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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --dark-color: #1f2937;
    --light-color: #f3f4f6;
    --border-color: #e5e7eb;
    --text-color: #374151;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: var(--light-color);
}

/* Page Transitions */
.page-content {
    animation: fadeIn 0.3s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Loading Spinner */
.loader {
    border: 3px solid var(--light-color);
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

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

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.9);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.loading-overlay.active {
    display: flex;
}

/* Header */
.header {
    background: white;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo img {
    height: 40px;
}

.nav-menu {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
}

.nav-menu a:hover {
    color: var(--primary-color);
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

/* Cards */
.card {
    background: white;
    border-radius: 8px;
    box-shadow: var(--shadow);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.card-header {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--border-color);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.625rem 1.25rem;
    border: none;
    border-radius: 6px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.3s;
    text-align: center;
}

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

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

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

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

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

.btn-sm {
    padding: 0.4rem 0.8rem;
    font-size: 0.85rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.25rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--dark-color);
}

.form-control {
    width: 100%;
    padding: 0.625rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.95rem;
    transition: border-color 0.3s;
}

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

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

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

table {
    width: 100%;
    border-collapse: collapse;
}

table th,
table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

table th {
    background: var(--light-color);
    font-weight: 600;
    color: var(--dark-color);
}

table tr:hover {
    background: #f9fafb;
}

/* Badges */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 12px;
    text-transform: uppercase;
}

.badge-success {
    background: #d1fae5;
    color: #065f46;
}

.badge-warning {
    background: #fef3c7;
    color: #92400e;
}

.badge-danger {
    background: #fee2e2;
    color: #991b1b;
}

.badge-info {
    background: #dbeafe;
    color: #1e40af;
}

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: 6px;
    margin-bottom: 1rem;
}

.alert-success {
    background: #d1fae5;
    color: #065f46;
    border-left: 4px solid var(--success-color);
}

.alert-danger {
    background: #fee2e2;
    color: #991b1b;
    border-left: 4px solid var(--danger-color);
}

.alert-info {
    background: #dbeafe;
    color: #1e40af;
    border-left: 4px solid var(--primary-color);
}

/* Grid System */
.grid {
    display: grid;
    gap: 1.5rem;
}

.grid-2 {
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
}

.grid-3 {
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
}

.grid-4 {
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}

/* Responsive */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 1rem;
    }
   
    .nav-menu {
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
    }
   
    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }
   
    table {
        font-size: 0.85rem;
    }
   
    table th,
    table td {
        padding: 0.5rem;
    }
}

/* Utilities */
.text-center {
    text-align: center;
}

.text-right {
    text-align: right;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }

.flex {
    display: flex;
}

.flex-between {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }