:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --success-color: #27ae60;
    --danger-color: #e74c3c;
    --warning-color: #f39c12;
    --light-bg: #ecf0f1;
    --dark-bg: #34495e;
    --text-dark: #2c3e50;
    --text-light: #7f8c8d;
    --border-color: #bdc3c7;
    --white: #ffffff;
    --shadow: 0 2px 10px rgba(0,0,0,0.1);
    --shadow-hover: 0 4px 15px rgba(0,0,0,0.15);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--light-bg);
    color: var(--text-dark);
    line-height: 1.6;
}

/* Login Page */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
}

.login-box {
    background: var(--white);
    padding: 40px;
    border-radius: 10px;
    box-shadow: var(--shadow-hover);
    width: 100%;
    max-width: 400px;
}

.login-box h1 {
    text-align: center;
    margin-bottom: 10px;
    color: var(--primary-color);
    font-size: 28px;
}

.login-box p {
    text-align: center;
    color: var(--text-light);
    margin-bottom: 30px;
}

/* Forms */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    color: var(--text-dark);
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-size: 14px;
    transition: border-color 0.3s;
}

.form-control:focus {
    outline: none;
    border-color: var(--secondary-color);
}

select.form-control {
    cursor: pointer;
}

/* Buttons */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-block;
}

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

.btn-primary:hover {
    background: #2980b9;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

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

.btn-success:hover {
    background: #229954;
}

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

.btn-danger:hover {
    background: #c0392b;
}

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

.btn-secondary:hover {
    background: #95a5a6;
}

.btn-block {
    width: 100%;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 12px;
}

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

.sidebar {
    width: 250px;
    background: var(--primary-color);
    color: var(--white);
    padding: 20px 0;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
}

.sidebar-header {
    padding: 0 20px 20px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.sidebar-header h2 {
    font-size: 20px;
    margin-bottom: 5px;
}

.sidebar-header p {
    font-size: 12px;
    color: rgba(255,255,255,0.7);
}

.sidebar-menu {
    list-style: none;
    padding: 20px 0;
}

.sidebar-menu li {
    margin-bottom: 5px;
}

.sidebar-menu a {
    display: block;
    padding: 12px 20px;
    color: var(--white);
    text-decoration: none;
    transition: background 0.3s;
}

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

.main-content {
    flex: 1;
    margin-left: 250px;
    padding: 20px;
}

.topbar {
    background: var(--white);
    padding: 15px 20px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    margin-bottom: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.topbar h1 {
    font-size: 24px;
    color: var(--primary-color);
}

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

.user-info span {
    color: var(--text-light);
    font-size: 14px;
}

/* Cards */
.card {
    background: var(--white);
    border-radius: 10px;
    box-shadow: var(--shadow);
    padding: 20px;
    margin-bottom: 20px;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--light-bg);
}

.card-header h3 {
    font-size: 18px;
    color: var(--primary-color);
}

.card-body {
    padding: 0;
}

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

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

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

table th,
table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid var(--light-bg);
}

table th {
    font-weight: 600;
    color: var(--text-dark);
    font-size: 14px;
}

table td {
    font-size: 14px;
    color: var(--text-dark);
}

table tbody tr:hover {
    background: #f8f9fa;
}

/* Stats Cards */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.stat-card {
    background: var(--white);
    padding: 20px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--secondary-color);
}

.stat-card h4 {
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 10px;
}

.stat-card .value {
    font-size: 28px;
    font-weight: bold;
    color: var(--primary-color);
}

/* Alerts */
.alert {
    padding: 12px 20px;
    border-radius: 5px;
    margin-bottom: 20px;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-danger {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-info {
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

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

.modal.show {
    display: flex;
}

.modal-content {
    background: var(--white);
    border-radius: 10px;
    width: 90%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    padding: 20px;
    border-bottom: 1px solid var(--light-bg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    font-size: 20px;
    color: var(--primary-color);
}

.modal-close {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-light);
}

.modal-body {
    padding: 20px;
}

.modal-footer {
    padding: 20px;
    border-top: 1px solid var(--light-bg);
    display: flex;
    justify-content: flex-end;
    gap: 10px;
}

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

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

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

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

.d-flex {
    display: flex;
}

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

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

.gap-10 {
    gap: 10px;
}

/* Loading */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255,255,255,.3);
    border-radius: 50%;
    border-top-color: var(--white);
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        width: 200px;
    }
    
    .main-content {
        margin-left: 200px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 576px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s;
    }
    
    .sidebar.show {
        transform: translateX(0);
    }
    
    .main-content {
        margin-left: 0;
    }
}