:root{--qs-tool:#7c3aed;--qs-tool-dark:#6d28d9;--qs-gradient:linear-gradient(135deg,#7c3aed 0%,#a78bfa 100%);--qs-light:#ede9fe}[data-theme="dark"]{--qs-light:rgba(124,58,237,0.15)}.qs-empty-chips{display:grid;grid-template-columns:auto 1fr;gap:0.45rem 0.75rem;align-items:center;max-width:420px;margin:1rem auto 0;text-align:left}.qs-empty-chips .qs-chip-label{font-size:0.72rem;font-weight:600;color:var(--ms-muted,#78716c);text-transform:uppercase;letter-spacing:0.05em}.qs-empty-chips .ic-example-chip{justify-self:start;text-align:left;font-family:var(--ms-font-mono,JetBrains Mono,monospace);font-size:0.85rem}.qs-empty-hint{color:var(--ms-muted,#78716c);font-size:0.8rem;margin:1.25rem 0 0;text-align:center}.qs-form-toggle{display:flex;border:1.5px solid var(--border);border-radius:0.5rem;overflow:hidden;margin-bottom:1rem}.qs-form-btn{flex:1;padding:0.5rem;font-weight:600;font-size:0.7rem;border:none;cursor:pointer;background:var(--bg-secondary);color:var(--text-secondary);transition:all 0.15s;font-family:var(--font-sans);text-align:center}.qs-form-btn.active{background:var(--qs-gradient);color:#fff}.qs-form-btn:hover:not(.active){background:var(--bg-tertiary)}[data-theme="dark"] .qs-form-btn{background:var(--bg-tertiary)}[data-theme="dark"] .qs-form-btn.active{background:var(--qs-gradient);color:#fff}.qs-coeff-row{display:flex;gap:0.5rem;align-items:center;margin-bottom:0.5rem}.qs-coeff-group{flex:1;text-align:center}.qs-coeff-label{display:block;font-size:0.6875rem;font-weight:600;color:var(--qs-tool);font-family:var(--font-mono);margin-bottom:0.25rem}.qs-coeff-input{width:100%;padding:0.4rem 0.5rem;text-align:center;border:1.5px solid var(--border);border-radius:0.375rem;font-size:0.875rem;font-weight:600;font-family:var(--font-mono);background:var(--bg-primary);color:var(--text-primary)}.qs-coeff-input:focus{outline:none;border-color:var(--qs-tool);box-shadow:0 0 0 3px rgba(124,58,237,0.1)}[data-theme="dark"] .qs-coeff-input{background:var(--bg-tertiary);border-color:var(--border)}.qs-method-select{width:100%;padding:0.5rem 0.75rem;border:1.5px solid var(--border);border-radius:0.5rem;font-size:0.8125rem;font-family:var(--font-sans);background:var(--bg-primary);color:var(--text-primary);cursor:pointer}[data-theme="dark"] .qs-method-select{background:var(--bg-tertiary);border-color:var(--border)}.qs-preview{background:var(--bg-secondary);border:1px solid var(--border);border-radius:0.5rem;padding:0.75rem 1rem;min-height:48px;display:flex;align-items:center;justify-content:center;overflow-x:auto;font-size:1.1rem}.qs-preview .katex-display{margin:0}[data-theme="dark"] .qs-preview{background:var(--bg-tertiary)}.qs-output-tabs{display:flex;border:1.5px solid var(--border);border-radius:0.5rem;overflow:hidden}.qs-output-tab{flex:1;padding:0.5rem;font-weight:600;font-size:0.8125rem;border:none;cursor:pointer;background:var(--bg-secondary);color:var(--text-secondary);transition:all 0.15s;font-family:var(--font-sans);text-align:center}.qs-output-tab.active{background:var(--qs-gradient);color:#fff}.qs-output-tab:hover:not(.active){background:var(--bg-tertiary)}[data-theme="dark"] .qs-output-tab{background:var(--bg-tertiary)}[data-theme="dark"] .qs-output-tab.active{background:var(--qs-gradient);color:#fff}.qs-panel{display:none;flex:1;min-height:0}.qs-panel.active{display:flex;flex-direction:column}#qs-panel-result .tool-result-card{flex:1}#qs-panel-graph{min-height:480px}#qs-panel-python{min-height:540px}.qs-result-section{padding:1.25rem}.qs-result-badge{display:inline-block;padding:0.3rem 