:root{--tool-primary:#0891b2;--tool-primary-dark:#0e7490;--tool-gradient:linear-gradient(135deg,#0891b2 0%,#06b6d4 100%);--tool-light:#ecfeff}[data-theme="dark"]{--tool-light:rgba(8,145,178,0.15)}.pde-mode-toggle{display:flex;flex-wrap:wrap;gap:0.375rem;margin-bottom:1rem}.pde-mode-toggle-row2{display:none}.pde-mode-btn{flex:1 1 auto;min-width:0;padding:0.5rem 0.75rem;font-weight:600;font-size:0.8125rem;border:1.5px solid var(--border,#e2e8f0);border-radius:var(--radius-full,9999px);cursor:pointer;background:var(--bg-secondary);color:var(--text-secondary);transition:all 0.2s ease;font-family:var(--font-sans);text-align:center;white-space:nowrap}.pde-mode-btn.active{background:var(--tool-gradient);color:#fff;border-color:var(--tool-primary);box-shadow:0 2px 8px rgba(8,145,178,0.25)}.pde-mode-btn:hover:not(.active){background:var(--tool-light);border-color:var(--tool-primary);color:var(--tool-primary)}.pde-mode-btn:active{transform:scale(0.96)}[data-theme="dark"] .pde-mode-btn{background:var(--bg-tertiary);border-color:var(--border)}[data-theme="dark"] .pde-mode-btn.active{background:var(--tool-gradient);color:#fff;border-color:var(--tool-primary)}[data-theme="dark"] .pde-mode-btn:hover:not(.active){background:rgba(255,255,255,0.08);border-color:var(--tool-primary);color:#67e8f9}#pde-heat-wrap,#pde-wave-wrap,#pde-laplace-wrap,#pde-poisson-wrap,#pde-transport-wrap,#pde-schrodinger-wrap,#pde-linear1-wrap{animation:pde-fadeIn 0.2s ease}@keyframes pde-fadeIn{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:translateY(0)}}.pde-mode-toggle~div .tool-input:focus,.pde-mode-toggle~div .tool-input-mono:focus{outline:none;border-color:var(--tool-primary);box-shadow:0 0 0 3px rgba(8,145,178,0.12)}.pde-preview{background:var(--bg-secondary,#f8fafc);border:1px solid var(--border,#e2e8f0);border-radius:var(--radius-md,0.5rem);padding:0.875rem 1rem;min-height:52px;display:flex;align-items:center;justify-content:center;overflow-x:auto;font-size:1.1rem;margin-top:1rem;transition:border-color 0.2s}.pde-preview .katex-display{margin:0}[data-theme="dark"] .pde-preview{background:var(--bg-tertiary);border-color:var(--border)}.pde-examples{display:flex;flex-wrap:wrap;gap:0.375rem}.pde-example-chip{padding:0.3rem 0.625rem;font-size:0.75rem;font-family:var(--font-mono);background:var(--bg-secondary,#f8fafc);border:1px solid var(--border,#e2e8f0);border-radius:var(--radius-full,9999px);cursor:pointer;transition:all 0.15s;color:var(--text-secondary);white-space:nowrap}.pde-example-chip:hover{background:var(--tool-primary);color:#fff;border-color:var(--tool-primary);transform:translateY(-1px)}.pde-example-chip:active{transform:translateY(0)}[data-theme="dark"] .pde-example-chip{background:var(--bg-tertiary);border-color:var(--border)}[data-theme="dark"] .pde-example-chip:hover{background:var(--tool-primary);color:#fff}.pde-formulas-toggle,.pde-syntax-toggle{display:flex;align-items:center;justify-content:space-between;padding:0.625rem 0.75rem;background:var(--bg-secondary,#f8fafc);border:1px solid var(--border,#e2e8f0);border-radius:var(--radius-md,0.5rem);cursor:pointer;font-size:0.8125rem;font-weight:600;color:var(--text-secondary);margin-top:0.625rem;transition:all 0.2s;user-select:none}.pde-formulas-toggle:hover,.pde-syntax-toggle:hover{background:var(--tool-light);border-color:var(--tool-primary);color:var(--tool-primary)}[data-theme="dark"] .pde-formulas-toggle,[data-theme="dark"] .pde-syntax-toggle{background:var(--bg-tertiary);border-color:var(--border)}.pde-formulas-content,.pde-syntax-content{border:1px