/* Product tokens: technical study workspace, calm reading, strong action contrast. */
:root{color-scheme:light;--bg:#f3f6f8;--panel:#fff;--text:#172d43;--muted:#526477;--border:#d8e1e7;--blue:#006c66;--soft:#e8f4f1;--yellow:#f0c75e;--side:#102c44;--focus:#087e99;--success:#166644;--danger:#a62f36;--radius:16px;--shadow:0 8px 32px #16365006;--speed:160ms;--sans:'DM Sans',system-ui,sans-serif;--head:'Manrope',system-ui,sans-serif}
*{box-sizing:border-box}html{scroll-padding-top:100px}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.65 var(--sans);overflow-wrap:break-word}body.dark{color-scheme:dark;--bg:#0d1c2b;--panel:#152a3d;--text:#edf3f9;--muted:#b1c0ce;--border:#395064;--blue:#8ce0cb;--soft:#213d45;--focus:#8eddef;--success:#9be7bb;--danger:#ffb0b4;--shadow:none}a{color:inherit;text-decoration:none}button,input,select{font:inherit}button,a{touch-action:manipulation}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.5}a,button,input,select{transition:background-color var(--speed),border-color var(--speed),color var(--speed),box-shadow var(--speed)}:focus-visible{outline:3px solid var(--focus);outline-offset:4px}button:active:not(:disabled),.button:active{filter:brightness(.92)}a:hover{color:var(--blue)}input,select{min-height:48px;max-width:100%;border:1px solid var(--border);border-radius:10px;background:var(--panel);color:var(--text);padding:11px 14px}input::placeholder{color:var(--muted);opacity:1}input[type=checkbox]{min-height:22px;min-width:22px;accent-color:var(--blue);vertical-align:middle;margin-right:8px}h1,h2,h3{font-family:var(--head);line-height:1.3;text-wrap:balance;margin:0;font-weight:800}h1{font-size:clamp(28px,3.2vw,38px);letter-spacing:-1.2px}h2{font-size:22px;letter-spacing:-.5px}h3{font-size:19px;margin:24px 0 10px}p{margin:12px 0;color:var(--muted)}.small{font-size:13px;color:var(--muted);line-height:1.6}.eyebrow{font-size:11px;letter-spacing:1.6px;font-weight:700;color:var(--blue);text-transform:uppercase}.ui-icon{width:21px;height:21px;display:inline-block;flex:none;vertical-align:middle;stroke:currentColor;fill:none;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}.skip-link{position:fixed;top:12px;left:12px;z-index:100;transform:translateY(-180%);background:var(--panel);border:2px solid var(--focus);border-radius:10px;padding:12px 18px}.skip-link:focus{transform:none}
/* Navigation */
aside{width:248px;background:var(--side);color:#bfcfdf;position:fixed;inset:0 auto 0 0;padding:32px 20px;display:flex;flex-direction:column;z-index:25}.brand,.login-brand{display:flex;align-items:center;gap:12px;font:800 21px/1.25 var(--head);color:white;letter-spacing:-.6px}.brand small,.login-brand small{display:block;font:700 9px/1.5 var(--sans);letter-spacing:2px;color:#a2b7ca;margin-top:6px}.brand-icon{display:grid;place-items:center;background:var(--yellow);color:var(--side);width:42px;height:46px;border-radius:12px;flex:none}.brand-icon .ui-icon{width:27px;height:27px}.nav-label{font-size:10px;letter-spacing:1.6px;margin:48px 14px 14px;color:#9cb3c8}nav{display:grid;gap:8px}nav a{position:relative;display:flex;align-items:center;gap:12px;padding:14px;border-radius:10px;min-height:50px;font-size:14px;font-weight:500}nav a span{font-size:14px}nav a b{margin-left:auto;border:1px solid #59718a;border-radius:6px;padding:0 6px;font-size:11px}nav a.active{background:#28465d;color:#fff}nav a.active:before{content:'';position:absolute;left:-20px;width:3px;height:25px;background:var(--yellow);border-radius:2px}nav a:hover{background:#213e55;color:white}.sidebar-note{margin-top:auto;padding:32px 14px 20px}.sidebar-note>span{font-size:10px;letter-spacing:1px;color:#9eb5c9}.sidebar-note p{font-size:13px;color:#c3d1de}.line-circuit{font:22px/1 monospace;color:#58768f;margin-top:24px}.source-link{display:flex;align-items:center;gap:10px;padding:14px;min-height:48px;border-top:1px solid #375269;color:#c3d1de;font-size:13px}.source-link:hover{color:#fff}.source-link[aria-current=page]{color:var(--yellow)}.shell{margin-left:248px}.shell>header{height:84px;background:var(--panel);border-bottom:1px solid var(--border);display:flex;justify-content:space-between;align-items:center;gap:20px;padding:0 40px;position:sticky;top:0;z-index:20}.breadcrumb{font-size:13px;color:var(--muted);white-space:nowrap}.breadcrumb span{margin:0 12px}.breadcrumb b{font-weight:600;color:var(--text)}.header-actions{display:flex;align-items:center;gap:20px}.private-badge{font-size:12px;color:var(--muted)}.icon-button{height:44px;width:44px;display:grid;place-items:center;border:1px solid var(--border);border-radius:12px;background:var(--panel);color:var(--text);flex:none}.icon-button:hover{background:var(--soft)}#profile-control{text-align:right}.profile-button,.sync-label{display:block;background:none;border:0;padding:0 4px;color:var(--text);margin-left:auto;font-size:13px}.profile-button{min-height:32px}.sync-label{font-size:11px;min-height:24px;color:var(--muted);text-decoration:underline;text-underline-offset:3px}main{max-width:1320px;margin:auto;padding:42px 40px 64px;min-height:calc(100vh - 150px)}footer{border-top:1px solid var(--border);padding:24px 40px;display:flex;gap:24px;justify-content:space-between;font-size:11px;letter-spacing:1px;color:var(--muted)}footer span{letter-spacing:0}
/* Dashboard and library */
.intro{display:flex;align-items:center;justify-content:space-between;gap:24px;margin-bottom:28px}.intro h1{margin:8px 0 10px}.intro p{font-size:15px;margin:0}.date-tag{font-size:12px;color:var(--muted);white-space:nowrap}.search{display:flex;gap:14px;align-items:center;background:var(--panel);border:1px solid var(--border);border-radius:12px;padding:0 18px;margin:0 0 28px;box-shadow:var(--shadow)}.search input{width:100%;background:none;border:0;padding:18px 0;font-size:15px;border-radius:0;outline:none;min-width:0}.search:focus-within{outline:3px solid var(--focus);outline-offset:3px}.search span{color:var(--blue)}.search kbd{font:12px var(--sans);border:1px solid var(--border);padding:0 6px;border-radius:4px;color:var(--muted)}.stats{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px;margin-bottom:32px}.stat{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius);padding:22px;min-width:0}.stat>span:not(.stat-icon){font-size:13px;font-weight:500;color:var(--muted)}.stat strong{display:block;font:800 32px/1.2 var(--head);letter-spacing:-1px;margin:17px 0 9px}.stat strong span{font:500 14px var(--sans);letter-spacing:0;color:var(--muted)}.stat small{font-size:12px;line-height:1.5;color:var(--muted);display:block}.stat-icon{display:grid;place-items:center;float:right;background:var(--soft);color:var(--blue);width:32px;height:32px;border-radius:9px;margin-left:8px}.stat-icon .ui-icon{width:18px;height:18px}.section-head{display:flex;justify-content:space-between;align-items:center;gap:20px;margin:30px 0 18px}.section-head a{font-size:13px;font-weight:600;color:var(--blue);min-height:44px;display:flex;align-items:center}.feature{display:grid;grid-template-columns:1.15fr 1fr;background:var(--side);border-radius:20px;overflow:hidden;color:white;min-height:320px}.feature-copy{padding:34px 36px;position:relative;z-index:1}.feature .eyebrow{color:#f4d783;font-size:11px}.feature h2{font-size:clamp(26px,2.5vw,34px);letter-spacing:-1px;margin:18px 0 14px}.feature p{font-size:15px;color:#c6d5e3;line-height:1.75}.feature-meta{font-size:12px;color:#c6d5e3;margin:20px 0 24px}.atom-art{background:var(--side);min-width:0;position:relative;display:grid;place-items:center}.atom-art .study-image{height:100%;width:100%;object-fit:cover;min-height:320px;border-radius:0}.button{display:inline-flex;align-items:center;justify-content:center;gap:12px;min-height:48px;border-radius:10px;padding:12px 