:root {
    --sidebar-width: 260px;
    --sidebar-bg: #111827;
    --page-bg: #f5f7fa;
}

body {
    margin: 0;
    background: var(--page-bg);
    color: #1f2937;
}

.app-wrapper {
    min-height: 100vh;
}

.app-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;

    width: var(--sidebar-width);

    background: var(--sidebar-bg);
    color: #ffffff;

    overflow-y: auto;
}

.app-main {
    margin-left: var(--sidebar-width);
    min-height: 100vh;
}

.app-topbar {
    min-height: 64px;

    display: flex;
    align-items: center;

    padding: 0 24px;

    background: #ffffff;

    border-bottom: 1px solid #e5e7eb;
}

.app-content {
    padding: 24px;
}

.sidebar-brand {
    padding: 20px;
    font-weight: 700;
}

.sidebar-nav {
    padding: 10px;
}

.sidebar-link {
    display: flex;
    align-items: center;

    gap: 10px;

    padding: 10px 12px;
    margin-bottom: 4px;

    border-radius: 8px;

    color: #d1d5db;

    text-decoration: none;
}

.sidebar-link:hover,
.sidebar-link.active {
    background: #1f2937;
    color: #ffffff;
}

@media (max-width: 991.98px) {
    .app-sidebar {
        transform: translateX(-100%);
        transition: transform .2s ease;
    }

    .app-sidebar.show {
        transform: translateX(0);
    }

    .app-main {
        margin-left: 0;
    }
}