/* PhysicsUK's knowledge graph. Shared question and moderation styles stay light. */
.pc-map{max-width:1800px;padding:22px 24px 0;--pc-graph-bg:#101c1a;--pc-graph-panel:#162420;--pc-graph-border:#2a3b35;--pc-graph-text:#e0ede6;--pc-graph-muted:#a0b5aa;--pc-mint:#72dfb5}
.pc-map .pc-heading{padding:0 2px 22px;gap:22px}
.pc-map .pc-brand{display:flex;gap:14px;align-items:center}
.pc-map .pc-brand-mark{display:grid;place-items:center;width:49px;height:49px;border:1px solid #d5e4dc;background:#eaf5ef;border-radius:13px;color:#087d62;font-size:35px;line-height:1}
.pc-map .pc-brand .pc-eyebrow{font-size:10px;letter-spacing:.2em;margin:0 0 1px}
.pc-map .pc-heading h1{font-size:29px;letter-spacing:-.05em;margin:0;font-weight:760}
.pc-map .pc-heading h1 span{color:#087d62}
.pc-map .pc-heading>p{margin:14px auto 0 0;font-size:13px}
.pc-map .pc-course{padding:7px 14px;font-size:12px;border-radius:8px;background:white}
.pc-map .pc-workspace-bar{display:flex;align-items:center;gap:16px;border:1px solid var(--pc-graph-border);border-bottom:0;border-radius:14px 14px 0 0;padding:0 18px;min-height:51px;background:var(--pc-graph-panel);color:var(--pc-graph-muted)}
.pc-map .pc-workspace-bar a{color:var(--pc-graph-muted)}
.pc-map .pc-breadcrumb{flex:1;min-width:0;gap:9px;padding:12px 0;font-size:12px;line-height:1.5}
.pc-map .pc-breadcrumb [aria-current]{color:var(--pc-graph-text)}
.pc-map .pc-workspace-bar .pc-back{margin:0;font-size:11px;white-space:nowrap}
.pc-map .pc-explorer-toggle{display:none;background:none;color:var(--pc-graph-text);border:0;font:600 12px system-ui;min-height:44px;padding:0 8px}
.pc-map .pc-workspace{grid-template-columns:218px minmax(0,1fr) 360px;height:clamp(650px,calc(100dvh - 190px),1000px);align-items:stretch;border-color:var(--pc-graph-border);border-radius:0 0 14px 14px;position:relative}
.pc-map .pc-explorer{background:var(--pc-graph-panel);border-right:1px solid var(--pc-graph-border);padding:22px 14px 16px;overflow:auto;min-width:0;color:var(--pc-graph-text);scrollbar-color:#42594e transparent;scrollbar-width:thin}
.pc-map .pc-explorer-heading{display:flex;justify-content:space-between;color:var(--pc-graph-muted);font-size:9px;letter-spacing:.16em;margin:0 2px 20px}
.pc-map .pc-explorer-heading span:last-child{letter-spacing:0;font-size:10px}
.pc-map .pc-search-label{font-size:11px;color:var(--pc-graph-muted);display:block;margin:0 0 6px}
.pc-map .pc-search-wrap{display:flex;align-items:center;gap:6px;background:#101c19;border:1px solid #385045;border-radius:7px;padding:0 9px}
.pc-map .pc-search-wrap>span{font-size:21px;color:var(--pc-graph-muted)}
.pc-map input#pc-search{width:100%;min-width:0;background:transparent;border:0;padding:9px 0;color:#e0ede6;font-size:12px;min-height:44px}
.pc-map input#pc-search::placeholder{color:#9aafa4}
.pc-map .pc-search-status{font-size:11px;margin:6px 0;color:var(--pc-mint);min-height:6px}
.pc-map .pc-tree-root{display:flex;align-items:center;gap:7px;color:var(--pc-graph-text);font-size:12px;font-weight:650;min-height:44px;margin:3px 0 8px;text-decoration:none}
.pc-map .pc-tree-root>span{color:var(--pc-mint);font-size:19px}
.pc-map .pc-tree-group{border:0;margin:0;padding:0}
.pc-map .pc-tree-group summary{min-height:44px;position:relative;padding:11px 3px;font-size:12px;color:#c6d7cc;line-height:1.5;list-style:none}
.pc-map .pc-tree-group summary::-webkit-details-marker{display:none}
