/* ==========================================
CSS VARIABLES (Required for Premium Styling)
========================================== */
:root {
--text-primary: #1e293b;
--text-secondary: #64748b;
--text-muted: #94a3b8;
--bg-primary: #ffffff;
--bg-secondary: #f8fafc;
--border-light: #f1f5f9;
--border-medium: #e2e8f0;
--primary: #5b21b6;
--primary-dark: #4c1d95;
--primary-light: #c4b5fd;
--primary-ultra-light: #f3e8ff;
--gradient-subtle: linear-gradient(135deg, #f5f3ff 0%, #ede9fe 100%);
--space-1: 4px;
--space-2: 8px;
--space-3: 12px;
--space-4: 16px;
--space-6: 24px;
--space-8: 32px;
--space-10: 40px;
--radius-md: 8px;
--radius-lg: 12px;
}
/* ==========================================
NON-CRITICAL CSS: Loaded after page paint
========================================== */
/* Results Section */
.results-section.show { display: block; animation: fadeIn 0.4s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
.results-grid { display: grid; grid-template-columns: 260px 1fr; gap: 15px; align-items: stretch; margin-top: 20px; }
.bmi-box { border-radius: 12px; padding: 24px 20px; color: white; text-align: center; height: 100%; display: flex; flex-direction: column; justify-content: center; position: relative; overflow: hidden; transition: background 0.4s ease; box-shadow: 0 4px 15px rgba(0,0,0,0.05); }
.bmi-box::before { content: ''; position: absolute; top: -50%; right: -50%; width: 200%; height: 200%; background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 60%); pointer-events: none; }
.bmi-box.underweight { background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%); }
.bmi-box.healthy { background: linear-gradient(135deg, #10b981 0%, #059669 100%); }
.bmi-box.overweight { background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%); }
.bmi-box.obese { background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%); }
.bmi-label { font-size: 0.9rem; opacity: 0.9; margin-bottom: 4px; position: relative; z-index: 1; font-weight: 500; }
.bmi-value-wrapper { display: flex; align-items: baseline; justify-content: center; gap: 10px; margin: 8px 0; }
.bmi-value { font-size: 4.5rem; font-weight: 700; line-height: 1; position: relative; z-index: 1; letter-spacing: -2px; }
.bmi-unit { font-size: 1.1rem; opacity: 0.85; font-weight: 500; position: relative; z-index: 1; }
.percentile-display { background: rgba(255, 255, 255, 0.2); border-radius: 8px; padding: 8px 12px; margin: 12px 0; position: relative; z-index: 1; }
.percentile-value { font-size: 1.5rem; font-weight: 700; line-height: 1; margin-bottom: 2px; }
.percentile-label { font-size: 0.75rem; opacity: 0.9; text-transform: uppercase; letter-spacing: 0.05em; }

/* ✅ NEW: Z-Score Display Styles */
.zscore-display { 
    background: rgba(255, 255, 255, 0.15); 
    border-radius: 8px; 
    padding: 6px 12px; 
    margin: 8px 0; 
    position: relative; 
    z-index: 1;
    text-align: center;
}
.zscore-value { 
    font-size: 1.2rem; 
    font-weight: 700; 
    line-height: 1; 
    margin-bottom: 2px;
    font-family: 'Courier New', monospace;
}
.zscore-label { 
    font-size: 0.7rem; 
    opacity: 0.9; 
    text-transform: uppercase; 
    letter-spacing: 0.05em; 
}

.bmi-category { font-size: 1.1rem; font-weight: 600; position: relative; z-index: 1; margin: 8px 0; }
.bmi-detail { font-size: 0.85rem; opacity: 0.9; position: relative; z-index: 1; line-height: 1.4; margin-bottom: 16px; }
.bmi-divider { width: 40px; height: 2px; background: rgba(255,255,255,0.3); margin: 0 auto 16px; position: relative; z-index: 1; }
.weight-gap-indicator { margin-top: 8px; text-align: center; position: relative; z-index: 1; }
.weight-gap-heading { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: rgba(255, 255, 255, 0.75); margin-bottom: 6px; }
.weight-gap-description { font-size: 0.9rem; font-weight: 500; color: rgba(255, 255, 255, 0.95); line-height: 1.4; }
.weight-gap-description strong { font-weight: 700; color: #ffffff; }