20px;font-size:14px;line-height:1.4;font-weight:700;color:#fff;background:#006c66;border:1px solid transparent;cursor:pointer;text-align:center}.button:hover{background:#005650;color:white}.button.yellow{background:var(--yellow);color:#142f45}.button.yellow:hover{background:#ffda7b}.button.secondary{background:var(--panel);color:var(--text);border:1px solid var(--border)}.button.secondary:hover{border-color:var(--blue);background:var(--soft)}.dark .button:not(.secondary):not(.yellow){background:#8ce0cb;color:#102e2a}.grid-two{display:grid;grid-template-columns:1.5fr 1fr;gap:22px;margin-top:28px}.panel{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow);min-width:0}.panel h2{font-size:20px}.panel h2+.small{margin-top:10px}.topics{display:flex;flex-wrap:wrap;gap:10px;margin-top:20px}.chip{display:inline-flex;align-items:center;min-height:44px;padding:9px 14px;background:var(--bg);border:1px solid var(--border);border-radius:8px;color:var(--text);font-size:13px}.chip:hover{background:var(--soft);border-color:var(--blue)}.review-panel{background:var(--soft);display:flex;flex-direction:column;align-items:flex-start;justify-content:center}.review-panel p{font-size:15px}.text-link{display:inline-flex;align-items:center;gap:8px;min-height:44px;border:0;background:none;color:var(--blue);font-size:14px;font-weight:700;padding:8px 0}.text-link:hover{text-decoration:underline;text-underline-offset:4px}.notice{font-size:13px;line-height:1.8;color:var(--muted);border-left:3px solid #be8a1a;border-radius:0 10px 10px 0;padding:16px 20px;margin-top:28px;background:var(--panel)}.notice strong{color:var(--text)}.filter-row{display:flex;gap:16px;align-items:flex-end;flex-wrap:wrap;margin:0 0 26px}.filter-row label{font-size:13px;font-weight:600;color:var(--muted);display:grid;gap:8px;flex:1;min-width:130px}.filter-row input,.filter-row select{width:100%;min-width:0}.lesson-card{display:flex;align-items:center;gap:24px}.lesson-card .button{margin-left:auto;flex:none}.lesson-card p{font-size:14px!important}.lesson-number{background:var(--soft);color:var(--blue);border-radius:12px;text-align:center;padding:16px 20px;font-size:11px;letter-spacing:1px}.lesson-number strong{display:block;font:800 30px var(--head);letter-spacing:-1px;margin-top:3px}.badge{display:inline-flex;align-items:center;padding:5px 10px;font-size:12px;border-radius:6px;background:var(--soft);color:var(--blue);font-weight:600}.empty{text-align:center;padding:48px 28px}.empty p{max-width:520px;margin:15px auto 24px}
/* Reading */
.article-head{margin-bottom:32px}.article-head h1{margin:12px 0}.article-head>p{font-size:18px}.progress-line{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-top:28px}.reader-layout{display:grid;grid-template-columns:218px minmax(0,760px);gap:28px;justify-content:center;align-items:start}.toc{padding:22px;position:sticky;top:108px}.toc a{display:block;min-height:44px;font-size:13px;padding:12px 0;line-height:1.6;border-bottom:1px solid var(--border);color:var(--muted)}.toc a:last-child{border:0;color:var(--blue);font-weight:700}.toc a:hover{color:var(--blue)}.toc-toggle{display:none}.article section{scroll-margin-top:108px;margin-bottom:24px;padding:32px}.article h2{font-size:25px;letter-spacing:-.7px}.article p{font-size:17px;line-height:1.9;color:var(--text);margin:18px 0}.article .note{background:var(--soft);border-left:3px solid #b68a24;padding:18px 20px;border-radius:0 8px 8px 0;font-size:14px;color:var(--muted)}.article label.small{display:flex;align-items:center;gap:8px;min-height:48px;border-top:1px solid var(--border);padding-top:18px;margin-top:24px;cursor:pointer}.visual{margin:24px 0;padding:14px;background:var(--bg);border:1px solid var(--border);border-radius:12px;text-align:center}.study-image{display:block;width:100%;height:auto;border-radius:8px;aspect-ratio:3/2;object-fit:contain}.visual:has(img[src*=gtd]) .study-image{aspect-ratio:2.5/1}.visual