@font-face {
  font-family: "Syne";
  src: url("/inelul-din-aer/assets/fonts/syne-latin-ext.woff2") format("woff2");
  font-style: normal;
  font-weight: 800;
  font-display: swap;
  unicode-range: U+0100-024F, U+1E00-1EFF, U+20A0-20AB;
}

@font-face {
  font-family: "Syne";
  src: url("/inelul-din-aer/assets/fonts/syne-latin.woff2") format("woff2");
  font-style: normal;
  font-weight: 800;
  font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+FEFF, U+FFFD;
}

@font-face {
  font-family: "Manrope";
  src: url("/inelul-din-aer/assets/fonts/manrope-latin-ext.woff2") format("woff2");
  font-style: normal;
  font-weight: 400 800;
  font-display: swap;
  unicode-range: U+0100-024F, U+1E00-1EFF, U+20A0-20AB;
}

@font-face {
  font-family: "Manrope";
  src: url("/inelul-din-aer/assets/fonts/manrope-latin.woff2") format("woff2");
  font-style: normal;
  font-weight: 400 800;
  font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+FEFF, U+FFFD;
}

:root {
  color-scheme: dark;
  --tunnel: #082629;
  --tunnel-deep: #051b1e;
  --air: #71e1c1;
  --air-muted: #a5cfc3;
  --vortex: #ff7259;
  --seed: #e6b85c;
  --pappus: #eff4df;
  --paper: #eff4df;
  --paper-warm: #e7ead5;
  --ink: #102326;
  --ink-muted: #536561;
  --line-dark: rgba(239, 244, 223, 0.2);
  --line-light: rgba(16, 35, 38, 0.2);
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --display: "Syne", "Arial Black", sans-serif;
  --body: "Manrope", "Avenir Next", sans-serif;
  --page-pad: clamp(1.25rem, 4vw, 4.75rem);
  --content-max: 96rem;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
  background: var(--tunnel);
}

body {
  margin: 0;
  min-width: 20rem;
  overflow-x: hidden;
  background: var(--tunnel);
  color: var(--pappus);
  font-family: var(--body);
  font-size: clamp(1rem, 0.92rem + 0.22vw, 1.15rem);
  line-height: 1.65;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: var(--vortex);
  color: var(--tunnel-deep);
}

a {
  color: inherit;
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

a:hover {
  text-decoration-color: var(--vortex);
}

:focus-visible {
  outline: 3px solid var(--vortex);
  outline-offset: 4px;
}

svg {
  display: block;
  max-width: 100%;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 0.75rem;
  left: 0.75rem;
  min-height: 2.75rem;
  padding: 0.65rem 1rem;
  transform: translateY(-180%);
  border: 2px solid var(--tunnel);
  background: var(--paper);
  color: var(--ink);
  font-weight: 800;
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: absolute;
  z-index: 20;
  top: 0;
  left: 0;
  display: flex;
  width: 100%;
  max-width: var(--content-max);
  align-items: center;
  justify-content: space-between;
  padding: 1.35rem var(--page-pad);
  pointer-events: none;
}

.site-header a,
.site-header span {
  pointer-events: auto;
}

.author-mark {
  display: inline-flex;
  min-width: 2.75rem;
  min-height: 2.75rem;
  align-items: center;
  gap: 0.7rem;
  color: var(--pappus);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-decoration: none;
  text-transform: uppercase;
}

.author-mark > span:first-child {
  display: grid;
  width: 2rem;
  height: 2rem;
  place-items: center;
  border: 1px solid var(--air);
  border-radius: 50%;
  color: var(--air);
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0;
}

.language-switch {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  font-family: var(--mono);
  font-size: 0.74rem;
}

.language-switch a,
.language-switch span {
  display: grid;
  min-width: 2.75rem;
  min-height: 2.75rem;
  place-items: center;
  border-radius: 50%;
  text-decoration: none;
}

.language-switch [aria-current="page"] {
  border: 1px solid var(--air);
  color: var(--air);
}

.eyebrow,
.section-index,
.tunnel-head,
.range-ends,
.source-note,
.adjacent-limit {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  line-height: 1.45;
  text-transform: uppercase;
}

