css/admin.css

```css
/* Admin Dashboard CSS */
.admin-login {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.login-container {
    width: 100%;
    max-width: 400px;
    padding: 20px;
}

.login-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

.admin-dashboard {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f8f9fa;
    min-height: 100vh;
}

/* Sidebar Styles */
.sidebar {
    position: fixed;
    top: 0;
    right: 0;
    width: 250px;
    height: 100vh;
    background: linear-gradient(180deg, #2c5aa0 0%, #1e3a8a 100%);
    color: white;
    transition: all 0.3s ease;
    z-index: 1000;
}

.sidebar-header {
    padding: 1.5rem 1rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-nav {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-nav .nav-item {
    margin: 0;
}

.sidebar-nav .nav-link {
    color: rgba(255, 255, 255, 0.8);
    padding: 0.75rem 1rem;
    text-decoration: none;
    display: block;
    transition: all 0.3s ease;
    border-right: 3px solid transparent;
}

.sidebar-nav .nav-link:hover,
.sidebar-nav .nav-link.active {
    background-color: rgba(255, 255, 255, 0.1);
    color: white;
    border-right-color: #ff6b35;
}

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

/* Main Content Area */
.main-content {
    margin-right: 250px;
    transition: all 0.3s ease;
}

.main-content.sidebar-collapsed {
    margin-right: 70px;
}

/* Top Bar */
.topbar {
    background: white;
    padding: 1rem 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 999;
}

.sidebar-toggle {
    background: none;
    border: none;
    font-size: 1.25rem;
    color: #6c757d;
    cursor: pointer;
    padding: 0.5rem;
}

/* Summary Cards */
.summary-card {
    border: none;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.summary-card:hover {
    transform: translateY(-5px);
}

.summary-card .card-title {
    font-size: 0.9rem;
    color: #6c757d;
    margin-bottom: 0.5rem;
}

.summary-card .card-number {
    font-size: 2rem;
    font-weight: bold;
    color: #2c5aa0;
    margin-bottom: 0;
}

.summary-card .icon {
    padding: 1rem;
    border-radius: 50%;
    background: rgba(44, 90, 160, 0.1);
}

/* Table Styles */
.table-responsive {
    border-radius: 10px;
    overflow: hidden;
}

.table {
    margin-bottom: 0;
}

.table th {
    background-color: #f8f9fa;
    border-bottom: 2px solid #dee2e6;
    font-weight: 600;
    color: #495057;
}

.table td {
    vertical-align: middle;
}

/* Modal Styles */
.modal-header {
    border-bottom: 1px solid #dee2e6;
    padding: 1.5rem;
}

.modal-footer {
    border-top: 1px solid #dee2e6;
    padding: 1.5rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .sidebar {
        width: 70px;
    }
    
    .sidebar .sidebar-header h4,
    .sidebar .nav-link span {
        display: none;
    }
    
    .sidebar .nav-link {
        text-align: center;
        padding: 1rem 0.5rem;
    }
    
    .sidebar .nav-link i {
        margin: 0;
        font-size: 1.25rem;
    }
    
    .main-content {
        margin-right: 70px;
    }
    
    .summary-card .card-number {
        font-size: 1.5rem;
    }
}

/* Custom Scrollbar */
.sidebar::-webkit-scrollbar {
    width: 5px;
}

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

.sidebar::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
}

.sidebar::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.5);
}
```