/* Chapter-specific layout only. Electricity's stylesheet owns the palette,
   typography, chrome, buttons, panel conventions and responsive shell. */
body{margin:0}.ab-root textarea,.ab-root select{font:inherit}.ab-root .ec-chapter-title{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.ab-root .ec-main{scroll-padding:20px}.ab-root .ec-heading{padding-bottom:16px}.ab-root .ec-workbench{flex:0 0 auto;min-height:0;align-items:flex-start}.ab-root .ec-scene{flex:0 0 auto;min-height:0;width:100%;padding:0 14px}.ab-root .ec-scene svg{display:block;width:100%;height:auto;max-width:580px;margin:auto}.ab-root .ec-scene svg text{font-family:var(--font-family);font-size:18px;font-weight:500}.ab-root .ec-panel{padding-top:14px}.ab-root .ec-note{font-size:14px;line-height:1.5}.ab-root .ec-formal p:last-child{font-size:16px}.ab-root .ec-main:focus{outline:none}.ab-steps{display:flex;gap:8px;flex-wrap:wrap;margin:16px 0}.ab-steps .ec-action{flex:1;font-size:13px;padding:10px;min-width:82px}.ab-root .ec-action[aria-pressed=true]{border-color:var(--ec-mint);background:var(--ec-hover);color:var(--ec-light)}.ab-root .ec-action.primary[aria-pressed=true]{background:var(--ec-mint);color:var(--ec-deep)}.ab-extra{width:100%;max-width:880px;padding:0 22px 24px;margin:0 auto;flex-shrink:0}.ab-root .ab-safety{font-size:12px;color:var(--ec-secondary);border-top:1px solid var(--ec-border);padding-top:12px;margin:16px 0}.ab-safety strong{color:var(--ec-cream);font-weight:600}.ab-root h2{font-size:21px;font-weight:600;line-height:1.35;color:var(--ec-text);margin:18px 0 12px}.ab-root h3{font-size:17px;font-weight:600;color:var(--ec-text);line-height:1.45;margin:10px 0}.ab-small{font-size:12px;line-height:1.5;color:var(--ec-secondary)}.ab-root a{color:var(--ec-mint);text-underline-offset:4px}.ab-root details{border-block:1px solid var(--ec-border);padding:14px 0;margin:20px 0}.ab-root summary{cursor:pointer;min-height:44px;display:flex;align-items:center;font-size:15px;font-weight:600;color:var(--ec-light)}.ab-root details p{font-size:15px;line-height:1.6;color:var(--ec-secondary)}.ab-root ol{padding-left:22px}.ab-root li{margin:10px 0}.ab-source{font-size:11px;color:var(--ec-muted);margin:22px 0}.ab-check{border-top:1px solid var(--ec-border);padding-top:18px;margin-top:26px}.ab-check .ec-actions{flex-direction:column;align-items:stretch}.ab-check .ec-action{justify-content:flex-start;text-align:left}.ab-check .ec-feedback{margin-top:16px}.ab-root .ab-count{font-size:12px;color:var(--ec-secondary);margin-left:auto}.ab-root .ec-controls .ec-next{margin-left:0}.ab-root .ec-map a{display:flex;gap:12px;text-decoration:none;align-items:center;border-bottom:1px solid var(--ec-border);padding:13px 0;width:100%;font-size:14px;line-height:1.45}.ab-map-num{color:var(--ec-muted);font-size:12px}.ab-root .ec-map [aria-current=step]{color:var(--ec-light);font-weight:700}.ab-map-name{flex:1}.ab-root .ec-map h2{margin:0}.ab-root .ec-map [data-action=close-map]{font-size:14px}.ab-root .ab-reading{max-width:680px;margin:0 auto;padding:4px 22px 0}.ab-reading p:not(.ec-focus){color:var(--ec-secondary);font-size:16px;line-height:1.6;margin:0 0 16px}.ab-equation{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap;padding:16px 0;border-block:1px solid var(--ec-border);margin:16px 0;font-size:20px;line-height:1.7;color:var(--ec-text)}.ab-equation>div{display:flex;align-items:center;justify-content:center;gap:8px;flex-wrap:wrap}.ab-term{white-space:nowrap}.ab-term