:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) {
    --ch15-ink: #15333d;
    --ch15-muted: #60757d;
    --ch15-line: #78929a;
    --ch15-grid: #d7e3e6;
    --ch15-surface: #f4f9f8;
    --ch15-surface-strong: #e3f2ef;
    --ch15-accent: #087f74;
    --ch15-secondary: #d17235;
    margin: clamp(1.1rem, 2.6vw, 1.8rem) 0;
    padding: clamp(1rem, 2.6vw, 1.45rem);
    border: 1px solid color-mix(in srgb, var(--ch15-accent) 18%, transparent);
    border-radius: 1.25rem;
    background: linear-gradient(145deg, #fbfdfc 0%, var(--ch15-surface) 100%);
    color: var(--ch15-ink);
    box-shadow: 0 0.8rem 2rem rgb(21 51 61 / 0.07);
    overflow: clip;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-heading {
    display: grid;
    gap: 0.2rem;
    margin-bottom: 0.9rem;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-heading h3 {
    margin: 0;
    font-size: clamp(1.16rem, 2.4vw, 1.42rem);
    line-height: 1.18;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-kicker {
    margin: 0;
    color: var(--ch15-accent);
    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.09em;
    text-transform: uppercase;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-controls {
    display: grid;
    grid-template-columns: repeat(var(--ch15-control-count, 4), minmax(0, 1fr));
    gap: 0.45rem;
    margin-bottom: 0.85rem;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-control {
    min-height: 2.55rem;
    padding: 0.55rem 0.68rem;
    border: 1px solid color-mix(in srgb, var(--ch15-line) 65%, transparent);
    border-radius: 0.72rem;
    background: rgb(255 255 255 / 0.86);
    color: var(--ch15-ink);
    font: inherit;
    font-size: 0.82rem;
    font-weight: 750;
    line-height: 1.15;
    cursor: pointer;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-control:hover {
    border-color: var(--ch15-accent);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-control[aria-pressed="true"] {
    border-color: var(--ch15-accent);
    background: var(--ch15-accent);
    color: #fff;
    box-shadow: 0 0.35rem 0.9rem rgb(8 127 116 / 0.22);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-stage {
    min-width: 0;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-drawing {
    position: relative;
    width: 100%;
    aspect-ratio: var(--ch15-drawing-ratio, 720 / 340);
    border-radius: 0.95rem;
    background: rgb(255 255 255 / 0.72);
    container-type: inline-size;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-drawing > svg {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-math-label {
    position: absolute;
    z-index: 2;
    max-width: 38%;
    color: var(--ch15-ink);
    font-size: clamp(0.66rem, 2.3cqw, 1rem);
    font-weight: 650;
    line-height: 1;
    white-space: nowrap;
    pointer-events: none;
    transform: translate(-50%, -50%);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-math-label[data-math-anchor="start"] {
    transform: translate(0, -50%);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-math-label[data-math-anchor="end"] {
    transform: translate(-100%, -50%);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-math-label :is(mjx-container, mjx-container[display="true"]) {
    margin: 0 !important;
    max-width: 100%;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-math-label.is-large {
    font-size: clamp(0.86rem, 3.4cqw, 1.45rem);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-math-label.is-small {
    font-size: clamp(0.6rem, 2cqw, 0.88rem);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-math-label.is-chip {
    padding: 0.25em 0.48em;
    border: 1px solid color-mix(in srgb, var(--ch15-line) 65%, transparent);
    border-radius: 0.5rem;
    background: rgb(255 255 255 / 0.94);
    box-shadow: 0 0.15rem 0.4rem rgb(21 51 61 / 0.08);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-math-label.is-wide {
