/* Pressure–Volume Loop · The Lab */
:root{
  --paper:#f7f7f2;--white:#fff;--ink:#171916;--soft:#4b4f47;--rule:#babeb3;--accent:#254dff;
  --loop:#b3261e;--loop-tint:#f6dcd8;
  --es:#8a5300;--ed:#00707f;--ea:#5d6158;--ghost:#9a9e94;
  --sans:'Space Grotesk',system-ui,-apple-system,'Segoe UI',sans-serif;
  --display:'Anton',Impact,'Arial Narrow Bold','Arial Narrow',sans-serif;
  --mono:ui-monospace,'SF Mono',Menlo,Consolas,'Liberation Mono',monospace;
  color-scheme:light;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.5 var(--sans);overflow-x:hidden;font-variant-numeric:tabular-nums}
a{color:var(--ink);text-decoration-color:var(--accent);text-decoration-thickness:2px;text-underline-offset:3px}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
[hidden]{display:none!important}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;margin:-1px;padding:0;border:0}
.skip{position:absolute;left:-9999px;top:0;background:var(--ink);color:var(--paper);padding:8px 12px;z-index:60}
.skip:focus{left:8px;top:8px}
.wrap{max-width:1240px;margin:0 auto;padding:0 18px}
/* Height of the sticky site bar (see the end of this file): sticky lesson parts sit below it, anchors land clear of it */
:root{--bar-h:78px}
@media (max-width:850px){:root{--bar-h:70px}}
@media (max-width:620px){:root{--bar-h:66px}}
html{scroll-padding-top:calc(var(--bar-h) + 8px)}
[id]{scroll-margin-top:calc(var(--bar-h) + 8px)}

.banner{margin:0;background:var(--ink);color:var(--paper);font-size:14px;line-height:1.4}
.banner .wrap{display:block;padding-top:9px;padding-bottom:9px}
.banner strong{color:#fff;margin-right:4px;letter-spacing:.01em}

/* Hero */
.hero{padding:22px 0 4px;display:grid;grid-template-columns:minmax(0,auto) minmax(0,1fr);gap:4px 36px;align-items:end}
.kicker{grid-column:1/-1;margin:0 0 4px;font-size:13px;font-weight:600;letter-spacing:.09em;text-transform:uppercase;color:var(--soft)}
.kicker .crumb{color:var(--ink);display:inline-block;padding:6px 0;margin:-6px 0}
h1{font-family:var(--display);font-weight:400;text-transform:uppercase;font-size:clamp(40px,6vw,76px);line-height:.9;margin:0;letter-spacing:.005em}
h1 span{color:var(--loop)}
.lede{font-size:16px;max-width:580px;margin:0 0 2px}
h2{font-family:var(--display);font-weight:400;text-transform:uppercase;letter-spacing:.02em;font-size:24px;line-height:1.05;margin:0}
h3{font-size:13px;letter-spacing:.08em;text-transform:uppercase;margin:18px 0 8px;font-weight:700}

/* Presets */
.presets{border-top:2px solid var(--ink);margin-top:18px;padding-top:10px;display:grid;grid-template-columns:auto minmax(0,1fr);gap:0 16px;align-items:center}
.presets .preset-note{grid-column:1/-1}
.eyebrow{font-family:var(--sans);font-size:13px;font-weight:700;letter-spacing:.08em;color:var(--soft);margin:0}
.preset-buttons{display:flex;flex-wrap:wrap;gap:8px}
.preset{font:inherit;font-weight:600;font-size:15px;min-height:44px;padding:8px 14px;border:2px solid var(--ink);background:var(--white);color:var(--ink);cursor:pointer;border-radius:0}
.preset:hover{background:var(--loop-tint)}
.preset[aria-pressed=true]{background:var(--ink);color:var(--paper)}
.preset-note{margin:8px 0 0;min-height:3em;max-width:980px;font-size:15px;color:var(--ink)}
.preset-note b{font-weight:700}

