body[data-course="mth140"],body[data-course="mth141"]{--tile:var(--hub-panel);--line:var(--hub-line);--ink:var(--hub-ink);--ink2:var(--hub-muted);--bg:var(--hub-bg);--navy:#10233A;--sign:var(--accent)}

/* Useful motion: a date rail and accessible detail sheets. */
.semester-rail{margin:22px 0;padding:20px;border:1px solid var(--line,#D7DFE9);border-radius:18px;background:var(--tile,#fff);color:var(--ink,#101B28)}
.rail-heading{display:flex;justify-content:space-between;align-items:start;gap:12px}.rail-heading h2{margin:0;font-size:1.08rem}.rail-heading p{margin:5px 0 14px;font-size:.82rem;color:var(--ink2,#4B596C)}
.rail-track{display:flex;gap:8px;overflow:auto;padding:8px 2px 15px;scroll-snap-type:x proximity}.rail-week{flex:0 0 66px;min-height:90px;border:1px solid var(--line,#D7DFE9);background:transparent;color:inherit;border-radius:12px;cursor:pointer;scroll-snap-align:start;font:inherit;font-size:.76rem;position:relative}.rail-week b{display:block;font-size:1rem;margin:5px 0}.rail-week[aria-pressed=true]{background:var(--navy,#10233A);color:#fff;border-color:transparent}.rail-week.today-week:after{content:'NOW';position:absolute;top:-9px;left:17px;background:var(--sign,#F69CC3);color:#10233A;font-size:.55rem;font-weight:800;border-radius:4px;padding:2px 4px}.rail-dots{display:flex;justify-content:center;gap:3px;height:8px}.rail-dot{width:5px;height:5px;border-radius:50%;background:var(--sign,#F69CC3)}.rail-dot.recorded{background:#369d70}.rail-summary{display:flex;justify-content:space-between;font-size:.75rem;color:var(--ink2,#4B596C);margin:0 0 12px}.rail-events{display:grid;gap:7px}.rail-event{display:flex;gap:12px;align-items:center;text-align:left;color:inherit;background:var(--hub-soft,var(--bg,#E9EDF1));border:0;border-radius:10px;padding:12px;width:100%;font:inherit;cursor:pointer}.rail-event time{min-width:45px;font-size:.75rem;font-weight:700}.rail-event span{flex:1;font-size:.84rem}.rail-event small{display:block;color:var(--ink2,#4B596C);font-size:.72rem;margin-top:3px}.rail-event .rail-status{flex:0;font-size:.72rem;white-space:nowrap}.rail-empty{font-size:.85rem;color:var(--ink2,#4B596C)}
.detail-sheet{position:fixed;inset:0 0 0 auto;width:min(620px,100%);height:100%;max-height:100%;max-width:100%;margin:0;border:0;padding:0;background:var(--tile,#fff);color:var(--ink,#101B28);box-shadow:-20px 0 80px #0003;overflow:auto}.detail-sheet::backdrop{background:#08152599;backdrop-filter:blur(3px)}.sheet-toolbar{position:sticky;top:0;z-index:5;background:var(--tile,#fff);border-bottom:1px solid var(--line,#D7DFE9);padding:16px 20px;display:flex;justify-content:space-between;align-items:center}.sheet-toolbar h2{font-size:.82rem;margin:0;text-transform:uppercase;letter-spacing:.12em}.sheet-close{border:1px solid var(--line,#D7DFE9);background:var(--hub-soft,var(--bg,#E9EDF1));color:inherit;border-radius:9px;font:inherit;padding:8px 12px;cursor:pointer}.sheet-content{padding:20px;list-style:none}.sheet-content>.tile,.sheet-content>li{margin:0;list-style:none}.sheet-content .head{cursor:default}.sheet-content .arrow{display:none}.sheet-content .body{display:block}.sheet-content .assessment{margin:0}.sheet-content .assessment>summary{pointer-events:none}.sheet-content .assessment>summary::after{display:none}body.sheet-open{overflow:hidden}