    max-width: 82%;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-panel[hidden] {
    display: none !important;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) svg {
    display: block;
    width: 100%;
    height: auto;
    max-height: 31rem;
    border-radius: 0.95rem;
    background: rgb(255 255 255 / 0.72);
    overflow: visible;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-visual-caption {
    margin: 0.75rem 0 0;
    color: var(--ch15-muted);
    font-size: 0.93rem;
    line-height: 1.5;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) :is(.ch15-axis, .ch15-tick, .ch15-wall, .ch15-measure-line) {
    fill: none;
    stroke: var(--ch15-ink);
    stroke-width: 1.4;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) :is(.ch15-wall, .ch15-measure-line) {
    stroke-width: 2;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) :is(.ch15-vector, .ch15-motion-line) {
    fill: none;
    stroke: var(--ch15-accent);
    stroke-width: 2.4;
    stroke-linecap: round;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) :is(.ch15-vector.is-secondary, .ch15-path-line.is-secondary, .ch15-plot-line.is-secondary) {
    stroke: var(--ch15-secondary);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-arrowhead {
    fill: none;
    stroke: var(--ch15-accent);
    stroke-width: 1.5;
    stroke-linecap: round;
    stroke-linejoin: round;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-arrowhead.is-secondary {
    stroke: var(--ch15-secondary);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) :is(.ch15-path-line, .ch15-plot-line) {
    fill: none;
    stroke: var(--ch15-accent);
    stroke-width: 2.4;
    stroke-linecap: round;
    stroke-linejoin: round;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) :is(.ch15-guide-line, .ch15-impulse-mark) {
    fill: none;
    stroke: var(--ch15-secondary);
    stroke-width: 1.4;
    stroke-dasharray: 6 5;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) :is(.ch15-panel-shape, .ch15-equation-box, .ch15-container) {
    fill: var(--ch15-surface);
    stroke: var(--ch15-line);
    stroke-width: 1.5;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-equation-box.is-strong {
    fill: var(--ch15-surface-strong);
    stroke: var(--ch15-accent);
    stroke-width: 2;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) :is(.ch15-particle-dot, .ch15-molecule, .ch15-data-point) {
    fill: var(--ch15-accent);
    stroke: #fff;
    stroke-width: 1.4;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) :is(.ch15-particle-dot.is-secondary, .ch15-data-point.is-secondary) {
    fill: var(--ch15-secondary);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-wall.is-target {
    stroke: var(--ch15-secondary);
    stroke-width: 2.8;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-collision-window {
    fill: var(--ch15-secondary);
    opacity: 0.72;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-bar {
    fill: color-mix(in srgb, var(--ch15-accent) 68%, #fff);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-bar.is-strong {
    fill: var(--ch15-accent);
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) text {
    fill: var(--ch15-ink);
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-equation {
    font-family: "STIX Two Math", "Times New Roman", serif;
    font-size: 25px;
    font-weight: 650;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-equation.is-large {
    font-size: 34px;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) .ch15-equation.is-small {
    font-size: 20px;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) :is(.ch15-small-label, .ch15-axis-label, .ch15-annotation, .ch15-tick-label, .ch15-footnote) {
    font-size: 16px;
    font-weight: 650;
}

