/* ================================================
   APPLICATION LAYOUT
   ================================================ */

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

/* ================================================
   SIDEBAR
   ================================================ */

.sidebar {
    width: 280px;
    background: var(--surface-color);
    border-right: 1px solid var(--border-color);
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    box-shadow: var(--shadow);
    z-index: 100;
}

.sidebar-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    background: var(--background-color);
}

.logo {
    display: flex;
    align-items: center;
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--primary-color);
}

.logo::before {
    content: "📧";
    margin-right: var(--spacing-sm);
    font-size: 1.5rem;
}

.nav-menu {
    padding: var(--spacing-md) 0;
}

.nav-item {
    display: block;
    width: 100%;
    padding: 0.75rem var(--spacing-lg);
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-normal);
    border: none;
    background: none;
    text-align: left;
    cursor: pointer;
    font-size: var(--font-size-sm);
    font-weight: 500;
}

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

.nav-item.active {
    background-color: var(--primary-color);
    color: white;
    font-weight: 600;
}

.nav-item.active::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: white;
}

.user-info {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    background: var(--surface-color);
}

.user-name {
    font-weight: 600;
    font-size: var(--font-size-sm);
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.user-org {
    font-size: var(--font-size-xs);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.logout-btn {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--danger-color);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: var(--font-size-xs);
    font-weight: 500;
    transition: background-color var(--transition-normal);
}

.logout-btn:hover {
    background-color: #dc2626;
}

/* ================================================
   MAIN CONTENT
   ================================================ */

.main-content {
    flex: 1;
    margin-left: 280px;
    min-height: 100vh;
    background: var(--background-color);
}

.page-header {
    background: var(--surface-color);
    padding: var(--spacing-xl) var(--spacing-xl);
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 0;
}

.page-title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.page-subtitle {
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
    margin-bottom: 0;
}

.page-content {
    padding: var(--spacing-xl);
}

/* ================================================
   GRID LAYOUTS
   ================================================ */

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.quick-actions {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.two-column-layout {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-xl);
}

.three-column-layout {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

/* ================================================
   MOBILE SIDEBAR
   ================================================ */

.sidebar-toggle {
    display: none;
    position: fixed;
    top: var(--spacing-md);
    left: var(--spacing-md);
    z-index: 1001;
    background: var(--primary-color);
    color: white;
    border: none;
    padding: var(--spacing-sm);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: var(--font-size-base);
}

/* ================================================
   RESPONSIVE DESIGN
   ================================================ */

@media (max-width: 1024px) {
    .two-column-layout {
        grid-template-columns: 1fr;
    }
    
    .three-column-layout {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform var(--transition-slow);
    }
    
    .sidebar.mobile-open {
        transform: translateX(0);
    }
    
    .sidebar-toggle {
        display: block;
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .page-header {
        padding: var(--spacing-lg) var(--spacing-md);
        padding-top: 4rem; /* Space for mobile toggle */
    }
    
    .page-content {
        padding: var(--spacing-md);
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .quick-actions {
        grid-template-columns: 1fr;
        gap: var(--spacing-sm);
    }
    
    .three-column-layout {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .page-title {
        font-size: var(--font-size-2xl);
    }
    
    .page-header {
        padding: var(--spacing-md);
        padding-top: 3.5rem;
    }
    
    .page-content {
        padding: var(--spacing-sm);
    }
    
    .sidebar {
        width: 100%;
    }
    
    .user-info {
        position: relative;
        margin-top: var(--spacing-md);
    }
}

/* ================================================
   LOADING SCREEN
   ================================================ */

.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--background-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.loading-screen .spinner {
    width: 3rem;
    height: 3rem;
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: var(--spacing-lg);
}

.loading-screen p {
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* ================================================
   CONTENT AREAS
   ================================================ */

.content-section {
    background: var(--surface-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    margin-bottom: var(--spacing-lg);
}

.content-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    background: var(--background-color);
}

.content-body {
    padding: var(--spacing-lg);
}

.content-footer {
    padding: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    background: var(--background-color);
}

/* ================================================
   HEADER ACTIONS
   ================================================ */

.page-header-actions {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.page-header-content {
    flex: 1;
}

.page-header-buttons {
    display: flex;
    gap: var(--spacing-sm);
    margin-left: var(--spacing-lg);
}

@media (max-width: 768px) {
    .page-header-actions {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .page-header-buttons {
        margin-left: 0;
        width: 100%;
    }
    
    .page-header-buttons .btn {
        flex: 1;
    }
}

/* ================================================
   OVERLAY & BACKDROP
   ================================================ */

.overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
    backdrop-filter: blur(2px);
}

.backdrop {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.3);
    z-index: 99;
}

/* ================================================
   SCROLLBAR STYLING
   ================================================ */

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

.sidebar::-webkit-scrollbar-track {
    background: var(--background-color);
}

.sidebar::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

.sidebar::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color);
}

/* ================================================
   ACCESSIBILITY
   ================================================ */

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .sidebar {
        border-right: 2px solid var(--text-primary);
    }
    
    .nav-item.active {
        border: 2px solid white;
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .sidebar {
        transition: none;
    }
}