figcaption{padding:12px 8px 6px;font-size:12px;line-height:1.7;color:var(--muted)}.particle-table{width:100%;border-collapse:collapse;font-size:14px}.particle-table th,.particle-table td{text-align:left;border-bottom:1px solid var(--border);padding:12px}.reference-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;margin:26px 0}.reference-grid figure{margin:0;min-width:0}.reference-grid img{width:100%;height:auto;aspect-ratio:3/4;object-fit:cover;object-position:top;border:1px solid var(--border);border-radius:10px}.reference-grid a:focus-visible{display:block}.reference-grid figcaption{font-size:13px;color:var(--muted);line-height:1.7;padding-top:12px}.reference-grid figcaption a{display:inline-flex;min-height:44px;align-items:center;color:var(--blue);font-size:12px}.legend-photo{width:220px;max-width:100%;height:auto;border:1px solid var(--border);border-radius:10px;margin-top:15px}.source-lesson{margin-bottom:24px}.material-note{margin:0 0 32px;padding:24px;font-size:15px}.material-note>strong{font-family:var(--head);font-size:18px}.material-note p{margin-bottom:0}.source-lesson>.small{font-size:13px}.source-lesson>p{font-size:15px}
/* Practice */
.quiz-wrap{max-width:900px;margin:32px auto}.quiz-top{display:flex;justify-content:space-between;gap:14px;font-size:13px;color:var(--muted)}progress{display:block;width:100%;height:8px;border:0;appearance:none;overflow:hidden;background:var(--border);border-radius:10px;margin:16px 0 28px;accent-color:var(--blue)}progress::-webkit-progress-bar{background:var(--border)}progress::-webkit-progress-value{background:var(--blue);border-radius:10px}.quiz-wrap>.panel{padding:32px}.quiz-wrap h2{font-size:25px!important}.options{display:grid;gap:12px;margin:28px 0}.option{display:flex;gap:14px;align-items:center;width:100%;min-height:60px;text-align:left;border:1px solid var(--border);border-radius:10px;padding:16px;background:var(--panel);color:var(--text);font-size:15px;line-height:1.6}.option span{border:1px solid var(--border);border-radius:7px;display:grid;place-items:center;width:30px;height:30px;font-size:12px;flex:none}.option:hover:not(:disabled){background:var(--soft);border-color:var(--blue)}.option.selected{border:2px solid var(--blue);padding:15px;background:var(--soft)}.option.correct{border-color:var(--success);background:color-mix(in srgb,var(--success) 8%,var(--panel))}.option.wrong{border-color:var(--danger);background:color-mix(in srgb,var(--danger) 8%,var(--panel))}.option:disabled{opacity:1}.feedback{background:var(--soft);border:1px solid var(--border);border-radius:10px;padding:20px;font-size:15px;line-height:1.8;margin:24px 0}.quiz-actions{display:flex;align-items:center;justify-content:space-between;gap:12px}.flash{display:flex;align-items:center;justify-content:center;flex-direction:column;min-height:350px;text-align:center;color:var(--text);cursor:pointer;width:100%;padding:40px!important}.flash h2{max-width:550px}.flash p{font-size:16px;max-width:540px;line-height:1.85}.flash .small{font-size:14px}.flash:hover{border-color:var(--blue)}.flash .text-link{margin-top:16px}
/* Access forms and administration */
body.entry-mode{background:var(--side)}.entry-mode aside,.entry-mode .shell>header,.entry-mode footer,.entry-mode .skip-link{display:none}.entry-mode .shell{margin:0}.entry-mode main{padding:0;max-width:none;min-height:100vh}.login-stage{min-height:100svh;display:grid;place-items:center;padding:40px 20px;position:relative;overflow:hidden;background:radial-gradient(ellipse at 80% 0,#24495e 0,transparent 60%),#0e2940}.login-stage:before{content:'';position:absolute;bottom:-520px;left:-480px;width:900px;height:900px;border:75px solid #164562;border-radius:50%;opacity:.6}.login-stage:after{content:'';position:absolute;width:850px;height:850px;right:-600px;top:-590px;border:1px solid #4c758c;border-radius:50%;opacity:.5}.login-card{position:relative;z-index:1;width:490px;max-width:100%;padding:40px;background:#fff;border:1px solid #d3e0e8;border-radius:20px;color:#172d43;box-shadow:0 24px 70px #0002}.login-brand{color:#172d43;justify-content:center;margin-bottom:38px;font-size:24px}.login-brand small{color:#526477}.login-card .eyebrow{color:#006c66}.login-card h1{font-size:28px;margin:12px 0;letter-spacing:-.7px}.login-card>p{font-size:15px;color:#526477}.login-card form{display:grid;gap:12px;margin-top:28px}.login-card label{font-size:14px;font-weight:600;color:#344d63;margin-top:4px}.login-card input{color:#172d43;background:white;border-color:#aebfcd;height:52px;font-size:16px;outline-color:#087e99}.login-card input[readonly]{background:#f3f6f8;color:#526477}.login-card input::placeholder{color:#64778a}.login-card .button{margin-top:8px;background:#006c66;color:white;width:100%;min-height:52px}.login-card .button:hover{background:#005650}.login-card #entry-error{margin:0;color:#a62f36;font-size:14px;line-height:1.6}.login-card #entry-error:empty{display:none}.login-card .text-link{color:#006c66}.login-card .forgot-link{display:flex;justify-content:center;align-items:center;min-height:48px;font-size:14px;color:#375d79;border-top:1px solid #e2e9ed;margin-top:6px;padding-top:8px}.login-card .forgot-link:hover{color:#006c66;text-decoration:underline}.login-card .login-note{margin:24px 0 0;font-size:12px;line-height:1.8;color:#526477}.password-wrap{position:relative}.password-wrap input{padding-right:52px;width:100%}.password-wrap button{position:absolute;right:4px;top:4px;width:44px;height:44px;display:grid;place-items:center;background:transparent;border:0;border-radius:8px;color:#375d79}.password-wrap button:hover{background:#e8f4f1}.password-hint{font-size:12px;color:#526477;margin:0}.access-row{display:flex;align-items:center;justify-content:space-between;gap:20px;border-bottom:1px solid var(--border);padding:20px 0}.access-row:last-child{border-bottom:0}.access-row:first-child{padding-top:0}.access-row .small{margin-bottom:0}.access-actions{display:flex;gap:10px;flex-wrap:wrap}.allow-form{display:flex;align-items:center;flex-wrap:wrap;gap:14px;margin:24px 0}.allow-form input{flex:1;min-width:180px}.reset-link{width:100%;margin:16px 0}.icon-button,.profile-button,.forgot-link{cursor:pointer}
@media(min-width:1500px){main{padding-top:48px}.intro{margin-bottom:34px}}
@media(max-width:1180px){aside{width:224px;padding-left:16px;padding-right:16px}.shell{margin-left:224px}.shell>header{padding:0 28px}.brand{font-size:18px}main{padding:32px 28px 56px}.stats{gap:12px}.stat{padding:18px}.stat-icon{float:none;margin:0 0 14px}.stat strong{margin-top:12px}.feature-copy{padding:28px}.reader-layout{grid-template-columns:185px minmax(0,1fr);gap:20px}.toc{padding:18px}.date-tag,.private-badge{display:none}.grid-two{grid-template-columns:1.35fr 1fr}}
@media(max-width:900px){.reader-layout{grid-template-columns:1fr}.toc{position:static}.toc .eyebrow{display:none}.toc-toggle{display:flex;align-items:center;justify-content:space-between;width:100%;min-height:48px;border:0;background:none;color:var(--text);font-size:15px;font-weight:700;padding:0}.toc-links[hidden]{display:none}.toc-links a{font-size:14px}.reference-grid{gap:14px}}
@media(max-width:900px){html{scroll-padding-top:90px}aside{position:relative;width:100%;padding:18px 20px;background:var(--side);display:flex;flex-direction:row;justify-content:space-between;align-items:center;gap:12px;z-index:25}.brand{font-size:18px;gap:9px}.brand-icon{height:38px;width:36px;border-radius:10px}.brand small{font-size:8px;letter-spacing:1.5px}.brand-icon .ui-icon{width:23px}.nav-label,.sidebar-note{display:none}nav{position:fixed;bottom:0;left:0;right:0;display:flex;gap:0;align-items:stretch;background:var(--panel);border-top:1px solid var(--border);padding:6px 8px calc(6px + env(safe-area-inset-bottom));z-index:35;box-shadow:0 -4px 24px #17324b08}nav a{flex:1;min-width:0;min-height:60px;flex-direction:column;justify-content:center;gap:4px;border-radius:8px;padding:7px 2px;font-size:10px;color:var(--muted);line-height:1.2}nav a span{font-size:10px}nav a .ui-icon{width:21px;height:21px}nav a b{display:none}nav a.active{background:var(--soft);color:var(--blue);font-weight:700}nav a.active:before{display:none}nav a:hover{background:var(--soft);color:var(--blue)}.source-link{padding:8px;min-height:44px;border:1px solid #56728a;border-radius:8px;flex:none;color:#e2edf7;font-size:12px;gap:6px}.source-link .ui-icon{width:17px}.source-link:hover{color:#fff}.shell{margin:0}.shell>header{height:80px;padding:0 20px;gap:12px}.breadcrumb{font-size:12px}.breadcrumb>span{margin:0 7px}.header-actions{gap:8px}.profile-button{font-size:11px}.sync-label{font-size:10px}.icon-button{width:44px;height:44px}.shell>main{padding:28px 20px 32px;min-height:60vh}.intro{display:block;margin-bottom:24px}.intro p{font-size:14px;line-height:1.8}.intro h1{font-size:29px;letter-spacing:-1px}.search{padding:0 14px;margin-bottom:24px}.search input{font-size:14px;padding:16px 0}.search kbd{display:none}.stats{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin-bottom:24px}.stat{padding:18px}.stat-icon{display:none}.stat>span:not(.stat-icon){font-size:12px}.stat strong{font-size:30px;margin:12px 0 8px}.stat small{font-size:12px}.stat strong span{font-size:12px}.section-head{margin:24px 0 16px;gap:10px}.section-head h2{font-size:19px}.section-head a{font-size:12px}.feature{grid-template-columns:1fr;min-height:0;border-radius:16px}.feature-copy{padding:28px 26px}.feature h2{font-size:29px}.feature p{font-size:14px}.feature p br{display:none}.feature-meta{font-size:12px}.atom-art{max-height:200px;overflow:hidden}.atom-art .study-image{min-height:200px;height:200px;object-fit:cover;object-position:50% 45%}.grid-two{grid-template-columns:1fr;gap:16px;margin-top:20px}.panel{padding:22px}.panel h2{font-size:19px}.notice{font-size:13px;padding:16px;margin-top:24px}.topics{gap:8px}.chip{font-size:12px;padding:9px 12px}.small{font-size:12px}.filter-row{gap:12px}.filter-row label{min-width:130px}.filter-row .button{width:100%}.lesson-card{align-items:flex-start;flex-wrap:wrap;gap:16px}.lesson-number{padding:12px 18px}.lesson-card>div:nth-child(2){flex:1;min-width:170px}.lesson-card .button{width:100%;margin:4px 0 0}.article-head h1{font-size:29px}.article-head>p{font-size:16px}.progress-line{align-items:flex-start;flex-direction:column;gap:12px}.progress-line .button{width:100%}.reader-layout{gap:20px}.article section{padding:24px 22px;scroll-margin-top:100px}.article h2{font-size:23px}.article p{font-size:16px;line-height:1.9}.article .note{padding:14px;font-size:14px}.article label.small{font-size:13px}.visual{padding:8px;margin:24px -8px}.visual figcaption{font-size:12px}.quiz-wrap{margin:24px auto}.quiz-wrap>.panel{padding:24px 20px}.quiz-wrap h2{font-size:23px!important}.quiz-top{font-size:12px;flex-wrap:wrap;gap:5px}.option{font-size:14px;padding:14px;min-height:64px}.option.selected{padding:13px}.option span{width:28px;height:28px}.feedback{font-size:14px;padding:16px}.quiz-actions{flex-wrap:wrap}.quiz-actions .button{flex:1;font-size:13px;padding:12px}.flash{padding:30px 22px!important;min-height:350px}.flash p{font-size:16px}.flash .small{font-size:14px}.reference-grid{grid-template-columns:1fr;gap:28px}.reference-grid img{aspect-ratio:auto;height:auto;max-height:520px;object-fit:contain;background:var(--bg)}.reference-grid figcaption{font-size:14px}.material-note{padding:20px}.source-lesson>.small{font-size:12px}.access-row{align-items:flex-start;flex-direction:column}.access-actions{width:100%}.access-actions .button{flex:1;font-size:12px}.allow-form{display:grid;grid-template-columns:1fr}.allow-form input{width:100%;min-width:0}.allow-form .button{width:100%}footer{padding:24px 20px calc(106px + env(safe-area-inset-bottom));font-size:11px;flex-direction:column;gap:8px}.entry-mode .shell>main{padding:0}.entry-mode nav{display:none}.login-stage{padding:28px 16px;min-height:100svh}.login-card{padding:30px 24px;border-radius:16px}.login-brand{font-size:23px;margin-bottom:30px}.login-brand .brand-icon{width:42px;height:46px}.login-card h1{font-size:27px}.login-card>p{font-size:14px}.login-card .login-note{font-size:12px}#admin-nav{font-size:9px}}
