:root{--color-primary:#2563eb;--color-primary-dark:#1d4ed8;--color-primary-light:#3b82f6;--color-secondary:#0f172a;--color-accent:#10b981;--color-warning:#f59e0b;--color-error:#ef4444;--bg-primary:#fff;--bg-secondary:#f8fafc;--bg-tertiary:#f1f5f9;--bg-card:#fff;--text-primary:#0f172a;--text-secondary:#475569;--text-tertiary:#94a3b8;--text-inverse:#fff;--border-light:#e2e8f0;--border-medium:#cbd5e1;--spacing-xs:.25rem;--spacing-sm:.5rem;--spacing-md:1rem;--spacing-lg:1.5rem;--spacing-xl:2rem;--spacing-2xl:3rem;--radius-sm:.375rem;--radius-md:.5rem;--radius-lg:.75rem;--radius-xl:1rem;--radius-full:9999px;--shadow-sm:0 1px 2px 0 #0000000d;--shadow-md:0 4px 6px -1px #0000001a, 0 2px 4px -2px #0000001a;--shadow-lg:0 10px 15px -3px #0000001a, 0 4px 6px -4px #0000001a;--transition-fast:.15s ease;--transition-normal:.2s ease;--safe-area-top:env(safe-area-inset-top,0px);--header-height:calc(3.5rem + 1px + 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var(--spacing-sm);font-size:.75rem}.toggle-group{background:var(--bg-tertiary);border-radius:var(--radius-md);padding:2px;display:inline-flex}.toggle-btn{padding:var(--spacing-xs) var(--spacing-md);color:var(--text-secondary);border-radius:var(--radius-sm);cursor:pointer;transition:all var(--transition-fast);background:0 0;border:none;font-size:.875rem;font-weight:500}.toggle-btn.active{background:var(--bg-primary);color:var(--text-primary);box-shadow:var(--shadow-sm)}.preset-group{gap:var(--spacing-xs);margin-bottom:var(--spacing-sm);flex-wrap:wrap;display:flex}.preset-btn{padding:var(--spacing-xs) var(--spacing-sm);border:1px solid var(--border-light);background:var(--bg-primary);color:var(--text-secondary);border-radius:var(--radius-full);cursor:pointer;transition:all var(--transition-fast);font-size:.75rem;font-weight:500}.preset-btn:hover{border-color:var(--color-primary);color:var(--color-primary)}.preset-btn.active{background:var(--color-primary);border-color:var(--color-primary);color:var(--text-inverse)}.form-group{margin-bottom:var(--spacing-lg);scroll-margin-top:calc(var(--header-height) + 12px)}.form-group input,.form-group select,.keyboard-visible .form-group,.keyboard-visible .form-group input,.keyboard-visible .form-group select{scroll-margin-top:calc(var(--header-height) + 12px)}.form-row{gap:var(--spacing-md);grid-template-columns:1fr 1fr;display:grid}.input-with-unit{align-items:stretch;display:flex}.input-with-unit input{border-top-right-radius:0;border-bottom-right-radius:0}.input-unit{padding:0 var(--spacing-md);background:var(--bg-tertiary);border:1px solid var(--border-medium);border-radius:0 var(--radius-md) var(--radius-md) 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0;flex:1}.calculator{max-width:560px;margin:0 auto}.results-card{top:var(--header-height);z-index:90;background:linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);color:var(--text-inverse);text-align:center;border:1px solid var(--color-primary-dark);padding:var(--spacing-sm) var(--spacing-md);max-height:280px;transition:opacity .15s,max-height .15s,padding .15s,margin .15s,border-width .15s;position:sticky;overflow:hidden}.results-card.keyboard-open{opacity:0;pointer-events:none;border-width:0;max-height:0;margin:0;padding:0;position:relative;top:auto}.results-grid{gap:var(--spacing-sm);grid-template-columns:1fr 1fr;display:grid}.result-item{padding:var(--spacing-xs) 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var(--radius-md) 0;color:var(--text-secondary);margin-bottom:var(--spacing-md);font-size:.8125rem}.disclaimer p{margin:0;line-height:1.5}.disclaimer-title{color:var(--text-primary);margin-bottom:var(--spacing-xs);font-weight:600}.section-header{align-items:center;gap:var(--spacing-sm);margin-bottom:var(--spacing-md);display:flex}.section-title{color:var(--text-primary);font-size:1rem;font-weight:600}.section-icon{font-size:1.25rem}.footer{background:var(--bg-primary);border-top:1px solid var(--border-light);padding:var(--spacing-lg) 0;margin-top:auto}.footer-content{text-align:center}.footer-links{justify-content:center;gap:var(--spacing-lg);margin-bottom:var(--spacing-md);display:flex}.footer-link{color:var(--text-secondary);font-size:.875rem}.footer-copyright{color:var(--text-tertiary);font-size:.75rem}.info-section{margin-top:var(--spacing-lg)}.info-section h2{margin-bottom:var(--spacing-md)}.info-section