b{color:var(--ec-mint);font-weight:700;margin-right:3px}.ab-term small{font-size:.7em;color:var(--ec-secondary);margin-left:3px}.ab-term sub{font-size:.65em}.ab-arrow{text-align:center;display:flex;flex-direction:column;font-size:27px;line-height:1.2;min-width:34px}.ab-arrow small{font-size:11px;color:var(--ec-cream);max-width:150px;line-height:1.4}.ab-plus{color:var(--ec-muted)}.ab-observation{min-height:3em}.ab-root select{width:100%;min-height:46px;border:1px solid var(--ec-border);border-radius:8px;background:var(--ec-deep);color:var(--ec-text);padding:10px 12px;max-width:100%}.ab-label{display:block;margin:10px 0 7px;font-size:14px;color:var(--ec-secondary)}.ab-workshop{margin:12px 0 22px}.ab-coefficients{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:16px 0}.ab-coefficient{border:1px solid var(--ec-border);border-radius:10px;background:var(--ec-surface);padding:12px 10px;min-width:0}.ab-coefficient .ab-side{color:var(--ec-secondary);font-size:11px;text-transform:uppercase;letter-spacing:.06em}.ab-coefficient .ab-term{font-size:22px;display:block;margin:8px 0;text-align:center}.ab-stepper{display:flex;align-items:center;justify-content:space-between;gap:8px}.ab-root .ab-stepper .ec-action{min-width:44px;min-height:44px;padding:7px;font-size:21px}.ab-stepper output{font-size:23px;font-variant-numeric:tabular-nums;color:var(--ec-light)}.ab-atoms{border-top:1px solid var(--ec-border);margin:18px 0}.ab-atom-row{display:grid;grid-template-columns:42px 1fr 1fr;gap:12px;border-bottom:1px solid var(--ec-border);padding:12px 0;align-items:start}.ab-atom-row>strong{color:var(--ec-light);font-size:17px}.ab-atom-row span{font-size:14px}.ab-atom-head{font-size:12px;color:var(--ec-secondary)}.ab-dots{display:flex;gap:3px;flex-wrap:wrap;max-width:100%;margin-top:6px}.ab-dots i{width:8px;height:8px;border-radius:50%;background:var(--atom);display:block;flex:0 0 8px}.ab-atom-row.match{border-left:2px solid var(--ec-mint);padding-left:8px}.ab-atom-row.mismatch{border-left:2px solid var(--ec-cream);padding-left:8px}.ab-status{font-size:17px;color:var(--ec-light);margin:14px 0;line-height:1.5}.ab-question{border-top:1px solid var(--ec-border);padding:18px 0;margin-top:20px}.ab-question textarea{display:block;width:100%;resize:vertical;min-height:94px;border:1px solid var(--ec-border);border-radius:8px;padding:10px 12px;background:var(--ec-deep);color:var(--ec-text);font-size:16px}.ab-question .ec-actions{gap:8px}.ab-question .ec-action{font-size:13px}.ab-question details{margin:12px 0}.ab-question .ab-question-tag{font-size:11px;color:var(--ec-mint);letter-spacing:.08em;text-transform:uppercase}.ab-reference{display:grid;gap:12px}.ab-reference article{border-top:1px solid var(--ec-border);padding-top:12px}.ab-tags{display:flex;gap:7px;flex-wrap:wrap;margin:10px 0}.ab-tags span{color:var(--ec-light);font-size:12px;border-bottom:1px solid var(--ec-border);padding:4px 0;margin-right:8px}.ab-results{display:grid;grid-template-columns:1fr 1fr;gap:14px}.ab-beaker-result{border-top:1px solid var(--ec-border);padding-top:12px}.ab-beaker-result strong{display:block;font-size:24px;font-weight:500;color:var(--ec-light)}.ab-beaker-result p{font-size:14px;color:var(--ec-secondary)}.ab-root .ab-link-grid{display:grid;gap:12px;grid-template-columns:1fr 1fr}.ab-link-grid .ec-action{justify-content:flex-start;text-align:left}.ab-filter{display:flex;gap:8px;flex-wrap:wrap;margin:16px 0}.ab-filter .ec-action{font-size:13px}.ab-ui-note{font-size:12px;color:var(--ec-muted)}
