/* Trainer design copied from the Standard Model course. */

:root{color-scheme:dark;--bg:#0d1420;--panel:#141f2d;--card:#1a2838;--text:#edf3f8;--muted:#afbfce;--line:#34475d;--blue:#89cfff;--green:#91e2c5;--amber:#f6cc86;--purple:#c3b6fb}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.65 system-ui,-apple-system,Segoe UI,sans-serif}button,input,select{font:inherit}button,a,input,select,summary{touch-action:manipulation}button{cursor:pointer;color:inherit}button:disabled{cursor:default;opacity:.6}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid var(--amber);outline-offset:4px}a{color:var(--blue)}p{margin:.6em 0 1em}h1,h2,h3{line-height:1.2}h1{font-size:clamp(2rem,5vw,3.2rem);letter-spacing:-.04em;margin:.4em 0}h2{font-size:clamp(1.55rem,3vw,2.05rem);margin:.4em 0 .7em}h3{font-size:1.1rem;margin:1.6em 0 .65em}.eyebrow{font-size:.75rem;text-transform:uppercase;letter-spacing:.16em;font-weight:750;color:var(--green)}.muted{color:var(--muted)}.small{font-size:.86rem}.shell{max-width:1200px;margin:auto;padding:32px 28px 70px}.hero{max-width:830px}.hero p{font-size:1.1rem;max-width:650px}.tabs{display:flex;gap:6px;flex-wrap:wrap;margin:24px 0 28px;padding-bottom:16px;border-bottom:1px solid var(--line)}.btn,.tabs button,.pill{min-height:44px;padding:9px 15px;border:1px solid var(--line);border-radius:10px;background:var(--panel);text-decoration:none;display:inline-flex;align-items:center;justify-content:center;gap:8px}.tabs button.active,.pill.active,.primary{background:#254a60!important;border-color:var(--blue)!important}.btn:hover,.pill:hover,.tabs button:hover{background:#26394d}.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.spread{justify-content:space-between}.hidden{display:none!important}.layout{display:grid;grid-template-columns:260px minmax(0,1fr);gap:28px}.sidebar{align-self:start;position:sticky;top:16px}.lesson-list{display:grid;gap:5px;margin-top:16px}.lesson-link{display:grid;grid-template-columns:25px 1fr;gap:8px;text-align:left;border:1px solid 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var(--blue);border-radius:0;color:var(--blue);background:none;line-height:inherit;font:inherit}.term:hover{color:white}.terms{margin:20px 0}.demo{margin:24px 0;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:20px}.demo h3{margin-top:0}.demo svg{display:block;width:100%;height:auto}.demo .caption{font-size:.82rem;color:var(--muted);margin-top:10px}.diagram-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.diagram-cards>div{border:1px solid var(--line);border-top:4px solid var(--blue);border-radius:10px;padding:16px}.diagram-cards>div:nth-child(2){border-top-color:var(--green)}.diagram-cards>div:nth-child(3){border-top-color:var(--amber)}.big-number{font-size:2.2rem;font-weight:700;line-height:1.1}.grid{display:grid;gap:12px}.g3{grid-template-columns:repeat(3,minmax(0,1fr))}.g4{grid-template-columns:repeat(4,minmax(0,1fr))}.choice{width:100%;text-align:left;display:block;margin:8px 0;padding:12px 14px;border:1px solid var(--line);border-radius:10px;background:var(--card)}.choice:hover:not(:disabled){border-color:var(--blue)}.choice.right{border-color:var(--green);background:#19382f}.choice.wrong{border-color:var(--amber);background:#392f23}.feedback{padding:10px 0;min-height:30px}.success{color:var(--green)}.question{margin-top:18px;border-top:1px solid var(--line);padding-top:14px}.question h3{margin-top:.4em}.quiz-feedback{min-height:40px}.lesson-footer{margin-top:28px;padding-top:20px;border-top:1px solid var(--line)}input,select{min-height:44px;padding:9px 12px;background:var(--bg);border:1px solid var(--line);border-radius:9px;color:var(--text);max-width:100%}input[type=search]{width:100%}input[type=range]{width:100%;accent-color:var(--green);padding:0}.field{display:block;text-align:left;border-left:4px solid