@font-face {
  font-family: 'Ysabeau';
  font-style: normal;
  font-weight: 350 550;
  font-display: swap;
  src: url(/fonts/ysabeau-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}
@font-face {
  font-family: 'Ysabeau';
  font-style: normal;
  font-weight: 350 550;
  font-display: swap;
  src: url(/fonts/ysabeau-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: 'Ysabeau';
  font-style: normal;
  font-weight: 350 550;
  font-display: swap;
  src: url(/fonts/ysabeau-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
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var(--line);border-radius:50%;width:210px;height:150px;transform:rotate(-25deg)}.diagram-orbit.o2{transform:rotate(25deg);width:260px}.diagram-node{position:absolute;width:8px;height:8px;border-radius:50%;background:var(--topic);box-shadow:0 0 0 8px var(--line)}.n1{top:42px;left:23%}.n2{right:17%;top:100px}.n3{bottom:30px;left:38%}.flow{list-style:none;display:flex;margin:0;padding:20px 12px;border-top:1px solid var(--line);gap:12px;color:var(--ink)}.flow li{flex:1;min-width:0;font-size:12px;line-height:1.6}.flow li+li:before{content:'→';position:absolute;margin-left:-12px;color:var(--muted)}.flow li>span{display:block;padding:0 7px}.flow li .mono{font-size:9px;color:var(--topic);margin-bottom:7px}.quiz{padding:32px 35px;border-radius:22px;margin-top:55px;display:grid;grid-template-columns:1fr auto;gap:20px}.quiz h2{font-size:31px;max-width:800px}.quiz .eyebrow{margin-bottom:16px}.quiz-options{display:flex;gap:10px;align-items:center}.quiz-options button{padding:12px 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i:nth-child(8n){margin-right:5px}.bitbar i[data-network-bit=true]{background:var(--accent);opacity:.8}.readouts{display:grid;grid-template-columns:1fr 1fr;gap:18px;border-top:1px solid var(--line);padding-top:22px;margin-top:20px}.readouts dt{font-size:11px;color:var(--muted)}.readouts dd{font:18px/1.8 'Courier New',monospace;margin:7px 0 0;overflow-wrap:anywhere}.readouts [data-range]{font-size:12px}.circuit-visual{width:100%;height:150px;stroke:var(--accent);stroke-width:2;fill:none}.circuit-visual text{font:17px 'Courier New',monospace;fill:var(--muted);stroke:none;text-anchor:middle}.circuit-visual circle{fill:var(--accent)}.light-path{display:flex;align-items:center;gap:16px;margin:34px 0 45px;font-size:30px}.light-path>i{position:relative;flex:1;height:1px;background:var(--line)}.light-path>i:before{content:'';width:8px;height:8px;background:var(--accent);position:absolute;top:-4px;border-radius:50%;animation:travel 5s ease-in-out infinite}.presets{display:flex;gap:8px;flex-wrap:wrap}.presets button{padding:8px 10px;border-radius:9px;font:10px/1.5 'Courier New',monospace}.scenario{border:0;padding:0;margin-top:26px}.scenario legend{font-size:13px;margin-bottom:15px}.scenario button{display:flex;align-items:center;justify-content:space-between;gap:14px;width:100%;text-align:left;padding:15px;border-radius:12px;margin:10px 0;font-size:12px;line-height:1.8}.scenario button[aria-pressed=true]{background:var(--ink);color:var(--paper)}.scenario-feedback{padding-top:15px;border-top:1px solid var(--line)}.scenario-feedback:empty{display:none}.footer{max-width:1380px;width:calc(100% - 72px);margin:0 auto 24px;border-radius:24px;padding:22px 28px;display:flex;justify-content:space-between;align-items:center;gap:25px;font-size:11px}.footer small{display:block;font:9px/1.7 'Courier New',monospace;margin-top:6px}.footer-centre{text-align:center}.release{position:relative;font-family:'Courier New',monospace;font-size:10px}.release summary{cursor:pointer;list-style:none}.release-panel{position:absolute;right:0;bottom:35px;min-width:300px;max-width:350px;display:grid;gap:12px;padding:20px;border-radius:15px;background:var(--solid)}.release-panel code{font-size:10px;overflow-wrap:anywhere}.release-panel span{font-size:10px;color:var(--muted)}
@keyframes turn{to{transform:rotate(360deg)}}@keyframes float{50%{transform:rotate(-6deg) translateY(-8px)}}@keyframes signal{to{stroke-dashoffset:-128}}@keyframes travel{0%{left:0}100%{left:100%}}
html[data-motion=off] *,html[data-motion=off] *:before,html[data-motion=off] *:after{animation-play-state:paused!important}html[data-theme=dark] .atlas-book{background:linear-gradient(125deg,#ffffff0e,transparent),var(--solid)}html[data-theme=dark] .atlas-icon{color:var(--ink)}html[data-theme=dark] :is(.card-top,.topic-card>div,.diagram,.path-title>svg){color:var(--accent)}
@media(min-width:1500px){.hero{padding:105px 0 100px}.atlas{height:410px}}
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@media(max-width:900px){nav{display:none}.menu-button{display:block}.header:has([data-menu][aria-expanded=true]) nav{display:flex;position:absolute;top:100%;left:0;right:0;background:var(--solid);border:1px solid var(--line);border-radius:20px;margin-top:10px;padding:20px;flex-wrap:wrap;justify-content:space-around}.hero{grid-template-columns:1fr 1fr;gap:30px}.hero h1{font-size:49px}.hero .lead{font-size:20px}.atlas-icon span{display:none}.atlas-icon.a5{left:14px}.hero .actions{gap:19px}.hero-art{border-radius:23px}.atlas{height:330px}.topic-grid{gap:15px}.topic-card{padding:22px 20px}.lesson-grid{grid-template-columns:1fr 1fr}.books-grid{grid-template-columns:1fr}.book-card{grid-template-columns:200px 1fr}.book-cover{min-height:260px}.book-note{padding:15px 0}.article-grid{grid-template-columns:1fr}.lesson-figure{position:static;max-width:650px;width:100%;margin:0 auto}.diagram-stage{height:210px}.quiz{grid-template-columns:1fr}.quiz-options{justify-content:start}.labs{grid-template-columns:1fr}.lab{max-width:800px}.book-invite{gap:30px}.book-invite .spines{transform:scale(.8)}.footer{flex-wrap:wrap}.footer-centre{order:3;flex-basis:100%;border-top:1px solid var(--line);padding-top:13px}.article-header{max-width:800px}}
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@media(max-width:370px){.brand>span:last-child{font-size:17px}.brand small{font-size:6px}.brand-icon svg{width:28px}.header-actions{gap:4px}.icon-button{width:30px;height:30px}.languages summary{padding:7px}.book-card{grid-template-columns:1fr}.book-cover{max-width:190px;min-height:270px;margin:auto}.topic-card{padding:16px 12px}.hero h1{font-size:39px}.atlas-icon span{max-width:66px;font-size:8px}.atlas-book{width:143px}.page-top>h1,.article-header h1{font-size:38px}}
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.footer-motion{font:9px/1.5 "Courier New",monospace;border:0;padding:5px;margin-top:3px;color:var(--muted)}

