.inertia-page {
    --tool-primary: #087f75;
    --tool-primary-hover: #08685f;
    --lab-bg: #f5f5f0;
    --lab-panel: #fff;
    --lab-soft: #eff4f0;
    --lab-border: #d8dfd9;
    --lab-text: #1d3435;
    --lab-muted: #576a69;
    --lab-accent: #087f75;
    --lab-gold: #99630c;
    --lab-coral: #b6503d;
    background: var(--lab-bg);
}
.inertia-page.dark-mode, .dark-mode .inertia-page {
    --tool-primary: #78ddc8;
    --tool-primary-hover: #a3ebdb;
    --lab-bg: #10191b;
    --lab-panel: #182528;
    --lab-soft: #203134;
    --lab-border: #34484a;
    --lab-text: #edf5ef;
    --lab-muted: #adc0bc;
    --lab-accent: #78ddc8;
    --lab-gold: #ffcc72;
    --lab-coral: #ffa18c;
}
.inertia-lab { max-width: 1264px; padding: 30px 32px 70px; margin: 0 auto; color: var(--lab-text); }
.inertia-lab *, .inertia-lab *::before, .inertia-lab *::after { box-sizing: border-box; }
.inertia-lab [hidden] { display: none !important; }
.inertia-lab :is(h1, h2, h3, p) { margin-top: 0; text-align: left; }
.inertia-lab h2 { font-size: 1.2rem; font-weight: 720; line-height: 1.4; }
.inertia-lab h3 { font-size: 1rem; font-weight: 700; }
.inertia-lab p { line-height: 1.65; padding: 0; }
.inertia-lab a { color: var(--lab-accent); text-underline-offset: 4px; }
.inertia-lab :is(button, select, input, summary, a):focus-visible { outline: 3px solid var(--lab-accent) !important; outline-offset: 4px !important; }
.inertia-lab :is(h2, #explore) { scroll-margin-top: 95px; }
.inertia-lab button { cursor: pointer; min-height: 42px; }
body.inertia-page #main-content button:not(.primary) { color: var(--lab-text) !important; background: var(--lab-panel) !important; border-color: var(--lab-border) !important; }
body.inertia-page #main-content button[aria-pressed="true"] { color: var(--lab-accent) !important; background: var(--lab-soft) !important; border-color: var(--lab-accent) !important; }
.inertia-lab .lab-heading { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr); align-items: center; gap: 44px; margin: 0 0 28px; text-align: left; color: var(--lab-text); }
.lab-heading > div { min-width: 0; }
.inertia-lab .lab-eyebrow { color: var(--lab-accent); font: 700 .66rem/1.5 monospace; letter-spacing: .13em; margin-bottom: 20px; }
.live-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--lab-accent); display: inline-block; margin-right: 7px; box-shadow: 0 0 0 4px color-mix(in srgb, var(--lab-accent) 12%, transparent); }
.lab-heading h1 { font-size: clamp(2.7rem, 5.6vw, 4.8rem); line-height: 1.08; letter-spacing: -.055em; margin-bottom: 19px; font-weight: 680; color: var(--lab-text); }
.lab-heading h1 em { color: var(--lab-accent); font-family: Georgia, serif; font-weight: 400; }
.lab-heading > div > p:last-child { color: var(--lab-muted); max-width: 620px; font-size: .96rem; margin-bottom: 0; }
.lab-heading strong { font-weight: 550; color: var(--lab-text); }
.hero-equation { border: 1px solid var(--lab-border); border-radius: 4px 30px 4px 30px; padding: 26px 22px; text-align: center; background: var(--lab-soft); }
.hero-equation .stage-eyebrow { color: var(--lab-muted); }
.hero-equation math { font-size: 2.8rem; margin: 16px 0; color: var(--lab-accent); }
.hero-equation p { font-size: .78rem !important; text-align: center; }
.lesson-path { display: flex; align-items: center; gap: 24px; border-block: 1px solid var(--lab-border); padding: 16px 0; margin-bottom: 28px; font-size: .77rem; }
.lesson-path a { text-decoration: none; color: var(--lab-text); }
.lesson-path a:hover { color: var(--lab-accent); }
