:root{--ep-tool:#4f46e5;--ep-tool-dark:#4338ca;--ep-gradient:linear-gradient(135deg,#4f46e5 0%,#818cf8 100%);--ep-light:#eef2ff}[data-theme="dark"]{--ep-light:rgba(79,70,229,0.15)}.ep-output-tabs{display:flex;border-bottom:1.5px solid var(--border);background:var(--bg-secondary);border-radius:0.75rem 0.75rem 0 0;overflow:hidden}.ep-output-tab{flex:1;padding:0.625rem 0.5rem;font-size:0.75rem;font-weight:600;border:none;cursor:pointer;background:transparent;color:var(--text-secondary);transition:all 0.15s;font-family:var(--font-sans);text-align:center;position:relative}.ep-output-tab.active{color:var(--ep-tool);background:var(--bg-primary)}.ep-output-tab.active::after{content:"";position:absolute;bottom:0;left:0;right:0;height:2px;background:var(--ep-tool)}.ep-output-tab:hover:not(.active){background:var(--bg-tertiary)}.ep-panel{display:none}.ep-panel.active{display:block}.ep-input-label{display:block;font-size:0.6875rem;font-weight:600;color:var(--text-secondary);text-transform:uppercase;letter-spacing:0.05em;margin-bottom:0.25rem}.ep-input{width:100%;padding:0.625rem 0.75rem;font-size:1rem;font-family:var(--font-mono);border:1.5px solid var(--border);border-radius:0.375rem;background:var(--bg-primary);color:var(--text-primary);text-align:left;transition:border-color 0.15s;box-sizing:border-box}.ep-input:focus{outline:none;border-color:var(--ep-tool);box-shadow:0 0 0 2px rgba(79,70,229,0.1)}.ep-input-hint{font-size:0.6875rem;color:var(--text-muted);margin-top:0.25rem}.ep-examples{display:flex;flex-wrap:wrap;gap:0.375rem}.ep-example-chip{padding:0.3rem 0.625rem;font-size:0.6875rem;font-weight:500;border-radius:2rem;border:1px solid var(--border);background:var(--bg-secondary);color:var(--text-secondary);cursor:pointer;transition:all 0.15s;font-family:var(--font-mono)}.ep-example-chip:hover{background:var(--ep-light);color:var(--ep-tool);border-color:var(--ep-tool)}.ep-verdict-badge{display:inline-block;padding:0.375rem 1rem;border-radius:0.75rem;font-size:1rem;font-weight:700;letter-spacing:0.05em;text-transform:uppercase}.ep-verdict-polar{background:linear-gradient(135deg,#4f46e5 0%,#818cf8 100%);color:#fff}.ep-verdict-nonpolar{background:linear-gradient(135deg,#059669 0%,#34d399 100%);color:#fff}.ep-verdict-ionic{background:linear-gradient(135deg,#dc2626 0%,#f87171 100%);color:#fff}.ep-result-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:0.5rem;margin:0.75rem 0}.ep-result-item{padding:0.5rem 0.375rem;background:var(--bg-secondary);border-radius:0.5rem;text-align:center;border:1px solid var(--border)}.ep-result-label{font-size:0.5625rem;font-weight:600;color:var(--text-muted);text-transform:uppercase;letter-spacing:0.05em;margin-bottom:0.125rem}.ep-result-value{font-size:0.8125rem;font-weight:700;color:var(--text-primary)}.ep-bond-table-wrap{overflow-x:auto;border:1px solid var(--border);border-radius:0.5rem;margin:0.75rem 0}.ep-bond-table{width:100%;border-collapse:collapse;font-size:0.75rem}.ep-bond-table th{background:var(--ep-light);color:var(--ep-tool-dark);font-weight:600;text-transform:uppercase;letter-spacing:0.05em;font-size:0.625rem;padding:0.5rem 0.625rem;text-align:left;border-bottom:1.5px solid var(--border)}.ep-bond-table td{padding:0.4375rem 0.625rem;border-bottom:1px solid