.pc-map .pc-tree-group summary::before{content:'›';display:inline-block;width:12px;color:#99b0a2;transform-origin:3px center}
.pc-map .pc-tree-group[open] summary::before{transform:rotate(90deg)}
.pc-map .pc-family-dot,.pc-map .pc-family-legend i{display:inline-block;width:6px;height:6px;background:var(--pc-node-color);border-radius:50%;margin-right:7px;vertical-align:middle}
.pc-map .pc-tree-group a{display:block;margin-left:15px;padding:10px 8px 10px 15px;min-height:44px;border-left:1px solid #354a40;color:#acbeb3;text-decoration:none;font-size:11px;line-height:1.65}
.pc-map .pc-tree-group a small{font-size:10px;margin-left:8px;color:#9daf9f}
.pc-map .pc-tree-group a:hover,.pc-map .pc-tree-group summary:hover{color:white;background:#1f3329;border-radius:5px}
.pc-map .pc-tree-group a[aria-current=page]{background:#234737;color:#9af0c9;border-left-color:#65d5a6;border-radius:0 5px 5px 0}
.pc-map .pc-family-legend{display:grid;gap:8px;margin-top:24px;border-top:1px solid var(--pc-graph-border);padding-top:18px;color:#a8bbae;font-size:10px}
.pc-map .pc-mechanics{--pc-node-color:#e1b675}
.pc-map .pc-electricity{--pc-node-color:#7dbae6}
.pc-map .pc-waves{--pc-node-color:#ba9ee8}
.pc-map .pc-skills{--pc-node-color:#82c8aa}
.pc-map .pc-mechanics,.pc-map .pc-electricity,.pc-map .pc-waves,.pc-map .pc-skills{background:transparent}
.pc-map .pc-canvas{display:flex;flex-direction:column;position:relative;min-height:0;padding:0;background:var(--pc-graph-bg);color:var(--pc-graph-text);overflow:hidden}
.pc-map .pc-toolbar{align-items:center;gap:10px;flex-wrap:wrap;z-index:2;padding:14px 18px 0;color:var(--pc-graph-muted)}
.pc-map .pc-view-switch{display:flex;gap:3px;border:1px solid var(--pc-graph-border);padding:3px;border-radius:8px;background:#14221d}
.pc-map .pc-view-switch button{min-height:37px;font:550 11px system-ui;border:0;padding:7px 12px;border-radius:5px;color:#a6bbae;background:transparent}
.pc-map .pc-view-switch button[aria-pressed=true]{background:#294b3b;color:#b9f4d8}
.pc-map .pc-view-switch button:disabled{opacity:.45;cursor:default}
.pc-map .pc-graph-count{font-size:10px}
.pc-map .pc-graph-viewport{flex:1;min-height:330px;position:relative;overflow:hidden;touch-action:none;cursor:grab;isolation:isolate;background-image:radial-gradient(#58716032 .7px,transparent .7px);background-size:22px 22px}
.pc-map .pc-graph-viewport:focus-visible{outline:2px solid var(--pc-mint);outline-offset:-5px}
.pc-map .pc-graph-viewport.pc-dragging,.pc-map .pc-dragging .pc-node{cursor:grabbing}
.pc-map .pc-graph{position:absolute;inset:0 auto auto 0;display:block;width:1800px;height:1740px;min-height:0;padding:0;transform-origin:0 0;will-change:transform;user-select:none}
.pc-map .pc-edges{position:absolute;inset:0;width:1800px;height:1740px;overflow:visible;pointer-events:none}
.pc-map .pc-edges line{vector-effect:non-scaling-stroke;stroke-width:1;fill:none}
.pc-map .pc-edges .pc-edge-topic{stroke:#607e6b;stroke-dasharray:3 5;opacity:.55}
.pc-map .pc-edges .pc-edge-line{stroke:#69c9a1;stroke-width:1.7;opacity:.65}
.pc-map .pc-edges .pc-edge-hit{stroke:transparent;stroke-width:20;pointer-events:stroke;cursor:pointer}
.pc-map .pc-edge:hover .pc-edge-line,.pc-map .pc-edge:focus .pc-edge-line,.pc-map .pc-edge-selected .pc-edge-line{stroke:#b3ffdb;stroke-width:3;opacity:1}
.pc-map .pc-edge:focus-visible{outline:none}
.pc-map .pc-edges .pc-edge-highlight{opacity:1}
