:root {
    --sidebar-width: 260px;
}

body {
    background: #f5f6f8;
    color: #17202a;
}

.app-shell {
    display: flex;
    min-height: 100vh;
}

.app-sidebar {
    width: var(--sidebar-width);
    background: #17202a;
    color: #fff;
    padding: 18px;
}

.app-sidebar.collapse {
    display: block;
}

.sidebar-brand {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 18px;
}

.sidebar-nav {
    display: grid;
    gap: 4px;
}

.sidebar-nav a {
    border-radius: 6px;
    color: rgba(255, 255, 255, 0.78);
    padding: 10px 12px;
    text-decoration: none;
}

.sidebar-nav a.active,
.sidebar-nav a:hover {
    background: rgba(255, 255, 255, 0.12);
    color: #fff;
}

.app-main {
    flex: 1;
    min-width: 0;
}

.app-topbar {
    align-items: center;
    background: #fff;
    border-bottom: 1px solid #e5e7eb;
    display: flex;
    gap: 14px;
    justify-content: space-between;
    padding: 16px 24px;
}

.app-topbar > div {
    flex: 1;
    min-width: 0;
}

.app-topbar h1 {
    font-size: 1.35rem;
    margin: 0;
}

.app-menu-toggle {
    display: none;
}

.metric-card {
    border-radius: 8px;
}

.metric-card h2 {
    font-size: 1.2rem;
}

.auth-body {
    align-items: center;
    background: #f5f6f8;
    display: flex;
    min-height: 100vh;
    justify-content: center;
}

.auth-card {
    background: #fff;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    max-width: 420px;
    padding: 28px;
    width: 100%;
}

@media (max-width: 900px) {
    .app-shell {
        display: block;
    }

    .app-menu-toggle {
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .app-sidebar {
        width: 100%;
        padding: 14px 18px;
    }

    .app-sidebar.collapse {
        display: none;
    }

    .app-sidebar.collapse.show {
        display: block;
    }

    .app-topbar {
        padding: 12px 16px;
    }
}