.math-workbench{margin:22px 0;border:1px solid var(--line,#D7DFE9);background:var(--tile,#fff);border-radius:18px;padding:20px;color:var(--ink,#101B28)}.math-workbench h2{font-size:1.05rem;margin:0}.math-workbench p{font-size:.84rem;color:var(--ink2,#4B596C)}.workbench-svg{display:block;width:100%;max-height:270px;background:var(--hub-soft,var(--bg,#E9EDF1));border-radius:12px;touch-action:none}.workbench-svg .grid{stroke:var(--line,#D7DFE9);stroke-width:1}.workbench-svg .axis{stroke:var(--ink2,#4B596C);stroke-width:1.4}.workbench-svg .curve{fill:none;stroke:#078896;stroke-width:3}.workbench-svg .tangent{stroke:#dc4a91;stroke-width:2}.workbench-svg circle{fill:#dc4a91;stroke:var(--tile,#fff);stroke-width:3;cursor:grab}.math-workbench label{display:block;margin:14px 0;font-size:.83rem}.math-workbench input[type=range]{display:block;width:100%;margin-top:10px;accent-color:#dc4a91;min-height:28px}.math-workbench output{display:block;font-size:1rem;font-weight:700;font-variant-numeric:tabular-nums;margin-top:12px}.workbench-legend{display:flex;gap:18px;font-size:.76rem;margin-top:10px}.workbench-legend span:first-child{color:#078896}.workbench-legend span:last-child{color:#dc4a91}
@media(max-width:600px){.detail-sheet{inset:auto 0 0;width:100%;height:92dvh;border-radius:22px 22px 0 0}.sheet-content{padding:14px}.semester-rail,.math-workbench{padding:16px}.rail-week{flex-basis:61px}}
@media(prefers-reduced-motion:no-preference){.detail-sheet[open]{animation:sheet-enter .22s ease-out}.rail-event{animation:rail-enter .18s ease-out}.rail-week{transition:background-color .15s,transform .15s}.rail-week:hover{transform:translateY(-2px)}@keyframes sheet-enter{from{transform:translateX(30px);opacity:0}to{transform:translateX(0);opacity:1}}@keyframes rail-enter{from{transform:translateY(5px);opacity:0}to{transform:translateY(0);opacity:1}}}

/* A proportionate plot and a control panel, without SVG letterboxing. */
.math-workbench{--plot-color:var(--strong,#078896);--plot-pink:#d63384;padding:24px;background:linear-gradient(135deg,color-mix(in srgb,var(--accent) 5%,var(--tile)),var(--tile) 55%);border-radius:22px;overflow:hidden;box-shadow:0 8px 28px #00000005}
.workbench-title{display:flex;justify-content:space-between;gap:16px;align-items:center;margin-bottom:22px}.workbench-kicker{display:block;font-size:.65rem;letter-spacing:.14em;text-transform:uppercase;font-weight:750;color:var(--strong);margin-bottom:7px}.math-workbench h2{font-size:clamp(1.1rem,2.2vw,1.5rem);letter-spacing:-.025em}.workbench-live{font-size:.68rem;font-weight:650;display:flex;gap:6px;align-items:center;color:var(--ink2);white-space:nowrap}.workbench-live:before{content:'';width:6px;height:6px;background:var(--strong);border-radius:50%;box-shadow:0 0 0 4px color-mix(in srgb,var(--accent) 15%,transparent)}
.workbench-layout{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(0,1fr);gap:28px;align-items:center}.workbench-plot,.workbench-controls{min-width:0}.workbench-svg{width:100%;height:auto;aspect-ratio:4/3;max-height:none;border:1px solid var(--line);background:radial-gradient(ellipse at 50% 45%,color-mix(in srgb,var(--accent) 9%,var(--bg)),var(--bg));border-radius:16px}.workbench-svg .grid{opacity:.55}.workbench-svg .curve{stroke:var(--plot-color);stroke-width:2.8}.workbench-svg .tangent{stroke:var(--plot-pink);stroke-width:2.3;fill:none}.workbench-svg .vector-path{stroke:var(--plot-color);stroke-dasharray:5 4;fill:none;stroke-width:1.6}.workbench-svg circle{fill:var(--plot-pink)}.workbench-svg .point-halo{fill:var(--plot-pink);opacity:.16;stroke:none}.workbench-svg .plot-labels{fill:var(--ink2);font:10px Archivo,system-ui,sans-serif}.math-workbench .workbench-equation{font-size:clamp(1.8rem,3vw,2.6rem);font-family:Georgia,serif;font-style:italic;color:var(--ink);margin:0 0 12px;letter-spacing:-.035em}.math-workbench .workbench-basis{font-size:.8rem;color:var(--strong);font-weight:650}.math-workbench label{font-weight:650;margin:20px 0 12px}.math-workbench input[type=range]{accent-color:var(--plot-pink);min-height:32px;cursor:ew-resize}.math-workbench output{background:var(--bg);border:1px solid var(--line);border-left:3px solid var(--plot-pink);border-radius:10px;padding:14px;font-size:.95rem;line-height:1.6}.workbench-legend{justify-content:center;gap:16px;font-size:.7rem;flex-wrap:wrap}.workbench-legend span{display:flex;align-items:center;gap:6px}.workbench-legend span:before{content:'';display:inline-block;width:14px;height:2px;background:currentColor}.workbench-legend span:first-child{color:var(--plot-color)}.workbench-legend span:last-child{color:var(--plot-pink)}.workbench-footer{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:16px}.workbench-footer span{font-size:.72rem;color:var(--ink2);line-height:1.4}.workbench-reset{border:1px solid var(--line);border-radius:8px;background:var(--tile);color:var(--ink);font:inherit;font-size:.75rem;padding:8px 12px;min-height:40px;cursor:pointer}
:root[data-theme="dark"] .math-workbench{--plot-pink:#ff83bd}
@media(prefers-color-scheme:dark){:root:not([data-theme="light"]) .math-workbench{--plot-pink:#ff83bd}}
@media(max-width:640px){.math-workbench{padding:18px}.workbench-layout{grid-template-columns:1fr;gap:20px}.workbench-title{margin-bottom:16px}.workbench-live{font-size:.6rem}.workbench-controls .workbench-equation{font-size:1.7rem}.math-workbench label{margin-top:14px}}
@media(prefers-reduced-motion:no-preference){.workbench-reset,.course-link{transition:background-color .18s,border-color .18s,box-shadow .18s}.workbench-reset:active{transform:scale(.97)}}

/* Course toolkit: existing controls, restored to the top. */
body[data-course] .top-toolkit{padding:0;margin:0 0 20px;border:1px solid color-mix(in srgb,var(--sign,#b8baff) 30%,var(--hub-line));border-radius:16px;overflow:hidden;background:linear-gradient(110deg,color-mix(in srgb,var(--sign,#b8baff) 8%,var(--hub-panel)),var(--hub-panel));box-shadow:0 5px 24px #00000004}
body[data-course] .top-toolkit>summary{display:flex;align-items:center;gap:12px;list-style:none;padding:14px 18px;cursor:pointer;flex-wrap:nowrap;margin:0;font-size:.95rem}
body[data-course] .top-toolkit>summary::-webkit-details-marker{display:none}
body[data-course] .top-toolkit>summary:after{content:'+';display:grid;place-items:center;flex:0 0 28px;height:28px;margin-left:4px;border:1px solid var(--hub-line);border-radius:50%;font-size:1.15rem;color:var(--hub-ink)}
body[data-course] .top-toolkit[open]>summary:after{content:'−'}
.toolkit-icon{display:grid;place-items:center;width:40px;height:40px;border:1px solid var(--hub-line);background:var(--hub-panel);border-radius:11px;color:var(--strong,var(--ink))}
.toolkit-title{font-weight:750;line-height:1.3;flex:1}
body[data-course] .top-toolkit>summary small{display:block;margin:3px 0 0;color:var(--hub-muted);font-size:.7rem;font-weight:450}
.toolkit-tags{display:flex;gap:6px;flex-wrap:wrap}.toolkit-tags span{padding:5px 8px;border:1px solid var(--hub-line);border-radius:6px;font-weight:550;font-size:.67rem;color:var(--hub-muted);background:var(--hub-panel)}
body[data-course] .top-toolkit>.tools-body,body[data-course] .top-toolkit>.tool-content{padding:0 18px 18px;border-top:1px solid var(--hub-line)}
@media(max-width:540px){.toolkit-tags{display:none}body[data-course] .top-toolkit>summary{padding:12px 14px}}

/* Interactive course experiments. */
.math-lab{scroll-margin-top:20px}.math-lab .workbench-title{margin-bottom:18px}.math-lab .workbench-title h2{font-size:clamp(1.45rem,3vw,2rem)}
.lab-expand,.lab-tabs button,.lab-presets button,.lab-answers button,.lab-start,.lab-play,.lab-plot-tools button{font:inherit;cursor:pointer;border:1px solid var(--line);background:var(--tile);color:var(--ink);border-radius:9px;min-height:42px;font-size:.78rem;font-weight:650;padding:9px 12px}
.lab-expand{flex-shrink:0}.lab-tabs{display:flex;gap:7px;flex-wrap:wrap;border-bottom:1px solid var(--line);padding-bottom:18px}.lab-tabs button[aria-pressed=true]{background:var(--accent-ink);color:var(--accent);border-color:transparent;box-shadow:0 3px 12px #00000010}.lab-intro{margin:22px 0 18px}.lab-intro h3{font-size:1.22rem;letter-spacing:-.02em;margin:0 0 6px}.lab-intro p{max-width:75ch;margin:0;line-height:1.6}
.math-lab .workbench-layout{grid-template-columns:minmax(0,1.25fr) minmax(0,1fr);align-items:start;gap:24px}.lab-plot-tools{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:8px}.lab-plot-tools>span{font-size:.68rem;letter-spacing:.06em;text-transform:uppercase;color:var(--ink2)}.lab-plot-tools>div{display:flex;gap:6px}.lab-plot-tools button{min-height:34px;padding:3px 12px;font-size:1rem}.math-lab .workbench-svg{aspect-ratio:4/3;touch-action:pan-y}.math-lab .workbench-svg [data-drag]{touch-action:none;cursor:grab;stroke-width:3;r:8}.math-lab .workbench-svg [data-drag]:active{cursor:grabbing}.math-lab .workbench-svg .lab-input-point{fill:var(--plot-color)}
.math-lab .workbench-svg .lab-hole{fill:var(--bg);stroke:var(--plot-color);stroke-width:2.5}.math-lab .workbench-svg .lab-original{stroke-dasharray:6 5;opacity:.6;stroke-width:1.7}.lab-guide,.lab-asymptote{stroke:var(--plot-pink);stroke-width:1;stroke-dasharray:4 4;fill:none;opacity:.6}.math-lab .workbench-svg .lab-orbit{fill:none;stroke:var(--plot-color);stroke-width:1;stroke-dasharray:4 4;opacity:.35}.lab-transformed-grid{fill:none;stroke:var(--plot-pink);stroke-width:1;opacity:.4}.lab-unit-original{fill:var(--plot-color);fill-opacity:.1;stroke:var(--plot-color);stroke-width:1.5;stroke-dasharray:4 3}.lab-unit{fill:var(--plot-pink);fill-opacity:.22;stroke:var(--plot-pink);stroke-width:2}
.math-lab .workbench-equation{font-size:clamp(1.3rem,2.1vw,1.8rem);line-height:1.5;margin-top:8px;min-height:2rem}.lab-matrix{display:inline-grid;grid-template-columns:repeat(2,minmax(1.8em,1fr));gap:4px 12px;padding:2px 10px;border-left:2px solid var(--ink);border-right:2px solid var(--ink);font-family:Archivo,system-ui,sans-serif;font-size:.85em;font-style:normal;text-align:center;vertical-align:middle}
.math-lab .lab-select{margin:10px 0;font-size:.76rem}.lab-select select{display:block;width:100%;margin-top:6px;min-height:42px;padding:8px 10px;border:1px solid var(--line);background:var(--tile);color:var(--ink);border-radius:8px;font:inherit}.lab-presets{display:flex;flex-wrap:wrap;gap:6px;margin:14px 0}.lab-presets button{font-size:.68rem;min-height:36px;padding:7px 9px}.lab-control{margin:12px 0}.lab-control-label{display:flex;align-items:center;justify-content:space-between;gap:6px}.math-lab .lab-control label{margin:0;font-size:.75rem;line-height:1.3}.lab-control input[type=number]{width:76px;min-height:36px;padding:6px;border:1px solid