:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) {
    --ch16-ink: #17333d;
    --ch16-muted: #60757d;
    --ch16-line: #78929a;
    --ch16-grid: #d7e3e6;
    --ch16-surface: #f4f9f8;
    --ch16-surface-strong: #e4f2ef;
    --ch16-accent: #087f74;
    --ch16-secondary: #cc7138;
    margin: clamp(1.1rem, 2.6vw, 1.8rem) 0;
    padding: clamp(1rem, 2.6vw, 1.45rem);
    border: 1px solid color-mix(in srgb, var(--ch16-accent) 18%, transparent);
    border-radius: 1.25rem;
    background: linear-gradient(145deg, #fbfdfc 0%, var(--ch16-surface) 100%);
    color: var(--ch16-ink);
    box-shadow: 0 0.8rem 2rem rgb(21 51 61 / 0.07);
    overflow: clip;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-heading {
    display: grid;
    gap: 0.2rem;
    margin-bottom: 0.9rem;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-heading h3 {
    margin: 0;
    font-size: var(--unit-text-heading-medium, 17px);
    line-height: 1.18;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-kicker {
    margin: 0;
    color: var(--ch16-accent);
    font-size: var(--unit-text-micro, 11px);
    font-weight: 800;
    letter-spacing: 0.09em;
    text-transform: uppercase;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-controls {
    display: grid;
    grid-template-columns: repeat(var(--ch16-control-count, 4), minmax(0, 1fr));
    gap: 0.45rem;
    margin-bottom: 0.85rem;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-control {
    height: 41px;
    min-width: 0;
    padding: 0.48rem 0.42rem;
    border: 1px solid color-mix(in srgb, var(--ch16-line) 65%, transparent);
    border-radius: 0.72rem;
    background: rgb(255 255 255 / 0.86);
    color: var(--ch16-ink);
    font: inherit;
    font-size: var(--unit-text-meta, 12px);
    font-weight: 750;
    line-height: 1;
    white-space: nowrap;
    text-overflow: ellipsis;
    overflow: hidden;
    cursor: pointer;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-control:hover {
    border-color: var(--ch16-accent);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-control[aria-pressed="true"] {
    border-color: var(--ch16-accent);
    background: var(--ch16-accent);
    color: #fff;
    box-shadow: 0 0.35rem 0.9rem rgb(8 127 116 / 0.22);
}

.ch16-visual .ch16-timeline {
    display: grid;
    grid-template-columns: auto auto minmax(7rem, 1fr) minmax(9rem, auto);
    align-items: center;
    gap: 0.55rem;
    margin: -0.15rem 0 0.85rem;
    padding: 0.58rem;
    border: 1px solid color-mix(in srgb, var(--ch16-line) 45%, transparent);
    border-radius: 0.82rem;
    background: rgb(255 255 255 / 0.72);
}

.ch16-visual .ch16-timeline-button {
    min-width: 4.5rem;
    min-height: 36px;
    padding: 0.4rem 0.7rem;
    border: 1px solid color-mix(in srgb, var(--ch16-accent) 52%, var(--ch16-grid));
    border-radius: 999px;
    background: #fff;
    color: var(--ch16-accent);
    font: inherit;
    font-size: var(--unit-text-meta, 12px);
    font-weight: 800;
    cursor: pointer;
}

.ch16-visual .ch16-timeline-button:hover,
.ch16-visual .ch16-timeline-button[aria-pressed="true"] {
    border-color: var(--ch16-accent);
    background: var(--ch16-accent);
    color: #fff;
}

.ch16-visual .ch16-timeline-scrub {
    width: 100%;
    min-width: 0;
    accent-color: var(--ch16-accent);
}