.theme-picker{position:relative}.theme-picker summary{list-style:none;cursor:pointer}.theme-picker summary::-webkit-details-marker{display:none}.theme-picker fieldset{position:absolute;z-index:50;right:0;top:52px;width:190px;padding:18px;border-radius:18px;background:var(--paper);box-shadow:0 15px 50px #0002;display:grid;gap:12px}.theme-picker legend{font-size:12px}.theme-picker label{display:flex;align-items:center;gap:10px;cursor:pointer}.theme-picker input{accent-color:var(--ink)}.site-network{display:flex;flex-wrap:wrap;justify-content:center;gap:14px 30px;border-top:1px solid var(--line);padding:28px 0;font-size:14px}.site-network a{padding:6px 0}.site-network a:hover{text-decoration:underline}

.photon-track{display:flex;align-items:center;gap:22px;height:90px;color:var(--accent)}.photon-end{font-size:30px}.photon-line{height:1px;background:var(--line);flex:1;position:relative}.photon-line i{position:absolute;top:-4px;left:0;width:9px;height:9px;border-radius:50%;background:var(--accent);box-shadow:0 0 16px var(--accent);transform:translateX(-50%)}.photon-caption{display:flex;justify-content:space-between;color:var(--muted);margin:-15px 0 28px;font-size:9px}.light-travel label{display:block;font-size:12px}.light-travel output{float:right;font:11px 'Courier New',monospace}.light-travel input[type=range]{width:100%;accent-color:var(--accent);margin-top:18px}.au-note{font-size:12px;line-height:1.8;border-left:2px solid var(--accent);padding-left:14px;margin-top:20px}.travel-controls{display:flex;align-items:end;gap:12px;flex-wrap:wrap;margin:25px 0}.travel-controls label{flex:1;min-width:135px}.travel-controls select{display:block;margin-top:8px;padding:10px;border:1px solid var(--line);border-radius:12px;color:var(--ink);background:var(--solid);width:100%}.travel-controls .pill{font-size:11px;padding:10px}.travel-status{font-size:12px!important}.light-travel .presets{display:flex;flex-wrap:wrap;gap:10px}.light-travel .presets button[aria-pressed=true]{background:var(--ink);color:var(--paper)}.theme-picker summary{display:grid;place-items:center;border:1px solid var(--line)}