/* Toolbar */
.toolbar{display:flex;flex-wrap:wrap;align-items:center;gap:8px 18px;border-top:1px solid var(--rule);padding:10px 0 0;margin-top:8px}
.tool-group{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.toggles{gap:0 14px}
.toggles .check{font-size:14px}
.btn{font:inherit;font-weight:600;min-height:44px;padding:8px 14px;border:2px solid var(--ink);background:var(--white);color:var(--ink);cursor:pointer;border-radius:0}
.btn:hover{background:var(--paper)}
.btn.primary{background:var(--accent);border-color:var(--accent);color:#fff;min-width:96px}
.btn.primary:hover{background:#1638d6}
.btn.primary[aria-pressed=true]{background:var(--ink);border-color:var(--ink)}
.btn.small{min-height:40px;padding:5px 12px;font-size:14px}
.btn:disabled{opacity:.5;cursor:not-allowed}
.check{display:inline-flex;align-items:center;gap:8px;font-weight:600;font-size:15px;min-height:44px;cursor:pointer}
.check input{width:20px;height:20px;margin:0;accent-color:var(--accent)}
.seg{display:inline-flex;align-items:center;border:0;margin:0;padding:0;gap:0}
.seg-label{font-size:13px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--soft);margin-right:8px}
.seg label{position:relative;cursor:pointer}
.seg input{position:absolute;opacity:0;inset:0;margin:0;cursor:pointer}
.seg label span{display:inline-flex;align-items:center;min-height:44px;padding:6px 14px;border:2px solid var(--ink);font-weight:700;background:var(--white)}
.seg label+label span{border-left:0}
sub{font-size:.72em;line-height:0}
.seg input:checked+span{background:var(--ink);color:var(--paper)}
.seg input:focus-visible+span{outline:3px solid var(--accent);outline-offset:2px}
kbd{font-family:var(--mono);font-size:.82em;border:1px solid currentColor;border-radius:3px;padding:0 4px}

/* Numbers strip */
.numbers{display:grid;grid-template-columns:1.3fr repeat(7,minmax(0,1fr));margin:14px 0 0;background:var(--white);border:1px solid var(--rule);border-top:3px solid var(--ink)}
.numbers>div{padding:8px 12px;border-left:1px solid var(--rule);min-width:0}
.numbers>div:first-child{border-left:0}
.numbers dt{font-size:12px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--soft);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.numbers dd{margin:0;font-size:24px;font-weight:600;line-height:1.15;white-space:nowrap}
.numbers dd small{font-size:12px;font-weight:500;color:var(--soft);margin-left:4px}
.numbers .hl dd{color:var(--loop)}
.numbers .status-cell dd{font-size:15px;font-weight:700;line-height:1.25;white-space:normal;padding-top:3px}
.status-cell dd.settled{color:#1d6b33}
.notice{margin:10px 0 0;padding:10px 14px;border:2px solid var(--loop);background:var(--loop-tint);font-weight:600}

/* Tabs (phone only) */
.tabs{display:flex;border:2px solid var(--ink);margin-top:14px}
.tabs [role=tab]{flex:1;font:inherit;font-weight:700;font-size:15px;background:var(--paper);color:var(--ink);border:0;border-left:2px solid var(--ink);padding:10px 8px;min-height:46px;cursor:pointer;text-transform:uppercase;letter-spacing:.05em}
.tabs [role=tab]:first-child{border-left:0}
.tabs [role=tab][aria-selected=true]{background:var(--ink);color:var(--paper)}

/* Lesson / Clinical values tabs (all widths) */
.lesson-tabs{display:flex;gap:0;margin-top:18px;border-bottom:3px solid var(--ink)}
.lesson-tabs [role=tab]{font:inherit;font-weight:700;font-size:15px;letter-spacing:.06em;text-transform:uppercase;min-height:46px;padding:10px 20px;border:2px solid var(--ink);border-bottom:0;background:var(--white);color:var(--ink);cursor:pointer;margin-right:6px}
.lesson-tabs [role=tab][aria-selected=true]{background:var(--ink);color:var(--paper)}
.lesson-tabs [role=tab]:hover:not([aria-selected=true]){background:var(--loop-tint)}

