:root{
  --bg:#f7f8fb;--panel:#ffffff;--panel2:#f1f4f8;--text:#172033;--muted:#667085;--border:#d8dee9;
  --accent:#3157d5;--accent2:#2546b5;--good:#19764a;--warn:#9a6700;--bad:#b42318;
  --s1:#4568dc;--s2:#7a5af8;--s3:#0e9384;--s4:#dc6803;--s5:#c11574;
  --shadow:0 8px 28px rgba(16,24,40,.09);--radius:16px;--header-h:68px;
}
@media (prefers-color-scheme:dark){:root{--bg:#0f1420;--panel:#161d2a;--panel2:#202938;--text:#eef2f7;--muted:#a5afbe;--border:#344054;--accent:#8aa2ff;--accent2:#b5c3ff;--good:#62d59b;--warn:#f4bd50;--bad:#ff8a80;--shadow:0 8px 28px rgba(0,0,0,.3)}}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:86px}body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;line-height:1.62}
button,input,textarea,select{font:inherit}.site-header{position:sticky;top:0;z-index:40;min-height:var(--header-h);display:flex;align-items:center;justify-content:space-between;gap:18px;padding:10px 18px;border-bottom:1px solid var(--border);background:color-mix(in srgb,var(--panel) 92%,transparent);backdrop-filter:blur(14px)}
.brand{display:flex;align-items:center;gap:10px;min-width:0}.brand-title{font-weight:750;font-size:18px;letter-spacing:-.01em}.brand-subtitle{font-size:12px;color:var(--muted)}.header-actions{display:flex;align-items:center;gap:8px;min-width:0}.search-box{display:flex;align-items:center;gap:7px;border:1px solid var(--border);background:var(--panel2);padding:7px 10px;border-radius:11px;min-width:240px}.search-box input{border:0;outline:0;background:transparent;color:var(--text);width:100%}.search-box input::placeholder{color:var(--muted)}
.btn,.icon-btn{border:1px solid var(--border);background:var(--panel);color:var(--text);border-radius:10px;cursor:pointer;min-height:40px}.btn{padding:8px 12px;font-weight:650}.btn:hover,.icon-btn:hover{border-color:var(--accent)}.btn.primary{background:var(--accent);border-color:var(--accent);color:white}.btn.secondary{background:var(--panel2)}.icon-btn{width:40px;padding:0;display:grid;place-items:center;font-size:22px}.count-badge{display:inline-grid;place-items:center;min-width:21px;height:21px;padding:0 6px;border-radius:999px;background:var(--accent);color:white;font-size:12px;margin-left:4px}.status-pill{padding:6px 9px;border-radius:999px;font-size:12px;border:1px solid var(--border);white-space:nowrap}.status-pill.online{color:var(--good);border-color:color-mix(in srgb,var(--good) 40%,var(--border));background:color-mix(in srgb,var(--good) 9%,var(--panel))}.status-pill.local{color:var(--warn);border-color:color-mix(in srgb,var(--warn) 40%,var(--border));background:color-mix(in srgb,var(--warn) 9%,var(--panel))}
.page-shell{display:grid;grid-template-columns:280px minmax(0,1fr);max-width:1500px;margin:0 auto}.toc-panel{position:sticky;top:var(--header-h);height:calc(100vh - var(--header-h));overflow:auto;padding:22px 14px;border-right:1px solid var(--border);background:var(--panel)}.toc-title{font-weight:750;margin:0 8px 10px}.toc-link{display:block;color:var(--muted);text-decoration:none;border-radius:9px;padding:6px 8px;font-size:13px;line-height:1.35}.toc-link.level-3{padding-left:20px;font-size:12.5px}.toc-link:hover,.toc-link.active{background:var(--panel2);color:var(--text)}.toc-link.active{box-shadow:inset 3px 0 0 var(--accent)}