var(--border);color:var(--text-primary);vertical-align:middle}.ep-bond-table tr:hover td{background:var(--bg-tertiary)}.ep-bond-type-badge{display:inline-block;padding:0.125rem 0.375rem;border-radius:0.25rem;font-size:0.625rem;font-weight:600}.ep-bond-nonpolar{background:#ecfdf5;color:#059669}.ep-bond-polar{background:#eef2ff;color:#4f46e5}.ep-bond-ionic{background:#fef2f2;color:#dc2626}[data-theme="dark"] .ep-bond-table th{background:rgba(79,70,229,0.2);color:#a5b4fc}[data-theme="dark"] .ep-bond-table td{color:var(--text-primary)}[data-theme="dark"] .ep-bond-nonpolar{background:rgba(5,150,105,0.15);color:#6ee7b7}[data-theme="dark"] .ep-bond-polar{background:rgba(79,70,229,0.15);color:#a5b4fc}[data-theme="dark"] .ep-bond-ionic{background:rgba(220,38,38,0.15);color:#fca5a5}.ep-verdict-card{padding:1rem;background:var(--bg-secondary);border-radius:0.5rem;border-left:3px solid var(--ep-tool);margin:0.75rem 0}.ep-verdict-card h4{font-size:0.875rem;font-weight:600;color:var(--text-primary);margin:0 0 0.375rem}.ep-verdict-card p{font-size:0.8125rem;color:var(--text-secondary);margin:0;line-height:1.6}.ep-3d-wrapper{margin:0.75rem 0}.ep-3d-viewer{height:380px;min-height:320px;position:relative;border:1.5px solid var(--border);border-radius:0.75rem;overflow:hidden;background:var(--bg-primary)}.ep-viewer-controls{display:flex;gap:0.25rem;padding:0.375rem 0;flex-wrap:wrap}.ep-viewer-ctrl-btn{padding:0.2rem 0.5rem;font-size:0.625rem;font-weight:600;font-family:var(--font-sans);border:1px solid var(--border);border-radius:0.375rem;background:var(--bg-secondary);color:var(--text-secondary);cursor:pointer;transition:all 0.15s}.ep-viewer-ctrl-btn:hover{background:var(--ep-light);color:var(--ep-tool);border-color:var(--ep-tool)}.ep-viewer-ctrl-btn.active{background:var(--ep-gradient);color:#fff;border-color:transparent}.ep-viewer-hint{font-size:0.5625rem;color:var(--text-muted);text-align:center;padding:0 0 0.125rem}.ep-3d-loading{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:4rem 1rem;gap:0.5rem}.ep-3d-loading-spinner{width:1.25rem;height:1.25rem;border:2px solid var(--border);border-top-color:var(--ep-tool);border-radius:50%;animation:ep-spin 0.8s linear infinite}.ep-3d-loading-text{font-size:0.6875rem;color:var(--text-muted);font-weight:500}@keyframes ep-spin{to{transform:rotate(360deg)}}[data-theme="dark"] .ep-3d-viewer{border-color:rgba(148,163,184,0.2)}.ep-steps-toggle{display:flex;align-items:center;gap:0.375rem;padding:0.5rem 0.625rem;margin:0.5rem 0 0.25rem;background:var(--bg-secondary);border:1px solid var(--border);border-radius:0.5rem;cursor:pointer;font-size:0.75rem;font-weight:600;color:var(--text-secondary);transition:all 0.15s;width:100%;text-align:left;font-family:var(--font-sans)}.ep-steps-toggle:hover{background:var(--bg-tertiary);color:var(--text-primary)}.ep-steps-toggle svg{transition:transform 0.2s;width:14px;height:14px;flex-shrink:0}.ep-steps-toggle.open svg{transform:rotate(180deg)}.ep-steps-wrap{overflow:hidden;max-height:0;transition:max-height 0.3s ease}.ep-steps-wrap.open{max-height:2000px}.ep-step{display:flex;gap:0.5rem;padding:0.5rem 0.625rem;margin:0.25rem 0;background:var(--bg-secondary);border-radius:0.375rem;border-left:2px solid var(--ep-tool);transition:background 