var(--line);border-radius:7px;font:inherit;font-size:.8rem;color:var(--ink);background:var(--tile);font-variant-numeric:tabular-nums}.math-lab .lab-control input[type=range]{margin:3px 0 0;min-height:32px}.lab-controls-many{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 14px}.lab-controls-many .lab-control:last-child:nth-child(odd){grid-column:1/-1}.lab-controls-many .lab-control-label{flex-wrap:wrap}.math-lab .workbench-footer{align-items:flex-start}.math-lab .workbench-footer>div{display:flex;gap:6px;flex-wrap:wrap;justify-content:end}.lab-play{font-size:.7rem;background:var(--accent-ink);color:var(--accent)}.lab-readout{padding:14px 16px;margin-top:16px;border:1px solid var(--line);border-left:3px solid var(--plot-pink);border-radius:10px;background:var(--bg);font-size:.85rem;line-height:1.6;font-variant-numeric:tabular-nums}.lab-readout b{display:block}.lab-readout span{display:block;font-size:.75rem;color:var(--ink2);margin-top:5px}
.lab-challenge{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;border-top:1px solid var(--line);margin-top:24px;padding-top:20px}.lab-challenge .workbench-kicker{margin:0}.lab-challenge p{margin:5px 0}.lab-question{flex:1 0 100%;border-radius:12px;background:var(--bg);padding:16px}.lab-question[hidden]{display:none}.lab-answers{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0}.lab-answers button{min-width:90px}.lab-answers button:disabled{opacity:.7;cursor:default}.lab-answers .lab-correct:disabled{border-color:var(--strong);color:var(--strong);opacity:1;box-shadow:inset 0 0 0 1px var(--strong)}.lab-feedback:empty{display:none}.math-lab .lab-feedback{color:var(--ink);line-height:1.65}.topic-lab-link{margin:14px 0 6px}
.lab-dialog{position:fixed;inset:12px;width:calc(100% - 24px);max-width:1500px;height:calc(100dvh - 24px);max-height:none;margin:auto;border:1px solid var(--line);padding:0;background:var(--tile);color:var(--ink);border-radius:22px;overflow:auto}.lab-dialog::backdrop{background:#06101cd9;backdrop-filter:blur(8px)}.lab-dialog .math-lab{margin:0;border:0;min-height:100%;border-radius:0}.lab-dialog .workbench-title{position:sticky;top:-24px;z-index:3;padding:14px 0;background:var(--tile)}body.lab-open{overflow:hidden}
@media(max-width:760px){.math-lab .workbench-layout{grid-template-columns:1fr}.math-lab .workbench-controls{border-top:1px solid var(--line);padding-top:16px}.lab-controls{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 14px}.lab-controls .lab-control:last-child:nth-child(odd){grid-column:1/-1}.lab-control-label{flex-wrap:wrap}}
@media(max-width:480px){.math-lab .workbench-title{align-items:start}.lab-expand{font-size:.7rem;padding:8px}.math-lab .workbench-title h2{font-size:1.3rem}.lab-tabs{gap:5px}.lab-tabs button{font-size:.68rem;padding:8px}.lab-intro h3{font-size:1.08rem}.lab-dialog{inset:0;width:100%;height:100dvh;border-radius:0}.lab-dialog .math-lab{padding:16px}.lab-dialog .workbench-title{top:-16px}.lab-controls{grid-template-columns:1fr}.lab-controls .lab-control-label{flex-wrap:nowrap}.lab-control input[type=number]{width:85px}.lab-challenge{align-items:start}.lab-question{padding:12px}}
@media(prefers-reduced-motion:no-preference){.lab-tabs button,.lab-presets button,.lab-answers button{transition:background-color .15s,border-color .15s,box-shadow .15s}.lab-dialog[open]{animation:rail-enter .18s ease-out}}
/* Output points must not block a draggable input when they overlap. */
.math-lab .workbench-svg circle:not([data-drag]){pointer-events:none;cursor:default}