:is(
    [data-unit-visual-extension="mole_particle_bridge"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="kelvin_proportionality"],
    [data-unit-visual-extension="molar_particle_equation"],
    [data-unit-visual-extension="kinetic_assumptions"],
    [data-unit-visual-extension="collision_pressure"],
    [data-unit-visual-extension="rms_speed_statistics"],
    [data-unit-visual-extension="temperature_mass_scaling"]
) :is(.ch15-tick-label, .ch15-footnote) {
    fill: var(--ch15-muted);
    font-size: 14px;
    font-weight: 550;
}

@media (max-width: 640px) {
    :is(
        [data-unit-visual-extension="mole_particle_bridge"],
        [data-unit-visual-extension="controlled_gas_laws"],
        [data-unit-visual-extension="kelvin_proportionality"],
        [data-unit-visual-extension="molar_particle_equation"],
        [data-unit-visual-extension="kinetic_assumptions"],
        [data-unit-visual-extension="collision_pressure"],
        [data-unit-visual-extension="rms_speed_statistics"],
        [data-unit-visual-extension="temperature_mass_scaling"]
    ) {
        margin-inline: -0.15rem;
        padding: 0.85rem;
        border-radius: 1rem;
    }

    :is(
        [data-unit-visual-extension="mole_particle_bridge"],
        [data-unit-visual-extension="controlled_gas_laws"],
        [data-unit-visual-extension="kelvin_proportionality"],
        [data-unit-visual-extension="molar_particle_equation"],
        [data-unit-visual-extension="kinetic_assumptions"],
        [data-unit-visual-extension="collision_pressure"],
        [data-unit-visual-extension="rms_speed_statistics"],
        [data-unit-visual-extension="temperature_mass_scaling"]
    ) .ch15-visual-controls {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 0.38rem;
    }

    :is(
        [data-unit-visual-extension="mole_particle_bridge"],
        [data-unit-visual-extension="controlled_gas_laws"],
        [data-unit-visual-extension="kelvin_proportionality"],
        [data-unit-visual-extension="molar_particle_equation"],
        [data-unit-visual-extension="kinetic_assumptions"],
        [data-unit-visual-extension="collision_pressure"],
        [data-unit-visual-extension="rms_speed_statistics"],
        [data-unit-visual-extension="temperature_mass_scaling"]
    ) .ch15-visual-control {
        min-height: 2.7rem;
        padding: 0.5rem 0.42rem;
        font-size: 0.75rem;
    }

    :is(
        [data-unit-visual-extension="mole_particle_bridge"],
        [data-unit-visual-extension="controlled_gas_laws"],
        [data-unit-visual-extension="kelvin_proportionality"],
        [data-unit-visual-extension="molar_particle_equation"],
        [data-unit-visual-extension="kinetic_assumptions"],
        [data-unit-visual-extension="collision_pressure"],
        [data-unit-visual-extension="rms_speed_statistics"],
        [data-unit-visual-extension="temperature_mass_scaling"]
    ) svg {
        width: 100%;
        max-width: 100%;
        margin-left: 0;
    }

    :is(
        [data-unit-visual-extension="mole_particle_bridge"],
        [data-unit-visual-extension="controlled_gas_laws"],
        [data-unit-visual-extension="kelvin_proportionality"],
        [data-unit-visual-extension="molar_particle_equation"],
        [data-unit-visual-extension="kinetic_assumptions"],
        [data-unit-visual-extension="collision_pressure"],
        [data-unit-visual-extension="rms_speed_statistics"],
        [data-unit-visual-extension="temperature_mass_scaling"]
    ) .ch15-visual-caption {
        font-size: 0.86rem;
        line-height: 1.45;
    }
}

@media (prefers-reduced-motion: reduce) {
    :is(
        [data-unit-visual-extension="mole_particle_bridge"],
        [data-unit-visual-extension="controlled_gas_laws"],
        [data-unit-visual-extension="kelvin_proportionality"],
        [data-unit-visual-extension="molar_particle_equation"],
        [data-unit-visual-extension="kinetic_assumptions"],
        [data-unit-visual-extension="collision_pressure"],
        [data-unit-visual-extension="rms_speed_statistics"],
        [data-unit-visual-extension="temperature_mass_scaling"]
    ) * {
        scroll-behavior: auto !important;
        transition: none !important;
        animation: none !important;
    }
}

[data-unit-visual-extension="sealed_gas_state_probe"] {
    --ch15-ink: #15333d;
    --ch15-muted: #60757d;
    --ch15-line: #78929a;
    --ch15-grid: #d7e3e6;
    --ch15-surface: #f4f9f8;
    --ch15-surface-strong: #e3f2ef;
    --ch15-accent: #087f74;
    --ch15-secondary: #d17235;
    margin: clamp(1.1rem, 2.6vw, 1.8rem) 0;
    padding: clamp(1rem, 2.6vw, 1.45rem);
    border: 1px solid color-mix(in srgb, var(--ch15-accent) 18%, transparent);
    border-radius: 1.25rem;
    background: linear-gradient(145deg, #fbfdfc 0%, var(--ch15-surface) 100%);
    color: var(--ch15-ink);
    box-shadow: 0 0.8rem 2rem rgb(21 51 61 / 0.07);
    overflow: clip;
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-visual-heading {
    display: grid;
    gap: 0.2rem;
    margin-bottom: 0.9rem;
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-visual-heading h3 {
    margin: 0;
    font-size: clamp(1.16rem, 2.4vw, 1.42rem);
    line-height: 1.18;
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-visual-kicker {
    margin: 0;
    color: var(--ch15-accent);
    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.09em;
    text-transform: uppercase;
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="collision_pressure"]
) .ch15-timeline {
    display: grid;
    grid-template-columns: auto auto minmax(8rem, 1fr) minmax(8rem, auto);
    align-items: center;
    gap: 0.55rem;
    margin: 0 0 0.8rem;
    padding: 0.65rem;
    border: 1px solid color-mix(in srgb, var(--ch15-line) 45%, transparent);
    border-radius: 0.85rem;
    background: rgb(255 255 255 / 0.78);
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="collision_pressure"]
) .ch15-timeline-button {
    min-height: 2.35rem;
    padding: 0.45rem 0.72rem;
    border: 1px solid color-mix(in srgb, var(--ch15-line) 70%, transparent);
    border-radius: 0.65rem;
    background: #fff;
    color: var(--ch15-ink);
    font: inherit;
    font-size: 0.8rem;
    font-weight: 800;
    cursor: pointer;
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="collision_pressure"]
) .ch15-timeline-button:is(:hover, [aria-pressed="true"]) {
    border-color: var(--ch15-accent);
    background: var(--ch15-accent);
    color: #fff;
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="collision_pressure"]
) .ch15-timeline-scrub {
    width: 100%;
    min-width: 0;
    accent-color: var(--ch15-accent);
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="collision_pressure"]
) .ch15-timeline-phase {
    color: var(--ch15-muted);
    font-size: 0.8rem;
    font-weight: 750;
    line-height: 1.25;
    text-align: right;
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="collision_pressure"]
) .ch15-dynamic-stage {
    min-width: 0;
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="collision_pressure"]
) .ch15-timeline-formulas {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 0.72rem;
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="collision_pressure"]
) .ch15-formula-chip {
    display: inline-flex;
    align-items: center;
    min-height: 2.15rem;
    padding: 0.4rem 0.68rem;
    border: 1px solid color-mix(in srgb, var(--ch15-accent) 28%, transparent);
    border-radius: 0.68rem;
    background: var(--ch15-surface-strong);
    color: var(--ch15-ink);
    font-size: 0.84rem;
    font-weight: 700;
    line-height: 1.2;
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="collision_pressure"]
) .ch15-formula-chip mjx-container {
    margin: 0 !important;
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="collision_pressure"]
) :is(.ch15-gas-chamber, .ch15-equation-box) {
    fill: var(--ch15-surface);
    stroke: var(--ch15-line);
    stroke-width: 1.5;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"]
) .ch15-piston {
    fill: var(--ch15-ink);
    opacity: 0.88;
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"]
) :is(.ch15-piston-rod, .ch15-piston-handle, .ch15-pressure-scale) {
    fill: none;
    stroke: var(--ch15-ink);
    stroke-width: 1.8;
    stroke-linecap: round;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"]
) .ch15-pressure-bar {
    fill: var(--ch15-secondary);
}

[data-unit-visual-extension="controlled_gas_laws"] .ch15-temperature-bar {
    fill: var(--ch15-accent);
}

[data-unit-visual-extension="collision_pressure"] .ch15-arrowhead.is-measure {
    stroke: var(--ch15-ink);
}