.content-wrap{min-width:0;padding:28px clamp(16px,4vw,64px) 80px}.course-article{max-width:940px;margin:0 auto}.feedback-guide{margin:0 0 26px;padding:13px 15px;border:1px solid var(--border);border-radius:12px;background:color-mix(in srgb,var(--panel2) 82%,var(--panel));color:var(--muted)}.feedback-guide-title{font-size:14px;font-weight:750;color:var(--text);margin-bottom:8px}.feedback-guide-steps{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:7px 18px}.feedback-guide-steps li{display:flex;gap:8px;align-items:flex-start;min-width:0}.feedback-guide-num{flex:0 0 auto;display:inline-grid;place-items:center;width:20px;height:20px;border:1px solid var(--border);border-radius:50%;font-size:11px;font-weight:750;color:var(--muted);background:var(--panel)}.feedback-guide-steps div{display:grid;gap:1px;min-width:0}.feedback-guide-steps strong{font-size:13px;color:var(--text);font-weight:680}.feedback-guide-steps small{font-size:12px;line-height:1.45;color:var(--muted)}.feedback-guide-steps b{font-weight:700;color:var(--text)}.feedback-guide-foot{margin-top:9px;padding-top:8px;border-top:1px solid color-mix(in srgb,var(--border) 72%,transparent);font-size:11.5px;line-height:1.45}.course-article h2{font-size:29px;line-height:1.2;margin:54px 0 18px;letter-spacing:-.025em}.course-article h3{font-size:22px;line-height:1.25;margin:38px 0 14px}.course-article p,.course-article li{font-size:16.5px}.course-article blockquote{margin:18px 0;padding:12px 16px;border-left:4px solid var(--accent);background:var(--panel2);border-radius:0 10px 10px 0;color:var(--muted)}.course-article code{background:var(--panel2);border:1px solid var(--border);padding:.08em .35em;border-radius:6px}.course-article hr{border:0;border-top:1px solid var(--border);margin:42px 0}.course-article ul,.course-article ol{padding-left:24px}
.math-block{overflow-x:auto;padding:12px 4px;margin:13px 0;text-align:center;min-height:42px}.math-inline{white-space:nowrap}.math-fallback{font-family:"STIX Two Math","Cambria Math",serif;color:var(--text)}
.interactive-lab{margin:18px 0 30px}.lab-card{border:1px solid var(--border);border-radius:var(--radius);background:var(--panel);box-shadow:var(--shadow);overflow:hidden}.lab-head{padding:15px 18px;border-bottom:1px solid var(--border);display:flex;justify-content:space-between;align-items:flex-start;gap:12px}.lab-title{font-weight:760;font-size:17px}.lab-subtitle{font-size:13px;color:var(--muted);margin-top:3px}.lab-body{padding:18px}.lab-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:18px}.lab-panel{border:1px solid var(--border);border-radius:13px;background:var(--panel2);padding:14px;min-width:0}.lab-controls{display:flex;flex-wrap:wrap;gap:10px;align-items:end}.control{display:grid;gap:5px;min-width:120px}.control label{font-size:12px;color:var(--muted);font-weight:650}.control input[type=range]{width:180px}.control input[type=number],.control select,.control input[type=text]{min-height:38px;border:1px solid var(--border);border-radius:9px;background:var(--panel);color:var(--text);padding:6px 8px}.metric-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:10px;margin-top:14px}.metric{border:1px solid var(--border);background:var(--panel);border-radius:11px;padding:10px}.metric small{display:block;color:var(--muted)}.metric strong{font-size:18px}.formula-box{font-family:"STIX Two Math","Cambria Math",serif;font-size:18px;text-align:center;padding:12px;border-radius:11px;border:1px solid var(--border);background:var(--panel);overflow:auto}.viz-svg{width:100%;height:auto;display:block;min-height:220px}.axis{stroke:var(--border);stroke-width:2}.gridline{stroke:color-mix(in srgb,var(--border) 65%,transparent);stroke-width:1}.vector{stroke:var(--s1);stroke-width:4;stroke-linecap:round}.vector2{stroke:var(--s2);stroke-width:4;stroke-linecap:round}.proj{stroke:var(--s3);stroke-width:2;stroke-dasharray:6 