p{color:var(--text-secondary);font-size:.9375rem}.info-section ul{color:var(--text-secondary);padding-left:var(--spacing-lg);margin-bottom:var(--spacing-md);font-size:.9375rem}.info-section li{margin-bottom:var(--spacing-xs)}.ad-placeholder{background:var(--bg-tertiary);border:2px dashed var(--border-medium);border-radius:var(--radius-md);padding:var(--spacing-lg);text-align:center;color:var(--text-tertiary);margin:var(--spacing-md) 0;font-size:.875rem;display:none}.page-content{padding:var(--spacing-xl) 0}.page-content h1{margin-bottom:var(--spacing-lg)}.page-content h2{margin-top:var(--spacing-xl);margin-bottom:var(--spacing-md)}.page-content p,.page-content ul{color:var(--text-secondary)}.back-link{align-items:center;gap:var(--spacing-xs);margin-bottom:var(--spacing-lg);font-size:.875rem;display:inline-flex}@media (width<=480px){h1{font-size:1.5rem}.form-row{grid-template-columns:1fr}.result-value-bar{font-size:2rem}.footer-links{gap:var(--spacing-sm);flex-direction:column}}.result-range{opacity:.8;margin-top:var(--spacing-xs);font-size:.75rem}.warnings-container{margin-top:var(--spacing-md);gap:var(--spacing-sm);flex-direction:column;display:flex}.warning{align-items:flex-start;gap:var(--spacing-sm);border-radius:var(--radius-md);padding:var(--spacing-sm) var(--spacing-md);background:#ffffff26;font-size:.875rem;line-height:1.4;display:flex}.warning-icon{flex-shrink:0}.warning-hookless_capped{background:#f59e0b33}.warning-low_pressure_inserts{background:#3b82f633}.warning-tire_too_narrow_hookless{background:#ef444433}.checkbox-label{align-items:center;gap:var(--spacing-sm);color:var(--text-primary);cursor:pointer;margin-bottom:var(--spacing-xs);font-size:.9375rem;font-weight:500;display:flex}.checkbox-label input[type=checkbox]{width:18px;height:18px;accent-color:var(--color-primary);cursor:pointer}.form-hint{color:var(--text-tertiary);margin:0;font-size:.75rem}.faq-list{gap:var(--spacing-md);flex-direction:column;display:flex}.faq-item{padding:0}.faq-summary{justify-content:space-between;align-items:center;gap:var(--spacing-md);cursor:pointer;min-height:48px;padding:var(--spacing-md) var(--spacing-lg);list-style:none;display:flex}.faq-summary::-webkit-details-marker{display:none}.faq-summary::marker{content:""}.faq-summary .faq-question,.page-content h2.faq-question{color:var(--text-primary);text-align:left;flex:1;margin:0;font-size:1.0625rem;font-weight:600}.faq-toggle{border:1.5px solid 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var(--transition-normal)}.blog-card:hover{box-shadow:var(--shadow-lg);transform:translateY(-2px)}.blog-card-link{color:inherit;text-decoration:none;display:block}.blog-card-link:hover{text-decoration:none}.blog-card-title{color:var(--text-primary);margin-bottom:var(--spacing-sm);transition:color var(--transition-fast);font-size:1.25rem;font-weight:600}.blog-card:hover .blog-card-title{color:var(--color-primary)}.blog-card-excerpt{color:var(--text-secondary);margin-bottom:var(--spacing-sm);line-height:1.6}.blog-card-meta{color:var(--text-tertiary);align-items:center;gap:var(--spacing-sm);font-size:.875rem;display:flex}.blog-card-separator{color:var(--text-tertiary)}.blog-post-header{margin-bottom:var(--spacing-xl);padding-bottom:var(--spacing-lg);border-bottom:1px solid var(--border-light)}.blog-post-header h1{margin-bottom:var(--spacing-sm)}.blog-post-meta{color:var(--text-tertiary);align-items:center;gap:var(--spacing-sm);font-size:.9375rem;display:flex}.blog-post-content{max-width:65ch}.blog-post-content h2{margin-top:var(--spacing-xl);margin-bottom:var(--spacing-md);font-size:1.375rem}.blog-post-content p{color:var(--text-secondary);margin-bottom:var(--spacing-md);line-height:1.75}.blog-post-content a{color:var(--color-primary);text-underline-offset:2px;text-decoration:underline}.blog-post-content a:hover{color:var(--color-primary-dark)}.blog-post-content strong{color:var(--text-primary);font-weight:600}.blog-post-footer{margin-top:var(--spacing-2xl);text-align:center}.blog-post-footer h3{margin-bottom:var(--spacing-sm)}.blog-post-footer p{color:var(--text-secondary);margin-bottom:var(--spacing-md)}@media (prefers-color-scheme:dark){:root{--bg-primary:#0f172a;--bg-secondary:#020617;--bg-tertiary:#1e293b;--bg-card:#1e293b;--text-primary:#f8fafc;--text-secondary:#94a3b8;--text-tertiary:#64748b;--border-light:#334155;--border-medium:#475569}}