.eyebrow {
  margin: 0 0 1.25rem;
  color: var(--air);
}

.hero {
  position: relative;
  display: grid;
  min-height: 100svh;
  max-width: var(--content-max);
  grid-template-columns: minmax(22rem, 0.88fr) minmax(32rem, 1.12fr);
  margin: 0 auto;
  background:
    linear-gradient(90deg, transparent calc(50% - 0.5px), rgba(113, 225, 193, 0.1) 50%, transparent calc(50% + 0.5px));
}

.hero-copy {
  position: relative;
  z-index: 2;
  display: flex;
  max-width: 48rem;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  padding: 7.5rem var(--page-pad) 5rem;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  font-family: var(--display);
  font-weight: 800;
  letter-spacing: -0.045em;
  line-height: 0.98;
}

h1 {
  width: 100%;
  max-width: 12ch;
  margin-bottom: clamp(1.75rem, 4vh, 3rem);
  font-size: clamp(3.7rem, 5.7vw, 6.8rem);
  text-wrap: balance;
}

h1 em {
  color: var(--vortex);
  font-style: normal;
}

body[data-lang="en"] h1 {
  font-size: clamp(3.3rem, 4.6vw, 5rem);
}

.mobile-break {
  display: none;
}

h2 {
  max-width: 13ch;
  margin-bottom: 1.75rem;
  font-size: clamp(2.9rem, 5.2vw, 5.9rem);
  text-wrap: balance;
}

h3 {
  font-size: clamp(1.4rem, 1.7vw, 2rem);
  line-height: 1.12;
}

.standfirst,
.lead {
  font-size: clamp(1.2rem, 1.05rem + 0.8vw, 1.8rem);
  line-height: 1.45;
}

.standfirst {
  max-width: 36rem;
  margin-bottom: 2rem;
  color: #d9e8dc;
}

.standfirst strong {
  color: var(--air);
  font-family: var(--mono);
  font-size: 0.92em;
  font-weight: 500;
}

.definition {
  position: relative;
  max-width: 34rem;
  margin-bottom: 2.25rem;
  padding: 1rem 0 0 3.1rem;
  border-top: 1px solid var(--line-dark);
  color: var(--air-muted);
  font-size: 0.83rem;
  line-height: 1.55;
}

.definition span {
  position: absolute;
  top: 1.08rem;
  left: 0;
  color: var(--air);
  font-family: var(--mono);
  font-size: 0.72rem;
}

.text-link {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  gap: 0.65rem;
  color: var(--pappus);
  font-weight: 800;
  text-decoration: none;
}

.text-link span {
  color: var(--air);
  transition: transform 160ms ease;
}

.text-link:hover span {
  transform: translateY(0.2rem);
}

.tunnel {
  position: relative;
  display: flex;
  min-height: 100svh;
  flex-direction: column;
  padding: 5rem clamp(1.15rem, 3vw, 3.5rem) 2.25rem;
  border-inline: 1px solid rgba(113, 225, 193, 0.12);
  background:
    linear-gradient(rgba(113, 225, 193, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(113, 225, 193, 0.035) 1px, transparent 1px),
    var(--tunnel-deep);
  background-size: 48px 48px;
}

.tunnel::before,
.tunnel::after {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 1px;
  background: linear-gradient(transparent, rgba(113, 225, 193, 0.4), transparent);
  content: "";
}

.tunnel::before { left: 11%; }
.tunnel::after { right: 11%; }

.tunnel-head {
  position: relative;
  z-index: 2;
  display: flex;
  min-height: 2.75rem;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  color: var(--air-muted);
}

.tunnel-head h2 {
  margin: 0;
  color: var(--pappus);
  font-family: var(--mono);
  font-size: inherit;
  font-weight: 500;
  letter-spacing: inherit;
  line-height: inherit;
  text-transform: uppercase;
}

.tunnel-head span::before {
  display: inline-block;
  width: 0.45rem;
  height: 0.45rem;
  margin-right: 0.55rem;
  border-radius: 50%;
  background: var(--vortex);
  content: "";
}