5}.label{fill:var(--text);font-size:14px}.muted-label{fill:var(--muted);font-size:12px}.bar-track{height:10px;border-radius:999px;background:color-mix(in srgb,var(--border) 70%,transparent);overflow:hidden}.bar-fill{height:100%;background:var(--s1);border-radius:999px}.bar-fill.alt{background:var(--s3)}.hist{display:grid;grid-template-columns:90px 1fr 54px;gap:8px;align-items:center;margin:7px 0}.hist-label{font-size:13px}.chip{display:inline-flex;align-items:center;padding:4px 8px;border-radius:999px;background:var(--panel2);border:1px solid var(--border);font-size:12px}.good{color:var(--good)}.warn{color:var(--warn)}.bad{color:var(--bad)}
.lab-head-actions{display:flex;align-items:center;gap:8px;flex:0 0 auto}.visual-feedback-trigger{position:relative;display:grid;place-items:center;width:30px;height:30px;padding:0;border:1px solid var(--border);border-radius:50%;background:var(--panel2);color:var(--muted);font-size:15px;font-weight:800;line-height:1;cursor:pointer}.visual-feedback-trigger:hover,.visual-feedback-trigger:focus-visible{color:var(--accent);border-color:var(--accent);outline:none}.visual-feedback-trigger.has-feedback{color:var(--accent);border-color:var(--accent);background:color-mix(in srgb,var(--accent) 12%,var(--panel))}.visual-feedback-trigger.has-feedback::after{content:attr(data-count);position:absolute;right:-7px;top:-7px;display:grid;place-items:center;min-width:17px;height:17px;padding:0 4px;border-radius:999px;background:var(--accent);color:white;font-size:10px;font-weight:750;line-height:1}
.normalization-ray{stroke:color-mix(in srgb,var(--muted) 42%,transparent);stroke-width:2;stroke-dasharray:5 6}.vector-legend{display:grid;gap:7px;margin-top:13px;color:var(--muted);font-size:13px}.vector-legend span{display:flex;align-items:center;gap:8px}.legend-swatch{display:inline-block;width:24px;height:4px;border-radius:999px}.legend-swatch.raw{background:var(--s1)}.legend-swatch.normalized{background:var(--s2)}
.rabi-control{margin-bottom:16px}.rabi-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.rabi-panel{padding:12px}.viz-heading{display:flex;justify-content:space-between;align-items:baseline;gap:10px;min-height:38px}.viz-heading strong{font-size:14px}.viz-heading span{color:var(--muted);font-size:12px;text-align:right}.rabi-svg{min-height:0}.pulse-area{fill:color-mix(in srgb,var(--s3) 30%,transparent)}.pulse-line{fill:none;stroke:var(--s3);stroke-width:4;stroke-linecap:round}.viz-note{min-height:42px;margin:6px 0 0;color:var(--muted);font-size:12px;line-height:1.45}
.selection-action{position:fixed;z-index:80;border:0;border-radius:999px;padding:9px 13px;background:var(--accent);color:white;font-weight:700;box-shadow:var(--shadow);cursor:pointer}.ask-dialog{width:min(620px,calc(100vw - 28px));border:1px solid var(--border);border-radius:16px;background:var(--panel);color:var(--text);padding:0;box-shadow:var(--shadow)}.ask-dialog::backdrop{background:rgba(0,0,0,.38)}.ask-dialog form{padding:18px}.dialog-head,.drawer-head{display:flex;justify-content:space-between;gap:12px;align-items:flex-start}.ask-dialog blockquote{max-height:160px;overflow:auto;margin:14px 0;padding:12px;background:var(--panel2);border-radius:10px;border-left:3px solid var(--accent)}.ask-dialog label{display:grid;gap:6px;font-weight:650}.ask-dialog textarea{resize:vertical;border:1px solid var(--border);background:var(--panel2);color:var(--text);border-radius:10px;padding:10px;min-height:120px}.dialog-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:12px}.form-status{font-size:13px;color:var(--muted);min-height:20px;margin-top:8px}