/* Guided lesson: one idea, one picture per step (mobile first) */
.guide{margin-top:14px}
.step{display:grid;grid-template-columns:minmax(0,1fr);gap:8px;align-content:start}
.step-kicker{margin:0;font-size:12px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--soft)}
.step h2{font-size:clamp(26px,7.4vw,40px);line-height:1}
.step-fig{margin:0;background:var(--white);border:1px solid var(--rule);border-top:3px solid var(--ink);padding:6px}
.lp{display:block;width:100%;height:auto;overflow:visible}
.fig-foot{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:6px 12px;margin-top:4px;padding:0 4px 2px}
.fig-foot .replay{margin-left:auto;min-height:44px}
.lp-legend{display:flex;flex-wrap:wrap;gap:4px 16px;margin:0;font-size:15px;font-weight:600}
.lp-legend span{display:inline-flex;align-items:center;gap:7px}
.lp-legend i{display:inline-block;width:26px;height:0;border-top:3px solid var(--loop)}
.lp-legend .lg-normal{border-top:2px dashed var(--ghost)}
.step-cap{margin:2px 0 0;font-size:17px;line-height:1.55;max-width:34em}
.step-cap b{font-weight:700}
dfn{font-style:normal;font-weight:700;background:linear-gradient(transparent 60%,var(--loop-tint) 60%)}
.step-nav{position:sticky;bottom:0;z-index:20;display:grid;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;gap:10px;margin-top:14px;padding:8px 0 calc(8px + env(safe-area-inset-bottom,0px));background:rgba(247,247,242,.97);border-top:2px solid var(--ink)}
.step-btn{min-height:48px;min-width:92px;font-size:16px}
.step-btn.primary{min-width:110px}
.step-where{display:grid;gap:5px;justify-items:center;min-width:0}
.step-progress{margin:0;font-size:14px;font-weight:700;white-space:nowrap}
.step-bar{display:block;width:100%;max-width:220px;height:5px;background:#e1e3dc}
.step-bar i{display:block;height:100%;width:0;background:var(--loop);transition:width .25s ease-out}
/* the SVG pictures */
.lp-t{font-family:var(--sans);font-size:13px;font-weight:500;fill:var(--ink)}
.lp-axis-label{font-size:14px;font-weight:700}
.lp-strong{font-weight:700;font-size:14px}
.lp-small{font-size:12px;fill:var(--soft)}
.lp-small.lp-strong{fill:var(--ink)}
.lp-red{fill:var(--loop)}.lp-blue{fill:var(--accent)}.lp-on-red{fill:#fff}
.lp-t{paint-order:stroke;stroke:rgba(255,255,255,.9);stroke-width:4px;stroke-linejoin:round}
.lp-on-red,.lp-pill-t{stroke:none}
.lp-axes line{stroke:var(--ink);stroke-width:2}
.lp-axis-head{fill:var(--ink)}
.lp-loop{fill:none;stroke:var(--loop);stroke-width:3.5;stroke-linejoin:round;stroke-linecap:round}
.lp-loop.lp-soft{stroke-width:2.5;opacity:.45}
.lp-done{fill:none;stroke:var(--soft);stroke-width:3;stroke-linecap:round;stroke-linejoin:round}
.lp-ghost{fill:none;stroke:var(--ghost);stroke-width:2.5;stroke-dasharray:7 5;stroke-linejoin:round}
.lp-dot{fill:var(--loop);stroke:#fff;stroke-width:3}
.lp-edge{fill:none;stroke:var(--accent);stroke-width:6;stroke-linecap:round;stroke-linejoin:round}
.lp-spot{fill:none;stroke:var(--accent);stroke-width:3.5}
.lp-guide{stroke:var(--ea);stroke-width:1.25;stroke-dasharray:4 4}
.lp-arrow line{stroke:var(--ink);stroke-width:2}.lp-arrow path{fill:var(--ink)}
.lp-arrow-red line{stroke:var(--loop)}.lp-arrow-red path{fill:var(--loop)}
.lp-arrow-blue line{stroke:var(--accent);stroke-width:2.5}.lp-arrow-blue path{fill:var(--accent)}
.lp-pill{fill:var(--white);stroke:var(--ink);stroke-width:1.5}
.lp-pill.open{fill:#e3f1e6;stroke:#1d6b33}
.lp-pill-t{font-size:12.5px;font-weight:700;fill:var(--ink)}
.lp-pill-t.open{fill:#1d6b33}
.ef-left{fill:#e1e3dc}.ef-out{fill:var(--loop)}.ef-frame{fill:none;stroke:var(--ink);stroke-width:1.5}
.hd-chamber,.hd-vessel{fill:var(--loop-tint);stroke:var(--ink);stroke-width:3;stroke-linejoin:round}
.hd-gap{fill:var(--loop-tint)}
.hd-leaf{fill:none;stroke:var(--ink);stroke-width:3.5;stroke-linecap:round;stroke-linejoin:round}
.hd-flow line{stroke:var(--loop);stroke-width:3}.hd-flow path{fill:var(--loop)}
.hd-flow-out line{stroke-dasharray:5 4}
.hd-lead{stroke:var(--soft);stroke-width:1}
.hd-dot{fill:var(--ink)}
.explore-intro{margin-top:16px}
.explore-intro h2{margin-bottom:6px}
.explore-intro p{margin:0;font-size:15px;max-width:900px}
@media (min-width:900px){
  .step{grid-template-columns:minmax(0,600px) minmax(0,1fr);grid-template-rows:auto auto 1fr;column-gap:32px;row-gap:10px}
  .step-fig{grid-column:1;grid-row:1/4}
  .step-kicker,.step h2,.step-cap{grid-column:2}
  .step-kicker{align-self:end;margin-top:6px}
  .step h2{font-size:38px}
  .step-cap{font-size:19px}
  .step-nav{position:static;max-width:600px;margin-top:16px}
}

