:root {
    --primary-color: #1a1a1a;
    --secondary-color: #2563eb;
    --accent-color: #3b82f6;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --bg-color: #ffffff;
    --bg-secondary: #f8fafc;
    --text-color: #1f2937;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

[data-theme="dark"] {
    --primary-color: #ffffff;
    --secondary-color: #60a5fa;
    --accent-color: #3b82f6;
    --success-color: #34d399;
    --warning-color: #fbbf24;
    --error-color: #f87171;
    --bg-color: #111827;
    --bg-secondary: #1f2937;
    --text-color: #f9fafb;
    --text-secondary: #d1d5db;
    --border-color: #374151;
    --shadow-color: rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    padding: 1rem 0;
    box-shadow: 0 2px 10px var(--shadow-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: white;
    text-decoration: none;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    color: white;
    text-decoration: none;
    transition: opacity 0.3s ease;
}

.nav-menu a:hover {
    opacity: 0.8;
}

.theme-toggle {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: white;
    padding: 0.5rem;
    border-radius: 50%;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.2);
}

/* Sidebar */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: 250px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    z-index: 999;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    overflow-y: auto;
}

.sidebar.active {
    transform: translateX(0);
}

.sidebar-header {
    padding: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.sidebar-close {
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
}

.sidebar-menu {
    padding: 1rem 0;
}

.sidebar-menu ul {
    list-style: none;
}

.sidebar-menu li {
    margin-bottom: 0.5rem;
}

.sidebar-menu a {
    display: flex;
    align-items: center;
    padding: 0.75rem 1rem;
    color: var(--text-color);
    text-decoration: none;
    transition: background-color 0.3s ease;
}

.sidebar-menu a:hover,
.sidebar-menu a.active {
    background: var(--accent-color);
    color: white;
}

.sidebar-menu .icon {
    margin-right: 0.75rem;
    width: 20px;
    height: 20px;
}

/* Main Content */
.main-content {
    margin-left: 0;
    padding: 2rem;
    transition: margin-left 0.3s ease;
}

.main-content.sidebar-open {
    margin-left: 250px;
}

/* Dashboard Cards */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.card {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px var(--shadow-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px var(--shadow-color);
}

.card-header {
    display: flex;
    justify-content: between;
    align-items: center;
    margin-bottom: 1rem;
}

.card-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-color);
}

.card-icon {
    width: 24px;
    height: 24px;
    color: var(--secondary-color);
}

.card-value {
    font-size: 2rem;
    font-weight: bold;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.card-description {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-color);
}

.form-input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-color);
    color: var(--text-color);
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.form-input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-color);
    color: var(--text-color);
    cursor: pointer;
}

.form-textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-color);
    color: var(--text-color);
    resize: vertical;
    min-height: 100px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-weight: 500;
    text-decoration: none;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--secondary-color), var(--accent-color));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

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

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

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

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

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

/* Tables */
.table-container {
    overflow-x: auto;
    border-radius: 12px;
    box-shadow: 0 4px 6px var(--shadow-color);
}

.table {
    width: 100%;
    background: var(--bg-color);
    border-collapse: collapse;
}

.table th,
.table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    background: var(--bg-secondary);
    font-weight: 600;
    color: var(--text-color);
}

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

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    border-left: 4px solid;
}

.alert-success {
    background: rgba(16, 185, 129, 0.1);
    border-left-color: var(--success-color);
    color: var(--success-color);
}

.alert-warning {
    background: rgba(245, 158, 11, 0.1);
    border-left-color: var(--warning-color);
    color: var(--warning-color);
}

.alert-error {
    background: rgba(239, 68, 68, 0.1);
    border-left-color: var(--error-color);
    color: var(--error-color);
}

.alert-info {
    background: rgba(59, 130, 246, 0.1);
    border-left-color: var(--accent-color);
    color: var(--accent-color);
}

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

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--bg-color);
    padding: 2rem;
    border-radius: 12px;
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.modal-title {
    font-size: 1.2rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
}

/* Loading Spinner */
.spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    border-top-color: var(--accent-color);
    animation: spin 1s linear infinite;
}

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

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        width: 100%;
    }
    
    .main-content.sidebar-open {
        margin-left: 0;
    }
    
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
    
    .nav-menu {
        display: none;
    }
    
    .table-container {
        font-size: 0.9rem;
    }
}

/* Utility Classes */
.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; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.flex { display: flex; }
.flex-1 { flex: 1; }
.justify-between { justify-content: space-between; }
.items-center { align-items: center; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }
.w-full { width: 100%; }
.hidden { display: none; }
.block { display: block; }
.inline-block { display: inline-block; }
.rounded { border-radius: 8px; }
.rounded-full { border-radius: 50%; }
.shadow { box-shadow: 0 4px 6px var(--shadow-color); }
.shadow-lg { box-shadow: 0 8px 25px var(--shadow-color); }