/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #007bff;
    --success: #28a745;
    --danger: #dc3545;
    --warning: #ffc107;
    --info: #17a2b8;
    --dark: #343a40;
    --light: #f8f9fa;
    --white: #ffffff;
    --gray: #6c757d;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: #333;
    background: #f4f7f9;
}

/* Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

.container-fluid {
    width: 100%;
    padding: 0 15px;
}

/* Grid System */
.row {
    display: flex;
    flex-wrap: wrap;
    margin: 0 -15px;
}

.col {
    flex: 1;
    padding: 0 15px;
}

.col-1 { flex: 0 0 8.333%; max-width: 8.333%; }
.col-2 { flex: 0 0 16.666%; max-width: 16.666%; }
.col-3 { flex: 0 0 25%; max-width: 25%; }
.col-4 { flex: 0 0 33.333%; max-width: 33.333%; }
.col-6 { flex: 0 0 50%; max-width: 50%; }
.col-8 { flex: 0 0 66.666%; max-width: 66.666%; }
.col-12 { flex: 0 0 100%; max-width: 100%; }

/* Navbar */
.navbar {
    background: var(--dark);
    color: var(--white);
    padding: 1rem 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

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

.navbar-brand {
    font-size: 1.25rem;
    font-weight: bold;
    color: var(--white);
    text-decoration: none;
}

.navbar-menu {
    display: flex;
    gap: 1rem;
    list-style: none;
}

.navbar-menu a {
    color: var(--white);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background 0.3s;
}

.navbar-menu a:hover {
    background: rgba(255,255,255,0.1);
}

.navbar-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--white);
    font-size: 1.5rem;
    cursor: pointer;
}

/* Cards */
.card {
    background: var(--white);
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    margin-bottom: 1.5rem;
    overflow: hidden;
}

.card-header {
    padding: 1rem 1.5rem;
    background: var(--light);
    border-bottom: 1px solid #dee2e6;
    font-weight: bold;
}

.card-body {
    padding: 1.5rem;
}

.card-footer {
    padding: 1rem 1.5rem;
    background: var(--light);
    border-top: 1px solid #dee2e6;
}

/* Stats Cards */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    text-align: center;
}

.stat-card h3 {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.stat-card p {
    color: var(--gray);
    font-size: 0.9rem;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #495057;
}

.form-control {
    width: 100%;
    padding: 0.75rem;
    font-size: 1rem;
    border: 1px solid #ced4da;
    border-radius: 4px;
    transition: border-color 0.15s;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(0,123,255,0.1);
}

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    text-align: center;
    text-decoration: none;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary { background: var(--primary); color: var(--white); }
.btn-success { background: var(--success); color: var(--white); }
.btn-danger { background: var(--danger); color: var(--white); }
.btn-warning { background: var(--warning); color: #000; }
.btn-info { background: var(--info); color: var(--white); }
.btn-secondary { background: var(--gray); color: var(--white); }

.btn:hover {
    opacity: 0.9;
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.btn-block {
    width: 100%;
    display: block;
}

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

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

table {
    width: 100%;
    border-collapse: collapse;
    background: var(--white);
}

th, td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid #dee2e6;
}

th {
    background: var(--light);
    font-weight: 600;
    color: #495057;
}

tr:hover {
    background: #f8f9fa;
}

/* Badges */
.badge {
    display: inline-block;
    padding: 0.35rem 0.65rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 4px;
    text-transform: uppercase;
}

.badge-pending { background: var(--warning); color: #000; }
.badge-approved { background: var(--success); color: var(--white); }
.badge-rejected { background: var(--danger); color: var(--white); }
.badge-verified { background: var(--success); color: var(--white); }
.badge-success { background: var(--success); color: var(--white); }
.badge-active { background: var(--success); color: var(--white); }
.badge-inactive { background: var(--gray); color: var(--white); }
.badge-admin { background: var(--danger); color: var(--white); }
.badge-staff { background: var(--warning); color: #000; }
.badge-student { background: var(--primary); color: var(--white); }

/* Alerts */
.alert {
    padding: 1rem;
    margin-bottom: 1rem;
    border-radius: 4px;
}

.alert-success { background: #d4edda; color: #155724; border: 1px solid #c3e6cb; }
.alert-danger { background: #f8d7da; color: #721c24; border: 1px solid #f5c6cb; }
.alert-warning { background: #fff3cd; color: #856404; border: 1px solid #ffeaa7; }
.alert-info { background: #d1ecf1; color: #0c5460; border: 1px solid #bee5eb; }

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

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.p-4 { padding: 2rem; }

.d-none { display: none; }
.d-block { display: block; }
.d-flex { display: flex; }

.justify-between { justify-content: space-between; }
.align-center { align-items: center; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }

/* Responsive - Tablet */
@media (max-width: 992px) {
    .col-md-6 { flex: 0 0 50%; max-width: 50%; }
    .col-md-12 { flex: 0 0 100%; max-width: 100%; }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Responsive - Mobile */
@media (max-width: 768px) {
    body {
        font-size: 14px;
    }
    
    .container {
        padding: 0 10px;
    }
    
    .row {
        margin: 0 -10px;
    }
    
    .col {
        padding: 0 10px;
    }
    
    [class*="col-"] {
        flex: 0 0 100%;
        max-width: 100%;
    }
    
    .navbar-menu {
        display: none;
        flex-direction: column;
        width: 100%;
        position: absolute;
        top: 100%;
        left: 0;
        background: var(--dark);
        padding: 1rem;
    }
    
    .navbar-menu.active {
        display: flex;
    }
    
    .navbar-toggle {
        display: block;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .stat-card h3 {
        font-size: 1.5rem;
    }
    
    .card-body {
        padding: 1rem;
    }
    
    table {
        font-size: 0.875rem;
    }
    
    th, td {
        padding: 0.5rem;
    }
    
    .btn {
        padding: 0.6rem 1rem;
        font-size: 0.875rem;
    }
    
    .form-control {
        padding: 0.6rem;
    }
}

/* Responsive - Small Mobile */
@media (max-width: 480px) {
    body {
        font-size: 13px;
    }
    
    .navbar-brand {
        font-size: 1rem;
    }
    
    .stat-card {
        padding: 1rem;
    }
    
    .stat-card h3 {
        font-size: 1.25rem;
    }
    
    table {
        font-size: 0.75rem;
    }
    
    th, td {
        padding: 0.4rem;
    }
    
    .btn-sm {
        padding: 0.4rem 0.8rem;
        font-size: 0.75rem;
    }
}

/* Print Styles */
@media print {
    .navbar, .btn, .navbar-toggle {
        display: none !important;
    }
    
    .card {
        box-shadow: none;
        border: 1px solid #ddd;
    }
}