solid var(--border,#e2e8f0);border-top:none;border-radius:0 0 var(--radius-md,0.5rem) var(--radius-md,0.5rem);overflow:hidden;animation:pde-slideDown 0.2s ease}@keyframes pde-slideDown{from{opacity:0;max-height:0}to{opacity:1;max-height:600px}}.pde-formulas-table{width:100%;border-collapse:collapse;font-size:0.8125rem}.pde-formulas-table th{background:var(--tool-light);color:var(--tool-primary);padding:0.5rem 0.625rem;text-align:left;font-weight:600;border-bottom:1.5px solid var(--border,#e2e8f0);font-size:0.75rem;text-transform:uppercase;letter-spacing:0.03em}.pde-formulas-table td{padding:0.5rem 0.625rem;border-bottom:1px solid var(--border,#e2e8f0);color:var(--text-primary);vertical-align:middle}.pde-formulas-table tr:last-child td{border-bottom:none}.pde-formulas-table tr:hover td{background:var(--tool-light)}[data-theme="dark"] .pde-formulas-table th{background:var(--tool-light)}[data-theme="dark"] .pde-formulas-table td{border-bottom-color:var(--border)}.pde-output-tabs{display:flex;border:1.5px solid var(--border,#e2e8f0);border-radius:var(--radius-md,0.5rem);overflow:hidden}.pde-output-tab{flex:1;padding:0.5rem 0.25rem;font-weight:600;font-size:0.8125rem;border:none;cursor:pointer;background:var(--bg-secondary);color:var(--text-secondary);transition:all 0.2s;font-family:var(--font-sans);text-align:center;position:relative}.pde-output-tab.active{background:var(--tool-gradient);color:#fff}.pde-output-tab:hover:not(.active){background:var(--tool-light);color:var(--tool-primary)}[data-theme="dark"] .pde-output-tab{background:var(--bg-tertiary)}[data-theme="dark"] .pde-output-tab.active{background:var(--tool-gradient);color:#fff}[data-theme="dark"] .pde-output-tab:hover:not(.active){background:rgba(255,255,255,0.08);color:#67e8f9}.pde-panel{display:none;flex:1;min-height:0}.pde-panel.active{display:flex;flex-direction:column;animation:pde-fadeIn 0.2s ease}#pde-panel-graph,#pde-panel-contour,#pde-panel-animate{min-height:480px}#pde-panel-python{min-height:540px}#pde-graph-container,#pde-contour-container,#pde-animate-container{width:100%;min-height:440px;border-radius:var(--radius-md)}.pde-action-row{display:flex;gap:0.5rem;margin-top:1rem}.pde-action-row .pde-compute-btn{flex:1;margin-top:0}.pde-compute-btn:disabled{opacity:0.6;cursor:not-allowed;pointer-events:none}.pde-random-btn{flex:0 0 auto;padding:0.75rem 1rem;font-weight:600;font-size:0.8125rem;font-family:var(--font-sans);border:1.5px solid var(--tool-primary);border-radius:var(--radius-md,0.5rem);background:var(--bg-primary);color:var(--tool-primary);cursor:pointer;transition:all 0.2s;display:inline-flex;align-items:center;gap:0.375rem}.pde-random-btn:hover{background:var(--tool-primary);color:#fff}.pde-random-btn:active{transform:scale(0.96)}[data-theme="dark"] .pde-random-btn{background:var(--bg-tertiary);border-color:var(--tool-primary);color:#67e8f9}[data-theme="dark"] .pde-random-btn:hover{background:var(--tool-primary);color:#fff}.pde-export-row{display:flex;gap:0.375rem;margin-top:0.625rem;flex-wrap:wrap;animation:pde-fadeIn 0.3s ease}.pde-export-btn{display:inline-flex;align-items:center;gap:0.25rem;padding:0.375rem 0.625rem;font-size:0.75rem;font-weight:600;font-family:var(--font-sans);border:1px solid