0.75rem;border-radius:9999px;font-size:0.75rem;font-weight:700;margin-bottom:1rem}.qs-badge-success{background:#dcfce7;color:#166534}.qs-badge-warning{background:#fef3c7;color:#92400e}.qs-badge-info{background:var(--qs-light);color:var(--qs-tool)}[data-theme="dark"] .qs-badge-success{background:rgba(16,185,129,0.2);color:#6ee7b7}[data-theme="dark"] .qs-badge-warning{background:rgba(245,158,11,0.2);color:#fbbf24}.qs-result-label{font-size:0.6875rem;font-weight:600;text-transform:uppercase;letter-spacing:0.05em;color:var(--text-muted);margin-bottom:0.25rem}.qs-result-math{max-width:100%;padding:0.75rem 0;text-align:center;overflow-x:auto}.qs-result-math .katex-display{margin:0;overflow-x:auto;overflow-y:hidden}.qs-result-detail{background:var(--bg-secondary);border:1px solid var(--border);border-radius:0.5rem;padding:0.75rem 1rem;margin-top:0.75rem;font-size:0.8125rem;color:var(--text-secondary)}[data-theme="dark"] .qs-result-detail{background:var(--bg-tertiary)}.qs-area-box{border-left:4px solid var(--qs-tool)!important}.qs-area-value{font-weight:700;color:var(--qs-tool);font-family:var(--font-mono,"JetBrains Mono",monospace)}.qs-area-hint{font-size:0.75rem;color:var(--text-muted)}.qs-method-badge{display:inline-block;background:var(--qs-light);color:var(--qs-tool);padding:0.2rem 0.625rem;border-radius:9999px;font-size:0.6875rem;font-weight:600}.qs-error{background:#fef3c7;border:1px solid #fbbf24;border-radius:0.5rem;padding:1.25rem;color:#92400e}.qs-error h4{margin:0 0 0.5rem;font-size:0.9375rem}.qs-error p{margin:0;font-size:0.8125rem}[data-theme="dark"] .qs-error{background:rgba(251,191,36,0.15);border-color:rgba(251,191,36,0.3);color:#fbbf24}.qs-steps-wrapper{border:1px solid var(--border);border-radius:0.75rem;overflow:hidden}.qs-steps-header{padding:0.75rem 1rem;background:var(--bg-secondary);font-weight:600;font-size:0.875rem;color:var(--text-primary);border-bottom:1px solid var(--border);display:flex;align-items:center;gap:0.5rem}[data-theme="dark"] .qs-steps-header{background:var(--bg-tertiary)}.qs-step{display:flex;gap:0.75rem;padding:0.75rem 1rem;border-bottom:1px solid var(--border);align-items:flex-start}.qs-step:last-child{border-bottom:none}.qs-step-number{min-width:24px;height:24px;background:var(--qs-tool);color:#fff;border-radius:50%;font-size:0.6875rem;font-weight:700;display:flex;align-items:center;justify-content:center;flex-shrink:0;margin-top:2px}.qs-step-content{flex:1;min-width:0}.qs-step-desc{font-size:0.8125rem;color:var(--text-secondary);margin-bottom:0.25rem;line-height:1.5}.qs-step-math{overflow-x:auto;padding:0.25rem 0}.qs-step-math .katex-display{margin:0;overflow-x:auto;overflow-y:hidden}.qs-examples{display:flex;flex-wrap:wrap;gap:0.375rem}.qs-example-chip{padding:0.3rem 0.625rem;font-size:0.6875rem;font-family:var(--font-sans);background:var(--bg-secondary);border:1px solid var(--border);border-radius:9999px;cursor:pointer;transition:all 0.15s;color:var(--text-secondary);white-space:nowrap;font-weight:500}.qs-example-chip:hover{background:var(--qs-tool);color:#fff;border-color:var(--qs-tool)}[data-theme="dark"] .qs-example-chip{background:var(--bg-tertiary)}#qs-graph-container{width:100%;min-height:440px;border-radius:var(--radius-md)}.js-plotly-plot .plotly .modebar{top:4px!important;right:4px!important}.qs-edu-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:1rem;margin-top:1rem}.qs-edu-card{background:var(--bg-secondary);border:1px