/* Clinical values */
.clinical{margin-top:16px}
.cv-intro-card h2{margin-bottom:8px}
.cv-disclaimer{margin:0 0 10px;padding:8px 12px;border-left:4px solid var(--loop);background:var(--loop-tint);font-weight:700}
.cv-intro,.cv-note{margin:0 0 8px;font-size:15px;max-width:900px}
.cv-note{color:var(--soft)}
.cv-layout{display:grid;grid-template-columns:minmax(0,340px) minmax(0,1fr);gap:16px;margin-top:16px;align-items:start}
.cv-side{position:sticky;top:calc(var(--bar-h) + 10px);max-height:calc(100vh - var(--bar-h) - 20px);overflow-y:auto}
.cv-side h3:first-child{margin-top:0}
.cv-states{display:grid;grid-template-columns:1fr 1fr;gap:6px}
.cv-state{font:inherit;font-weight:600;font-size:14px;line-height:1.2;text-align:left;min-height:44px;padding:6px 9px;border:2px solid var(--ink);background:var(--white);color:var(--ink);cursor:pointer;border-radius:0}
.cv-state small{display:block;font-size:11px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--soft)}
.cv-state:hover{background:var(--loop-tint)}
.cv-state[aria-pressed=true]{background:var(--ink);color:var(--paper)}
.cv-state[aria-pressed=true] small{color:#d9dbd3}
.cv-state-note{font-size:14px;min-height:4em}
.cv-state-note p{margin:10px 0 0}
.cv-model-note{color:var(--soft)}
.cv-status-row{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-top:12px;padding-top:10px;border-top:1px solid var(--rule)}
.cv-status{margin:0;font-weight:700;font-size:14px}
.cv-buttons{display:inline-flex;gap:6px;flex-shrink:0}
.cv-baseline{margin:0 0 8px;font-size:15px;max-width:900px;padding:8px 12px;border:1px solid var(--rule);background:var(--paper)}
.cv-sources a{word-break:break-all}
.cv-status.settled{color:#1d6b33}
.sliders.compact{grid-template-columns:1fr;gap:4px}
.sliders.compact .slider label{font-size:14px}
.sliders.compact .slider output{font-size:16px}
.sliders.compact input[type=range]{height:32px}
.cv-legend{display:flex;flex-wrap:wrap;gap:4px 18px;font-size:13px;font-weight:600;color:var(--soft);margin-bottom:6px}
.cv-legend span{display:inline-flex;align-items:center;gap:6px}
.cv-legend i{display:inline-block;position:relative}
.lg-band{width:22px;height:12px;background:#bfe0e4;border:1px solid var(--ed)}
.lg-typ{width:3px;height:16px;background:var(--ink)}
.lg-dot{width:13px;height:13px;border-radius:50%;background:var(--loop);border:2px solid var(--white);box-shadow:0 0 0 1px var(--loop)}
.lg-base{width:10px;height:10px;border-radius:50%;border:2px solid var(--soft);background:var(--white)}
.cv-list{list-style:none;margin:0;padding:0}
.cv-loading{padding:12px 0;color:var(--soft)}
.cv-row{display:grid;grid-template-columns:minmax(0,15rem) minmax(0,1fr) minmax(0,10.5rem);gap:2px 16px;align-items:center;padding:10px 0 8px;border-top:1px solid #e1e3dc}
.cv-row:first-child{border-top:0}
.cv-name b{display:block;font-size:15px;line-height:1.25}
.cv-ref{display:block;font-size:13px;color:var(--soft)}
.cv-bar{position:relative;height:34px}
.cv-track{position:absolute;left:0;right:0;top:12px;height:6px;background:#eceee8;border:1px solid #d3d6cc}
.cv-band{position:absolute;top:6px;height:18px;background:#bfe0e4;border:1px solid var(--ed);min-width:3px}
.cv-typ{position:absolute;top:3px;width:3px;height:24px;margin-left:-1.5px;background:var(--ink)}
.cv-base{position:absolute;top:9px;width:12px;height:12px;margin-left:-6px;border-radius:50%;border:2px solid var(--soft);background:var(--white)}
.cv-dot{position:absolute;top:6px;width:18px;height:18px;margin-left:-9px;border-radius:50%;background:var(--loop);border:3px solid var(--white);box-shadow:0 0 0 1px var(--loop);transition:left .25s ease-out}
.cv-row.out .cv-dot{background:var(--white);border:4px solid var(--loop);box-shadow:none}
.cv-row.offscale .cv-dot{border-radius:2px}
.cv-axis{position:absolute;left:0;right:0;top:24px;display:flex;justify-content:space-between;font-size:11px;color:var(--soft);line-height:1}
.cv-now{text-align:right;white-space:nowrap}
.cv-num{font-size:22px;font-weight:600;color:var(--loop)}
.cv-now small{font-size:12px;color:var(--soft);margin-left:4px}
.cv-flag{display:block;font-size:13px;font-weight:600;color:var(--soft);white-space:normal}
.cv-row.out .cv-flag{color:var(--loop)}
.cv-shift{grid-column:2/-1;display:flex;flex-wrap:wrap;gap:4px 14px;font-size:14px;font-weight:600}
.cv-shift b{font-size:17px;margin-right:2px}
.cv-exp{color:var(--ink)}
.cv-exp.dir-up b,.cv-exp.dir-down b{color:var(--accent)}
.cv-model{color:var(--soft)}
.cv-model.differ{color:var(--loop)}
.cv-cite{grid-column:1/-1;margin:2px 0 0;font-size:12px;color:var(--soft)}
.cv-cite span{color:var(--ink)}
.cv-sources{margin-top:16px}
.cv-sources h2{margin-bottom:8px}
.cv-sources ul{padding-left:18px;margin:0}
.cv-sources li{margin-bottom:6px;font-size:14px}