.questions-drawer{position:fixed;z-index:70;top:0;right:0;height:100vh;width:min(520px,94vw);background:var(--panel);border-left:1px solid var(--border);box-shadow:var(--shadow);transform:translateX(105%);transition:transform .2s ease;padding:18px;overflow:auto}.questions-drawer.open{transform:translateX(0)}.drawer-backdrop{position:fixed;z-index:65;inset:0;background:rgba(0,0,0,.32)}.drawer-tools{display:flex;gap:8px;flex-wrap:wrap;margin:16px 0}.drawer-tools select{min-height:40px;border:1px solid var(--border);background:var(--panel2);color:var(--text);border-radius:9px;padding:6px 8px}.question-item{border:1px solid var(--border);border-radius:13px;padding:12px;margin:10px 0;background:var(--panel2)}.question-item blockquote{font-size:13px;margin:8px 0;padding:8px 10px;border-left:3px solid var(--accent);background:var(--panel)}.question-meta{display:flex;gap:8px;flex-wrap:wrap;font-size:12px;color:var(--muted)}.question-text{font-weight:680;margin-top:8px}.question-actions{display:flex;gap:7px;flex-wrap:wrap;margin-top:10px}.question-actions button{min-height:34px;border:1px solid var(--border);border-radius:8px;background:var(--panel);color:var(--text);cursor:pointer}.muted{color:var(--muted);font-size:13px}.empty-state{padding:30px 10px;text-align:center;color:var(--muted)}
.toast-host{position:fixed;z-index:100;right:16px;bottom:16px;display:grid;gap:8px}.toast{background:var(--text);color:var(--bg);padding:10px 12px;border-radius:10px;box-shadow:var(--shadow);max-width:340px}.search-hit{background:color-mix(in srgb,var(--warn) 26%,transparent);border-radius:3px}.search-hidden{display:none!important}
.matrix-grid{display:inline-grid;grid-template-columns:repeat(2,44px);grid-auto-rows:38px;place-items:center;border-left:2px solid var(--text);border-right:2px solid var(--text);padding:0 8px;margin:0 8px}.amplitude-paths{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:12px}.amp-node{padding:12px;border:1px solid var(--border);border-radius:12px;text-align:center;background:var(--panel)}.energy-levels{display:grid;gap:24px;padding:18px 8px}.energy-level{position:relative;border-top:3px solid var(--s1);height:1px}.energy-level span{position:absolute;left:0;top:-26px;font-weight:700}.energy-level small{position:absolute;right:0;top:-25px;color:var(--muted)}.pulse{height:70px;position:relative;border-bottom:1px solid var(--border);overflow:hidden}.pulse svg{width:100%;height:100%}.quiz-item{border-top:1px solid var(--border);padding:12px 0}.quiz-item:first-child{border-top:0}.quiz-answer{margin-top:8px;padding:9px 10px;border-radius:9px;background:var(--panel2);display:none}.quiz-item.open .quiz-answer{display:block}
.mobile-only{display:none}
@media(max-width:980px){.page-shell{grid-template-columns:1fr}.toc-panel{position:fixed;z-index:60;left:0;top:var(--header-h);height:calc(100vh - var(--header-h));width:min(320px,90vw);transform:translateX(-105%);transition:transform .2s ease;box-shadow:var(--shadow)}.toc-panel.open{transform:translateX(0)}.mobile-only{display:grid}.lab-grid{grid-template-columns:1fr}.search-box{min-width:0;width:min(330px,35vw)}}
@media(max-width:720px){.site-header{align-items:flex-start;flex-direction:column;padding:10px 12px}.header-actions{width:100%;flex-wrap:wrap}.search-box{width:100%;order:3}.content-wrap{padding:20px 13px 60px}.course-article h2{font-size:25px}.course-article h3{font-size:20px}.course-article p,.course-article li{font-size:16px}.lab-body{padding:13px}.lab-controls{align-items:stretch}.control{min-width:100%;}.control input[type=range]{width:100%}.rabi-grid{grid-template-columns:1fr}.questions-drawer{width:96vw}.status-pill{display:none}.amplitude-paths{grid-template-columns:1fr}.amplitude-paths .arrow-text{transform:rotate(90deg)}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important;animation:none!important}}

