/* CSS Variables for OpenMed Premium */
:root {
    /* Base Colors - OpenEvidence Style */
    --bg-main: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-surface: #ffffff;
    
    --text-primary: #1e293b;
    --text-secondary: #334155;
    --text-tertiary: #64748b;
    --text-quaternary: #94a3b8;
    
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-bg: #eff6ff;
    --primary-border: #bfdbfe;

    --border-light: #f1f5f9;
    --border-base: #e2e8f0;
    --border-dark: #cbd5e1;

    --success: #059669;
    --success-bg: #d1fae5;
    
    --error: #ef4444;
    --error-bg: #fef2f2;
    --error-border: #fecaca;

    /* Evidence Levels */
    --evidence-i: #059669;
    --evidence-ii: #10b981;
    --evidence-iii: #84cc16;
    --evidence-iv: #eab308;
    --evidence-v: #f97316;
    
    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    
    /* Shadows - softer and larger for premium feel */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.04), 0 2px 4px -2px rgb(0 0 0 / 0.04);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.04), 0 4px 6px -4px rgb(0 0 0 / 0.04);
    --shadow-float: 0 20px 25px -5px rgb(0 0 0 / 0.08), 0 8px 10px -6px rgb(0 0 0 / 0.08);
    --shadow-focus: 0 0 0 3px rgba(37, 99, 235, 0.2);
    
    /* Radii */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-pill: 9999px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 500ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.history-empty {
    text-align: center;
    color: var(--text-tertiary);
    font-size: 13px;
    height: 100%;
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.6;
}