var(--blue);min-height:92px;padding:15px}.field.gauge{border-left-color:var(--green)}.field.higgs{border-left-color:var(--amber)}.field.active{outline:2px solid var(--blue)}.field-symbol{font-size:1.15rem;font-weight:700}.field-name{font-size:.8rem;color:var(--muted);line-height:1.45}.badge{display:inline-block;padding:3px 8px;border:1px solid var(--line);border-radius:7px;font-size:.78rem;color:var(--muted)}.filter-row{margin:18px 0}.empty{grid-column:1/-1;padding:20px;color:var(--muted)}details{border:1px solid var(--line);border-radius:10px;padding:12px 16px;margin:16px 0}summary{cursor:pointer;font-weight:650}table{border-collapse:collapse;width:100%;font-size:.9rem}td,th{text-align:left;padding:12px;border-bottom:1px solid var(--line)}th{color:var(--green)}.table-scroll{overflow-x:auto}.notice{padding:12px 16px;background:#263142;border-left:3px solid var(--purple);font-size:.9rem;border-radius:0 10px 10px 0}.check-list{display:grid;gap:10px}.check-row{padding:12px 15px;border:1px solid var(--line);border-radius:10px;background:var(--panel)}.check-row strong{display:block}.check-row.yes{border-left:4px solid var(--green)}.check-row.no{border-left:4px solid var(--amber)}.glossary-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:18px 0}.glossary-grid h3{margin-top:0}.glossary-grid p{font-size:.92rem}.source-list li{margin:8px 0}dialog{color:var(--text);background:var(--panel);border:1px solid var(--line);border-radius:18px;max-width:560px;width:calc(100% - 36px);padding:24px;box-shadow:0 24px 90px #0009}dialog::backdrop{background:#050b13b8}dialog h2{margin-top:12px}.skip{position:absolute;left:20px;top:-80px;background:var(--panel);padding:10px;z-index:2}.skip:focus{top:10px}footer{margin-top:38px;color:var(--muted);font-size:.82rem}.quiz-progress{font-size:.85rem;color:var(--muted)}.quiz-settings{margin-bottom:20px}.quiz-settings label{display:block;margin-bottom:6px}.match-note{font-size:.9rem}.counter-tiles{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:16px 0}.counter-tiles>div{border:1px solid var(--line);border-radius:10px;padding:14px}.counter-total{font-size:1.5rem;color:var(--green);font-weight:700}.mobile-index{display:none}.motion{transition:transform .4s}.family-buttons{margin-bottom:14px}.symbol-chip{display:inline-block;border:1px solid var(--line);border-radius:8px;padding:8px 12px;margin:4px;font-size:1.05rem}.lesson-topic{scroll-margin-top:16px}.resume-note{margin-top:12px}.level-map{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:0 0 22px}.level-card{background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:17px;min-width:0}.level-card.current{border-color:var(--blue);background:#192d40}.level-card.complete{border-color:var(--green)}.level-code{font-size:1.35rem;font-weight:750;color:var(--blue);line-height:1.1}.level-card.complete .level-code{color:var(--green)}.level-card h2{font-size:1.05rem;margin:6px 0}.level-card p{font-size:.89rem;margin:4px 0 10px;color:var(--muted)}.level-card progress{margin:8px 0 4px}.level-card .row{margin-top:9px}.level-card .btn{font-size:.85rem;min-height:38px;padding:6px 10px}.level-heading{font-size:.83rem;color:var(--green);font-weight:750;letter-spacing:.04em;padding:13px 9px 5px;border-top:1px solid var(--line);margin-top:5px}.level-heading:first-child{border-top:0;margin-top:0}.lesson-list .level-heading{grid-column:1/-1}.level-crumb{display:inline-block;color:var(--amber);font-weight:700;margin:0 0 8px;font-size:.9rem}.gold-stage{margin-top:18px;padding:20px;border:1px solid #846d39;border-radius:12px;background:linear-gradient(135deg,#372f22,#242d37)}.gold-stage .eyebrow{color:var(--amber)}.gold-tiles{display:flex;flex-wrap:wrap;gap:5px;margin:14px 0}.gold-tiles .symbol-chip{border-color:#94784b;background:#3b3326}.legend-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin:16px 