:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --secondary: #8b5cf6;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --dark: #1f2937;
    --light: #f3f4f6;
    --white: #ffffff;
    --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-2: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-3: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.15);
}

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

body {
    font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--dark);
}

/* Login Page Styles */
.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.login-box {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 50px 40px;
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 450px;
    animation: slideUp 0.5s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-header {
    text-align: center;
    margin-bottom: 40px;
}

.login-header h1 {
    font-size: 32px;
    font-weight: 700;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 10px;
}

.login-header p {
    color: #6b7280;
    font-size: 14px;
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--dark);
    font-size: 14px;
}

.form-control {
    width: 100%;
    padding: 14px 18px;
    border: 2px solid #e5e7eb;
    border-radius: 12px;
    font-size: 15px;
    transition: all 0.3s ease;
    background: var(--white);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

.btn {
    padding: 14px 28px;
    border: none;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background: var(--gradient-1);
    color: var(--white);
    width: 100%;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.5);
}

.btn-secondary {
    background: var(--light);
    color: var(--dark);
}

.btn-secondary:hover {
    background: #e5e7eb;
}

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

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

.btn-sm {
    padding: 8px 16px;
    font-size: 13px;
}

/* Dashboard Layout */
.dashboard {
    display: flex;
    min-height: 100vh;
    background: #f9fafb;
}

.sidebar {
    width: 280px;
    background: var(--white);
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.05);
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    z-index: 100;
}

.sidebar-header {
    padding: 30px 20px;
    border-bottom: 1px solid #e5e7eb;
}

.sidebar-header h2 {
    font-size: 24px;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.sidebar-menu {
    padding: 20px 0;
}

.menu-item {
    display: flex;
    align-items: center;
    padding: 14px 20px;
    color: #6b7280;
    text-decoration: none;
    transition: all 0.3s ease;
    border-left: 3px solid transparent;
}

.menu-item:hover {
    background: #f3f4f6;
    color: var(--primary);
    border-left-color: var(--primary);
}

.menu-item.active {
    background: #eff6ff;
    color: var(--primary);
    border-left-color: var(--primary);
    font-weight: 600;
}

.menu-item i {
    margin-right: 12px;
    font-size: 18px;
    width: 24px;
}

.main-content {
    margin-left: 280px;
    flex: 1;
    padding: 30px;
    width: calc(100% - 280px);
}

.top-bar {
    background: var(--white);
    padding: 20px 30px;
    border-radius: 16px;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.page-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--dark);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 15px;
}

.user-avatar {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    background: var(--gradient-1);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-weight: 600;
    font-size: 18px;
}

/* Cards */
.card {
    background: var(--white);
    border-radius: 16px;
    padding: 25px;
    box-shadow: var(--shadow);
    margin-bottom: 25px;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid #f3f4f6;
}

.card-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--dark);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
    margin-bottom: 30px;
}

.stat-card {
    background: var(--white);
    border-radius: 16px;
    padding: 25px;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
    transition: transform 0.3s ease;
}

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

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 100px;
    height: 100px;
    background: var(--gradient-1);
    opacity: 0.1;
    border-radius: 50%;
    transform: translate(30%, -30%);
}

.stat-icon {
    width: 60px;
    height: 60px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    margin-bottom: 15px;
    color: var(--white);
}

.stat-icon.blue {
    background: var(--gradient-3);
}

.stat-icon.purple {
    background: var(--gradient-1);
}

.stat-icon.pink {
    background: var(--gradient-2);
}

.stat-value {
    font-size: 32px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 5px;
}

.stat-label {
    color: #6b7280;
    font-size: 14px;
}

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

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

table thead {
    background: #f9fafb;
}

table th {
    padding: 15px;
    text-align: left;
    font-weight: 600;
    color: var(--dark);
    font-size: 14px;
    border-bottom: 2px solid #e5e7eb;
}

table td {
    padding: 15px;
    border-bottom: 1px solid #f3f4f6;
    color: #4b5563;
}

table tbody tr:hover {
    background: #f9fafb;
}

/* Badge */
.badge {
    display: inline-block;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

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

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

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

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

/* Alert */
.alert {
    padding: 15px 20px;
    border-radius: 12px;
    margin-bottom: 20px;
    font-size: 14px;
}

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

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

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

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--white);
    border-radius: 20px;
    padding: 30px;
    max-width: 600px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    animation: slideUp 0.3s ease;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid #f3f4f6;
}

.modal-title {
    font-size: 22px;
    font-weight: 600;
}

.close-modal {
    background: none;
    border: none;
    font-size: 28px;
    cursor: pointer;
    color: #6b7280;
    transition: color 0.3s;
}

.close-modal:hover {
    color: var(--danger);
}

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

.mt-3 {
    margin-top: 20px;
}

.mb-3 {
    margin-bottom: 20px;
}

.flex {
    display: flex;
}

.gap-2 {
    gap: 10px;
}

.justify-between {
    justify-content: space-between;
}

.items-center {
    align-items: center;
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s ease;
    }
    
    .sidebar.active {
        transform: translateX(0);
    }
    
    .main-content {
        margin-left: 0;
        width: 100%;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .top-bar {
        flex-direction: column;
        gap: 15px;
    }
}

/* Placeholder page styles */
.placeholder-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 400px;
    text-align: center;
}

.placeholder-icon {
    font-size: 80px;
    color: #d1d5db;
    margin-bottom: 20px;
}

.placeholder-title {
    font-size: 24px;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 10px;
}

.placeholder-text {
    color: #6b7280;
    font-size: 16px;
}