:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #60a5fa;
    --primary-rgb: 37, 99, 235;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --border-color: #e2e8f0;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 30px rgba(0,0,0,0.1);
    --radius: 8px;
    --radius-lg: 12px;
    --transition: 0.3s ease;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --sidebar-width: 240px;
    --navbar-height: 64px;
}

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

body {
    font-family: var(--font-family);
    background: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

#app {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

#app-container {
    display: flex;
    flex: 1;
}

a {
    color: var(--primary-color);
    text-decoration: none;
}

button {
    cursor: pointer;
    font-family: inherit;
    border: none;
    background: none;
    color: inherit;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--text-muted);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* Main Content */
#page-content {
    flex: 1;
    padding: 24px;
    margin-left: var(--sidebar-width);
    min-height: calc(100vh - var(--navbar-height));
    transition: margin-left var(--transition);
}

/* Login Page */
.login-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    margin: 0;
    padding: 20px;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 999;
}

.login-card {
    background: var(--bg-primary);
    padding: 48px 40px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 400px;
}

.login-card .logo {
    text-align: center;
    font-size: 48px;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.login-card h1 {
    font-size: 28px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 4px;
}

.login-card .subtitle {
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 32px;
    font-size: 14px;
}

.login-card .form-group {
    margin-bottom: 20px;
}

.login-card .form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 6px;
    font-size: 14px;
}

.login-card .form-group input {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 14px;
    transition: var(--transition);
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.login-card .form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(var(--primary-rgb), 0.1);
}

.login-card .btn {
    width: 100%;
    padding: 12px;
    font-size: 16px;
    font-weight: 600;
    border-radius: var(--radius);
    background: var(--primary-color);
    color: white;
    transition: var(--transition);
}

.login-card .btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(var(--primary-rgb), 0.3);
}

.login-card .btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.login-card .error-message {
    color: #ef4444;
    font-size: 14px;
    text-align: center;
    margin-top: 12px;
    display: none;
}

/* Page Header */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    flex-wrap: wrap;
    gap: 12px;
}

.page-header h2 {
    font-size: 24px;
    font-weight: 700;
}

.page-header .page-actions {
    display: flex;
    gap: 8px;
    align-items: center;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    border: none;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition);
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    box-shadow: 0 4px 12px rgba(var(--primary-rgb), 0.3);
}

.btn-success {
    background: #22c55e;
    color: white;
}

.btn-success:hover {
    background: #16a34a;
}

.btn-danger {
    background: #ef4444;
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
}

.btn-warning {
    background: #f59e0b;
    color: white;
}

.btn-warning:hover {
    background: #d97706;
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border-color);
}

.btn-sm {
    padding: 4px 10px;
    font-size: 12px;
}

.btn-lg {
    padding: 12px 24px;
    font-size: 16px;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

/* Form */
.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 4px;
    font-size: 14px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 14px;
    transition: var(--transition);
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(var(--primary-rgb), 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 80px;
}

/* Utilities */
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.text-success { color: #22c55e; }
.text-danger { color: #ef4444; }
.text-warning { color: #f59e0b; }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }
.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.gap-8 { gap: 8px; }
.gap-12 { gap: 12px; }
.gap-16 { gap: 16px; }
.w-full { width: 100%; }
.hidden { display: none !important; }
.relative { position: relative; }

/* Empty State */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-muted);
}

.empty-state i {
    font-size: 64px;
    margin-bottom: 16px;
    opacity: 0.3;
}

.empty-state h3 {
    font-size: 20px;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

/* Loading */
.loading-spinner {
    display: inline-block;
    width: 24px;
    height: 24px;
    border: 3px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

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

.loading-container {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 40px;
    min-height: 200px;
}

/* Responsive */
@media (max-width: 768px) {
    #page-content {
        margin-left: 0;
        padding: 16px;
    }
    
    .page-header h2 {
        font-size: 20px;
    }
    
    .login-card {
        padding: 32px 24px;
    }
}

@media (max-width: 480px) {
    .login-card {
        padding: 24px 16px;
    }
}