:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --info-color: #3b82f6;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-dark: #1e293b;
    
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --text-light: #ffffff;
    
    --border-color: #e2e8f0;
    --border-radius: 8px;
    --border-radius-sm: 4px;
    --border-radius-lg: 12px;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    
    --transition-fast: 150ms ease-in-out;
    --transition-base: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;
}

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

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

#loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--bg-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--bg-tertiary);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

#loading-screen p {
    margin-top: 1rem;
    color: var(--text-secondary);
    font-size: var(--font-size-lg);
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.hidden {
    display: none !important;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    font-size: var(--font-size-base);
    font-weight: 500;
    line-height: 1.5;
    text-align: center;
    text-decoration: none;
    border: 1px solid transparent;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    color: var(--text-light);
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
}

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

.btn-secondary:hover:not(:disabled) {
    background-color: var(--bg-tertiary);
    border-color: var(--text-muted);
}

.btn-danger {
    background-color: var(--danger-color);
    border-color: var(--danger-color);
    color: var(--text-light);
}

.btn-danger:hover:not(:disabled) {
    background-color: #dc2626;
    border-color: #dc2626;
}

.btn-success {
    background-color: var(--success-color);
    border-color: var(--success-color);
    color: var(--text-light);
}

.btn-success:hover:not(:disabled) {
    background-color: #059669;
    border-color: #059669;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: var(--font-size-sm);
}

.btn-lg {
    padding: 0.875rem 1.75rem;
    font-size: var(--font-size-lg);
}

.btn-block {
    width: 100%;
}

.card {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.card-header {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--bg-primary);
}

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

.card-body {
    padding: 1.5rem;
}

.card-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-secondary);
}

.alert {
    padding: 1rem 1.25rem;
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
    border-left: 4px solid;
}

.alert-success {
    background-color: #ecfdf5;
    border-color: var(--success-color);
    color: #065f46;
}

.alert-danger {
    background-color: #fef2f2;
    border-color: var(--danger-color);
    color: #991b1b;
}

.alert-warning {
    background-color: #fffbeb;
    border-color: var(--warning-color);
    color: #92400e;
}

.alert-info {
    background-color: #eff6ff;
    border-color: var(--info-color);
    color: #1e40af;
}

.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.625rem;
    font-size: var(--font-size-xs);
    font-weight: 600;
    line-height: 1;
    border-radius: var(--border-radius-sm);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.badge-primary {
    background-color: #dbeafe;
    color: var(--primary-dark);
}

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

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

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

.badge-info {
    background-color: #e0e7ff;
    color: #3730a3;
}

.badge-neutral {
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
}

@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
    
    .btn {
        width: 100%;
    }
    
    .btn-block {
        margin-bottom: 0.5rem;
    }
}