.bmi-controls { background: white; border-radius: 12px; padding: 10px; border: 2px solid #f1f5f9; height: 100%; box-shadow: 0 4px 15px rgba(0,0,0,0.03); display: flex; flex-direction: column; justify-content: center; }
.bmi-title { font-size: 0.9rem; font-weight: 600; color: #64748b; margin-bottom: 8px; display: flex; align-items: center; gap: 6px; }
.percentile-scale { margin: 8px 0; padding: 10px; background: #f8fafc; border-radius: 10px; border: 2px solid #e2e8f0; }
.percentile-scale-title { font-size: 0.8rem; font-weight: 600; color: #475569; margin-bottom: 6px; }
.percentile-categories { display: flex; width: 100%; margin-bottom: 4px; }
.percentile-categories span { flex: 1; text-align: center; font-size: 0.65rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.02em; }
.cat-underweight { color: #3b82f6; } .cat-healthy { color: #10b981; } .cat-overweight { color: #f59e0b; } .cat-obese { color: #ef4444; }
.percentile-bar { height: 10px; border-radius: 5px; background: linear-gradient(90deg, #3b82f6 0%, #3b82f6 5%, #10b981 5%, #10b981 85%, #f59e0b 85%, #f59e0b 95%, #ef4444 95%, #ef4444 100%); position: relative; margin: 6px 0; }
.percentile-marker { position: absolute; top: -3px; width: 16px; height: 16px; background: white; border: 3px solid #1e293b; border-radius: 50%; transform: translateX(-50%); box-shadow: 0 2px 4px rgba(0,0,0,0.2); transition: left 0.5s ease; }
.percentile-labels { display: flex; justify-content: space-between; font-size: 0.7rem; color: #64748b; margin-top: 4px; font-weight: 500; }
.ideal-weight { background: #f8fafc; border-radius: 10px; padding: 10px; border: 2px solid #e2e8f0; margin: 8px 0; }
.ideal-weight-title { font-size: 0.85rem; font-weight: 600; color: #1e293b; margin-bottom: 6px; display: flex; align-items: center; gap: 6px; }
.ideal-weight-range { font-size: 1.3rem; font-weight: 700; color: #5b21b6; text-align: center; margin: 6px 0; }
.ideal-weight-range .mass-unit { font-size: 0.95rem; font-weight: 500; color: #64748b; }
.ideal-weight-unit { font-size: 0.85rem; color: #64748b; text-align: center; }
.health-risk { background: #eff6ff; border-radius: 10px; padding: 10px; border-left: 4px solid #3b82f6; margin-top: 8px; }
.health-risk-title { font-size: 0.85rem; font-weight: 600; color: #1e40af; margin-bottom: 4px; display: flex; align-items: center; gap: 6px; }
.health-risk-text { font-size: 0.9rem; color: #1e3a8a; line-height: 1.5; margin: 0; }
.category-section { grid-column: 1 / -1; background: white; border-radius: 12px; padding: 12px; border: 2px solid #f1f5f9; box-shadow: 0 4px 15px rgba(0,0,0,0.03); margin-top: 15px; }
.category-header { display: flex; align-items: flex-start; gap: 10px; margin-bottom: 12px; }
.category-icon { width: 32px; height: 32px; background: linear-gradient(135deg, #5b21b6 0%, #8b5cf6 100%); border-radius: 8px; display: flex; align-items: center; justify-content: center; color: white; font-size: 1.2rem; flex-shrink: 0; }
.category-title { font-size: 1rem; font-weight: 600; color: #1e293b; margin-bottom: 4px; }
.category-desc { font-size: 0.85rem; color: #64748b; line-height: 1.4; }
.category-table { width: 100%; border-collapse: collapse; font-size: 0.85rem; color: #334155; }
.category-table th { background: #f8fafc; padding: 10px; text-align: left; font-weight: 600; color: #64748b; border-bottom: 2px solid #e2e8f0; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em; }
.category-table td { padding: 10px; border-bottom: 1px solid #f1f5f9; font-weight: 400 !important; }
.category-table tr:hover { background: #f8fafc; }
.category-table tr.current-category td { font-weight: 600 !important; background: #f3e8ff; }
.cat-dot { display: inline-block; width: 12px; height: 12px; border-radius: 50%; margin-right: 8px; vertical-align: middle; }
.cat-dot.underweight { background: #3b82f6; } .cat-dot.healthy { background: #10b981; } .cat-dot.overweight { background: #f59e0b; } .cat-dot.obese { background: #ef4444; }
.badge { padding: 4px 12px; border-radius: 12px; font-size: 0.8rem; font-weight: 600; display: inline-block; }
.badge-selected { background: #f3e8ff; color: #5b21b6; } .badge-default { background: #f1f5f9; color: #94a3b8; }