0}.legend-card{display:grid;gap:3px;justify-items:start;text-align:left;border:1px solid var(--line);background:#152b3a;border-radius:10px;padding:10px 14px;min-width:0}.legend-card:hover,.legend-card.active{border-color:var(--blue);background:#1b3948}.legend-card svg{width:160px;max-width:100%;height:auto;overflow:visible}.legend-detail{padding:8px 18px 16px;border:1px solid var(--line);border-radius:10px;background:#102434}.legend-detail h3{margin:8px 0}.feynman-figure{margin:14px 0;padding:14px;border:1px solid var(--line);background:#102434;border-radius:12px}.feynman-figure figcaption{font-size:.89rem;color:var(--muted)}.feynman-svg{display:block;width:100%;height:auto;min-height:215px;max-height:360px}.feynman-svg .particle,.legend-card .particle{fill:none;stroke:#89cfff;stroke-width:3}.feynman-svg .gauge,.legend-card .gauge{fill:none;stroke:#f6cc86;stroke-width:3}.feynman-svg .gluon,.legend-card .gluon{fill:none;stroke:#c3b6fb;stroke-width:3}.feynman-svg .scalar,.legend-card .scalar{fill:none;stroke:#91e2c5;stroke-width:3;stroke-dasharray:10 7}.feynman-svg .vertex,.legend-card .vertex{fill:#fff0c8;stroke:#f6cc86;stroke-width:2}.feynman-svg .diagram-label{fill:#edf3f8;font:18px system-ui,sans-serif}.feynman-svg.is-explaining .diagram-part{opacity:.28}.feynman-svg.is-explaining .diagram-part.active{opacity:1;filter:drop-shadow(0 0 4px #fff8)}.diagram-selector,.diagram-steps{gap:7px}.diagram-selector .pill,.diagram-steps .pill{font-size:.86rem;padding:7px 11px;min-height:40px}.diagram-steps{margin-bottom:14px}
@media(max-width:850px){.level-map{grid-template-columns:1fr 1fr}.layout{grid-template-columns:1fr}.sidebar{position:static}.lesson-list{grid-template-columns:1fr 1fr}.sidebar>h2{font-size:1.3rem}.g4{grid-template-columns:repeat(3,1fr)}}
@media(max-width:560px){.legend-grid{grid-template-columns:1fr 1fr}.legend-card{padding:9px}.legend-card svg{width:120px}.feynman-figure{padding:8px}.feynman-svg{min-height:180px}.level-map{grid-template-columns:1fr}.level-card{padding:13px 16px}.level-card p{margin:2px 0 6px}.level-card .row{margin-top:5px}.shell{padding:22px 16px 45px}.panel,.card{padding:18px}.tabs{gap:5px;margin:18px 0}.tabs button{padding:8px 11px;font-size:.88rem}.g3,.g4,.glossary-grid,.diagram-cards{grid-template-columns:1fr}.lesson-list{grid-template-columns:1fr}.mobile-index{display:block}.sidebar .lesson-list{display:none}.sidebar.expanded .lesson-list{display:grid}.sidebar>h2{display:none}.demo{padding:16px}.counter-tiles{grid-template-columns:1fr}.lesson-link{padding:8px}.hero p{font-size:1rem}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{transition:none!important;animation:none!important}html{scroll-behavior:auto}}
@media print{body{background:white;color:#111}.shell{padding:0;max-width:none}.tabs,.sidebar,.lesson-footer,footer,.term-list,.checkpoints,.demo button,.demo select,.demo input,.hero{display:none!important}.layout{display:block}.panel,.card,.demo{background:white;border-color:#bbb;color:#111}.muted,.caption{color:#444!important}.term{color:#111}.point,.takeaway{color:#111!important;background:white!important}.reader h3{break-after:avoid}.demo,.takeaway{break-inside:avoid}svg text{fill:#111}}
.concept-map{margin:28px 0;padding:20px;border:1px solid var(--line);border-radius:14px;background:#102434}.concept-map figcaption{font-weight:750;font-size:1.05rem;margin-bottom:12px}.concept-row{display:flex;align-items:stretch;gap:8px;margin:10px 0}.concept-step{flex:1;min-width:0;display:flex;align-items:center;justify-content:center;text-align:center;padding:12px 10px;border:1px solid #4c7892;border-radius:10px;background:#1c384a;font-weight:650;line-height:1.3;font-size:.93rem}.concept-row:nth-of-type(2) .concept-step{border-color:#567d68;background:#19332e}.concept-arrow{align-self:center;color:var(--amber);font-size:1.3rem;line-height:1}.concept-map .caption{margin:.7em 0 0;font-size:.85rem;color:var(--muted)}.layer{border-top:1px solid var(--line);padding-top:12px;margin-top:14px}.layer h3{margin:0 0 5px;color:var(--green);font-size:.85rem;text-transform:uppercase;letter-spacing:.06em}.layer p{margin:0}.glossary-grid details{margin:0;background:var(--card);align-self:start}.glossary-grid summary{color:var(--blue);font-size:1rem}.glossary-grid .layer p{font-size:.92rem}dialog{max-height:min(82vh,850px);overflow:auto}