.tunnel-figure {
  position: relative;
  z-index: 1;
  display: flex;
  min-height: 0;
  flex: 1 1 auto;
  flex-direction: column;
  justify-content: center;
  margin: 0;
}

#wind-tunnel {
  width: min(100%, 40rem);
  max-height: min(66vh, 45rem);
  margin: auto;
  overflow: visible;
}

.flow {
  fill: none;
  stroke: url("#air-fade");
  stroke-dasharray: 5 12;
  stroke-linecap: round;
  stroke-width: 1.5;
  animation: air-rise 3.8s linear infinite;
}

.flow-b,
.flow-d,
.flow-f { animation-delay: -1.9s; }

.flow-c,
.flow-e { animation-duration: 4.6s; }

.vortex {
  opacity: 1;
  transform-box: fill-box;
  transform-origin: center;
  transition: opacity 420ms ease, transform 520ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.vortex-ghost {
  fill: none;
  stroke: var(--vortex);
  stroke-dasharray: 4 8;
  stroke-opacity: 0.28;
  stroke-width: 10;
}

.vortex-front {
  fill: rgba(255, 114, 89, 0.04);
  stroke: var(--vortex);
  stroke-linecap: round;
  stroke-width: 9;
  filter: none;
}

.vortex-arrow {
  fill: none;
  stroke: var(--air);
  stroke-linecap: round;
  stroke-width: 1.5;
  animation: ring-drift 2.5s ease-in-out infinite alternate;
}

.solid-disc {
  fill: rgba(239, 244, 223, 0.9);
  stroke: var(--pappus);
  stroke-width: 2;
  transition: opacity 240ms ease, transform 300ms ease;
  transform-box: fill-box;
  transform-origin: center;
}

.pappus-lines line {
  stroke: var(--pappus);
  stroke-linecap: round;
  stroke-width: 1.05;
  transition: opacity 220ms ease;
}

.hub {
  fill: var(--seed);
}

.beak,
.achene-rib {
  fill: none;
  stroke: var(--seed);
  stroke-linecap: round;
  stroke-width: 2.2;
}

.achene {
  fill: var(--seed);
  stroke: #ffd989;
  stroke-width: 1;
}

.achene-rib {
  stroke: rgba(8, 38, 41, 0.55);
  stroke-width: 1;
}

.diagram-labels path {
  fill: none;
  stroke: rgba(239, 244, 223, 0.35);
  stroke-dasharray: 2 4;
  stroke-width: 1;
}

.diagram-labels text {
  fill: var(--air-muted);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.diagram-labels .air-direction {
  fill: var(--air);
}

figcaption {
  color: var(--air-muted);
  font-family: var(--mono);
  font-size: 0.69rem;
  line-height: 1.5;
}

.tunnel-figure figcaption {
  max-width: 38rem;
  margin: 0 auto 1rem;
}

.control {
  position: relative;
  z-index: 3;
  max-width: 42rem;
  margin: 0 auto;
}

.control label {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.02em;
}

.control output {
  color: var(--air);
  font-family: var(--mono);
  font-size: 1.15rem;
  font-weight: 500;
}

.control input[type="range"] {
  width: 100%;
  min-height: 2.75rem;
  margin: 0.4rem 0 0;
  padding: 0;
  accent-color: var(--vortex);
  appearance: none;
  background: transparent;
  cursor: ew-resize;
}

.control input[type="range"]::-webkit-slider-runnable-track {
  height: 2px;
  background: linear-gradient(90deg, var(--vortex) 0 var(--range-progress, 100%), rgba(239, 244, 223, 0.26) var(--range-progress, 100%));
}

.control input[type="range"]::-moz-range-track {
  height: 2px;
  background: rgba(239, 244, 223, 0.26);
}

.control input[type="range"]::-moz-range-progress {
  height: 2px;
  background: var(--vortex);
}

.control input[type="range"]::-webkit-slider-thumb {
  width: 1.55rem;
  height: 1.55rem;
  margin-top: -0.72rem;
  appearance: none;
  border: 4px solid var(--tunnel-deep);
  border-radius: 50%;
  background: var(--vortex);
  box-shadow: 0 0 0 1px var(--vortex);
}