/* Cards and stage */
.card{background:var(--white);border:1px solid var(--rule);border-top:3px solid var(--ink);padding:16px;min-width:0}
.card-head{display:flex;justify-content:space-between;align-items:baseline;gap:6px 14px;flex-wrap:wrap;margin-bottom:8px}
.card-sub{margin:0;font-size:13px;color:var(--soft)}
.stage{display:grid;grid-template-columns:minmax(0,55fr) minmax(0,45fr);gap:16px;margin-top:16px}
.canvas-box{position:relative;width:100%}
.pv-box{aspect-ratio:1.12/1}
.wig-box{height:100%;min-height:300px}
.plot-card{display:flex;flex-direction:column}
.plot-card .wig-box{flex:1}
canvas{display:block;width:100%;height:100%;touch-action:pan-y}
.legend{display:flex;flex-wrap:wrap;gap:4px 16px;margin:8px 0 0;font-size:13px;color:var(--soft);font-weight:600}
.legend span{display:inline-flex;align-items:center;gap:6px}
.key{margin:4px 0 0;font-size:13px;color:var(--soft)}
.key b{color:var(--ink)}
.sw{display:inline-block;width:20px;height:0;border-top:3px solid}
.sw-loop{border-color:var(--loop)}.sw-es{border-color:var(--es)}.sw-ed{border-color:var(--ed)}
.sw-ea{border-top:2px dashed var(--ea)}.sw-ghost{border-top:2px dashed var(--ghost)}
.sw-ao{border-color:var(--accent)}.sw-la{border-top:2px dashed var(--es)}.sw-v{border-color:var(--ink);border-top-width:2px}