@media(max-width:390px){.shell>header{padding:0 16px}.shell>main{padding-left:16px;padding-right:16px}.breadcrumb{max-width:120px;white-space:normal;line-height:1.4}.brand{font-size:17px}.source-link{font-size:11px}.source-link .ui-icon{display:none}h1{font-size:27px}.stat{padding:16px}.feature-copy{padding:26px 22px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}
.option .answer-marker{margin-left:auto;max-width:105px;font-size:11px;font-weight:700;color:var(--text);text-align:right;flex:none}.option:has(.answer-marker){flex-wrap:wrap}.option .answer-marker:before{content:'✓ ';}.option.wrong .answer-marker:before{content:'• ';}.article h2:focus,.intro h1:focus{outline:none}.article h2:focus-visible,.intro h1:focus-visible{outline:3px solid var(--focus);outline-offset:6px}
@media(max-width:900px){.option .answer-marker{max-width:none;width:100%;margin-left:44px;text-align:left}}
.login-stage{grid-template-columns:minmax(0,1fr)}.login-card{width:100%;max-width:490px;min-width:0;justify-self:center}
.note-viewer{padding:0;border:1px solid var(--border);border-radius:16px;background:var(--panel);color:var(--text);width:min(1100px,calc(100% - 32px));max-width:none;max-height:calc(100svh - 32px);box-shadow:0 24px 90px #0006;overflow:auto;overscroll-behavior:contain}.note-viewer::backdrop{background:#061421d9;backdrop-filter:blur(3px)}.note-viewer-header{position:sticky;top:0;display:flex;align-items:center;justify-content:space-between;gap:20px;padding:16px 20px;background:var(--panel);border-bottom:1px solid var(--border);z-index:1}.note-viewer-header h2{font-size:17px;line-height:1.5}.note-viewer-close{flex:none}.note-viewer-body{display:flex;align-items:center;justify-content:center;padding:16px;background:var(--bg);min-height:120px}.note-viewer-body img{display:block;max-width:100%;width:auto;height:auto;max-height:calc(100svh - 170px);object-fit:contain;border-radius:6px}.note-viewer-help{font-size:12px;color:var(--muted);text-align:center;margin:0;padding:12px 18px}.reference-grid a img,.legend-photo{cursor:zoom-in}@media(max-width:900px){.note-viewer{width:calc(100% - 16px);max-height:calc(100svh - 24px);border-radius:12px}.note-viewer-header{padding:12px;gap:10px}.note-viewer-header h2{font-size:14px}.note-viewer-body{padding:8px}.note-viewer-body img{max-height:calc(100svh - 180px)}.note-viewer-help{font-size:12px;padding:12px}}
/* Course diagrams, source annotations and per-lesson activities */
.search-hit{display:block;margin:12px 0}.lesson-card{margin-bottom:20px}.lesson-card h2{margin-top:10px}.lesson-card p{font-size:14px}.circuit-figure svg{display:block;width:100%;max-height:330px;color:var(--text,#17344a)}.circuit-figure figcaption,.visual figcaption{font-size:13px;line-height:1.6;margin-top:12px}.formula{font-size:20px;font-weight:700;padding:18px;background:rgba(0,145,133,.08);border-radius:12px}.electron-track{position:relative;overflow:hidden;aspect-ratio:4/1;border:2px solid #718ca0;border-radius:30px;background:rgba(0,145,133,.07);margin-bottom:16px}.electron-track span{position:absolute;top:35%;left:0;font-weight:700;color:#00776e;animation:electron-drift 6s linear infinite;animation-delay:calc(var(--offset)*-1s)}.electron-track.paused span{animation-play-state:paused}@keyframes electron-drift{from{transform:translateX(-40px)}to{transform:translateX(900px)}}.wiring-exercise{margin:20px 0;padding:16px;border:1px solid #91aebb;border-radius:12px}.wiring-exercise .visual{margin:0}.wiring-exercise [aria-pressed=true]{background:#00776e;color:white}.article a{overflow-wrap:anywhere}.dark .circuit-figure svg{color:#d8e7ef}.dark .electron-track span{color:#65e2cd}@media(max-width:600px){.wiring-exercise .quiz-actions{flex-direction:column}.circuit-figure{padding:8px}.circuit-figure figcaption{font-size:12px}.quiz-top{gap:12px;flex-wrap:wrap}}