.pc-map .pc-edges .pc-edge-muted{opacity:.18}
.pc-map .pc-edges .pc-edge-selected{opacity:1}
.pc-map .pc-node{position:absolute;display:flex;align-items:center;justify-content:center;z-index:2;min-height:44px;width:44px;height:44px;padding:0;border:0;border-radius:50%;background:transparent;box-shadow:none;text-decoration:none;transform:translate(-50%,-50%) scale(var(--pc-inverse-scale,1));transform-origin:center;transition:opacity .15s;color:#c7d9cd;font-size:12px}
.pc-map .pc-node:hover{box-shadow:none;background:transparent}
.pc-map .pc-node-dot{display:block;width:8px;height:8px;border-radius:50%;background:var(--pc-node-color);box-shadow:0 0 0 4px #12221b}
.pc-map .pc-node-major .pc-node-dot{width:13px;height:13px;box-shadow:0 0 0 5px #21352a,0 0 18px #86c49d1c}
.pc-map .pc-node-label{position:absolute;top:38px;left:50%;transform:translateX(-50%);width:130px;text-align:center;font:500 11px/1.4 system-ui;color:#c7d9cd;text-shadow:0 1px 5px #101c1a,0 -1px 5px #101c1a;pointer-events:none}
.pc-map .pc-node small{display:none;font:10px/1.5 system-ui;color:#93b09d;margin-top:4px}
.pc-map .pc-node:not(.pc-node-major) .pc-node-label{opacity:0}
.pc-map .pc-show-labels .pc-node .pc-node-label,.pc-map .pc-node:hover .pc-node-label,.pc-map .pc-node:focus .pc-node-label,.pc-map .pc-node-found .pc-node-label,.pc-map .pc-selected .pc-node-label{opacity:1}
.pc-map .pc-graph[data-mode=local] .pc-node-label{font-size:12px;width:145px}
.pc-map .pc-graph[data-mode=local] .pc-node small{display:block}
.pc-map .pc-node-muted{opacity:.3}
.pc-map .pc-node-highlight{opacity:1}
.pc-map .pc-node:hover,.pc-map .pc-node:focus{z-index:4;opacity:1}
.pc-map .pc-node:hover .pc-node-label,.pc-map .pc-node:focus .pc-node-label{background:#182d23;border:1px solid #45634f;border-radius:6px;padding:7px;top:39px;color:white;text-shadow:none}
.pc-map .pc-selected{background:transparent!important}
.pc-map .pc-selected .pc-node-dot,.pc-map .pc-node-found .pc-node-dot{width:17px;height:17px;background:#8be7b7;box-shadow:0 0 0 6px #315a43,0 0 0 10px #203a2b}
.pc-map .pc-selected .pc-node-label{color:#a6f3ca;font-weight:700}
.pc-map .pc-node:focus-visible{outline:2px solid #cbf6df;outline-offset:3px}
.pc-map .pc-graph-watermark{position:absolute;bottom:22px;left:23px;pointer-events:none;font-size:11px;font-weight:750;letter-spacing:.13em;color:#728c7c;opacity:.75}
.pc-map .pc-graph-watermark>span{color:#91d3af}
.pc-map .pc-graph-watermark small{display:block;font-size:8px;font-weight:450;letter-spacing:.28em;margin-top:3px}
.pc-map .pc-graph-controls{position:absolute;bottom:16px;right:18px;display:flex;align-items:center;gap:1px;background:#1c3026;border:1px solid #3b5444;border-radius:9px;padding:3px;cursor:default}
.pc-map .pc-graph-controls button{min-width:40px;min-height:40px;background:transparent;border:0;color:#d4e9dc;font:500 19px system-ui;border-radius:5px;cursor:pointer}
.pc-map .pc-graph-controls button[data-graph-action=fit]{font-size:11px;border-left:1px solid #3b5444;border-radius:0;margin-left:5px}
.pc-map .pc-graph-controls button:hover{background:#304d3a}
.pc-map .pc-graph-controls output{margin:0;min-width:40px;text-align:center;font:11px system-ui;color:#afcbbb}
.pc-map .pc-graph-footer{padding:6px 20px 16px;color:#a1b8aa;font-size:11px}
.pc-map .pc-graph-footer p{font-size:11px;margin:4px 0}
.pc-map .pc-graph-footer .pc-gesture-help{color:#8aa192;font-size:10px}