.lower{display:grid;grid-template-columns:minmax(0,1.45fr) minmax(0,1fr);gap:16px;margin-top:16px}
.hint{margin:0 0 12px;font-size:14px;color:var(--soft)}

/* Sliders */
.sliders{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px 26px}
.slider{min-width:0}
.slider-top{display:flex;justify-content:space-between;align-items:baseline;gap:8px}
.slider label{font-weight:700;font-size:15px}
.slider label .what{display:block;font-weight:500;font-size:13px;color:var(--soft)}
.slider output{font-size:20px;font-weight:600;white-space:nowrap}
.slider output small{font-size:12px;color:var(--soft);font-weight:500;margin-left:3px}
.slider .changed{color:var(--loop)}
.range-ends{display:flex;justify-content:space-between;font-size:12px;color:var(--soft);margin-top:-2px}
input[type=range]{-webkit-appearance:none;appearance:none;width:100%;height:36px;background:transparent;margin:4px 0 0;cursor:pointer}
input[type=range]::-webkit-slider-runnable-track{height:4px;background:var(--ink)}
input[type=range]::-moz-range-track{height:4px;background:var(--ink)}
input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;appearance:none;width:26px;height:26px;margin-top:-11px;border-radius:50%;background:var(--white);border:3px solid var(--loop)}
input[type=range]::-moz-range-thumb{width:20px;height:20px;border-radius:50%;background:var(--white);border:3px solid var(--loop)}
input[type=range]:focus-visible{outline:3px solid var(--accent);outline-offset:2px}

/* Tables */
.beat-table{width:100%;border-collapse:collapse;font-size:14px}
.beat-table th,.beat-table td{text-align:left;padding:5px 0;border-bottom:1px solid #e1e3dc;vertical-align:baseline}
.beat-table th{font-weight:500;color:var(--soft);padding-right:10px}
.beat-table td{text-align:right;font-weight:600;white-space:nowrap}
.table-card h2{margin-bottom:8px}
.checks td{white-space:normal}
.ok{color:#1d6b33}.off{color:var(--loop)}

/* About */
.about{margin-top:16px}
.about-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:8px 36px}
.about p,.about li{font-size:15px;max-width:620px}
.about ul{padding-left:18px;margin:0}
.about li{margin-bottom:6px}
.refs li{font-size:14px}
.eq{font-family:var(--mono);font-size:13px;line-height:1.55;background:var(--paper);border:1px solid var(--rule);padding:12px 14px;overflow-x:auto;margin:0;white-space:pre}

footer{margin-top:48px;border-top:2px solid var(--ink)}
footer .wrap{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;padding-top:14px;padding-bottom:40px;font-size:14px}