.control input[type="range"]::-moz-range-thumb {
  width: 1.55rem;
  height: 1.55rem;
  border: 4px solid var(--tunnel-deep);
  border-radius: 50%;
  background: var(--vortex);
  box-shadow: 0 0 0 1px var(--vortex);
}

.control input[type="range"]:focus-visible {
  border-radius: 0.2rem;
  outline-offset: 0;
}

.range-ends {
  display: flex;
  justify-content: space-between;
  margin-top: -0.2rem;
  color: var(--air-muted);
  font-size: 0.6rem;
  letter-spacing: 0.04em;
}

.state-explanation {
  min-height: 2.9em;
  margin: 0.75rem 0 0;
  color: var(--pappus);
  font-size: 0.78rem;
  line-height: 1.45;
}

.control-note {
  margin: 0.35rem 0 0;
  color: var(--air-muted);
  font-size: 0.68rem;
  line-height: 1.45;
}

.mechanism,
.comparison,
.scope,
.sources {
  position: relative;
  padding: clamp(5rem, 10vw, 10rem) var(--page-pad);
}

.mechanism > *,
.comparison > *,
.scope > *,
.sources > * {
  width: 100%;
  max-width: var(--content-max);
  min-width: 0;
  margin-inline: 0;
}

.site-footer > * {
  max-width: var(--content-max);
}

.section-index {
  padding-bottom: 1rem;
  border-bottom: 1px solid currentColor;
  opacity: 0.56;
}

.mechanism {
  display: grid;
  max-width: var(--content-max);
  grid-template-columns: minmax(18rem, 0.75fr) minmax(28rem, 1.25fr);
  gap: clamp(2.5rem, 8vw, 8rem);
  margin: 0 auto;
  border-top: 1px solid var(--line-dark);
  background: var(--tunnel);
}

.mechanism .section-index,
.mechanism .measurements,
.mechanism .adjacent-limit {
  grid-column: 1 / -1;
}

.mechanism-copy {
  align-self: center;
}

.mechanism-copy h2 {
  color: var(--air);
}

.mechanism-copy p:not(.eyebrow) {
  max-width: 45rem;
  color: #cad9cf;
}

.mechanism-copy strong {
  color: var(--vortex);
  font-family: var(--mono);
}

.boundary-figure {
  align-self: center;
  margin: 0;
  padding: 1rem 0 0;
}

.boundary-figure svg {
  width: 100%;
  overflow: visible;
}

.boundary-flow path {
  fill: none;
  stroke: var(--air);
  stroke-dasharray: 4 9;
  stroke-opacity: 0.32;
  stroke-width: 1.4;
}

.halos ellipse {
  fill: rgba(113, 225, 193, 0.08);
  stroke: rgba(113, 225, 193, 0.25);
  stroke-width: 1;
}

.filaments circle {
  fill: var(--pappus);
}

.spacing {
  fill: none;
  stroke: var(--vortex);
  stroke-width: 1;
}

.boundary-figure text {
  fill: var(--air-muted);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.03em;
}

.boundary-figure .halo-label {
  fill: var(--air);
}

.measurements {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin: 1rem 0 0;
  border-top: 1px solid var(--line-dark);
  border-bottom: 1px solid var(--line-dark);
}

.measurements > div {
  position: relative;
  padding: 1.5rem clamp(0.8rem, 2vw, 2rem) 1.75rem 0;
}

.measurements > div + div {
  padding-left: clamp(0.8rem, 2vw, 2rem);
  border-left: 1px solid var(--line-dark);
}

.measurements dt {
  margin-bottom: 0.65rem;
  color: var(--air-muted);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.measurements dd {
  margin: 0;
  color: var(--pappus);
  font-family: var(--mono);
  font-size: clamp(1.55rem, 2.6vw, 3rem);
  line-height: 1.1;
}

.measurements small {
  display: block;
  margin-top: 0.75rem;
  color: var(--air-muted);
  font-family: var(--body);
  font-size: 0.65rem;
  line-height: 1.4;
}

.adjacent-limit {
  max-width: none;
  margin-top: -4rem;
  padding-top: 1rem;
  color: var(--air-muted);
  text-transform: none;
}