.ch16-visual .ch16-timeline-phase {
    min-width: 0;
    color: var(--ch16-muted);
    font-size: var(--unit-text-meta, 12px);
    font-weight: 750;
    line-height: 1.25;
    text-align: right;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-stage {
    min-width: 0;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-drawing {
    position: relative;
    width: 100%;
    aspect-ratio: var(--ch16-drawing-ratio, 720 / 340);
    border-radius: 0.95rem;
    background: rgb(255 255 255 / 0.72);
    container-type: inline-size;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-drawing > svg {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    max-height: none;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-math-label {
    position: absolute;
    z-index: 2;
    max-width: 42%;
    color: var(--ch16-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="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-math-label[data-math-anchor="start"] {
    transform: translate(0, -50%);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-math-label[data-math-anchor="end"] {
    transform: translate(-100%, -50%);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-math-label :is(mjx-container, mjx-container[display="true"]) {
    margin: 0 !important;
    max-width: 100%;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-math-label.is-state {
    font-size: clamp(0.92rem, 4.2cqw, 1.7rem);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-math-label.is-emphasis {
    font-size: clamp(0.8rem, 3.2cqw, 1.25rem);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-math-label.is-small {
    font-size: clamp(0.64rem, 1.85cqw, 0.86rem);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-math-label.is-axis {
    font-size: clamp(0.64rem, 2.05cqw, 0.92rem);
    font-weight: 750;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-math-label.is-tick {
    color: var(--ch16-muted);
    font-size: clamp(0.56rem, 1.65cqw, 0.74rem);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-math-label.is-chip {
    max-width: 78%;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-math-label.is-footnote {
    max-width: 82%;
    color: var(--ch16-muted);
    font-size: clamp(0.58rem, 1.75cqw, 0.78rem);
    font-weight: 650;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-panel[hidden] {
    display: none !important;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) 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="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-visual-caption {
    margin: 0.75rem 0 0;
    color: var(--ch16-muted);
    font-size: var(--unit-text-small, 14px);
    line-height: 1.5;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) :is(.ch16-axis, .ch16-tick, .ch16-measure-line, .ch16-mechanism-line, .ch16-ledger-rule) {
    fill: none;
    stroke: var(--ch16-ink);
    stroke-width: 1.3;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) :is(.ch16-measure-line, .ch16-cylinder-wall, .ch16-piston-face) {
    fill: none;
    stroke: var(--ch16-ink);
    stroke-width: 2;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) :is(.ch16-vector, .ch16-plot-route, .ch16-cycle-path) {
    fill: none;
    stroke: var(--ch16-accent);
    stroke-width: 2.4;
    stroke-linecap: round;
    stroke-linejoin: round;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) :is(.ch16-vector.is-secondary, .ch16-plot-route.is-secondary, .ch16-measure-line.is-secondary) {
    stroke: var(--ch16-secondary);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-plot-route.is-neutral {
    stroke: var(--ch16-line);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-arrowhead {
    fill: none;
    stroke: var(--ch16-accent);
    stroke-width: 1.5;
    stroke-linecap: round;
    stroke-linejoin: round;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-arrowhead.is-secondary {
    stroke: var(--ch16-secondary);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-arrowhead.is-neutral {
    stroke: var(--ch16-line);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) :is(.ch16-system-box, .ch16-ledger-box) {
    fill: rgb(228 242 239 / 0.62);
    stroke: var(--ch16-accent);
    stroke-width: 2;
    stroke-dasharray: 8 6;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-system-box.is-boundary {
    stroke-dasharray: 10 7;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) :is(.ch16-formula-chip, .ch16-constraint-card) {
    fill: #fff;
    stroke: color-mix(in srgb, var(--ch16-accent) 35%, var(--ch16-grid));
    stroke-width: 1.2;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-molecule {
    fill: #fff;
    stroke: var(--ch16-accent);
    stroke-width: 2;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-energy-store {
    fill: #fff;
    stroke: var(--ch16-line);
    stroke-width: 1.4;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) :is(.ch16-energy-level, .ch16-energy-packet) {
    fill: var(--ch16-accent);
}

[data-unit-visual-extension="energy_transfer_boundary"] .ch16-energy-level {
    opacity: 0.24;
}

[data-unit-visual-extension="energy_transfer_boundary"] .ch16-energy-packet {
    stroke: #fff;
    stroke-width: 2;
    vector-effect: non-scaling-stroke;
}

[data-unit-visual-extension="energy_transfer_boundary"] .ch16-energy-packet.is-secondary {
    fill: var(--ch16-secondary);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-state-symbol {
    fill: var(--ch16-accent);
    font: 800 2.1rem/1 ui-monospace, SFMono-Regular, Menlo, monospace;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) :is(.ch16-heat-wave, .ch16-cycle-path) {
    fill: none;
    stroke: var(--ch16-secondary);
    stroke-width: 2.2;
    stroke-linecap: round;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-mechanism-wheel {
    fill: #fff;
    stroke: var(--ch16-secondary);
    stroke-width: 2;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-gas-fill {
    fill: rgb(8 127 116 / 0.08);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-piston-face.is-ghost {
    stroke: var(--ch16-secondary);
    stroke-dasharray: 7 6;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-swept-volume {
    fill: rgb(204 113 56 / 0.16);
    stroke: var(--ch16-secondary);
    stroke-width: 1.3;
    stroke-dasharray: 5 4;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-rigid-stop {
    fill: var(--ch16-ink);
    opacity: 0.78;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-zero-route {
    stroke: var(--ch16-line);
    stroke-width: 1.5;
    stroke-dasharray: 5 5;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-work-area {
    fill: rgb(8 127 116 / 0.15);
    stroke: none;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-work-area.is-secondary {
    fill: rgb(204 113 56 / 0.16);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-state-point {
    fill: #fff;
    stroke: var(--ch16-accent);
    stroke-width: 2;
    vector-effect: non-scaling-stroke;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-state-point.is-end {
    fill: var(--ch16-accent);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-state-point.is-end.is-secondary {
    fill: var(--ch16-secondary);
    stroke: var(--ch16-secondary);
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-state-point.is-end.is-neutral {
    fill: var(--ch16-line);
    stroke: var(--ch16-line);
}

.ch16-visual :is(.is-motion-result, .is-motion-result-shape, .is-force-result) {
    transition: opacity 180ms linear;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) :is(.ch16-equation, .ch16-annotation, .ch16-small-label, .ch16-axis-label, .ch16-tick-label, .ch16-footnote) {
    fill: var(--ch16-ink);
    paint-order: stroke;
    stroke: rgb(255 255 255 / 0.94);
    stroke-width: 3px;
    stroke-linejoin: round;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-equation {
    font: 750 1.05rem/1.2 ui-monospace, SFMono-Regular, Menlo, monospace;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-equation.is-small {
    font-size: 0.86rem;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-annotation {
    font: 700 0.82rem/1.15 system-ui, sans-serif;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-small-label {
    fill: var(--ch16-muted);
    font: 800 0.71rem/1.1 system-ui, sans-serif;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-axis-label {
    font: 800 1rem/1 ui-monospace, SFMono-Regular, Menlo, monospace;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-tick-label {
    fill: var(--ch16-muted);
    font: 650 0.69rem/1 ui-monospace, SFMono-Regular, Menlo, monospace;
}

:is(
    [data-unit-visual-extension="internal_energy_state"],
    [data-unit-visual-extension="energy_transfer_boundary"],
    [data-unit-visual-extension="piston_work_geometry"],
    [data-unit-visual-extension="first_law_ledger"],
    [data-unit-visual-extension="process_constraints"],
    [data-unit-visual-extension="work_sign_pv"]
) .ch16-footnote {
    fill: var(--ch16-muted);
    font: 650 0.72rem/1.1 system-ui, sans-serif;
}

@media (max-width: 620px) {
    :is(
        [data-unit-visual-extension="internal_energy_state"],
        [data-unit-visual-extension="energy_transfer_boundary"],
        [data-unit-visual-extension="piston_work_geometry"],
        [data-unit-visual-extension="first_law_ledger"],
        [data-unit-visual-extension="process_constraints"],
        [data-unit-visual-extension="work_sign_pv"]
    ) {
        padding: 0.82rem;
        border-radius: 1rem;
    }

    :is(
        [data-unit-visual-extension="internal_energy_state"],
        [data-unit-visual-extension="energy_transfer_boundary"],
        [data-unit-visual-extension="piston_work_geometry"],
        [data-unit-visual-extension="first_law_ledger"],
        [data-unit-visual-extension="process_constraints"],
        [data-unit-visual-extension="work_sign_pv"]
    ) .ch16-visual-controls {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 0.38rem;
    }

    :is(
        [data-unit-visual-extension="internal_energy_state"],
        [data-unit-visual-extension="energy_transfer_boundary"],
        [data-unit-visual-extension="piston_work_geometry"],
        [data-unit-visual-extension="first_law_ledger"],
        [data-unit-visual-extension="process_constraints"],
        [data-unit-visual-extension="work_sign_pv"]
    ) .ch16-visual-control {
        height: 38px;
        padding-inline: 0.34rem;
        font-size: var(--unit-text-meta, 12px);
    }

    :is(
        [data-unit-visual-extension="internal_energy_state"],
        [data-unit-visual-extension="energy_transfer_boundary"],
        [data-unit-visual-extension="piston_work_geometry"],
        [data-unit-visual-extension="first_law_ledger"],
        [data-unit-visual-extension="process_constraints"],
        [data-unit-visual-extension="work_sign_pv"]
    ) .ch16-visual-caption {
        font-size: var(--unit-text-small, 14px);
    }

    .ch16-visual .ch16-timeline {
        grid-template-columns: auto auto minmax(0, 1fr);
        gap: 0.42rem;
        padding: 0.5rem;
    }

    .ch16-visual .ch16-timeline-button {
        min-width: 4rem;
        min-height: 34px;
        padding-inline: 0.58rem;
    }

    .ch16-visual .ch16-timeline-phase {
        grid-column: 1 / -1;
        min-height: 1.25em;
        text-align: left;
    }
}

@media (prefers-reduced-motion: reduce) {
    :is(
        [data-unit-visual-extension="internal_energy_state"],
        [data-unit-visual-extension="energy_transfer_boundary"],
        [data-unit-visual-extension="piston_work_geometry"],
        [data-unit-visual-extension="first_law_ledger"],
        [data-unit-visual-extension="process_constraints"],
        [data-unit-visual-extension="work_sign_pv"]
    ) * {
        scroll-behavior: auto !important;
        transition-duration: 0.001ms !important;
        animation-duration: 0.001ms !important;
        animation-iteration-count: 1 !important;
    }

}