.worked-example,.key-concept{margin:22px 0;padding:18px 22px;border-radius:12px;line-height:1.7}.worked-example{background:rgba(19,113,134,.06);border-left:3px solid #17798c}.key-concept{background:rgba(0,145,133,.07);border-left:3px solid #008b7e}.worked-example h3,.key-concept h3{margin:0 0 8px;font-size:14px;letter-spacing:.03em}.worked-example p,.key-concept p{margin:0}.chapter-opening h3{margin-top:24px;font-size:16px}.chapter-opening ul,.chapter-summary ul{padding-left:22px;line-height:1.8}.chapter-opening li,.chapter-summary li{margin:8px 0}.dark .worked-example,.dark .key-concept{background:rgba(117,204,198,.08)}

.dynamic-gif-image{display:block;width:100%;height:auto;border-radius:12px;aspect-ratio:16/7}.gif-toggle{margin:16px 0 4px}.outlet-figure svg{display:block;width:100%;height:auto;max-height:420px}.outlet-figure{background:#f8fbfc}.outlet-figure figcaption{color:#354e60;font-size:13px;line-height:1.7}.dark .outlet-figure{background:#edf4f6}
.lighting-demo{padding:24px!important;background:#f7fafc!important;border:1px solid #cedee6!important}.lighting-heading{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:18px}.lighting-status{font-size:12px;font-weight:600;color:#36586b;background:#e6eff3;padding:7px 10px;border-radius:20px}.lighting-art{display:block;width:100%;height:auto}.lighting-legend{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:18px 0}.lighting-legend>div{padding:14px;background:#fff;border:1px solid #d9e5eb;border-radius:12px}.lighting-legend strong{font-size:14px;color:#173b50;display:flex;align-items:center;gap:8px}.lighting-legend p{font-size:13px!important;line-height:1.6!important;color:#405f71!important;margin:8px 0 0!important}.wire-key{display:inline-grid;place-items:center;width:25px;height:25px;border-radius:7px;color:white;font-size:12px}.wire-key.phase{background:#b63c48}.wire-key.return{background:#94600e}.wire-key.neutral{background:#286b9f}.lighting-action{display:flex;align-items:center;gap:16px;flex-wrap:wrap;margin:20px 0}.lighting-action p{font-size:13px!important;line-height:1.6!important;margin:0!important;color:#405f71!important}.lighting-demo figcaption{font-size:12px;line-height:1.7;color:#405f71;border-top:1px solid #d2e1e8;padding-top:14px}.dark .lighting-demo .eyebrow{color:#216273}.dark .lighting-demo .lighting-status{color:#36586b}@media(max-width:600px){.lighting-demo{padding:14px!important}.lighting-legend{grid-template-columns:1fr}.lighting-legend>div{display:grid;grid-template-columns:100px 1fr;align-items:center;gap:10px}.lighting-legend p{margin:0!important}.lighting-action{align-items:stretch;flex-direction:column}.lighting-toggle{width:100%}.lighting-heading{align-items:flex-start;flex-direction:column}}

.lighting-stage{position:relative}.lighting-stage .lighting-toggle{position:absolute;left:26.625%;top:19%;width:19.25%;height:42%;min-height:44px;min-width:44px;background:transparent;border:2px solid transparent;border-radius:15px;padding:0;cursor:pointer;touch-action:manipulation}.lighting-stage .lighting-toggle:hover{background:rgba(0,125,119,.05);border-color:rgba(0,125,119,.3)}.lighting-stage .lighting-toggle:focus-visible{outline:3px solid #008b81;outline-offset:3px;background:rgba(0,125,119,.06)}.lighting-sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}@media(max-width:600px){.lighting-stage .lighting-toggle{width:19.25%;border-radius:8px}}