.app {
    --sidebar-current: var(--sidebar-w);
    display: grid;
    grid-template-columns: var(--sidebar-current) minmax(0, 1fr);
    height: 100vh;
    height: 100dvh;
    overflow: hidden;
    background: var(--color-nav-bg);
}

.app[data-rail] {
    --sidebar-current: var(--sidebar-rail-w);
}

.sidebar {
    grid-column: 1;
    display: flex;
    flex-direction: column;
    width: var(--sidebar-current);
    height: 100vh;
    height: 100dvh;
    padding: 0 12px 16px;
    overflow-x: hidden;
    overflow-y: auto;
    overscroll-behavior: contain;
    background: var(--color-nav-bg);
    color: var(--color-nav-text);
    transition: width 0.2s ease;
}

.sidebar::-webkit-scrollbar {
    width: 6px;
}

.sidebar::-webkit-scrollbar-thumb {
    border-radius: 3px;
    background: rgb(255 255 255 / 0.12);
}

.nav-backdrop {
    display: none;
}

.sidebar__header {
    display: flex;
    flex: none;
    align-items: center;
    gap: var(--sp-2);
    height: 68px;
    padding-inline: 4px 0;
}

.brand {
    display: flex;
    flex: 1;
    align-items: center;
    gap: 10px;
    min-width: 0;
    color: var(--color-nav-text-strong);
    text-decoration: none;
}

.brand:hover {
    text-decoration: none;
}

.brand__mark {
    display: grid;
    flex: none;
    place-items: center;
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: #fff;
    color: var(--color-nav-bg);
    font-weight: var(--weight-bold);
    font-size: var(--text-md);
}

.brand__text {
    min-width: 0;
}

.brand__name {
    display: block;
    font-size: var(--text-lg);
    font-weight: var(--weight-bold);
    line-height: 1.15;
    letter-spacing: -0.01em;
}

.brand__sub {
    display: block;
    overflow: hidden;
    font-size: var(--text-sm);
    color: rgb(255 255 255 / 0.55);
    text-overflow: ellipsis;
    white-space: nowrap;
}

.nav-toggle--sidebar {
    display: grid;
    flex: none;
    place-items: center;
    width: 36px;
    height: 36px;
    padding: 0;
    border: 0;
    border-radius: 8px;
    background: transparent;
    color: rgb(255 255 255 / 0.6);
    transition: background var(--transition-fast), color var(--transition-fast);
}

.nav-toggle--sidebar:hover {
    background: rgb(255 255 255 / 0.1);
    color: #fff;
}

.topbar .nav-toggle--topbar {
    display: none;
    flex: none;
    margin-inline-start: -6px;
}

.sidebar__cta {
    padding: var(--sp-3) 0 var(--sp-2);
}

.sidebar__cta .btn {
    width: 100%;
    justify-content: center;
}

.nav-section {
    margin-top: var(--sp-4);
    padding: 0 12px 4px;
    overflow: hidden;
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: var(--weight-medium);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: rgb(255 255 255 / 0.6);
    text-overflow: ellipsis;
    white-space: nowrap;
}

.sidebar ul {
    display: grid;
    gap: 2px;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    padding: 8px 12px;
    border-radius: 8px;
    color: rgb(255 255 255 / 0.8);
    font-size: var(--text-base);
    text-decoration: none;
    transition: background var(--transition-fast), color var(--transition-fast);
}

.nav-item:hover {
    background: rgb(255 255 255 / 0.05);
    color: #fff;
    text-decoration: none;
}

.nav-item[aria-current="page"] {
    background: rgb(255 255 255 / 0.1);
    color: #fff;
    font-weight: var(--weight-medium);
}

.nav-item:focus-visible {
    outline-color: var(--color-accent-gold);
}

.nav-item__label {
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.nav-item__count {
    padding: 2px 6px;
    border-radius: 6px;
    background: rgb(255 255 255 / 0.1);
    color: rgb(255 255 255 / 0.7);
    font-size: 10px;
    font-weight: var(--weight-medium);
    letter-spacing: 0.03em;
    font-variant-numeric: tabular-nums;
}

.app[data-rail] .sidebar {
    padding-inline: 8px;
}

.app[data-rail] .sidebar__header {
    justify-content: center;
    padding: 0;
}

.app[data-rail] .brand {
    display: none;
}

.app[data-rail] :is(.nav-item__label, .nav-item__count, .sidebar__cta-label) {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
}

.app[data-rail] .nav-section {
    height: 1px;
    margin: var(--sp-3) 8px;
    padding: 0;
    background: rgb(255 255 255 / 0.12);
    color: transparent;
}

.app[data-rail] .nav-item {
    justify-content: center;
    width: 40px;
    height: 40px;
    margin-inline: auto;
    padding: 0;
}

.app[data-rail] .nav-item .icon {
    width: 18px;
    height: 18px;
}

.app[data-rail] .sidebar__cta .btn {
    width: 40px;
    margin-inline: auto;
    padding: 0;
}

.main {
    grid-column: 2;
    display: flex;
    flex-direction: column;
    min-width: 0;
    min-height: 0;
    margin: 8px 8px 8px 0;
    overflow: hidden;
    border-radius: 18px;
    background: var(--color-bg);
    box-shadow: 0 0 0 1px rgb(255 255 255 / 0.06);
}

.topbar {
    display: flex;
    flex: none;
    align-items: center;
    gap: var(--sp-3);
    height: var(--topbar-h);
    padding: 0 var(--sp-4) 0 20px;
    border-bottom: var(--border-width) solid var(--color-border);
    background: var(--color-surface);
}

.breadcrumb {
    min-width: 0;
}

.breadcrumb ol {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    min-width: 0;
    font-size: var(--text-md);
    color: var(--color-text-muted);
}

.breadcrumb li {
    flex: none;
    white-space: nowrap;
}

.breadcrumb li:last-child {
    flex: 0 1 auto;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
}

.breadcrumb li + li::before {
    content: '/';
    margin-inline-end: var(--sp-2);
    color: var(--color-border-strong);
}

.breadcrumb [aria-current="page"] {
    color: var(--color-text);
    font-weight: var(--weight-medium);
}

.content {
    display: flex;
    flex: 1 1 auto;
    flex-direction: column;
    gap: var(--sp-3);
    min-width: 0;
    min-height: 0;
    padding: var(--sp-4) 20px var(--sp-5);
    overflow-y: auto;
}

.page-header {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--sp-3);
}

.page-header__titles {
    flex: 1 1 24rem;
    min-width: 0;
}

.page-header__title {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px;
}

.page-header__sub {
    margin-top: 2px;
    font-size: var(--text-md);
    color: var(--color-text-muted);
}

.page-header__actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--sp-2);
}

/* Two-column work areas  */
.split {
    display: grid;
    grid-template-columns: minmax(0, 1fr) var(--split-aside, 340px);
    gap: var(--sp-3);
    align-items: start;
}

@media (max-width: 1100px) {
    .split {
        grid-template-columns: minmax(0, 1fr);
    }
}

/* Tablet: rail that expands as an overlay */
@media (min-width: 768px) and (max-width: 1199px) {
    .app {
        grid-template-columns: var(--sidebar-rail-w) minmax(0, 1fr);
    }

    .app[data-nav-open] .sidebar {
        position: fixed;
        inset: 0 auto 0 0;
        z-index: var(--z-drawer);
        width: var(--sidebar-w);
        box-shadow: var(--shadow-lg);
    }
}

/* Phone: off-canvas drawer */
@media (max-width: 767px) {
    .app {
        grid-template-columns: minmax(0, 1fr);
    }

    .main {
        grid-column: 1;
        margin: 0;
        border-radius: 0;
    }

    .topbar .nav-toggle--topbar {
        display: inline-grid;
    }

    .sidebar {
        position: fixed;
        inset: 0 auto 0 0;
        z-index: var(--z-drawer);
        width: min(calc(var(--sidebar-w) + 40px), 85vw);
        transform: translateX(-100%);
        visibility: hidden;
        transition: transform 0.2s ease, visibility 0s linear 0.2s;
    }

    .app[data-nav-open] .sidebar {
        transform: none;
        visibility: visible;
        box-shadow: var(--shadow-lg);
        transition: transform 0.2s ease, visibility 0s;
    }

    .topbar {
        gap: var(--sp-2);
        padding: 0 var(--sp-3);
    }

    .breadcrumb li:not(:last-child) {
        display: none;
    }

    .breadcrumb li:last-child::before {
        display: none;
    }

    .content {
        padding: var(--sp-3) var(--sp-3) var(--sp-5);
    }

    .page-header__actions {
        width: 100%;
    }
}

@media (max-width: 1199px) {
    .app[data-nav-open] .nav-backdrop {
        display: block;
        position: fixed;
        inset: 0;
        z-index: calc(var(--z-drawer) - 1);
        background: var(--color-backdrop);
    }
}

html.nav-locked {
    overflow: hidden;
}