/* Login Overlay */
.login-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--color-background);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    padding: var(--space-4);
}

.login-card {
    background-color: var(--color-surface);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--color-border);
    padding: var(--space-6) var(--space-5);
    width: 100%;
    max-width: 400px;
}

.login-header {
    text-align: center;
    margin-bottom: var(--space-5);
}

/* App Layout Structure */
.app-container {
    display: flex;
    min-height: 100vh;
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    width: 260px;
    background-color: var(--color-surface);
    border-right: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-normal);
    z-index: 100;
}

.sidebar-header {
    padding: var(--space-4);
    display: flex;
    align-items: center;
    gap: var(--space-2);
    border-bottom: 1px solid var(--color-border);
}

.logo-icon {
    color: var(--color-primary);
    width: 28px;
    height: 28px;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: var(--color-primary);
}

.nav-links {
    flex: 1;
    padding: var(--space-3) var(--space-2);
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    overflow-y: auto;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-md);
    color: var(--color-text-muted);
    font-weight: 500;
    transition: all var(--transition-fast);
}

.nav-item i {
    width: 20px;
    height: 20px;
}

.nav-item:hover {
    background-color: var(--color-surface-hover);
    color: var(--color-text-main);
}

.nav-item.active {
    background-color: var(--color-primary-light);
    color: #fff;
}

.sidebar-footer {
    padding: var(--space-3);
    border-top: 1px solid var(--color-border);
}

/* Main Content Area */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Topbar */
.topbar {
    height: 72px;
    background-color: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--space-4);
    z-index: 10;
}

.header-title-area h2 {
    font-size: 1.25rem;
}

.view-container {
    flex: 1;
    padding: var(--space-4);
    overflow-y: auto;
    background-color: var(--color-background);
}

/* Mobile responsive */
.mobile-only {
    display: none;
}

@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        bottom: 0;
        transform: translateX(-100%);
    }

    .sidebar.open {
        transform: translateX(0);
        box-shadow: var(--shadow-lg);
    }

    .mobile-only {
        display: block;
    }

    .topbar {
        justify-content: flex-start;
        gap: var(--space-3);
    }
    
    .header-actions {
        margin-left: auto;
    }
}