.lesson-path a span { color: var(--lab-accent); font: .7rem monospace; margin-right: 8px; }
.lesson-path > span { color: var(--lab-muted); }
.experiment-heading { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; margin-bottom: 12px; }
.experiment-heading h2 { margin: 0; font-size: .96rem; }
.experiment-heading > span { color: var(--lab-muted); font-size: .75rem; }
.experiment-strip { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 10px; }
body.inertia-page #main-content .experiment-strip button { display: flex; flex-direction: column; align-items: start; gap: 6px; padding: 15px !important; border-radius: 10px !important; text-align: left; color: var(--lab-text) !important; background: var(--lab-panel) !important; border-color: var(--lab-border) !important; }
body.inertia-page #main-content .experiment-strip button[aria-pressed="true"] { border-color: var(--lab-accent) !important; box-shadow: inset 0 -3px var(--lab-accent) !important; background: var(--lab-soft) !important; }
.experiment-strip .experiment-icon { font-size: 1.4rem; color: var(--lab-accent); height: 28px; line-height: 1; }
.experiment-strip strong { font-size: .8rem; font-weight: 700; }
.experiment-strip small { font-size: .69rem; line-height: 1.5; color: var(--lab-muted); font-weight: 400; }
.experiment-brief { display: flex; align-items: center; gap: 18px; padding: 18px 0 24px; }
.experiment-brief > span { color: var(--lab-accent); font: 700 .62rem monospace; white-space: nowrap; }
.inertia-lab .experiment-note { font-size: .8rem; color: var(--lab-muted); flex: 1; margin: 0; }
.experiment-brief a { white-space: nowrap; font-size: .73rem; }
.lab-workspace { display: grid; grid-template-columns: minmax(0, 1fr) 310px; grid-template-areas: "visual controls"; gap: 24px; margin-bottom: 38px; align-items: start; }
.lab-panel { background: var(--lab-panel); border: 1px solid var(--lab-border); border-radius: 14px; padding: 28px; margin-bottom: 28px; min-width: 0; }
.controls { grid-area: controls; padding: 22px; margin: 0; }
.controls h2 { font-size: .94rem; }
.controls > button { width: 100%; }
.panel-heading { display: flex; align-items: center; gap: 12px; margin-bottom: 19px; }
.panel-heading h2 { margin: 0; }
.step-number { font: 700 .78rem monospace; color: var(--lab-accent); display: grid; place-items: center; background: var(--lab-soft); border: 1px solid var(--lab-border); border-radius: 50%; width: 34px; height: 34px; flex-shrink: 0; }
.inertia-lab label { display: block; font-size: .78rem; font-weight: 650; margin-bottom: 8px; }
.inertia-lab select { max-width: 100%; min-width: 0; width: 100%; color: var(--lab-text); background: var(--lab-soft); border: 1px solid var(--lab-border); border-radius: 7px; padding: 9px 11px; font-size: .82rem; min-height: 42px; }
.range-control { margin: 17px 0; }
.range-control label { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 4px 8px; }
.range-control output { color: var(--lab-accent); font-variant-numeric: tabular-nums; font-weight: 750; }
.inertia-lab input[type="range"] { width: 100%; accent-color: var(--lab-accent); padding: 0; margin: 0; cursor: pointer; min-height: 24px; background: transparent; box-shadow: none; border: 0; }
.range-endpoints { display: flex; justify-content: space-between; font-size: .66rem; color: var(--lab-muted); margin-bottom: 8px; }
.inertia-lab .small-note { font-size: .73rem; line-height: 1.6; color: var(--lab-muted); margin-bottom: 12px; }
.control-divider { border-top: 1px solid var(--lab-border); margin: 23px 0; }
.axis-presets { display: flex; gap: 6px; }
.inertia-lab .axis-presets button { font-size: .7rem !important; padding: 7px 9px !important; flex: 1; }
.visual-column { grid-area: visual; min-width: 0; }
.workspace-label { font: 700 .62rem/1.6 monospace; letter-spacing: .06em; margin: 0 0 13px; display: flex; align-items: center; color: var(--lab-accent); }
.workspace-label > span:last-child { margin-left: auto; color: var(--lab-muted); font: .73rem sans-serif; letter-spacing: 0; }
.specimen-stage { border-radius: 13px; padding: 22px 22px 16px; color: #eaf5f6; background: radial-gradient(ellipse at 50% 45%, #1b3340, #101e2a 75%); border: 1px solid #314753; overflow: hidden; }
.stage-top { display: flex; align-items: center; justify-content: space-between; gap: 15px; }
.stage-eyebrow { font: .6rem monospace; color: #a2c0cc; letter-spacing: .1em; }
.stage-top h2 { font-size: 1.2rem; margin: 7px 0 0; }
.inertia-lab .view-label { color: #b7cbd4; font-size: .64rem; }
.inertia-lab .view-label select { color: #eaf5f6; background: #1a303f; border-color: #3e5664; width: 145px; margin-top: 5px; font-size: .73rem; }
.inertia-lab canvas { display: block; background: transparent; border: 0; border-radius: 0; box-shadow: none; padding: 0; }
.canvas-wrap { position: relative; }
#specimen { width: 100%; height: 390px; cursor: crosshair; touch-action: pan-y; }
.canvas-hint { position: absolute; bottom: 4px; left: 50%; transform: translateX(-50%); font-size: .67rem; white-space: nowrap; color: #9cb7c1; pointer-events: none; }
.inertia-lab .scene-description { font-size: .71rem; line-height: 1.55; color: #b7cbd4; margin: 12px 0; }
.stage-legend, .chart-legend { display: flex; flex-wrap: wrap; gap: 8px 18px; font-size: .67rem; line-height: 1.5; }
.stage-legend { color: #c1d2d8; padding-top: 12px; border-top: 1px solid #2c4250; }
.legend-dot { display: inline-block; width: 8px; height: 8px; margin-right: 5px; border-radius: 50%; }
.mass-dot { background: #2ab6a1; }
.inertia-dot { background: #ffc25b; }
.reference-dot { background: var(--lab-coral); }
.legend-line { display: inline-block; height: 2px; width: 14px; background: #ff8d7c; margin-right: 5px; vertical-align: middle; }
.result-strip { display: grid; grid-template-columns: 1.2fr 1fr 1fr; gap: 12px; padding: 22px 0; }
.result-strip > div { border-left: 2px solid var(--lab-border); padding-left: 15px; }
.result-strip > div:first-child { border-left-color: var(--lab-accent); }
.result-strip span { font: .58rem/1.6 monospace; letter-spacing: .035em; color: var(--lab-muted); display: block; margin-bottom: 7px; }
.result-strip strong { display: block; font-size: clamp(1.45rem, 2.5vw, 2rem); font-variant-numeric: tabular-nums; line-height: 1.2; overflow-wrap: anywhere; }
.result-strip > div:first-child strong { color: var(--lab-accent); }
.result-strip small { font-size: .67rem; color: var(--lab-muted); }
.live-explanation { padding: 18px 20px; border: 1px solid var(--lab-border); background: var(--lab-soft); border-radius: 10px; }
.inertia-lab .live-insight { font-size: .82rem; margin: 8px 0 12px; }
.worked-equation { font: .82rem/1.7 monospace; color: var(--lab-accent); overflow-wrap: anywhere; }
.element-inspector { border-block: 1px solid var(--lab-border); margin: 22px 0 0; padding: 17px 0 0; }
.element-inspector summary { font-size: .86rem; font-weight: 650; cursor: pointer; margin-bottom: 17px; }
.element-inspector summary span { float: right; font: .75rem monospace; color: var(--lab-accent); }
.piece-readout { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 14px 0; }
.piece-readout div { padding: 12px; background: var(--lab-panel); border: 1px solid var(--lab-border); border-radius: 7px; min-width: 0; }
.piece-readout dt { font-size: .7rem; color: var(--lab-muted); }
.piece-readout dd { margin: 8px 0 0; font: 650 .76rem monospace; overflow-wrap: anywhere; color: var(--lab-accent); }
.piece-explanation { font-size: .78rem; color: var(--lab-text); padding-left: 13px; border-left: 2px solid var(--lab-accent); }
.lab-panel > p { color: var(--lab-muted); font-size: .85rem; margin-bottom: 22px; }
.integral-grid { display: grid; grid-template-columns: 1fr 1.1fr; gap: 32px; align-items: start; }
.integral-grid > div { min-width: 0; }
.integral-copy { color: var(--lab-muted); font-size: .81rem; }
.partition-row { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px; }
.partition-row label { margin: 0; }
.partition-row select { width: auto; max-width: 100%; font-size: .76rem; }
.sum-box { background: var(--lab-soft); border-radius: 7px; padding: 13px; margin: 12px 0; overflow-x: auto; }
.sum-box > span { color: var(--lab-muted); font: .66rem monospace; }
.sum-box math { font-size: .98rem; margin: 12px 0 0; }
.convergence-readout { display: grid; grid-template-columns: 1fr auto; gap: 10px; background: var(--lab-soft); padding: 16px; border-radius: 8px; margin: 20px 0; }
.convergence-readout span { font: .65rem/1.7 monospace; color: var(--lab-muted); }
.convergence-readout strong { font: .82rem monospace; color: var(--lab-accent); }
.distribution { border-left: 1px solid var(--lab-border); padding-left: 30px; }
.distribution p { font-size: .78rem; color: var(--lab-muted); }
#distribution-chart, #motion-chart { display: block; width: 100%; height: auto; overflow: visible; }
.chart-legend { color: var(--lab-muted); margin-bottom: 12px; }
.chart-legend .inertia-dot { background: var(--lab-gold); }
.data-details { margin-top: 18px; border-top: 1px solid var(--lab-border); padding-top: 15px; font-size: .8rem; }
.data-details summary { cursor: pointer; color: var(--lab-accent); font-weight: 650; }
.data-details > p { color: var(--lab-muted); font-size: .8rem; margin-top: 15px; }
.table-scroll { overflow-x: auto; margin-top: 14px; }
.inertia-lab table { width: 100%; border-collapse: collapse; font-size: .72rem; background: transparent; color: var(--lab-text); }
.inertia-lab caption { color: var(--lab-muted); padding-bottom: 10px; text-align: left; }
.inertia-lab th, .inertia-lab td { padding: 8px; text-align: right; border-bottom: 1px solid var(--lab-border); background: transparent; }
.inertia-lab th { color: var(--lab-muted); }
.derivation-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.derivation-grid article { background: var(--lab-soft); border-left: 2px solid var(--lab-border); padding: 21px; border-radius: 4px; min-width: 0; }
.derivation-label { font: 700 .61rem/1.6 monospace; color: var(--lab-accent); letter-spacing: .055em; }
.derivation-grid h3 { margin: 10px 0 16px; }
.derivation-grid p { font-size: .78rem; color: var(--lab-muted); margin: 14px 0 0; }
.equation { font-size: 1rem; padding: 8px 0; overflow-x: auto; min-height: 45px; }
.equation math { margin: 0; }
.motion-panel { border-top: 3px solid var(--lab-accent); }
.motion-controls { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-bottom: 20px; }
.motion-controls .range-control { flex: 1 1 220px; max-width: 300px; margin: 0 12px 0 0; }
.comparison-verdict { border-block: 1px solid var(--lab-border); padding: 20px 0; margin: 22px 0; }
.comparison-verdict > strong { display: block; color: var(--lab-accent); font-size: 1.3rem; letter-spacing: -.02em; }
.comparison-verdict > p { font-size: .8rem; color: var(--lab-muted); margin: 10px 0 16px; }
.inertia-bars { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
.inertia-bars > div { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 10px; font-size: .7rem; }
.inertia-bars b { font: .7rem monospace; }
.inertia-bars meter { width: 100%; height: 12px; border: 0; background: var(--lab-soft); border-radius: 8px; }
.inertia-bars meter::-webkit-meter-bar { background: var(--lab-soft); border: 0; }
.inertia-bars meter::-webkit-meter-optimum-value { background: var(--lab-accent); }
.inertia-bars meter::-moz-meter-bar { background: var(--lab-accent); }
#reference-bar::-webkit-meter-optimum-value { background: var(--lab-coral); }
#reference-bar::-moz-meter-bar { background: var(--lab-coral); }
.motion-comparison { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.motion-body { background: var(--lab-soft); border-radius: 10px; border: 1px solid var(--lab-border); padding: 18px; min-width: 0; border-top: 3px solid var(--lab-accent); }
.motion-body:last-child { border-top-color: var(--lab-coral); }
.motion-body:last-child .derivation-label, .motion-body:last-child dd { color: var(--lab-coral); }
.motion-body h3 { margin: 9px 0 12px; font-size: .8rem; line-height: 1.7; min-height: 2.8em; }
.motion-body canvas { background: #101e2a; border-radius: 8px; width: 100%; height: auto; aspect-ratio: 520/280; }
.motion-body dl { display: grid; grid-template-columns: repeat(4, 1fr); gap: 7px; margin: 18px 0 0; }
.motion-body dt { font-size: .64rem; color: var(--lab-muted); min-height: 2.8em; }
.motion-body dd { margin: 6px 0 0; font: 650 .87rem monospace; color: var(--lab-accent); overflow-wrap: anywhere; }
.motion-timeline { background: var(--lab-soft); padding: 14px 20px; border-radius: 8px; margin: 18px 0 24px; }
.motion-timeline .range-control { margin: 0; }
.motion-timeline .small-note { margin: 5px 0 0; }
.motion-story { display: grid; grid-template-columns: 1fr 1.4fr; align-items: center; gap: 30px; }
.motion-story h3 { margin: 10px 0; }
.motion-story p { font-size: .8rem; }
#motion-status { font-size: .82rem; color: var(--lab-text); margin: 18px 0 10px; }
.motion-panel > .small-note { margin: 0; }
.lab-takeaways h2 { margin: 32px 0 22px; font-size: 1.4rem; }
.lab-takeaways > div { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 30px; }
.lab-takeaways strong { font-size: .88rem; }
.lab-takeaways article p { color: var(--lab-muted); font-size: .8rem; margin: 9px 0 0; }
.inertia-lab .sources { color: var(--lab-muted); margin: 30px 0 0; font-size: .74rem; }
@media (max-width: 1050px) {
    .inertia-lab { padding: 24px 20px 45px; }
    .lab-workspace { grid-template-columns: minmax(0, 1fr) 270px; gap: 18px; }
    .controls { padding: 18px; }
    .experiment-strip { gap: 7px; }
    body.inertia-page #main-content .experiment-strip button { padding: 12px !important; }
    .workspace-label > span:last-child { display: none; }
    .inertia-bars { gap: 15px; }
    .inertia-bars > div { grid-template-columns: 1fr auto; }
    .inertia-bars meter { grid-column: 1 / -1; grid-row: 2; }
}
@media (max-width: 780px) {
    .inertia-lab .lab-heading { grid-template-columns: minmax(0, 1fr); gap: 22px; }
    .lab-heading h1 { font-size: clamp(2.65rem, 8vw, 3.8rem); }
    .hero-equation { display: grid; grid-template-columns: auto 1fr; gap: 10px 20px; padding: 18px; text-align: left; border-radius: 10px; }
    .hero-equation .stage-eyebrow { grid-column: 1 / -1; }
    .hero-equation math { font-size: 2.2rem; margin: 0; }