0.15s}.ep-step:hover{background:var(--bg-tertiary)}.ep-step-number{width:1.25rem;height:1.25rem;border-radius:50%;background:var(--ep-gradient);color:#fff;display:flex;align-items:center;justify-content:center;font-size:0.5625rem;font-weight:700;flex-shrink:0;margin-top:0.0625rem}.ep-step-content{flex:1;min-width:0}.ep-step-desc{font-size:0.75rem;font-weight:500;color:var(--text-primary);margin-bottom:0.125rem}.ep-step-math{overflow-x:auto;font-size:0.6875rem;color:var(--text-secondary);line-height:1.4}.ep-search-input{width:100%;padding:0.5rem 0.75rem;font-size:0.8125rem;border:1.5px solid var(--border);border-radius:0.375rem;background:var(--bg-primary);color:var(--text-primary);font-family:var(--font-sans);margin-bottom:0.75rem;box-sizing:border-box}.ep-search-input:focus{outline:none;border-color:var(--ep-tool)}.ep-table-wrap{overflow-x:auto;max-height:400px;overflow-y:auto;border:1px solid var(--border);border-radius:0.5rem}.ep-table{width:100%;border-collapse:collapse;font-size:0.75rem}.ep-table th{position:sticky;top:0;background:var(--ep-light);color:var(--ep-tool-dark);font-weight:600;text-transform:uppercase;letter-spacing:0.05em;font-size:0.625rem;padding:0.5rem 0.625rem;text-align:left;border-bottom:1.5px solid var(--border);z-index:1}.ep-table td{padding:0.4375rem 0.625rem;border-bottom:1px solid var(--border);color:var(--text-primary);vertical-align:middle}.ep-table tr:hover td{background:var(--bg-tertiary)}.ep-table-btn{padding:0.2rem 0.5rem;font-size:0.625rem;font-weight:600;border:1px solid var(--ep-tool);border-radius:0.25rem;background:transparent;color:var(--ep-tool);cursor:pointer;transition:all 0.15s;font-family:var(--font-sans)}.ep-table-btn:hover{background:var(--ep-gradient);color:#fff;border-color:transparent}.ep-polarity-badge{display:inline-block;padding:0.125rem 0.375rem;border-radius:0.25rem;font-size:0.6875rem;font-weight:500}.ep-badge-polar{background:var(--ep-light);color:var(--ep-tool-dark)}.ep-badge-nonpolar{background:#ecfdf5;color:#059669}[data-theme="dark"] .ep-table th{background:rgba(79,70,229,0.2);color:#a5b4fc}[data-theme="dark"] .ep-table-btn{color:#a5b4fc;border-color:#a5b4fc}[data-theme="dark"] .ep-badge-polar{background:rgba(79,70,229,0.15);color:#a5b4fc}[data-theme="dark"] .ep-badge-nonpolar{background:rgba(5,150,105,0.15);color:#6ee7b7}[data-theme="dark"] .ep-rule-table th{background:rgba(79,70,229,0.2);color:#a5b4fc}.ep-edu-card{padding:1rem;background:var(--bg-secondary);border-radius:0.5rem}.ep-edu-card h4{font-size:0.875rem;font-weight:600;color:var(--text-primary);margin:0 0 0.375rem}.ep-edu-card p{font-size:0.8125rem;color:var(--text-secondary);margin:0;line-height:1.6}.ep-edu-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:0.75rem;margin:1rem 0}.ep-callout{display:flex;gap:0.75rem;padding:1rem;border-radius:0.5rem;margin:1rem 0}.ep-callout-icon{font-size:1.25rem;flex-shrink:0}.ep-callout-text{font-size:0.8125rem;line-height:1.6;color:var(--text-secondary)}.ep-callout-insight{background:#eef2ff;border-left:3px solid #4f46e5}.ep-callout-tip{background:#fffbeb;border-left:3px solid #d97706}[data-theme="dark"] .ep-callout-insight{background:rgba(79,70,229,0.1)}[data-theme="dark"] .ep-callout-tip{background:rgba(217,119,6,0.1)}.ep-en-scale{display:flex;align-items:center;justify-content:center;gap:0.25rem;padding:1rem;background:var(--bg-secondary);border-radius:0.75rem;margin:1rem 