@media(min-width:760px){.ab-root .ec-scene{flex:1 1 55%!important;min-height:0!important;padding:12px 0}.ab-root .ec-panel{flex:0 0 42%;align-self:flex-start;padding:14px 0 20px 24px}.ab-coefficients{grid-template-columns:repeat(4,minmax(0,1fr))}.ab-root .ab-reading{max-width:880px;padding:12px 22px}.ab-root .ab-extra{padding-top:12px}.ab-check .ec-actions{flex-direction:row;flex-wrap:wrap}.ab-check .ec-action{flex:1}.ab-root .ec-map .ec-action{font-size:14px}}
@media(max-width:430px){.ab-root .ec-heading{padding-inline:22px}.ab-root .ec-scene svg text{font-size:19px}.ab-equation{font-size:18px}.ab-equation .ab-arrow{flex-basis:100%;font-size:26px}.ab-equation .ab-arrow small{max-width:none}.ab-root .ab-link-grid{grid-template-columns:1fr}.ab-coefficient .ab-term{font-size:20px}.ab-atoms{font-variant-numeric:tabular-nums}}

.ab-root{grid-template-columns:minmax(0,1fr)}.ab-root .ec-chapter-title{min-width:0}
.ab-root .ec-topbar button,.ab-root .ec-topbar a{flex-shrink:0}

.ab-root{grid-template-columns:minmax(0,1fr)}.ab-root .ec-topbar button,.ab-root .ec-topbar a{flex-shrink:0}.ab-root .ec-chapter-title{min-width:0}.ab-root .ec-scene{min-width:0}.ab-controls{padding:8px 0}.ab-control{margin:12px 0}.ab-control label{display:block;color:var(--ec-secondary);font-size:14px;margin-bottom:6px}.ab-control input[type=range]{display:block;width:100%;min-height:44px;accent-color:var(--ec-mint)}.ab-root .ec-workbench{padding-top:8px}.ab-readout{border-left:2px solid var(--ec-mint);padding:4px 0 4px 15px;color:var(--ec-text);font-size:16px;line-height:1.5;margin:16px 0}.ab-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.ab-card{padding:15px;border:1px solid var(--ec-border);border-radius:10px;background:var(--ec-surface);min-width:0}.ab-card strong{display:block;color:var(--ec-light);font-size:20px;margin-bottom:8px}.ab-card p{font-size:14px;color:var(--ec-secondary);margin:8px 0}.ab-controls .ec-actions{flex-wrap:wrap;gap:8px}.ab-controls .ec-action{font-size:13px}.ab-controls output{font-weight:600;color:var(--ec-light)}.ab-notebook{border-collapse:collapse;width:100%;font-size:14px}.ab-notebook th,.ab-notebook td{padding:12px 8px;text-align:left;border-bottom:1px solid var(--ec-border);vertical-align:top;overflow-wrap:anywhere}.ab-notebook th{color:var(--ec-mint)}.ab-ion{font-size:20px;color:var(--ec-light);margin:16px 0}.ab-question input{font:inherit;font-size:16px;max-width:100%;width:100%;min-height:46px;color:var(--ec-text);background:var(--ec-deep);border:1px solid var(--ec-border);border-radius:8px;padding:10px}.ab-root .ab-note{font-size:12px;line-height:1.6;color:var(--ec-muted)}.ab-root .ab-workshop{margin-top:12px}.ab-root .ab-pairs{display:flex;gap:12px;flex-wrap:wrap}.ab-pairs span{padding:12px;border:1px solid var(--ec-border);border-radius:10px;background:var(--ec-surface)}.ab-swatches{display:flex;gap:4px}.ab-swatches span{height:28px;flex:1}.ab-root .ab-evidence{margin-top:0}.ab-root .ab-evidence .ab-extra{padding-top:0}.ab-root [data-action=next]{white-space:nowrap}.ab-root .ab-reading{padding-bottom:15px}.ab-reference-note{border-left:2px solid var(--ec-cream);padding-left:14px}.ab-root .ab-exact-label{color:var(--ec-mint);font-size:11px;letter-spacing:.1em;text-transform:uppercase}
@media(max-width:430px){.ab-grid{grid-template-columns:1fr}.ab-root .ec-scene svg text{font-size:18px}.ab-notebook th,.ab-notebook td{padding:10px 5px}.ab-coefficient .ab-term{font-size:18px}.ab-root .ab-arrow{flex-basis:100%}}