@media (max-width:1100px){
  .numbers{grid-template-columns:repeat(4,minmax(0,1fr))}
  .numbers>div:nth-child(4n+1){border-left:0}
  .numbers>div:nth-child(n+5){border-top:1px solid var(--rule)}
  .cv-row{grid-template-columns:minmax(0,1fr) auto}
  .cv-name{grid-column:1}.cv-now{grid-column:2;grid-row:1}
  .cv-bar,.cv-shift{grid-column:1/-1}
}
@media (max-width:899px){
  .explore{display:flex;flex-direction:column}
  .numbers{order:1}.tabs{order:2}.stage{order:3}.toolbar{order:4}.presets{order:5}.lower{order:6}.about{order:7}
  .presets{grid-template-columns:1fr;margin-top:16px}
  .presets .eyebrow{margin-bottom:8px}
  .toolbar{border-top:0;margin-top:4px}
  .hero{grid-template-columns:1fr;padding-top:16px}
  .lede{margin-top:8px;font-size:15px}
  .stage,.lower,.about-grid{grid-template-columns:1fr}
  .stage{margin-top:10px}
  .tabpanel:not(.active){display:none}
  .explore [id]{scroll-margin-top:calc(var(--bar-h) + 130px)}
  .numbers{position:sticky;top:var(--bar-h);z-index:10;box-shadow:0 2px 0 rgba(23,25,22,.06)}
  .numbers>div{padding:5px 8px}
  .numbers dd{font-size:18px}
  .numbers dt{font-size:11px;letter-spacing:.03em}
  .numbers dd small{font-size:11px;margin-left:2px}
  .numbers .status-cell dd{font-size:13px;padding-top:1px}
  .pv-box{aspect-ratio:auto;height:min(92vw,62vh);min-height:300px}
  .wig-box{height:min(92vw,62vh);min-height:300px}
  .sliders{grid-template-columns:1fr}
  input[type=range]{height:44px}
  input[type=range]::-webkit-slider-thumb{width:32px;height:32px;margin-top:-14px}
  input[type=range]::-moz-range-thumb{width:26px;height:26px}
  .lesson-tabs{margin-top:14px}
  .lesson-tabs [role=tab]{flex:1;padding:8px 6px;margin-right:0;font-size:13px;letter-spacing:.04em;line-height:1.15}
  .lesson-tabs [role=tab]+[role=tab]{border-left:0}
  .cv-layout{grid-template-columns:1fr}
  .cv-side{position:static;max-height:none;overflow:visible}
}
@media (max-width:520px){
  .wrap{padding:0 14px}
  .card{padding:12px}
  .preset-buttons{display:grid;grid-template-columns:1fr 1fr}
  .preset{font-size:14px;padding:8px 8px}
  .toolbar{gap:10px}
  .tool-group:first-child{display:grid;grid-template-columns:auto 1fr 1fr;width:100%}
  .tool-group:first-child .btn{padding:8px 8px;font-size:14px}
  .numbers dd{font-size:16px}
  .numbers dd small{display:block;margin:0;font-size:10px;line-height:1.1}
  .numbers dt{font-size:10px}
  .hero{padding-top:12px}
  .kicker{font-size:12px;letter-spacing:.06em}
  h1{font-size:clamp(30px,8.6vw,40px)}
  .lede{font-size:15px;line-height:1.4;margin-top:6px}
}
@media (prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
@media print{.numbers,.cv-side{position:static}}

/* Site top bar, matching the homepage's view A (Astra) bar. Scoped names so it cannot collide with lab.css or a lesson's CSS. */
.site-top{position:sticky;top:0;z-index:50;background:rgba(247,247,242,.96);border-bottom:1px solid #171916;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);font-family:'Space Grotesk',system-ui,-apple-system,'Segoe UI',sans-serif}
.site-top-in{max-width:1600px;margin:0 auto;padding-inline:clamp(22px,4vw,64px);height:78px;display:flex;align-items:center;gap:28px}
.site-brand{font-weight:700;font-size:27px;letter-spacing:-.08em;color:#171916;text-decoration:none;white-space:nowrap}
.site-brand span{color:#254dff;padding-inline:5px}
.site-nav{margin-left:auto;display:flex;align-items:center;gap:26px}
.site-nav a{color:#171916;text-decoration:none;font-size:13px;white-space:nowrap}
.site-nav a:hover{color:#254dff}
.site-nav a[aria-current]{color:#254dff;font-weight:600;text-decoration:underline;text-decoration-thickness:2px;text-underline-offset:6px}
.site-top a:focus-visible{outline:3px solid #254dff;outline-offset:3px}
@media(max-width:850px){.site-top-in{height:70px}.site-nav{gap:17px}.site-nav a{font-size:12px}}
@media(max-width:620px){.site-top-in{height:66px;gap:15px}.site-brand{font-size:24px}.site-nav{gap:18px}.site-nav a{display:none}.site-nav a.site-nav-home,.site-nav a.site-nav-lab{display:block}}
@media print{.site-top{position:static}}