@media(max-width:560px){.concept-row{flex-direction:column}.concept-step{min-height:46px}.concept-arrow{transform:rotate(90deg)}.concept-map{padding:14px}}

.atlas-label{display:block;margin:1em 0}.atlas-select{display:block;width:100%;margin-top:.3em;background:var(--card);border:1px solid var(--line);color:var(--text);border-radius:9px;padding:.65em}.atlas-card{border:1px solid var(--line);border-radius:14px;padding:1.1em;background:var(--card)}.atlas-card h4{font-size:1.25em;margin:.7em 0 .3em}.atlas-facts{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:.5em}.atlas-facts div{border:1px solid var(--line);border-radius:8px;padding:.55em;display:flex;flex-direction:column}.atlas-facts span{color:var(--green);overflow-wrap:anywhere}.atlas-card details{border-top:1px solid var(--line);padding:.5em 0}.atlas-card summary,.atlas-physical summary{cursor:pointer;font-weight:700}.atlas-detail{border-top:1px solid var(--line)}.atlas-detail p{margin:.75em 0;border-bottom:1px solid var(--line);padding-bottom:.65em}.atlas-physical{margin:1em 0;padding:.8em;border:1px solid var(--line);border-radius:10px}.atlas-table-wrap{overflow-x:auto}.atlas-table-wrap table{border-collapse:collapse;min-width:650px;width:100%;font-size:.87em}.atlas-table-wrap th,.atlas-table-wrap td{padding:.55em;text-align:left;border-bottom:1px solid var(--line)}@media(max-width:540px){.atlas-facts{grid-template-columns:1fr 1fr}.atlas-card{padding:.8em}}
.review-meter{display:flex;justify-content:space-between;gap:1em;font-size:.8em;color:var(--muted)}.review-note{min-height:3em;padding:.8em;border:1px solid var(--line);border-radius:9px;background:var(--card)}#runningRange{display:block;width:100%;margin:.6em 0 1em}


#theory-site-nav{position:relative;z-index:20;display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:12px 24px;padding:13px clamp(16px,4vw,42px);background:#071219;color:#eaf4ef;border-bottom:1px solid #44636a;font:600 13px/1.4 system-ui,-apple-system,Segoe UI,sans-serif}
#theory-site-nav a{color:#eaf4ef;text-decoration:none}#theory-site-nav a:hover{text-decoration:underline;text-underline-offset:4px;color:#e5b986}#theory-site-nav a:focus-visible{outline:3px solid #e5b986;outline-offset:4px}
#theory-site-nav .theory-site-brand{font-weight:800;letter-spacing:.06em;white-space:nowrap}#theory-site-nav .theory-site-brand span{color:#a8e3df;font-weight:500;letter-spacing:.16em;font-size:.81em;margin-left:5px}
#theory-site-nav .theory-site-links{display:flex;gap:10px 24px;align-items:center;flex-wrap:wrap}#theory-site-nav .theory-site-label{color:#a6bbb9;font:600 10px/1.3 ui-monospace,SFMono-Regular,monospace;letter-spacing:.1em;text-transform:uppercase}
#theory-site-nav .theory-site-parent{color:#e5b986;white-space:nowrap}#theory-site-nav .theory-site-parent:hover{color:#f6d9b4}
@media(max-width:600px){#theory-site-nav{align-items:flex-start}#theory-site-nav .theory-site-label{width:100%}#theory-site-nav .theory-site-links{gap:8px 16px}}
@media print{#theory-site-nav{display:none}}

#theory-site-nav a[aria-current="page"]{color:#e5b986;text-decoration:underline;text-underline-offset:5px}
#theory-site-nav .theory-site-links>a{min-height:44px;display:inline-flex;align-items:center}
.theory-course-path{max-width:1200px;margin:0 auto 32px;padding:18px clamp(16px,4vw,24px);border-top:1px solid #34475d;font:600 13px/1.5 system-ui,-apple-system,Segoe UI,sans-serif}