var(--border,#e2e8f0);border-radius:var(--radius-full,9999px);background:var(--bg-secondary,#f8fafc);color:var(--text-secondary);cursor:pointer;transition:all 0.15s}.pde-export-btn:hover{background:var(--tool-primary);color:#fff;border-color:var(--tool-primary);transform:translateY(-1px);box-shadow:0 2px 6px rgba(8,145,178,0.2)}.pde-export-btn:active{transform:translateY(0);box-shadow:none}[data-theme="dark"] .pde-export-btn{background:var(--bg-tertiary);border-color:var(--border)}[data-theme="dark"] .pde-export-btn:hover{background:var(--tool-primary);color:#fff}.pde-result-math{padding:1.5rem;overflow-x:auto;max-width:100%;min-width:0}.pde-result-math .katex-display{margin:0.5rem 0;overflow-x:auto;overflow-y:hidden}.pde-result-label{font-size:0.75rem;font-weight:600;text-transform:uppercase;letter-spacing:0.05em;color:var(--tool-primary);margin-bottom:0.75rem}.pde-result-main{font-size:1.1rem;color:var(--text-primary);overflow-x:auto;padding:0.5rem 0;min-height:2rem}.pde-result-detail{display:flex;flex-wrap:wrap;gap:0.375rem;margin-top:0.75rem;align-items:center}.pde-method-badge{display:inline-flex;align-items:center;gap:0.25rem;background:var(--tool-light);color:var(--tool-primary);padding:0.2rem 0.625rem;border-radius:9999px;font-size:0.6875rem;font-weight:600}.pde-classify-badge{display:inline-block;background:#f0fdf4;color:#15803d;padding:0.2rem 0.625rem;border-radius:9999px;font-size:0.6875rem;font-weight:600}[data-theme="dark"] .pde-classify-badge{background:rgba(22,163,74,0.15);color:#4ade80}.pde-verified-badge{display:inline-flex;align-items:center;gap:0.2rem;background:#dcfce7;color:#16a34a;padding:0.2rem 0.625rem;border-radius:9999px;font-size:0.6875rem;font-weight:600}[data-theme="dark"] .pde-verified-badge{background:rgba(22,163,74,0.15);color:#4ade80}.pde-error-badge{display:inline-block;background:#fef2f2;color:#dc2626;padding:0.2rem 0.625rem;border-radius:9999px;font-size:0.6875rem;font-weight:600}[data-theme="dark"] .pde-error-badge{background:rgba(220,38,38,0.15);color:#f87171}.pde-meta-row{display:flex;flex-wrap:wrap;gap:0;margin-top:0.625rem;padding:0.5rem 0.75rem;background:var(--bg-secondary,#f8fafc);border-radius:var(--radius-md,0.5rem);border:1px solid var(--border,#e2e8f0)}.pde-meta-item{font-size:0.75rem;font-family:var(--font-mono);color:var(--text-secondary);white-space:nowrap;padding:0.125rem 0}.pde-meta-item:not(:last-child)::after{content:"·";color:var(--border,#cbd5e1);margin:0 0.5rem;font-weight:700}[data-theme="dark"] .pde-meta-row{background:var(--bg-tertiary)}.pde-steps-btn{display:inline-flex;align-items:center;gap:0.375rem;margin-top:1rem;padding:0.5rem 1rem;font-size:0.8125rem;font-weight:600;font-family:var(--font-sans);border:1.5px solid var(--tool-primary);border-radius:var(--radius-full,9999px);background:transparent;color:var(--tool-primary);cursor:pointer;transition:all 0.15s}.pde-steps-btn:hover{background:var(--tool-primary);color:#fff}.pde-steps-container{margin-top:1rem;border:1px solid var(--border,#e2e8f0);border-radius:var(--radius-md,0.5rem);overflow:hidden;animation:pde-fadeIn 0.3s ease}.pde-steps-header{display:flex;align-items:center;gap:0.5rem;padding:0.625rem 1rem;background:var(--tool-light);font-weight:600;font-size:0.8125rem;color:var(--tool-primary);border-bottom:1px solid var(--border,#e2e8f0)}[data-theme="dark"] .pde-steps-header{background:var(--tool-light)}.pde-steps-header