/* v0.2 feedback types */
.feedback-kind{display:grid;grid-template-columns:1fr 1fr;gap:10px;border:0;padding:0;margin:12px 0 14px}.feedback-kind label{display:flex;gap:9px;align-items:flex-start;border:1px solid var(--border);border-radius:12px;padding:10px;background:var(--panel2);cursor:pointer}.feedback-kind input{margin-top:4px}.feedback-kind span{display:grid;gap:2px}.feedback-kind small{color:var(--muted)}.feedback-kind label:has(input:checked){border-color:var(--accent);outline:1px solid var(--accent)}.chip.question{background:color-mix(in srgb,var(--accent) 14%,transparent)}.chip.comment{background:color-mix(in srgb,var(--warning,#c98b2e) 16%,transparent)}.question-item.comment-item{border-left:3px solid var(--warning,#c98b2e)}
@media(max-width:560px){.feedback-kind{grid-template-columns:1fr}}

/* v0.3 public feedback privacy + marks */
.feedback-section-badges{display:inline-flex;gap:6px;align-items:center;margin-left:10px;vertical-align:middle;font-size:12px;font-weight:650;letter-spacing:0}.feedback-count{display:inline-flex;align-items:center;gap:3px;padding:2px 7px;border-radius:999px;border:1px solid var(--border);white-space:nowrap}.feedback-count.question{color:var(--accent2);background:color-mix(in srgb,var(--accent) 13%,transparent);border-color:color-mix(in srgb,var(--accent) 35%,var(--border))}.feedback-count.comment{color:var(--warn);background:color-mix(in srgb,var(--warn) 14%,transparent);border-color:color-mix(in srgb,var(--warn) 35%,var(--border))}.feedback-mark-question,.feedback-mark-comment,.feedback-mark-both{border-radius:3px;padding:0 .08em;color:inherit}.feedback-mark-question{background:color-mix(in srgb,var(--accent) 22%,transparent);box-shadow:inset 0 -2px 0 color-mix(in srgb,var(--accent) 70%,transparent)}.feedback-mark-comment{background:color-mix(in srgb,var(--warn) 24%,transparent);box-shadow:inset 0 -2px 0 color-mix(in srgb,var(--warn) 75%,transparent)}.feedback-mark-both{background:linear-gradient(135deg,color-mix(in srgb,var(--accent) 23%,transparent) 0 49%,color-mix(in srgb,var(--warn) 25%,transparent) 51% 100%);box-shadow:inset 0 -2px 0 color-mix(in srgb,var(--accent) 55%,var(--warn))}.feedback-fallback{border-radius:7px;padding-left:8px;margin-left:-8px}.feedback-fallback-question{box-shadow:inset 3px 0 0 var(--accent)}.feedback-fallback-comment{box-shadow:inset 3px 0 0 var(--warn)}.feedback-fallback-both{box-shadow:inset 3px 0 0 var(--accent),inset 6px 0 0 var(--warn)}.feedback-summary-item{display:flex;align-items:center;justify-content:space-between;gap:12px;border:1px solid var(--border);border-radius:12px;background:var(--panel2);padding:11px 12px;margin:9px 0}.feedback-summary-counts{display:flex;gap:6px;flex-wrap:wrap;margin-top:6px}

@media(max-width:680px){.feedback-guide-steps{grid-template-columns:1fr}.feedback-guide{padding:12px 13px}}

/* ---------- Multi-topic home ---------- */
.brand-home{color:inherit;text-decoration:none}.brand-home:hover{text-decoration:underline}
.home-body{margin:0;background:var(--bg,Canvas);color:var(--text,CanvasText);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}
