:root {
    --primary-color: #667eea;
    --primary-dark: #5568d3;
    --secondary-color: #764ba2;
    --success-color: #1cc88a;
    --info-color: #36b9cc;
    --warning-color: #f6c23e;
    --danger-color: #e74a3b;
    --light-color: #f8f9fc;
    --dark-color: #2d3748;
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-color: #2d3748;
    --sidebar-width: 260px;
    --font-family: 'Inter', system-ui, -apple-system, sans-serif;
    --transition-speed: 0.3s;
    --shadow-sm: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.075);
    --shadow-md: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 1rem 3rem rgba(0, 0, 0, 0.175);
    --radius-sm: 0.375rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
}

* {
    box-sizing: border-box;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    overflow-x: hidden;
    line-height: 1.6;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    color: #1a202c;
    margin-bottom: 1rem;
    line-height: 1.2;
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.75rem;
}

/* Layout */
.main-content {
    margin-left: var(--sidebar-width);
    padding: 2rem;
    min-height: 100vh;
    transition: margin-left var(--transition-speed) ease;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: linear-gradient(180deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    z-index: 1000;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-speed) ease;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
}

.sidebar::-webkit-scrollbar {
    width: 8px;
}

.sidebar::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.1);
}

.sidebar::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 4px;
}

.sidebar-brand {
    height: 4.375rem;
    text-decoration: none;
    font-size: 1.2rem;
    font-weight: 800;
    padding: 1.5rem 1rem;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 0.05rem;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-nav {
    padding: 1rem 0;
    list-style: none;
    flex: 1;
}

.nav-item {
    position: relative;
    margin-bottom: 0.25rem;
}

.nav-link {
    display: flex;
    align-items: center;
    padding: 1rem;
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s;
    border-radius: var(--radius-sm);
    margin: 0 0.5rem;
}

.nav-link:hover,
.nav-link.active {
    color: #fff;
    background-color: rgba(255, 255, 255, 0.15);
    transform: translateX(5px);
}

.nav-link i {
    margin-right: 0.75rem;
    font-size: 1.1rem;
    width: 1.5rem;
    text-align: center;
}

.sidebar-divider {
    margin: 1rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.15);
}

.sidebar-heading {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05rem;
    color: rgba(255, 255, 255, 0.5);
    padding: 0 1rem;
    margin: 1rem 0 0.5rem;
}

/* Cards */
.card {
    background-color: var(--card-bg);
    border: none;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s, box-shadow 0.2s;
    margin-bottom: 1.5rem;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.card-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    border-bottom: none;
    padding: 1.25rem 1.5rem;
    font-weight: 700;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.card-body {
    padding: 1.5rem;
}

/* Forms */
.form-label {
    font-weight: 600;
    color: var(--dark-color);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.form-control,
.form-select {
    border: 2px solid #e2e8f0;
    border-radius: var(--radius-sm);
    padding: 0.75rem 1rem;
    font-size: 1rem;
    transition: all 0.2s;
    background-color: white;
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
    outline: none;
}

.form-control:hover,
.form-select:hover {
    border-color: var(--primary-dark);
}

.form-check-input {
    width: 1.25rem;
    height: 1.25rem;
    border: 2px solid #e2e8f0;
    cursor: pointer;
}

.form-check-input:checked {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.form-check-label {
    margin-left: 0.5rem;
    cursor: pointer;
}

textarea.form-control {
    resize: vertical;
    min-height: 100px;
}

.invalid-feedback,
.text-danger {
    color: var(--danger-color);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

/* Buttons */
.btn {
    border-radius: var(--radius-sm);
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    transition: all 0.2s;
    border: none;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background-color: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background-color: #5a6268;
}

.btn-success {
    background-color: var(--success-color);
    color: white;
}

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

.btn-warning {
    background-color: var(--warning-color);
    color: #1a202c;
}

.btn-info {
    background-color: var(--info-color);
    color: white;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

/* Tables */
.table-responsive {
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.table {
    margin-bottom: 0;
}

.table thead th {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    font-weight: 700;
    text-transform: uppercase;
    font-size: 0.85rem;
    border: none;
    padding: 1rem;
}

.table tbody tr {
    transition: background-color 0.2s;
}

.table tbody tr:hover {
    background-color: #f8f9fc;
}

.table tbody td {
    padding: 1rem;
    vertical-align: middle;
    border-bottom: 1px solid #e3e6f0;
}

/* Badges */
.badge {
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.75rem;
}

.bg-success {
    background-color: var(--success-color) !important;
}

.bg-warning {
    background-color: var(--warning-color) !important;
}

.bg-danger {
    background-color: var(--danger-color) !important;
}

.bg-info {
    background-color: var(--info-color) !important;
}

.bg-secondary {
    background-color: var(--secondary-color) !important;
}

/* Alerts */
.alert {
    border-radius: var(--radius-md);
    padding: 1rem 1.25rem;
    border: none;
    margin-bottom: 1rem;
}

.alert-warning {
    background-color: #fff3cd;
    color: #856404;
}

.alert-success {
    background-color: #d4edda;
    color: #155724;
}

.alert-danger {
    background-color: #f8d7da;
    color: #721c24;
}

/* Pagination */
.pagination {
    gap: 0.5rem;
}

.page-link {
    border: none;
    border-radius: var(--radius-sm);
    padding: 0.5rem 1rem;
    color: var(--primary-color);
    font-weight: 600;
    transition: all 0.2s;
}

.page-link:hover {
    background-color: var(--primary-color);
    color: white;
}

.page-item.active .page-link {
    background-color: var(--primary-color);
    color: white;
}

/* Utilities */
.shadow-sm {
    box-shadow: var(--shadow-sm) !important;
}

.shadow {
    box-shadow: var(--shadow-md) !important;
}

.shadow-lg {
    box-shadow: var(--shadow-lg) !important;
}

.text-muted {
    color: #6c757d !important;
}

.text-primary {
    color: var(--primary-color) !important;
}

.text-success {
    color: var(--success-color) !important;
}

.text-danger {
    color: var(--danger-color) !important;
}

.text-warning {
    color: var(--warning-color) !important;
}

.border-left-primary {
    border-left: 0.25rem solid var(--primary-color) !important;
}

.border-left-success {
    border-left: 0.25rem solid var(--success-color) !important;
}

.border-left-info {
    border-left: 0.25rem solid var(--info-color) !important;
}

.border-left-warning {
    border-left: 0.25rem solid var(--warning-color) !important;
}

/* Loading States */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
    }

    .main-content {
        margin-left: 0;
        padding: 1rem;
    }

    .nav-link {
        padding: 0.75rem;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    h3 {
        font-size: 1.25rem;
    }
}

/* Print Styles */
@media print {

    .sidebar,
    .btn,
    .pagination {
        display: none !important;
    }

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