.pc-map .pc-line-legend{display:flex;gap:18px;flex-wrap:wrap;font-size:10px;margin-top:12px;color:#a8c3b2}
.pc-map .pc-line-legend i{display:inline-block;width:19px;border-top:2px solid #69c9a1;vertical-align:middle;margin-right:6px}
.pc-map .pc-line-legend span:last-child i{border-top:1px dashed #7f9989}
.pc-map .pc-link-list{display:block;margin:0;padding:0 18px 10px;border-top:1px solid var(--pc-graph-border);max-height:190px;overflow:auto;scrollbar-width:thin}
.pc-map .pc-link-list summary{color:#bcd4c5;padding:12px 2px;font-size:11px;min-height:44px}
.pc-map .pc-link-list summary>span{margin-left:6px;color:#88a693}
.pc-map .pc-link-list nav{display:grid;grid-template-columns:1fr 1fr;gap:4px 10px}
.pc-map .pc-link-list a{background:none;border:0;border-radius:4px;padding:9px 6px;color:#abc7b7;font-size:11px;min-height:44px;margin:0}
.pc-map .pc-link-list a span{color:var(--pc-mint);margin-right:5px}
.pc-map .pc-link-list a:hover,.pc-map .pc-link-list .pc-active-link{background:#233e2f;color:#d7f6e5;box-shadow:none}
.pc-map .pc-detail{padding:27px 25px;border-left:1px solid #d1dfd6;overflow:auto;min-height:0;scrollbar-color:#b9cec0 transparent;scrollbar-width:thin;background:#fcfefa}
.pc-map .pc-detail h2{font-size:26px;font-weight:650;letter-spacing:-.04em;margin:12px 0 16px}
.pc-map .pc-detail>.pc-eyebrow{font-size:9px;letter-spacing:.14em}
.pc-map .pc-detail p,.pc-map .pc-detail li{font-size:13px}
.pc-map .pc-detail .pc-lead{line-height:1.8;font-size:14px}
.pc-map .pc-detail section{padding-top:22px;margin-top:22px}
.pc-map .pc-detail h3{font-size:15px;font-weight:650}
.pc-map .pc-equation{background:#eaf4eb;font-size:18px}
.pc-map .pc-button{font-size:12px;background:#087d62;border-radius:6px}
.pc-map .pc-footnote{border:0;padding:14px 2px;font-size:10px}
.pc-map .pc-return-graph{display:none}
.pc-map:not(.pc-enhanced) .pc-explorer-toggle{display:none}
.pc-map [hidden]{display:none!important}
.pc-map .pc-canvas button:focus-visible,.pc-map .pc-explorer a:focus-visible,.pc-map .pc-explorer summary:focus-visible,.pc-map .pc-explorer input:focus-visible,.pc-map .pc-link-list a:focus-visible,.pc-map .pc-link-list summary:focus-visible{outline:2px solid #b4f1d1;outline-offset:2px}
.pc-map:not(.pc-enhanced) .pc-workspace{height:auto}
.pc-map:not(.pc-enhanced) .pc-view-switch,.pc-map:not(.pc-enhanced) .pc-graph-controls,.pc-map:not(.pc-enhanced) .pc-gesture-help,.pc-map:not(.pc-enhanced) .pc-graph-watermark{display:none}
.pc-map:not(.pc-enhanced) .pc-graph-viewport{overflow:visible;touch-action:auto;min-height:0}
.pc-map:not(.pc-enhanced) .pc-graph{position:static;width:auto;height:auto;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));padding:20px;gap:22px}
.pc-map:not(.pc-enhanced) .pc-edges{display:none}
.pc-map:not(.pc-enhanced) .pc-node{position:static;transform:none;width:100%;height:auto;min-height:80px;flex-direction:column;gap:10px;border-radius:8px}
.pc-map:not(.pc-enhanced) .pc-node .pc-node-label{position:static;transform:none;opacity:1;max-width:100%}
@media(min-width:1600px){.pc-map .pc-workspace{grid-template-columns:235px minmax(0,1fr) 390px}.pc-map .pc-detail{padding:32px}}
@media(max-width:1200px){.pc-map .pc-workspace{grid-template-columns:minmax(0,1fr) 340px}.pc-map.pc-enhanced .pc-explorer{display:none}.pc-map .pc-explorer-toggle{display:block}.pc-map.pc-explorer-open .pc-explorer{display:block;position:absolute;inset:0 auto 0 0;width:260px;z-index:8;box-shadow:15px 0 40px #0005}.pc-map:not(.pc-enhanced) .pc-workspace{grid-template-columns:200px minmax(0,1fr)}.pc-map:not(.pc-enhanced) .pc-detail{grid-column:1/-1}}