span{font-weight:400;font-size:0.75rem;color:var(--text-muted)}.pde-steps-cas-badge{display:inline-block;background:var(--bg-secondary);color:var(--text-muted);padding:0.125rem 0.5rem;border-radius:9999px;font-size:0.625rem;font-weight:700;text-transform:uppercase;letter-spacing:0.05em;margin-left:auto}.pde-step{display:flex;gap:0.75rem;padding:0.875rem 1rem;border-bottom:1px solid var(--border-light,#f1f5f9);align-items:flex-start}.pde-step:last-child{border-bottom:none}[data-theme="dark"] .pde-step{border-bottom-color:var(--border)}.pde-step-num{flex:0 0 auto;width:24px;height:24px;border-radius:50%;background:var(--tool-gradient);color:#fff;display:flex;align-items:center;justify-content:center;font-size:0.6875rem;font-weight:700;margin-top:0.125rem}.pde-step-body{flex:1;min-width:0}.pde-step-title{font-size:0.6875rem;font-weight:600;text-transform:uppercase;letter-spacing:0.04em;color:var(--text-muted);margin-bottom:0.25rem}.pde-step-math{overflow-x:auto;overflow-y:hidden;font-size:1rem;padding:0.25rem 0}.pde-step-math .katex-display{margin:0;overflow-x:auto;overflow-y:hidden;white-space:nowrap;display:inline-block;min-width:min-content}.pde-error{background:#fef3c7;border:1px solid #fbbf24;border-radius:var(--radius-md);padding:1.25rem;color:#92400e;animation:pde-fadeIn 0.2s ease}.pde-error h4{margin:0 0 0.5rem;font-size:0.9375rem;font-weight:700}.pde-error ul{margin:0.5rem 0 0;padding-left:1.25rem;font-size:0.8125rem;line-height:1.7}[data-theme="dark"] .pde-error{background:rgba(251,191,36,0.15);border-color:rgba(251,191,36,0.3);color:#fbbf24}@keyframes pde-spin{to{transform:rotate(360deg)}}.pde-spinner{width:14px;height:14px;border:2px solid var(--border);border-top-color:var(--tool-primary);border-radius:50%;animation:pde-spin 0.6s linear infinite}.pde-sep{border:none;border-top:1px solid var(--border,#e2e8f0);margin:0.75rem 0}.pde-anim-controls{display:flex;align-items:center;gap:0.5rem;padding:0.625rem 0.75rem;background:var(--bg-secondary,#f8fafc);border:1px solid var(--border,#e2e8f0);border-radius:var(--radius-md,0.5rem);margin-top:0.5rem}[data-theme="dark"] .pde-anim-controls{background:var(--bg-tertiary);border-color:var(--border)}.pde-anim-btn{display:inline-flex;align-items:center;justify-content:center;gap:0.25rem;padding:0.35rem 0.625rem;font-size:0.75rem;font-weight:600;font-family:var(--font-sans);border:1.5px solid var(--tool-primary);border-radius:var(--radius-full,9999px);background:transparent;color:var(--tool-primary);cursor:pointer;transition:all 0.15s;flex-shrink:0}.pde-anim-btn:hover{background:var(--tool-primary);color:#fff}.pde-anim-btn:active{transform:scale(0.95)}.pde-anim-slider{flex:1;min-width:0;accent-color:var(--tool-primary);height:4px;cursor:pointer}.pde-anim-time{font-size:0.75rem;color:var(--text-muted);font-family:var(--font-mono);min-width:4rem;text-align:right;flex-shrink:0}.tool-empty-state .pde-empty-icon{font-size:3rem;margin-bottom:0.75rem;opacity:0.35;line-height:1}#pde-result-content{min-width:0;overflow-x:hidden}@media (max-width:768px){.pde-mode-toggle{gap:0.25rem}.pde-mode-btn{padding:0.4rem 0.5rem;font-size:0.75rem}}@media (max-width:600px){.pde-mode-toggle{flex-wrap:wrap}.pde-mode-btn{flex:0 0 calc(50% - 0.25rem);padding:0.45rem 0.5rem;font-size:0.75rem}.pde-output-tabs{flex-wrap:wrap}.pde-output-tab{flex:0 0 33.33%}.pde-export-row{flex-wrap:wrap}.pde-anim-controls{flex-wrap:wrap}}@media (max-width:400px){.pde-mode-btn{flex:0 0 calc(50% - 0.125rem);font-size:0.6875rem}}