solid var(--border);border-radius:0.5rem;padding:1.25rem}.qs-edu-card h4{font-size:0.875rem;font-weight:700;color:var(--text-primary);margin-bottom:0.375rem}.qs-edu-card p{font-size:0.8125rem;color:var(--text-secondary);line-height:1.6;margin:0}[data-theme="dark"] .qs-edu-card{background:var(--bg-tertiary)}.qs-methods-table{width:100%;border-collapse:collapse;font-size:0.8125rem;margin-top:0.75rem}.qs-methods-table th,.qs-methods-table td{padding:0.5rem 0.75rem;text-align:left;border-bottom:1px solid var(--border)}.qs-methods-table th{font-weight:600;color:var(--text-primary);background:var(--bg-secondary)}.qs-methods-table td{color:var(--text-secondary)}[data-theme="dark"] .qs-methods-table th{background:var(--bg-tertiary)}.faq-item{border-bottom:1px solid var(--border)}.faq-item:last-child{border-bottom:none}.faq-question{display:flex;align-items:center;justify-content:space-between;width:100%;padding:0.875rem 0;background:none;border:none;font-size:0.875rem;font-weight:600;color:var(--text-primary);cursor:pointer;text-align:left;font-family:var(--font-sans);gap:0.75rem}.faq-answer{display:none;padding:0 0 0.875rem;font-size:0.8125rem;line-height:1.7;color:var(--text-secondary)}.faq-item.open .faq-answer{display:block}.faq-chevron{transition:transform 0.2s;flex-shrink:0}.faq-item.open .faq-chevron{transform:rotate(180deg)}@keyframes qs-fadeInUp{from{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}.qs-anim{opacity:0}.qs-anim.qs-visible{animation:qs-fadeInUp 0.5s ease-out forwards}.qs-anim.qs-visible.qs-anim-d1{animation-delay:0.1s}.qs-anim.qs-visible.qs-anim-d2{animation-delay:0.2s}.qs-anim.qs-visible.qs-anim-d3{animation-delay:0.3s}.qs-anim.qs-visible.qs-anim-d4{animation-delay:0.4s}.qs-anim.qs-visible.qs-anim-d5{animation-delay:0.5s}.qs-anim.qs-visible.qs-anim-d6{animation-delay:0.6s}@media (prefers-reduced-motion:reduce){.qs-anim{opacity:1;animation:none!important}.qs-disc-draw{stroke-dasharray:none;stroke-dashoffset:0;animation:none!important}}.qs-disc-viz{display:grid;grid-template-columns:repeat(3,1fr);gap:1.25rem;margin:1.5rem 0}@media (max-width:600px){.qs-disc-viz{grid-template-columns:1fr;max-width:280px;margin-left:auto;margin-right:auto}}.qs-disc-card{border:1.5px solid var(--border);border-radius:0.75rem;overflow:hidden;transition:transform 0.2s,box-shadow 0.2s}.qs-disc-card:hover{transform:translateY(-3px);box-shadow:0 6px 20px rgba(0,0,0,0.08)}[data-theme="dark"] .qs-disc-card:hover{box-shadow:0 6px 20px rgba(0,0,0,0.3)}.qs-disc-canvas{width:100%;aspect-ratio:1;background:var(--bg-secondary);display:block;position:relative;overflow:hidden}[data-theme="dark"] .qs-disc-canvas{background:var(--bg-tertiary)}.qs-disc-info{padding:0.75rem 1rem;border-top:1px solid var(--border)}.qs-disc-title{font-weight:700;font-size:0.8125rem;color:var(--text-primary);margin-bottom:0.125rem}.qs-disc-desc{font-size:0.75rem;color:var(--text-muted);line-height:1.5}.qs-disc-draw{stroke-dasharray:400;stroke-dashoffset:400}.qs-visible .qs-disc-draw{animation:qs-drawParabola 1.2s ease-out forwards}@keyframes qs-drawParabola{to{stroke-dashoffset:0}}.qs-concept-hero{display:flex;align-items:center;justify-content:center;gap:0.5rem;padding:2rem 1rem;margin:1.5rem 0;background:var(--bg-secondary);border:1px solid var(--border);border-radius:0.75rem;flex-wrap:wrap}[data-theme="dark"] .qs-concept-hero{background:var(--bg-tertiary)}.qs-concept-block{text-align:center;animation:qs-fadeInUp 