@media(max-width:900px){.pc-map{padding:16px 14px 0}.pc-map .pc-heading>p{display:none}.pc-map .pc-heading{justify-content:space-between;padding-bottom:18px}.pc-map .pc-workspace{grid-template-columns:1fr;height:auto}.pc-map .pc-canvas{height:620px}.pc-map .pc-detail{border-left:0;border-top:1px solid var(--pc-line);padding:28px;overflow:visible}.pc-map .pc-workspace-bar{gap:10px;padding:0 10px}.pc-map .pc-workspace-bar .pc-back{display:none}.pc-map.pc-explorer-open .pc-explorer{bottom:auto;height:620px}.pc-map .pc-detail [tabindex]{scroll-margin-top:20px}}
@media(max-width:560px){.pc-map{padding:12px 8px 0}.pc-map .pc-heading{display:flex;gap:10px;padding:0 4px 16px}.pc-map .pc-brand{gap:8px}.pc-map .pc-brand-mark{width:34px;height:38px;font-size:26px;border-radius:8px}.pc-map .pc-heading h1{font-size:22px}.pc-map .pc-brand .pc-eyebrow{font-size:8px}.pc-map .pc-course{margin:0;padding:7px 9px;font-size:10px;flex-shrink:1}.pc-map .pc-course span{font-size:9px}.pc-map .pc-breadcrumb{font-size:10px;gap:5px}.pc-map .pc-toolbar{padding:12px 12px 0}.pc-map .pc-view-switch button{padding:6px 10px;min-height:38px}.pc-map .pc-graph-count{font-size:9px}.pc-map .pc-canvas{height:540px}.pc-map .pc-graph-viewport{min-height:280px}.pc-map .pc-graph-footer{padding:3px 14px 12px}.pc-map .pc-graph-footer p{font-size:10px}.pc-map .pc-graph-controls{bottom:12px;right:12px}.pc-map .pc-graph-controls button{min-width:38px;min-height:40px}.pc-map .pc-graph-watermark{bottom:20px;left:15px;font-size:9px}.pc-map .pc-graph-watermark small{font-size:7px}.pc-map .pc-node-label{width:100px;font-size:10px}.pc-map .pc-graph[data-mode=local] .pc-node-label{width:108px;font-size:11px}.pc-map .pc-link-list{max-height:135px}.pc-map .pc-link-list nav{grid-template-columns:1fr}.pc-map .pc-detail{padding:26px 22px}.pc-map.pc-explorer-open .pc-explorer{height:540px}.pc-map:not(.pc-enhanced) .pc-workspace{display:block}.pc-map:not(.pc-enhanced) .pc-canvas{height:auto}.pc-map .pc-explorer-toggle{font-size:11px}}
@media(prefers-reduced-motion:reduce){.pc-map .pc-node{transition:none}.pc-map .pc-detail{animation:none}}
@media(max-width:900px){.pc-map .pc-return-graph{display:flex;align-items:center;min-height:44px;font-size:12px;margin:-10px 0 16px}.pc-map #pc-graph-viewport{scroll-margin-top:16px}}
.pc-hub{max-width:1440px}.pc-hub-hero{display:grid;grid-template-columns:1fr 1.2fr;gap:48px;align-items:center;margin:10px 0 44px}.pc-hub .pc-hub-hero h1{font-size:clamp(38px,4.4vw,64px)}.pc-hub-hero .pc-lead{font-size:17px;max-width:500px;margin:22px 0}.pc-hub-graph{display:block;min-width:0;text-decoration:none}.pc-hub-graph img{display:block;width:100%;height:auto;border-radius:20px}.pc-hub-graph span{display:block;font-size:12px;text-align:right;color:#537167;margin-top:14px}.pc-hub .pc-course-card{max-width:none;background:#f1f7f2;padding:26px 30px}.pc-hub .pc-features{gap:50px}.pc-hub .pc-features span{font:600 12px system-ui;letter-spacing:.1em}.pc-hub .pc-features section{border-top:1px solid #d9e8e2;padding-top:22px}@media(max-width:800px){.pc-hub-hero{grid-template-columns:1fr;gap:28px}.pc-hub-graph{max-width:650px}.pc-hub .pc-features{gap:24px}.pc-hub .pc-hub-hero h1{font-size:44px}}