/* Reuse the Electricity implementation directly: one palette, type hierarchy,
   control style, fixed shell and mobile navigation. Scientific colours live in SVG. */
@import url('../electricity/electricity.css');
body{margin:0}.he-app .he-top-title{display:none}.he-app .ec-chapter-title{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.he-app .ec-main{scroll-padding:20px}.he-app #main:focus{outline:none}.he-app .he-heading{padding-bottom:16px}.he-eyebrow{font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--ec-mint);margin:0 0 10px}.he-eyebrow span{margin:0 8px;color:var(--ec-muted)}.he-layout{display:flex;flex-direction:column;width:100%;max-width:1050px;margin:0 auto;gap:0;flex-shrink:0}.he-lab{min-width:0;padding:0 22px}.he-lab-top{display:flex;justify-content:space-between;gap:10px;font-size:10px;letter-spacing:.1em;color:var(--ec-mint);padding:12px 0;border-bottom:1px solid var(--ec-border)}.he-figure{padding:12px 0 0}.he-figure svg{display:block;width:100%;height:auto;max-width:580px;margin:auto;overflow:visible}.he-figure text{font-family:var(--font-family,'Manrope',sans-serif);font-size:17px;font-weight:500}.he-lab-controls{padding:10px 0}.he-choices{display:flex;gap:8px;flex-wrap:wrap;margin:0 0 8px}.he-app .he-choices .ec-action{font-size:13px;flex:1 1 auto;padding:10px 12px}.he-app .ec-action[aria-pressed=true]{border-color:var(--ec-mint);background:var(--ec-hover);color:var(--ec-light)}.he-range{display:block;font-size:14px;color:var(--ec-secondary)}.he-range output{float:right;font-weight:600;color:var(--ec-mint)}.he-range input{display:block;width:100%;min-height:44px;accent-color:var(--ec-mint);margin:0}.he-observation{font-size:16px;line-height:1.5;color:var(--ec-text);margin:12px 0 16px;border-left:2px solid var(--ec-mint);padding:4px 0 4px 15px}.he-model-note{font-size:12px;line-height:1.5;color:var(--ec-secondary);margin:0 0 20px}.he-explain{padding:16px 22px 20px;min-width:0}.he-explain p:not(.he-eyebrow){font-size:16px;line-height:1.5;color:var(--ec-secondary);margin:0 0 16px}.he-app .he-explain .he-listen{font-size:14px;background:transparent;border:0;border-bottom:1px solid var(--ec-border);border-radius:0;padding:8px 0;color:var(--ec-secondary)}.he-extra,.he-check,.he-source{width:calc(100% - 44px);max-width:836px;margin:20px auto;flex-shrink:0}.he-app details{border-block:1px solid var(--ec-border);padding:14px 0;margin-top:16px}.he-app summary{cursor:pointer;font-weight:600;font-size:15px;color:var(--ec-light);min-height:44px;display:flex;align-items:center}.he-app details p,.he-app details li{font-size:15px;line-height:1.6;color:var(--ec-secondary)}.he-app li{margin:10px 0}.he-app ol{padding-left:22px}.he-app a{color:var(--ec-mint);text-underline-offset:4px}.he-flow{display:flex;align-items:center;gap:12px;flex-wrap:wrap;justify-content:center;padding:16px 0;border-block:1px solid var(--ec-border)}.he-flow span{font-size:14px}.he-flow b{color:var(--ec-mint)}.he-small{font-size:12px;color:var(--ec-secondary);line-height:1.5}.he-facts{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.he-facts span{padding:14px 0;border-top:1px solid var(--ec-border);font-size:13px;color:var(--ec-secondary)}.he-facts strong{display:block;color:var(--ec-cream);font-size:26px;font-weight:500}.he-spectrum-key{display:flex;flex-wrap:wrap;gap:12px}.he-spectrum-key span{font-size:13px;border-top:4px solid var(--c);padding-top:5px;flex:1}.he-check{border-top:1px solid var(--ec-border);padding:18px 0 0}.he-app h2{font-size:21px;line-height:1.35;font-weight:600;color:var(--ec-text);margin:12px 0 18px}.he-check-options{display:flex;flex-wrap:wrap;gap:10px}.he-app .he-check-options .ec-action{font-size:15px;text-align:left;justify-content:flex-start}.he-feedback{font-size:16px;color:var(--ec-light);margin:16px 0 0;line-height:1.45;min-height:24px}.he-source{font-size:11px;color:var(--ec-muted);padding-bottom:14px}.he-app .he-count{color:var(--ec-secondary);font-size:12px;margin-left:auto}.he-app .ec-controls .ec-next{margin-left:0}.he-app .he-map h2{margin:0}.he-map-links a{display:flex!important;align-items:center;gap:12px;padding:13px 0!important;border-bottom:1px solid var(--ec-border);text-decoration:none;min-height:44px;width:100%;font-size:14px;color:var(--ec-mint)}.he-map-links small{color:var(--ec-muted)}.he-map-links a span:first-of-type{flex:1}.he-map-links [aria-current]{color:var(--ec-light);font-weight:700}.he-text-only{display:block;max-width:880px}.he-question{padding:18px 0;border-top:1px solid var(--ec-border);margin:20px 0}.he-question-tag{color:var(--ec-mint);font-size:11px;letter-spacing:.1em}.he-question h3{font-size:18px;font-weight:600;line-height:1.5;margin:10px 0 16px;color:var(--ec-text)}.he-question form{display:flex;flex-wrap:wrap;gap:8px}.he-question label{display:block;flex-basis:100%;font-size:14px;color:var(--ec-secondary)}.he-question input,.he-question textarea{width:100%;min-width:0;border-radius:8px;border:1px solid var(--ec-border);background:var(--ec-deep);color:var(--ec-text);padding:10px 12px;font:inherit;font-size:16px}.he-question input{flex:1 1 160px;min-height:46px}.he-question textarea{resize:vertical;min-height:90px;margin:8px 0}.he-question [role=status]{color:var(--ec-light);font-size:16px}.he-question .he-rubric{border-left:2px solid var(--ec-mint);padding-left:15px}.he-recap-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}.he-recap-grid a{border:1px solid var(--ec-border);background:var(--ec-surface);border-radius:10px;padding:14px;text-decoration:none;color:var(--ec-text);font-size:15px;font-weight:600}.he-recap-grid a:hover{background:var(--ec-hover)}.he-complete{border-left:2px solid var(--ec-mint);padding:4px 0 4px 15px;color:var(--ec-text);font-size:16px;line-height:1.5}.he-image-study{max-width:580px;margin:20px auto 26px;border-block:1px solid var(--ec-border);padding:14px 0}.he-image-study h2{font-size:21px;margin:0}.he-image-study p{margin-bottom:0}
@media(min-width:760px){.he-layout{flex-direction:row;align-items:flex-start;padding:0 24px}.he-lab{flex:1 1 55%;padding:0}.he-explain{flex:0 0 42%;padding:22px 0 20px 24px}.he-layout.he-text-only{display:block;padding:0 22px}.he-text-only .he-explain{padding:12px 0}.he-figure text{font-size:16px}}
@media(max-width:760px){.he-check-options{flex-direction:column}.he-check-options button{width:100%}.he-recap-grid{grid-template-columns:1fr}.he-flow{gap:10px}.he-flow span{font-size:12px}.he-facts{gap:8px}.he-facts span{font-size:11px}.he-facts strong{font-size:23px}}
@media(max-width:430px){}

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