.comparison {
  color-scheme: light;
  display: grid;
  grid-template-columns: minmax(20rem, 0.8fr) minmax(30rem, 1.2fr);
  gap: clamp(3rem, 8vw, 8rem);
  background: var(--paper);
  color: var(--ink);
}

.comparison .section-index {
  grid-column: 1 / -1;
}

.comparison .eyebrow {
  color: #357c6d;
}

.comparison-copy {
  align-self: center;
}

.comparison-copy h2 {
  color: var(--ink);
}

.comparison-copy .lead {
  max-width: 41rem;
  color: #334c4a;
}

.area-comparison {
  align-self: center;
  margin: 0;
}

.area-visual {
  display: grid;
  grid-template-columns: minmax(9rem, 1fr) auto minmax(9rem, 1fr);
  align-items: center;
  gap: clamp(1rem, 2vw, 2.5rem);
}

.material-disc {
  position: relative;
  display: grid;
  aspect-ratio: 1;
  place-items: center;
  border-radius: 50%;
}

.material-disc > span {
  position: absolute;
  z-index: 2;
  padding: 0.15rem 0.35rem;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--mono);
  font-size: clamp(0.9rem, 1.5vw, 1.25rem);
}

.material-disc--full {
  max-width: 16rem;
  background: var(--vortex);
  box-shadow: inset 0 0 0 1px var(--ink);
}

.material-disc--pappus {
  max-width: 21rem;
  border: 1px dashed #75948e;
}

.material-disc--pappus svg {
  width: 100%;
  overflow: visible;
}

#comparison-pappus line {
  stroke: var(--ink);
  stroke-linecap: round;
  stroke-width: 0.75;
}

#comparison-pappus + circle {
  fill: var(--seed);
}

.equals {
  color: var(--ink-muted);
  font-family: var(--mono);
  font-size: 1.5rem;
}

.area-equation {
  display: grid;
  max-width: 34rem;
  grid-template-columns: max-content 1fr max-content;
  align-items: center;
  gap: 0.75rem;
  margin: 2.5rem 0 1.5rem;
  color: var(--ink);
  font-family: var(--mono);
}

.area-equation .fraction-line {
  height: 1px;
  background: var(--ink-muted);
}

.area-equation strong {
  grid-column: 1 / -1;
  color: #c44835;
  font-family: var(--display);
  font-size: clamp(2.5rem, 5vw, 5rem);
  line-height: 1;
}

.area-comparison figcaption {
  max-width: 40rem;
  color: var(--ink-muted);
}

.scope {
  color-scheme: light;
  background: var(--paper-warm);
  color: var(--ink);
}

.scope .eyebrow {
  color: #357c6d;
}

.scope-copy {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2rem, 8vw, 8rem);
  margin-top: clamp(3rem, 7vw, 6rem);
}

.scope-copy .eyebrow {
  grid-column: 1 / -1;
  margin-bottom: -1.5rem;
}

.scope-copy h2,
.scope-copy p {
  align-self: end;
  margin-bottom: 0;
}

.scope-copy .lead {
  max-width: 42rem;
  color: #334c4a;
}

.method-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2rem, 8vw, 8rem);
  margin-top: clamp(4rem, 8vw, 8rem);
  padding-top: 2rem;
  border-top: 1px solid var(--line-light);
}

.method-grid section {
  max-width: 40rem;
}

.method-grid h3 {
  margin-bottom: 1.25rem;
}

.method-grid p {
  color: #415552;
}

.calculation {
  margin-top: clamp(3rem, 7vw, 6rem);
  border-top: 1px solid var(--line-light);
  border-bottom: 1px solid var(--line-light);
}

.calculation summary {
  display: flex;
  min-height: 4.25rem;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  cursor: pointer;
  font-weight: 800;
  list-style: none;
}

.calculation summary::-webkit-details-marker {
  display: none;
}

.calculation summary span {
  display: grid;
  width: 2.75rem;
  height: 2.75rem;
  flex: 0 0 auto;
  place-items: center;
  border: 1px solid var(--ink);
  border-radius: 50%;
  font-family: var(--mono);
  font-weight: 400;
  transition: transform 180ms ease;
}