.home-header{max-width:1180px;margin:0 auto;padding:56px 28px 28px;display:flex;gap:28px;justify-content:space-between;align-items:flex-end}.home-header h1{font-size:clamp(2rem,5vw,3.7rem);line-height:1.02;margin:6px 0 14px;letter-spacing:-.04em}.home-header p{max-width:760px;color:var(--muted);font-size:1.05rem;line-height:1.65;margin:0}.home-kicker{font-size:.78rem;text-transform:uppercase;letter-spacing:.15em;color:var(--muted);font-weight:700}.home-version{white-space:nowrap;color:var(--muted);font-size:.9rem;padding-bottom:5px}.home-main{max-width:1180px;margin:0 auto;padding:0 28px 70px}.home-toolbar{display:flex;justify-content:space-between;align-items:end;gap:14px;padding:16px 0 24px;border-top:1px solid var(--border)}.home-toolbar label{display:grid;gap:6px;font-size:.8rem;color:var(--muted)}.home-toolbar select{min-width:160px}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:18px;margin:18px 0}.section-heading h2{font-size:1.35rem;margin:0 0 5px}.section-heading p{margin:0;color:var(--muted)}.topic-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:16px}.topic-card{border:1px solid var(--border);border-radius:18px;background:var(--panel);padding:20px}.topic-card-head{display:grid;grid-template-columns:48px 1fr;gap:14px;align-items:start}.topic-icon{width:48px;height:48px;border-radius:14px;border:1px solid var(--border);display:grid;place-items:center;font-size:1.2rem;font-weight:750;background:var(--panel-2)}.topic-card h3{margin:0 0 6px;font-size:1.12rem}.topic-card p{margin:0;color:var(--muted);line-height:1.55}.language-links{display:grid;gap:8px;margin-top:18px}.language-link{display:flex;justify-content:space-between;gap:12px;align-items:center;border-top:1px solid var(--border);padding:11px 2px 2px;color:inherit;text-decoration:none}.language-link:hover span{text-decoration:underline}.language-link small{color:var(--muted)}.home-note{margin-top:24px;padding:16px 18px;border:1px solid var(--border);border-radius:14px;background:color-mix(in srgb,var(--panel) 90%,transparent);display:grid;gap:5px;color:var(--muted)}.home-note strong{color:var(--text)}.char-counter{text-align:right;color:var(--muted);font-size:.78rem;margin-top:-10px}
@media(max-width:700px){.home-header{padding-top:32px;display:block}.home-version{margin-top:18px}.home-toolbar{align-items:stretch;flex-direction:column}.home-toolbar select{width:100%}.topic-grid{grid-template-columns:1fr}}

/* v0.4 draggable visualizations */
.viz-drag{touch-action:none;cursor:crosshair;user-select:none;-webkit-user-select:none}.drag-dot{fill:var(--accent);fill-opacity:.16;stroke:var(--accent);stroke-width:1.5;cursor:grab}

/* ---------- Guided course reading ---------- */
html{scroll-padding-top:calc(var(--header-h) + 18px)}
.course-article h1{font-size:clamp(28px,4vw,38px);line-height:1.18;letter-spacing:-.03em;margin:4px 0 20px}
.course-article h2[id]{border-top:1px solid var(--border);padding-top:28px}
.course-article h3[id]{color:var(--text)}
.course-goal{font-size:18px!important;line-height:1.7;padding:18px 20px;background:var(--panel2);border-left:4px solid var(--accent);border-radius:0 12px 12px 0}
.learning-route{padding:16px 20px 16px 42px!important;background:var(--panel);border:1px solid var(--border);border-radius:12px}
.learning-route li{margin:7px 0}
.course-article p.learning-route{display:flex;flex-wrap:wrap;gap:10px;padding:14px!important}
.learning-route .btn{text-decoration:none}
.lab-experiment{padding:12px 16px;border-left:3px solid var(--s3);background:color-mix(in srgb,var(--s3) 6%,var(--panel));border-radius:0 10px 10px 0}
.chapter-summary{padding:12px 16px;border:1px solid var(--border);border-radius:10px;background:var(--panel2);margin:24px 0}