.recalculate-btn { grid-column: 1 / -1; width: 100%; padding: 16px; background: #5b21b6; color: white; border: none; border-radius: 10px; font-size: 1.05rem; font-weight: 600; cursor: pointer; transition: all 0.2s; margin-top: 15px; letter-spacing: 0.5px; }
.recalculate-btn:hover { background: #4c1d95; transform: translateY(-2px); box-shadow: 0 6px 20px rgba(91, 33, 182, 0.3); }
/* Related Calculators */
.related-calculators { max-width: 800px; width: 100%; margin: 40px auto 32px; }
.related-calculators h3 { font-size: 1.0625rem; font-weight: 600; color: #1e293b; margin-bottom: 16px; text-align: left; }
.related-calculators-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 12px; }
.related-calc-card { display: flex; align-items: center; gap: 12px; padding: 14px 18px; background: white; border: 1px solid #f1f5f9; border-radius: 12px; text-decoration: none; color: #1e293b; transition: all 0.2s ease; box-shadow: 0 2px 4px rgba(0,0,0,0.02); }
.related-calc-card:hover { border-color: #3b82f6; transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.06); }
.related-calc-icon { font-size: 1.25rem; background: #dbeafe; width: 36px; height: 36px; display: flex; align-items: center; justify-content: center; border-radius: 8px; flex-shrink: 0; }
.related-calc-title { font-weight: 600; font-size: 0.9375rem; color: #1e293b; line-height: 1.3; }
/* Article Content */
.article-content { max-width: 800px; margin: 0 auto; padding: 40px 20px 80px; }
.article-content h2 { font-size: 1.75rem; font-weight: 700; margin-top: 60px; margin-bottom: 20px; color: #1e293b; scroll-margin-top: 100px; }
.article-content h3 { font-size: 1.25rem; font-weight: 600; margin-top: 32px; margin-bottom: 16px; color: #1e293b; }
.article-content p { margin-bottom: 20px; color: #475569; line-height: 1.8; font-size: 1.0625rem; }
.article-content ul, .article-content ol { margin-bottom: 20px; padding-left: 24px; }
.article-content li { margin-bottom: 12px; color: #475569; line-height: 1.8; font-size: 1.0625rem; }
.article-content strong { color: #5b21b6; font-weight: 600; }
.article-content a { color: #2563eb; text-decoration: underline; }
.article-content a:hover { color: #1d4ed8; }
/* Citation Links */
.citation { color: #5b21b6; font-weight: 600; text-decoration: none; font-size: 0.875rem; vertical-align: super; }
.citation:hover { text-decoration: underline; }
/* UPGRADED: Formula Box Styles */
.formula-box { background: var(--gradient-subtle); border: 2px solid var(--primary-light); border-radius: var(--radius-lg); padding: var(--space-6); margin: var(--space-6) 0; text-align: center; }
.formula-box h3 { margin-top: 0; color: var(--primary-dark); font-size: 1.125rem; margin-bottom: var(--space-4); }
.formula-display { font-family: 'Courier New', monospace; font-size: 1.25rem; font-weight: 700; color: var(--primary); background: var(--bg-primary); padding: var(--space-4); border-radius: var(--radius-md); margin: var(--space-3) 0; border: 1px solid var(--border-light); }
.formula-example { background: var(--bg-primary); padding: var(--space-4); border-radius: var(--radius-md); margin-top: var(--space-4); text-align: left; border: 1px solid var(--border-light); }
.formula-example h4 { margin-top: 0; font-size: 0.9375rem; color: var(--text-primary); margin-bottom: var(--space-3); }
.formula-step { font-family: 'Courier New', monospace; font-size: 0.9375rem; color: var(--text-secondary); margin: var(--space-2) 0; padding-left: var(--space-4); border-left: 3px solid var(--primary-light); }
/* BMI Table */
.bmi-table { width: 100%; border-collapse: collapse; margin: 32px 0; font-size: 1rem; }
.bmi-table th, .bmi-table td { padding: 16px; border: 1px solid #e2e8f0; text-align: left; }
.bmi-table th { background: #f8fafc; font-weight: 600; color: #1e293b; }
.bmi-table tr:hover { background: #f8fafc; }
/* UPGRADED: FAQ Items (Reduced Spacing) */
.faq-item { padding: 16px 0; border-bottom: 1px solid #e2e8f0; }
.faq-item:last-child { border-bottom: none; }