.calculation[open] summary span {
  transform: rotate(45deg);
}

.calculation > div {
  max-width: 56rem;
  padding: 0 0 2rem;
  color: #415552;
}

.calculation code {
  display: block;
  overflow-x: auto;
  margin: 0.5rem 0 1.5rem;
  padding: 1rem;
  border-left: 3px solid var(--vortex);
  background: rgba(255, 255, 255, 0.32);
  color: var(--ink);
  font-family: var(--mono);
  font-size: clamp(0.78rem, 1.4vw, 1rem);
  white-space: nowrap;
}

.sources {
  display: grid;
  grid-template-columns: minmax(16rem, 0.65fr) minmax(30rem, 1.35fr);
  gap: clamp(3rem, 8vw, 8rem);
  border-top: 1px solid var(--line-dark);
  background: var(--tunnel-deep);
}

.sources h2 {
  max-width: 8ch;
  color: var(--air);
}

.sources ol {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: sources;
}

.sources li {
  position: relative;
  padding: 1.5rem 0 1.5rem 3.3rem;
  border-top: 1px solid var(--line-dark);
  counter-increment: sources;
}

.sources li::before {
  position: absolute;
  top: 1.65rem;
  left: 0;
  color: var(--vortex);
  content: counter(sources, decimal-leading-zero);
  font-family: var(--mono);
  font-size: 0.72rem;
}

.sources li a {
  display: inline-block;
  max-width: 52rem;
  color: var(--pappus);
  font-weight: 800;
  overflow-wrap: anywhere;
}

.sources li span {
  display: block;
  margin-top: 0.45rem;
  color: var(--air-muted);
  font-size: 0.78rem;
}

.source-note {
  grid-column: 2;
  max-width: 52rem;
  color: var(--air-muted);
  text-transform: none;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  padding: 2rem var(--page-pad);
  border-top: 1px solid var(--line-dark);
  background: var(--tunnel-deep);
  color: var(--air-muted);
  font-family: var(--mono);
  font-size: 0.7rem;
}

.site-footer p {
  margin: 0;
}

.site-footer a {
  color: var(--pappus);
}

.back-to-top {
  position: fixed;
  z-index: 30;
  right: 1rem;
  bottom: 1rem;
  display: grid;
  width: 3rem;
  height: 3rem;
  place-items: center;
  transform: translateY(5rem);
  border: 1px solid var(--air);
  border-radius: 50%;
  background: rgba(5, 27, 30, 0.93);
  color: var(--air);
  text-decoration: none;
  transition: transform 180ms ease;
}

.back-to-top.is-visible,
.back-to-top:focus-visible {
  transform: translateY(0);
}

.not-found {
  position: relative;
  display: flex;
  width: min(100%, 66rem);
  min-height: 100svh;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  margin: 0 auto;
  padding: 5rem var(--page-pad);
}

.not-found h1 {
  max-width: 11ch;
  margin-bottom: 1.5rem;
}

.not-found > p:not(.eyebrow) {
  max-width: 34rem;
  color: var(--air-muted);
  font-size: 1.15rem;
}

.not-found-ring {
  position: absolute;
  z-index: -1;
  top: 50%;
  right: 3vw;
  width: clamp(11rem, 32vw, 24rem);
  aspect-ratio: 2.4 / 1;
  transform: translateY(-50%) rotate(-8deg);
  border: clamp(0.65rem, 1.5vw, 1.2rem) solid var(--vortex);
  border-radius: 50%;
  opacity: 0.55;
}

@keyframes air-rise {
  to { stroke-dashoffset: -34; }
}

@keyframes ring-drift {
  to { transform: translateX(7px); }
}

@media (max-width: 68rem) {
  .hero {
    grid-template-columns: 0.9fr 1.1fr;
  }

  .hero-copy {
    padding-right: 2rem;
  }

  h1 {
    font-size: clamp(3.4rem, 6.8vw, 5.3rem);
  }

  .diagram-labels text {
    font-size: 10px;
  }

  .mechanism,
  .comparison {
    gap: 3rem;
  }
}

@media (max-width: 54rem) {
  .site-header {
    position: absolute;
  }

  .hero {
    display: block;
    background: var(--tunnel);
  }

  .hero-copy {
    min-height: 86svh;
    padding-top: 7.5rem;
    padding-bottom: 4rem;
  }

