

.main__inner {
    max-width: 1500px;
}

/* ---------- Responsive: sidebar como drawer ---------- */

@media (max-width: 900px) {
    .app {
        grid-template-columns: 1fr;
        grid-template-rows: var(--topbar-h) 1fr;
        grid-template-areas:
            "topbar"
            "main";
    }

    .brand {
        display: none;
    }

    .sidebar {
        position: fixed;
        inset: 0 auto 0 0;
        z-index: 60;
        width: min(85vw, var(--sidebar-w));
        box-shadow: var(--shadow-3);
        transform: translateX(-100%);
        transition: transform 0.18s ease;
    }

    .app[data-drawer="open"] .sidebar {
        display: flex;
        transform: translateX(0);
    }

    .app[data-sidebar="collapsed"] .sidebar {
        display: flex;
    }

    .app[data-drawer="open"] .scrim {
        display: block;
    }

    .sidebar__resizer {
        display: none;
    }

    .main {
        padding: var(--sp-4) var(--sp-3);
    }
}

.scrim {
    display: none;
    position: fixed;
    inset: 0;
    background: var(--overlay);
    z-index: 55;
}