.theory-course-path p{color:#afbfce;margin:0 0 12px}.theory-course-steps{display:flex;flex-wrap:wrap;align-items:center;gap:12px}
.theory-course-steps a{display:inline-flex;align-items:center;min-height:44px;border:1px solid #34475d;border-radius:8px;padding:8px 12px;color:#a8e3df;text-decoration:none}
.theory-course-steps a[aria-current="page"]{border-color:#e5b986;color:#e5b986}.theory-course-steps a:hover{border-color:#e5b986;color:#e5b986}
.theory-course-steps a:focus-visible{outline:3px solid #e5b986;outline-offset:4px}.theory-course-steps span{color:#afbfce}
@media(max-width:600px){.theory-course-steps{gap:7px}.theory-course-steps a{font-size:12px;padding:8px 10px}}
@media print{.theory-course-path{display:none}}



/* Shared source attribution for the free science education collection. */
.education-logo{min-width:0;max-width:100%;text-decoration:none}
.education-logo-copy{display:flex;flex-direction:column;gap:5px;min-width:0}
.education-logo-title{display:block;font-weight:800;line-height:1.2;white-space:nowrap}
.education-logo-category{font-weight:500;font-size:.76em;letter-spacing:.15em;margin-left:6px;color:#afc1c0}
.education-logo-name{display:block;max-width:280px;margin:0;font:500 12px/1.45 system-ui,-apple-system,Segoe UI,sans-serif;letter-spacing:0;color:#c5d3d1;white-space:normal;overflow-wrap:normal}
.reading-nav .education-logo,#theory-site-nav .education-logo{display:inline-flex;flex-direction:column;align-items:flex-start;justify-content:center;gap:5px;white-space:normal;flex-shrink:0;letter-spacing:0}
#theory-site-nav .education-logo-title{font-size:16px;letter-spacing:.04em}
#theory-site-nav .education-logo-name{font-size:12px;color:#c5d3d1}
.reading-nav .education-logo-name{font-size:12px;color:var(--muted,#afc1c0)}
.education-provider{max-width:760px;margin:24px 0;padding:18px 20px;border:1px solid #658b925e;border-left:3px solid #a8e3df;border-radius:6px;background:#10232b;color:#edf4ef;text-align:left}
.education-provider-kicker{display:block;margin-bottom:7px;font:700 11px/1.4 system-ui,-apple-system,Segoe UI,sans-serif;letter-spacing:.1em;text-transform:uppercase;color:#a8e3df}
.education-provider .education-provider-brand,.hero .education-provider .education-provider-brand{display:flex;flex-wrap:wrap;align-items:baseline;gap:5px 10px;margin:0 0 7px;max-width:none;font:650 15px/1.5 system-ui,-apple-system,Segoe UI,sans-serif;color:#edf4ef}
.education-provider-brand strong{font-weight:750}
.education-provider .education-provider-description,.hero .education-provider .education-provider-description{margin:0;max-width:68ch;font:400 14px/1.65 system-ui,-apple-system,Segoe UI,sans-serif;color:#c5d3d1}
.education-course-credit{margin:16px 0 0;font:400 14px/1.65 system-ui,-apple-system,Segoe UI,sans-serif;color:var(--muted,#afc1c0)}
.education-course-credit strong{font-weight:650;color:var(--ink,#edf4ef)}
.education-footer-credit{display:block;margin:0 0 10px;font:400 13px/1.65 system-ui,-apple-system,Segoe UI,sans-serif;color:inherit}
.education-footer-credit strong{font-weight:650}
.footer-brand .education-logo-name{margin-top:6px}
@media(max-width:1050px){.site-header{flex-wrap:wrap;padding-top:20px;padding-bottom:20px}.site-header .main-nav{margin-left:auto}}
@media(max-width:640px){.education-logo-name{max-width:260px;font-size:12px}.site-header .main-nav{margin-left:0}.education-provider{padding:15px 16px;margin:20px 0}.education-provider .education-provider-brand,.hero .education-provider .education-provider-brand{display:block;font-size:15px}.education-provider-brand strong{display:block}.education-provider-brand .education-brand-divider{display:none}.reading-nav .education-logo{flex-basis:100%;align-items:flex-start}.education-course-credit{font-size:13px}}
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