0.6s ease-out both}.qs-concept-block:nth-child(1){animation-delay:0.1s}.qs-concept-block:nth-child(2){animation-delay:0.2s}.qs-concept-block:nth-child(3){animation-delay:0.3s}.qs-concept-block:nth-child(4){animation-delay:0.4s}.qs-concept-block:nth-child(5){animation-delay:0.5s}.qs-concept-symbol{font-family:var(--font-mono);font-size:1.75rem;font-weight:700;color:var(--text-primary);line-height:1}.qs-concept-label{font-size:0.6875rem;font-weight:600;text-transform:uppercase;letter-spacing:0.06em;margin-top:0.375rem;color:var(--text-muted)}.qs-c-a{color:var(--qs-tool)}.qs-c-b{color:#10b981}.qs-c-c{color:#f59e0b}.qs-c-eq{color:var(--text-muted)}.qs-callout{display:flex;gap:0.75rem;padding:1rem 1.25rem;border-radius:0.625rem;margin:1rem 0;align-items:flex-start}.qs-callout-icon{font-size:1.25rem;flex-shrink:0;margin-top:0.125rem}.qs-callout-text{font-size:0.8125rem;line-height:1.6;color:var(--text-secondary)}.qs-callout-text strong{color:var(--text-primary)}.qs-callout-insight{background:var(--qs-light);border:1px solid rgba(124,58,237,0.2)}.qs-callout-tip{background:#dcfce7;border:1px solid rgba(16,185,129,0.2)}[data-theme="dark"] .qs-callout-tip{background:rgba(16,185,129,0.1);border-color:rgba(16,185,129,0.2)}.qs-real-world{background:var(--bg-secondary);border:1.5px solid var(--border);border-radius:0.75rem;overflow:hidden;margin:1.25rem 0}[data-theme="dark"] .qs-real-world{background:var(--bg-tertiary)}.qs-rw-header{padding:0.75rem 1rem;background:var(--qs-light);font-size:0.8125rem;font-weight:700;color:var(--qs-tool);display:flex;align-items:center;gap:0.5rem}.qs-rw-body{padding:1rem 1.25rem;display:grid;grid-template-columns:1fr 1fr;gap:1rem;align-items:start}@media (max-width:600px){.qs-rw-body{grid-template-columns:1fr}}.qs-rw-body p{font-size:0.8125rem;color:var(--text-secondary);line-height:1.7;margin:0}@media print{body>*:not(#qsPrintArea){display:none!important}#qsPrintArea{display:block!important;position:static!important;width:100%!important;padding:0!important;margin:0!important;background:#fff!important;color:#000!important}}.qs-print-root{position:absolute;left:-9999px;top:0;width:700px;padding:30px;font-family:Inter,sans-serif;font-size:11px;background:#fff;color:#0f172a}.qs-print-wrapper{max-width:100%}.qs-print-title{text-align:center;font-size:1.25rem;font-weight:700;margin-bottom:0.25rem}.qs-print-info{text-align:center;color:#333;font-size:0.8rem;margin-bottom:0.75rem}.qs-print-problems{font-size:0.85rem}.qs-print-section{font-weight:700;font-size:0.9rem;margin:0.5rem 0 0.25rem;padding-bottom:0.15rem;border-bottom:1px solid #333}.qs-print-item{display:flex;align-items:baseline;gap:0.35rem;margin-bottom:0.4rem}.qs-print-num{font-weight:600;min-width:1.2rem}.qs-print-eq{font-family:"JetBrains Mono",monospace;font-weight:500;font-size:0.85rem}.qs-print-blank{flex:1;border-bottom:1px solid #333;margin-left:0.25rem;min-width:40px}.qs-print-answer-key{margin-top:1.5rem;padding-top:1rem;border-top:2px solid #333;page-break-before:always}.qs-print-answer-title{font-weight:700;font-size:1rem;margin-bottom:0.5rem}.qs-print-answer-row{font-size:0.75rem;margin-bottom:0.2rem}.qs-print-footer{text-align:center;color:#666;font-size:0.7rem;margin-top:1rem}@media (max-width:767px){.qs-coeff-input{font-size:0.8125rem}.qs-concept-symbol{font-size:1.25rem}.qs-concept-hero{padding:1.25rem 0.75rem;gap:0.5rem}.qs-form-btn{font-size:0.625rem;padding:0.4rem 0.25rem}}