:is(
    [data-unit-visual-extension="sealed_gas_state_probe"],
    [data-unit-visual-extension="controlled_gas_laws"],
    [data-unit-visual-extension="collision_pressure"]
) .ch15-data-point.is-active {
    fill: var(--ch15-secondary);
    stroke: #fff;
    stroke-width: 2.2;
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-visual-drawing {
    position: relative;
    width: 100%;
    aspect-ratio: var(--ch15-drawing-ratio, 720 / 360);
    border-radius: 0.95rem;
    background: rgb(255 255 255 / 0.72);
    container-type: inline-size;
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-visual-drawing > svg {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-math-label {
    position: absolute;
    z-index: 2;
    max-width: 40%;
    color: var(--ch15-ink);
    font-size: clamp(0.66rem, 2.3cqw, 1rem);
    font-weight: 650;
    line-height: 1;
    white-space: nowrap;
    pointer-events: none;
    transform: translate(-50%, -50%);
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-math-label[data-math-anchor="start"] {
    transform: translate(0, -50%);
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-math-label[data-math-anchor="end"] {
    transform: translate(-100%, -50%);
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-math-label.is-large {
    font-size: clamp(0.86rem, 3.4cqw, 1.45rem);
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-math-label.is-small {
    font-size: clamp(0.6rem, 2cqw, 0.88rem);
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-math-label.is-chip {
    padding: 0.25em 0.48em;
    border: 1px solid color-mix(in srgb, var(--ch15-line) 65%, transparent);
    border-radius: 0.5rem;
    background: rgb(255 255 255 / 0.94);
}

[data-unit-visual-extension="sealed_gas_state_probe"] :is(.ch15-vector, .ch15-motion-line) {
    fill: none;
    stroke: var(--ch15-accent);
    stroke-width: 2.4;
    stroke-linecap: round;
    vector-effect: non-scaling-stroke;
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-arrowhead {
    fill: none;
    stroke: var(--ch15-accent);
    stroke-width: 1.5;
    stroke-linecap: round;
    stroke-linejoin: round;
}

[data-unit-visual-extension="sealed_gas_state_probe"] :is(.ch15-particle-dot, .ch15-molecule) {
    fill: var(--ch15-accent);
    stroke: #fff;
    stroke-width: 1.4;
    vector-effect: non-scaling-stroke;
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-impulse-mark {
    fill: none;
    stroke: var(--ch15-secondary);
    stroke-width: 1.4;
    stroke-dasharray: 6 5;
    vector-effect: non-scaling-stroke;
}

[data-unit-visual-extension="sealed_gas_state_probe"] .ch15-visual-caption {
    margin: 0.75rem 0 0;
    color: var(--ch15-muted);
    font-size: 0.93rem;
    line-height: 1.5;
}

@media (max-width: 640px) {
    [data-unit-visual-extension="sealed_gas_state_probe"] {
        margin-inline: -0.15rem;
        padding: 0.85rem;
        border-radius: 1rem;
    }

    :is(
        [data-unit-visual-extension="sealed_gas_state_probe"],
        [data-unit-visual-extension="controlled_gas_laws"],
        [data-unit-visual-extension="collision_pressure"]
    ) .ch15-timeline {
        grid-template-columns: repeat(2, minmax(0, auto));
        gap: 0.42rem;
    }

    :is(
        [data-unit-visual-extension="sealed_gas_state_probe"],
        [data-unit-visual-extension="controlled_gas_laws"],
        [data-unit-visual-extension="collision_pressure"]
    ) .ch15-timeline-scrub {
        grid-column: 1 / -1;
        grid-row: 2;
    }

    :is(
        [data-unit-visual-extension="sealed_gas_state_probe"],
        [data-unit-visual-extension="controlled_gas_laws"],
        [data-unit-visual-extension="collision_pressure"]
    ) .ch15-timeline-phase {
        grid-column: 1 / -1;
        text-align: left;
    }

    :is(
        [data-unit-visual-extension="sealed_gas_state_probe"],
        [data-unit-visual-extension="controlled_gas_laws"],
        [data-unit-visual-extension="collision_pressure"]
    ) .ch15-formula-chip {
        flex: 1 1 100%;
        justify-content: center;
        text-align: center;
    }

    [data-unit-visual-extension="sealed_gas_state_probe"] .ch15-visual-caption {
        font-size: 0.86rem;
        line-height: 1.45;
    }
}

@media (prefers-reduced-motion: reduce) {
    :is(
        [data-unit-visual-extension="sealed_gas_state_probe"],
        [data-unit-visual-extension="controlled_gas_laws"],
        [data-unit-visual-extension="collision_pressure"]
    ) * {
        scroll-behavior: auto !important;
        transition: none !important;
        animation: none !important;
    }
}