:root {
    /* Color Palette - Enterprise Blue Theme */
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --info-color: #3b82f6;

    /* Sidebar & Header */
    --sidebar-bg: #0f172a;
    --sidebar-text: #94a3b8;
    --sidebar-active-bg: #1e293b;
    --sidebar-active-text: #ffffff;
    --header-bg: #ffffff;
    --header-border: #e2e8f0;

    /* Backgrounds */
    --body-bg: #f1f5f9;
    --card-bg: #ffffff;

    /* Text */
    --text-main: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;

    /* Borders */
    --border-color: #e2e8f0;
    --border-radius: 6px;
    --border-radius-lg: 8px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--body-bg);
    color: var(--text-main);
    line-height: 1.5;
    font-size: 14px;
    height: 100vh;
    overflow: hidden;
}

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

/* Sidebar */
.sidebar {
    width: 250px;
    background-color: var(--sidebar-bg);
    color: var(--sidebar-text);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
    transition: width var(--transition-normal);
}

.sidebar-header {
    height: 64px;
    display: flex;
    align-items: center;
    padding: 0 var(--spacing-lg);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: #fff;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo i {
    color: var(--primary-color);
}

.sidebar-nav {
    flex: 1;
    padding: var(--spacing-md) 0;
    overflow-y: auto;
}

.nav-item {
    display: block;
    padding: var(--spacing-sm) var(--spacing-lg);
    color: var(--sidebar-text);
    text-decoration: none;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-weight: 500;
    border-left: 3px solid transparent;
}

.nav-item:hover {
    color: #fff;
    background-color: rgba(255, 255, 255, 0.05);
}

.nav-item.active {
    color: var(--sidebar-active-text);
    background-color: var(--sidebar-active-bg);
    border-left-color: var(--primary-color);
}

.nav-item i {
    width: 20px;
    text-align: center;
}

.sidebar-footer {
    padding: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.user-mini-profile {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: #fff;
}

.avatar {
    width: 32px;
    height: 32px;
    background-color: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
}

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

/* Header */
.top-header {
    height: 64px;
    background-color: var(--header-bg);
    border-bottom: 1px solid var(--header-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--spacing-xl);
    flex-shrink: 0;
}

.header-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-main);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

/* Content Area */
.content-area {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-xl);
}

/* Components */

/* Cards */
.card {
    background-color: var(--card-bg);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    margin-bottom: var(--spacing-lg);
}

.card-header {
    padding: var(--spacing-md) var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.card-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-main);
}

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-fast);
    border: 1px solid transparent;
    gap: 0.5rem;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #fff;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
}

.btn-secondary {
    background-color: #fff;
    border-color: var(--border-color);
    color: var(--text-main);
}

.btn-secondary:hover {
    background-color: #f8fafc;
    border-color: #cbd5e1;
}

.btn-danger {
    background-color: #fee2e2;
    color: var(--danger-color);
}

.btn-danger:hover {
    background-color: #fecaca;
}

.btn-success {
    background-color: #dcfce7;
    color: #166534;
}

.btn-success:hover {
    background-color: #bbf7d0;
}

.btn-sm {
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
}

/* Forms */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
    color: var(--text-main);
}

.form-control {
    width: 100%;
    padding: 0.5rem 0.75rem;
    font-size: 0.875rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: border-color var(--transition-fast);
    background-color: #fff;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Tables */
.table-container {
    overflow-x: auto;
}

.table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}

.table th {
    text-align: left;
    padding: 0.75rem 1rem;
    background-color: #f8fafc;
    color: var(--text-secondary);
    font-weight: 600;
    border-bottom: 1px solid var(--border-color);
}

.table td {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-main);
}

.table tbody tr:hover {
    background-color: #f8fafc;
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.125rem 0.5rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 500;
}

.badge-success { background-color: #dcfce7; color: #166534; }
.badge-warning { background-color: #fef3c7; color: #92400e; }
.badge-danger { background-color: #fee2e2; color: #991b1b; }
.badge-info { background-color: #dbeafe; color: #1e40af; }
.badge-gray { background-color: #f1f5f9; color: #475569; }

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.stat-card {
    background: #fff;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-xs);
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-main);
}

.stat-trend {
    font-size: 0.75rem;
    margin-top: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.trend-up { color: var(--success-color); }
.trend-down { color: var(--danger-color); }

/* Upload Area */
.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 3rem;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-fast);
    background-color: #f8fafc;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background-color: #eff6ff;
}

.upload-icon {
    font-size: 3rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

/* Utilities */
.text-right { text-align: right; }
.text-center { text-align: center; }
.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-4 { margin-top: 1rem; }
.mb-4 { margin-bottom: 1rem; }
.flex { display: flex; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: 0.5rem; }
.gap-4 { gap: 1rem; }
.w-full { width: 100%; }

/* Login Page Specific */
.login-page {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
    background-color: #f1f5f9;
}

.login-card {
    width: 100%;
    max-width: 400px;
    background: #fff;
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-logo {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* Modals */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-fast);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background-color: #fff;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 500px;
    transform: translateY(-20px);
    transition: transform var(--transition-fast);
}

.modal-overlay.active .modal {
    transform: translateY(0);
}

.modal-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-main);
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.25rem;
    color: var(--text-secondary);
    cursor: pointer;
}

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

.modal-footer {
    padding: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-md);
}