0;overflow-x:auto}.ep-en-element{display:flex;flex-direction:column;align-items:center;gap:0.125rem;padding:0.375rem 0.5rem;border-radius:0.5rem;min-width:3rem;text-align:center}.ep-en-symbol{font-size:1rem;font-weight:700;font-family:var(--font-mono)}.ep-en-value{font-size:0.625rem;font-weight:600}.ep-bond-type-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:0.75rem;margin:1rem 0}.ep-bond-type-card{padding:1rem;border-radius:0.5rem;text-align:center;border:1.5px solid var(--border)}.ep-bond-type-card h4{font-size:0.875rem;font-weight:600;margin:0 0 0.25rem}.ep-bond-type-card .ep-delta{font-family:var(--font-mono);font-size:1.25rem;font-weight:700;margin:0.25rem 0}.ep-bond-type-card p{font-size:0.75rem;color:var(--text-secondary);margin:0}.ep-rule-table{width:100%;border-collapse:collapse;font-size:0.8125rem}.ep-rule-table th{background:var(--ep-light);color:var(--ep-tool-dark);font-weight:600;text-transform:uppercase;letter-spacing:0.04em;font-size:0.6875rem;padding:0.625rem 0.75rem;text-align:left;border-bottom:2px solid var(--ep-tool)}.ep-rule-table td{padding:0.5rem 0.75rem;border-bottom:1px solid var(--border);color:var(--text-primary);vertical-align:middle}.ep-rule-table tr:hover td{background:var(--bg-tertiary)}.ep-section-num{display:inline-flex;align-items:center;justify-content:center;width:1.75rem;height:1.75rem;border-radius:50%;background:var(--ep-gradient);color:#fff;font-size:0.8125rem;font-weight:700;margin-right:0.5rem;flex-shrink:0}.ep-process{position:relative;padding-left:2.5rem}.ep-process::before{content:"";position:absolute;left:1.0625rem;top:0.5rem;bottom:0.5rem;width:2px;background:linear-gradient(to bottom,var(--ep-tool) 0%,rgba(79,70,229,0.15) 100%)}.ep-process-step{position:relative;padding:0.75rem 1rem;margin-bottom:0.75rem;background:var(--bg-secondary);border-radius:0.5rem;border-left:3px solid var(--ep-tool)}.ep-process-step::before{content:attr(data-step);position:absolute;left:-2.5rem;top:0.75rem;width:1.75rem;height:1.75rem;border-radius:50%;background:var(--ep-gradient);color:#fff;display:flex;align-items:center;justify-content:center;font-size:0.75rem;font-weight:700;z-index:1}.ep-process-step h4{font-size:0.875rem;font-weight:600;color:var(--text-primary);margin:0 0 0.25rem}.ep-process-step p{font-size:0.8125rem;color:var(--text-secondary);margin:0;line-height:1.6}.ep-anim{opacity:0;transform:translateY(1rem);transition:opacity 0.5s ease,transform 0.5s ease}.ep-anim.ep-visible{opacity:1;transform:translateY(0)}.ep-anim-d1{transition-delay:0.1s}.ep-anim-d2{transition-delay:0.2s}.ep-anim-d3{transition-delay:0.3s}.ep-anim-d4{transition-delay:0.4s}.ep-anim-d5{transition-delay:0.5s}.ep-anim-d6{transition-delay:0.6s}@keyframes ep-pop{0%{transform:scale(0);opacity:0}70%{transform:scale(1.15)}100%{transform:scale(1);opacity:1}}@media (prefers-reduced-motion:reduce){.ep-anim{opacity:1;transform:none;transition:none}}@media (max-width:640px){.ep-3d-viewer{height:260px;min-height:220px}.ep-result-grid{grid-template-columns:repeat(2,1fr)}.ep-edu-grid{grid-template-columns:1fr}.ep-bond-type-grid{grid-template-columns:1fr}.ep-en-scale{flex-wrap:wrap}.ep-process{padding-left:2rem}.ep-process-step::before{left:-2rem;width:1.5rem;height:1.5rem;font-size:0.6875rem}}