  .tunnel {
    min-height: 58rem;
    padding-top: 2rem;
  }

  #wind-tunnel {
    max-height: 42rem;
  }

  .mechanism,
  .comparison,
  .scope-copy,
  .method-grid,
  .sources {
    grid-template-columns: minmax(0, 1fr);
  }

  .mechanism {
    display: grid;
  }

  .mechanism .section-index,
  .mechanism .measurements,
  .mechanism .adjacent-limit,
  .comparison .section-index,
  .source-note {
    grid-column: 1;
  }

  .scope-copy .eyebrow {
    grid-column: 1;
  }

  .scope-copy {
    gap: 1.5rem;
  }

  .scope-copy .eyebrow {
    margin-bottom: 0;
  }

  .area-comparison {
    max-width: 42rem;
  }
}

@media (max-width: 38rem) {
  :root {
    --page-pad: 1.125rem;
  }

  .site-header {
    padding-top: 0.75rem;
    padding-bottom: 0.75rem;
  }

  .author-mark > span:last-child {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0 0 0 0);
    white-space: nowrap;
    clip-path: inset(50%);
  }

  .hero-copy {
    min-height: 100svh;
    justify-content: flex-end;
    padding-top: 6rem;
    padding-bottom: 3rem;
  }

  h1 {
    margin-bottom: 1.5rem;
    font-size: clamp(2.7rem, 13.1vw, 4.1rem);
    line-height: 0.96;
  }

  body[data-lang="en"] h1 {
    font-size: clamp(2.25rem, 11.2vw, 4rem);
  }

  .mobile-break {
    display: block;
  }

  h2 {
    font-size: clamp(2.1rem, 10vw, 3.5rem);
  }

  .standfirst,
  .lead {
    font-size: 1.13rem;
  }

  .definition {
    margin-bottom: 1.4rem;
  }

  .tunnel {
    min-height: 52rem;
    margin: 0;
    padding: 1.25rem 0.75rem 1.5rem;
    border-inline: 0;
    background-size: 36px 36px;
  }

  .tunnel::before { left: 6%; }
  .tunnel::after { right: 6%; }

  .tunnel-head {
    padding-inline: 0.45rem;
  }

  #wind-tunnel {
    width: 100%;
    max-height: 35rem;
  }

  .diagram-labels text {
    font-size: 9px;
  }

  .tunnel-figure figcaption,
  .control {
    padding-inline: 0.45rem;
  }

  .control-note {
    font-size: 0.64rem;
  }

  .mechanism,
  .comparison,
  .scope,
  .sources {
    padding-top: 4.75rem;
    padding-bottom: 4.75rem;
  }

  .measurements {
    grid-template-columns: 1fr;
  }

  .measurements > div,
  .measurements > div + div {
    padding: 1.25rem 0;
    border-top: 1px solid var(--line-dark);
    border-left: 0;
  }

  .measurements > div:first-child {
    border-top: 0;
  }

  .measurements dd {
    font-size: 1.85rem;
  }

  .area-visual {
    gap: 0.65rem;
  }

  .material-disc > span {
    font-size: 0.72rem;
  }

  .area-equation {
    font-size: 0.78rem;
  }

  .sources li {
    padding-left: 2.4rem;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
    gap: 0.75rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  .flow {
    stroke-dasharray: 5 10;
  }
}

@media print {
  :root {
    color-scheme: light;
  }

  body,
  .hero,
  .tunnel,
  .mechanism,
  .sources,
  .site-footer {
    background: white !important;
    color: var(--ink) !important;
  }

  .site-header,
  .back-to-top,
  .control input,
  .text-link {
    display: none !important;
  }

  .hero,
  .tunnel {
    min-height: 0;
  }

  .hero {
    display: block;
  }

  .hero-copy {
    min-height: 0;
    padding-top: 2rem;
  }

  .standfirst,
  .mechanism-copy p:not(.eyebrow),
  .sources li a,
  .site-footer a {
    color: var(--ink) !important;
  }
}