.check-question{margin:22px 0;padding:0;border:1px solid color-mix(in srgb,var(--accent) 45%,var(--border));border-radius:12px;background:var(--panel);overflow:hidden}
.check-question summary{padding:15px 18px;cursor:pointer;color:var(--accent2);font-weight:700;line-height:1.5}
.check-question[open] summary{border-bottom:1px solid var(--border);background:var(--panel2)}
.check-question>p,.check-question>div,.check-question>ul,.check-question>ol{margin:14px 18px}
.check-question>ul,.check-question>ol{padding-left:22px}
.check-question summary::marker{color:var(--accent)}
.quiz-item[open] .quiz-answer{display:block}
.quiz-item>summary{cursor:pointer;font-weight:700;padding:5px 0}
.quiz-item .quiz-answer a{display:inline-block;margin-top:10px}
details.feedback-guide{margin:18px 0 26px}
details.feedback-guide>summary{cursor:pointer;color:var(--text);font-weight:650}
details.feedback-guide[open]>summary{margin-bottom:14px}
.course-article a{color:var(--accent2);text-underline-offset:3px}
.course-article a.btn.primary{color:var(--panel)}
.course-article pre{max-width:100%;overflow-x:auto;padding:16px;border:1px solid var(--border);border-radius:12px;background:var(--panel2);line-height:1.6}
.course-article pre code{display:block;padding:0;border:0;background:transparent;font-size:14px}
.lab-body table{width:100%;table-layout:fixed;border-collapse:collapse;margin:16px 0;font-size:14px}
.lab-body th,.lab-body td{padding:9px 7px;border-bottom:1px solid var(--border);text-align:right;overflow-wrap:anywhere}
.lab-body th:first-child,.lab-body td:first-child{text-align:left}
.lab-body thead{background:var(--panel2)}
.lab-controls .control{max-width:100%}
.control select{min-width:0;max-width:100%;width:100%}
.toc-link.level-2{font-weight:700;margin-top:8px}
.toc-link.level-3{padding-left:24px}
:is(summary,button,a,input,select):focus-visible{outline:3px solid var(--accent);outline-offset:3px}
.lab-grid>*,.metric-row>*{min-width:0}
.lab-title,.lab-subtitle,.metric strong,.course-article summary{overflow-wrap:anywhere}
.local-pending-feedback{padding:12px 20px;border-bottom:1px solid var(--border)}
.pending-feedback-item{padding:14px 0;border-top:1px solid var(--border);overflow-wrap:anywhere}
.pending-feedback-body{white-space:pre-wrap}
.pending-feedback-actions{display:flex;flex-wrap:wrap;gap:8px}
@media(max-width:720px){.course-goal{font-size:17px!important;padding:14px}.learning-route{padding-left:34px!important}.check-question summary{padding:13px 14px}.check-question>p,.check-question>div,.check-question>ul,.check-question>ol{margin:12px 14px}}

/* Feedback availability and count share one header control. */
.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
.feedback-toggle{display:inline-flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:6px;max-width:100%}
.feedback-toggle>span{white-space:nowrap}
.feedback-toggle .count-badge{margin-left:0}
.feedback-availability{display:inline-grid;place-items:center;flex:0 0 16px;width:16px;line-height:1;font-weight:800;color:var(--muted)}
.feedback-availability.online{color:var(--good)}
.feedback-availability.local,.feedback-offline-label{color:var(--warn)}
.feedback-toggle[data-status="online"]{border-color:color-mix(in srgb,var(--good) 40%,var(--border))}
.feedback-toggle[data-status="local"]{border-color:var(--warn);background:color-mix(in srgb,var(--warn) 9%,var(--panel))}
.feedback-offline-label{font-size:12px}
.feedback-toggle:hover,.feedback-toggle:focus-visible{border-color:var(--accent)}
.feedback-toggle:focus-visible{outline:2px solid var(--accent);outline-offset:2px}