:root {
    --primary-color: #165DFF;
    --primary-dark: #0E42D2;
    --secondary-color: #6B7280;
    --success-color: #10B981;
    --danger-color: #EF4444;
    --warning-color: #F59E0B;
    --bg-light: #F9FAFB;
    --bg-white: #FFFFFF;
    --text-primary: #111827;
    --text-secondary: #6B7280;
    --border-color: #E5E7EB;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-light);
    color: var(--text-primary);
    line-height: 1.6;
}

.navbar {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    box-shadow: var(--shadow);
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.5rem;
}

.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.card {
    border: none;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

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

.stat-card {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    border-radius: 16px;
    padding: 1.5rem;
    box-shadow: var(--shadow-lg);
}

.stat-card.success {
    background: linear-gradient(135deg, #10B981 0%, #059669 100%);
}

.stat-card.warning {
    background: linear-gradient(135deg, #F59E0B 0%, #D97706 100%);
}

.stat-card.info {
    background: linear-gradient(135deg, #3B82F6 0%, #2563EB 100%);
}

.stat-card h3 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.stat-card p {
    font-size: 1rem;
    opacity: 0.9;
}

.table {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
}

.table thead {
    background: var(--bg-light);
}

.table thead th {
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    font-size: 0.875rem;
    letter-spacing: 0.05em;
    border-bottom: 2px solid var(--border-color);
}

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

.table tbody tr:hover {
    background: var(--bg-light);
}

.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.login-card {
    width: 100%;
    max-width: 450px;
    padding: 2.5rem;
    background: white;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
}

.login-card h2 {
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.login-card p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.form-control, .form-select {
    border-radius: 10px;
    border: 2px solid var(--border-color);
    padding: 0.875rem 1rem;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.form-control:focus, .form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(22, 93, 255, 0.1);
}

.form-label {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.alert {
    border-radius: 10px;
    border: none;
}

.nav-pills .nav-link {
    border-radius: 10px;
    padding: 0.75rem 1.25rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all 0.3s ease;
}

.nav-pills .nav-link:hover {
    background: var(--bg-light);
    color: var(--primary-color);
}

.nav-pills .nav-link.active {
    background: var(--primary-color);
    color: white;
}

.sidebar {
    background: white;
    border-radius: 16px;
    box-shadow: var(--shadow);
    padding: 1.5rem;
    min-height: calc(100vh - 100px);
}

.user-info {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 1.5rem;
    border-radius: 12px;
    margin-bottom: 1.5rem;
}

.user-info .avatar {
    width: 60px;
    height: 60px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.footer {
    background: white;
    padding: 1.5rem;
    margin-top: 3rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-secondary);
}

@media (max-width: 768px) {
    .sidebar {
        min-height: auto;
        margin-bottom: 1.5rem;
    }
    
    .stat-card {
        margin-bottom: 1rem;
    }
}

.loading {
    opacity: 0.6;
    pointer-events: none;
}

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

.fade-in {
    animation: fadeIn 0.3s ease forwards;
}