    .hero-equation p { font-size: .73rem !important; text-align: left; }
    .lesson-path { gap: 12px; justify-content: space-between; font-size: .68rem; }
    .lesson-path a span { display: block; margin-bottom: 5px; }
    .lesson-path > span { display: none; }
    .experiment-strip { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .experiment-heading > span { display: none; }
    .experiment-brief { flex-wrap: wrap; gap: 10px; }
    .experiment-note { flex-basis: 80% !important; }
    .experiment-brief a { margin-left: auto; }
    .lab-workspace { display: flex; flex-direction: column; gap: 16px; }
    .visual-column { display: contents; }
    .workspace-label { order: 0; margin: 0; }
    .specimen-stage { order: 1; width: 100%; }
    .controls { order: 2; width: 100%; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px 18px; }
    .controls > :not(.range-control) { grid-column: 1 / -1; }
    .controls :is(.panel-heading, .range-control, .small-note, label, .control-divider, h2) { margin: 0; }
    .controls .sum-box { margin: 0; }
    .controls [data-dimension="hollow"] { grid-column: 1 / -1; }
    .result-strip { order: 3; width: 100%; padding: 8px 0; }
    .live-explanation { order: 4; width: 100%; }
    .element-inspector { order: 5; width: 100%; margin-top: 0; }
    .result-strip > div { padding-left: 9px; }
    .result-strip span { font-size: .55rem; }
    .lab-panel { padding: 22px 18px; }
    .integral-grid, .derivation-grid, .motion-story { grid-template-columns: 1fr; gap: 24px; }
    .distribution { border-left: 0; border-top: 1px solid var(--lab-border); padding: 22px 0 0; }
    .motion-controls .range-control { flex-basis: 100%; max-width: none; margin: 0 0 10px; }
    .motion-comparison { grid-template-columns: 1fr; }
    .lab-takeaways > div { grid-template-columns: 1fr; gap: 22px; }
}
@media (max-width: 520px) {
    .inertia-lab { padding: 20px 14px 40px; }
    .inertia-lab .lab-heading { gap: 18px; }
    .hero-equation { grid-template-columns: 1fr; gap: 12px; }
    .hero-equation math { font-size: 1.9rem; }
    .hero-equation p { text-align: center; }
    .lab-heading h1 { font-size: 2.8rem; }
    .lab-heading > div > p:last-child { font-size: .85rem; }
    .lab-eyebrow { font-size: .57rem !important; }
    .experiment-strip { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .experiment-strip button:last-child { grid-column: 1 / -1; }
    body.inertia-page #main-content .experiment-strip button:last-child { display: grid; grid-template-columns: 30px 1fr; gap: 4px 10px; }
    .experiment-strip button:last-child .experiment-icon { grid-row: span 2; }
    .specimen-stage { padding: 16px 12px; }
    .stage-top { gap: 10px; }
    .stage-eyebrow { font-size: .52rem; }
    .stage-top h2 { font-size: 1.05rem; }
    .inertia-lab .view-label select { width: 122px; }
    #specimen { height: 300px; }
    .canvas-hint { font-size: .58rem; }
    .stage-legend { gap: 8px 12px; font-size: .61rem; }
    .inertia-bars { grid-template-columns: 1fr; }
    .element-inspector summary span { float: none; display: block; margin-top: 8px; }
    .piece-readout { gap: 5px; }
    .piece-readout div { padding: 9px; }
    .piece-readout dd { font-size: .7rem; }
    .motion-body { padding: 12px; }
    .motion-body dl { gap: 5px; }
    .motion-body dt { font-size: .61rem; }
    .motion-body dd { font-size: .78rem; }
    .comparison-verdict > strong { font-size: 1.16rem; }
}
@media (prefers-reduced-motion: reduce) { .inertia-lab * { scroll-behavior: auto !important; transition: none !important; } }