.science-model{border-radius:24px;padding:22px;overflow:hidden;min-width:0}.science-heading{display:flex;align-items:center;justify-content:space-between;gap:15px}.science-heading .mono{font-size:10px;letter-spacing:0}.science-heading .pill{font-size:10px;padding:6px 10px;flex-shrink:0}.science-canvas{display:block;width:100%;height:auto;margin:16px 0}.science-controls{display:grid;gap:17px}.science-controls label{font-size:12px}.science-controls output{float:right;font:12px 'Courier New',monospace}.science-controls input{display:block;width:100%;accent-color:var(--accent);margin-top:15px}.science-reading{display:block;border-top:1px solid var(--line);margin-top:20px;padding:16px 0;font:13px/1.7 'Courier New',monospace;overflow-wrap:anywhere}.science-model>.small{margin-bottom:0}.concept-icon{height:180px;display:grid;place-items:center}.concept-flow .flow{border-top:1px solid var(--line)}.lesson-figure:has(.science-model){position:static}.science-model .readouts{grid-template-columns:1fr}.science-model .travel-controls{gap:9px}.science-model .travel-controls label{min-width:100%}@media(max-width:650px){.science-model{padding:18px}.science-heading{align-items:start}.science-canvas{margin:10px 0}.site-network{display:flex}}

.cyber-feature{display:inline-block;margin-bottom:10px;color:var(--accent)}.cyber-practice{padding-top:25px}.cyber-practice>p{max-width:780px}.cyber-cases{display:grid;grid-template-columns:1fr 1fr;gap:24px;margin-top:30px}.cyber-case{padding:28px;border-radius:25px}.cyber-case h3{margin-top:20px}.cyber-case fieldset{border:0;padding:0;display:grid;gap:10px}.cyber-case button{padding:13px 16px;border-radius:14px;text-align:left;font-size:12px}.cyber-case button[aria-pressed=true]{background:var(--ink);color:var(--paper)}.cyber-feedback{padding-top:20px;font-size:13px}.cyber-feedback p{margin:8px 0 0}.cyber-feedback[hidden]{display:none}@media(max-width:650px){.cyber-cases{grid-template-columns:1fr}.cyber-case{padding:22px}}

/* Pulse endpoints align with source and receiver; the visible line represents the full distance. */
.photon-track{position:relative;padding:0 15px;gap:0}.photon-end{position:absolute;left:0;z-index:1}.photon-end:last-child{left:auto;right:0}.travel-loop{display:flex!important;align-items:center;gap:8px}.travel-loop input{accent-color:var(--accent);width:17px;height:17px}.travel-loop-note{margin:10px 0 24px}.travel-quick{font-size:11px;padding:10px 14px}

.read-full{margin-bottom:24px;font-size:13px}.book-cover{color:inherit;text-decoration:none;transition:transform .2s}.book-cover:hover{transform:translateY(-4px)}.book-cover:focus-visible{outline:2px solid var(--accent);outline-offset:5px}

/* Original EPUB cover artwork, shown uncropped on the bookshelf. */
.book-cover.illustrated{display:block;align-self:start;padding:0;border:0;min-height:0;max-width:none;width:100%;aspect-ratio:var(--cover-ratio);background:transparent;border-radius:3px 10px 10px 3px;overflow:hidden;box-shadow:7px 12px 24px #0003}
.book-cover.illustrated img{display:block;width:100%;height:auto;object-fit:contain}
.book-note .book-title{font-size:clamp(21px,2vw,28px);line-height:1.5;margin:0 0 7px}
.book-note .book-author{font-size:12px;color:var(--muted);margin:0 0 19px}
@media(max-width:650px){.book-note .book-title{font-size:20px}.book-note .book-author{font-size:11px}.book-note .read-full{padding:10px 13px;font-size:11px}}
@media(max-width:370px){.book-cover.illustrated{max-width:190px}.book-note .book-title{margin-top:8px}}