.faq-item h3 { margin-top: 0; font-size: 1.1rem; }
.faq-item p { margin-bottom: 0; }
/* UPGRADED: Medical Disclaimer (Standout Styling) */
.medical-disclaimer {
background: #fffbeb;
border: 1px solid #fde68a;
border-left: 4px solid #f59e0b;
border-radius: 8px;
padding: 20px;
margin: 48px 0;
display: flex;
gap: 16px;
align-items: flex-start;
box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
}
.disclaimer-icon { font-size: 1.5rem; flex-shrink: 0; line-height: 1; }
.disclaimer-content { flex: 1; }
.disclaimer-content strong { color: #92400e; font-size: 1rem; display: block; margin-bottom: 8px; }
.disclaimer-content p { margin: 0; color: #78350f; font-size: 0.95rem; line-height: 1.6; }


/* References Section */
.references-section { margin-top: 60px; padding-top: 32px; border-top: 2px solid #e2e8f0; }
.references-section h3 { font-size: 1.25rem; font-weight: 600; color: #1e293b; margin-bottom: 20px; }
.references-list { list-style: none; padding: 0; margin: 0; counter-reset: ref-counter; }
.references-list li { margin-bottom: 16px; padding-left: 40px; position: relative; color: #475569; font-size: 0.9375rem; line-height: 1.6; counter-increment: ref-counter; }
.references-list li::before { content: '[' counter(ref-counter) ']'; position: absolute; left: 0; color: #5b21b6; font-weight: 600; }

.references-list a { 
    color: #1e3a8a; /* Very dark blue to ensure 3:1 contrast against gray text */
    font-weight: 600; /* Bold weight provides a non-color visual cue */
    text-decoration: none; 
}
.references-list a:hover { 
    color: #172554; /* Even darker on hover */
}

.references-list strong { color: #1e293b; font-weight: 600; }



/* Responsive for Results & Content */
@media (max-width: 768px) {
.results-grid { grid-template-columns: 1fr !important; gap: 12px; }
.bmi-box { min-height: auto; position: static; margin-bottom: 0; width: 100%; padding: 20px 12px; }
.bmi-controls { min-height: auto; width: 100%; padding: 10px; }
.category-section { width: 100%; overflow-x: auto; padding: 12px; margin-top: 12px; }
}
@media (max-width: 640px) {
/* Calculator Mobile Adjustments */
.bmi-value { font-size: 4.5rem; }
.bmi-unit { font-size: 1rem; }
.percentile-value { font-size: 1.3rem; }
.bmi-category { font-size: 1rem; }
.ideal-weight-range { font-size: 1.2rem; }
.category-table { font-size: 0.8rem; }
.category-table th, .category-table td { padding: 8px 6px; }
.bmi-controls { padding: 10px; }
.ideal-weight { margin: 8px 0; padding: 10px; }
.percentile-scale { margin: 8px 0; padding: 10px; }
.health-risk { margin-top: 8px; padding: 10px; }
.health-risk-text { font-size: 0.85rem; }
/* UPGRADED: SEO Content Mobile Adjustments (Reduced Margins) */
 .article-content { padding: 24px 2px 48px; }
 .article-content h2 { font-size: 1.4rem; margin-top: 40px; margin-bottom: 16px; }
 .article-content h3 { font-size: 1.1rem; margin-top: 24px; margin-bottom: 12px; }
 .article-content p { font-size: 0.95rem; margin-bottom: 16px; line-height: 1.7; }
 .article-content li { font-size: 0.95rem; margin-bottom: 10px; }
 .article-content ul, .article-content ol { padding-left: 20px; }
 /* Formula Box Mobile */
 .formula-box { padding: 20px 16px; margin: 24px 0; }
 .formula-box h3 { font-size: 1rem; }
 .formula-display { font-size: 1rem; padding: 14px; }
 .formula-example { padding: 16px; }
 .formula-example h4 { font-size: 0.875rem; }
 .formula-step { font-size: 0.85rem; padding-left: 12px; }
 /* BMI Table Mobile */
 .bmi-table { font-size: 0.85rem; }
 .bmi-table th, .bmi-table td { padding: 10px 8px; }
 /* FAQ Mobile */
 .faq-item { padding: 12px 0; }
 .faq-item h3 { font-size: 1rem; }
 .faq-item p { font-size: 0.9rem; }
 /* References Mobile */
 .references-section { margin-top: 40px; padding-top: 24px; }
 .references-section h3 { font-size: 1rem; }
 .references-list li { font-size: 0.85rem; padding-left: 32px; }
 /* Medical Disclaimer Mobile */
 .medical-disclaimer { padding: 16px; margin: 32px 0; flex-direction: column; gap: 8px; }
 .disclaimer-content p { font-size: 0.875rem; }
}