/* AIVN360: a small, dependency-free editorial system. */
:root {
  --paper:#f4f2eb;
  --white:#fffef9;
  --ink:#252c29;
  --muted:#5b635c;
  --line:#d7d9ce;
  --accent:#d4a72c;
  --green:#204f44;
  --dark:#1b3029;
  --serif:Georgia,'Times New Roman',serif;
  --sans:Inter,'Segoe UI',Arial,sans-serif;
  --mono:'SFMono-Regular',Consolas,monospace;
}

* {
  box-sizing:border-box;
}

html {
  scroll-behavior:smooth;
  scroll-padding-top:105px;
}

body {
  margin:0;
  color:var(--ink);
  background:var(--paper);
  font-family:var(--sans);
  font-size:16px;
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
}

a {
  color:inherit;
  text-decoration-thickness:1px;
  text-underline-offset:.25em;
}

a:hover {
  color:var(--green);
}

button,input {
  font:inherit;
}

a,button,input {
  touch-action:manipulation;
}

a:focus-visible,button:focus-visible,input:focus-visible,[tabindex]:focus-visible {
  outline:3px solid var(--green);
  outline-offset:5px;
}

img {
  display:block;
  max-width:100%;
  height:auto;
}

h1,h2,h3,p,figure {
  margin:0;
}

h1,h2,h3 {
  line-height:1.16;
  font-weight:500;
}

h1,h2 {
  font-family:var(--serif);
  letter-spacing:-.045em;
}

h1 {
  font-size:clamp(2.9rem,4.7vw,4.75rem);
}

h2 {
  font-size:clamp(2.3rem,3.8vw,3.65rem);
}

h3 {
  font-size:1.16rem;
  line-height:1.4;
  font-weight:600;
  letter-spacing:-.02em;
}

p+p {
  margin-top:1em;
}

em {
  font-weight:400;
  color:var(--green);
}

[hidden] {
  display:none!important;
}

.section-shell {
  max-width:1320px;
  padding-left:clamp(24px,5.7vw,82px);
  padding-right:clamp(24px,5.7vw,82px);
  margin-left:auto;
  margin-right:auto;
}

.section-space {
  padding-top:100px;
  padding-bottom:100px;
}

.eyebrow {
  font-family:var(--mono);
  font-size:.69rem;
  letter-spacing:.12em;
  text-transform:uppercase;
  line-height:1.7;
  font-weight:500;
  margin-bottom:25px;
}

.small-square {
  width:7px;
  height:7px;
  background:var(--accent);
  display:inline-block;
  margin-right:10px;
  vertical-align:2px;
}

.lead {
  font-size:1.35rem;
  line-height:1.55;
  letter-spacing:-.015em;
}

.small-text {
  font-size:.78rem;
  line-height:1.65;
  color:var(--muted);
}

.text-link {
  display:inline-flex;
  align-items:center;
  gap:18px;
  font-size:.88rem;
  font-weight:600;
  text-decoration:none;
  border-bottom:1px solid currentColor;
  padding-bottom:5px;
}

.text-link span {
  font-size:1.15rem;
}

.button {
  display:inline-flex;
  justify-content:space-between;
  align-items:center;
  gap:35px;
  min-height:50px;
  padding:13px 21px;
  color:var(--white);
  background:var(--green);
  font-size:.83rem;
  font-weight:600;
  text-decoration:none;
  transition:background .2s;
}

.button:hover {
  background:#153c32;
  color:white;
}

.button span {
  font-size:1.2rem;
  font-weight:400;
}

.button-light {
  color:var(--ink);
  background:var(--paper);
}

.button-light:hover {
  background:white;
  color:var(--ink);
}

.actions {
  display:flex;
  align-items:center;
  flex-wrap:wrap;
  gap:25px;
  margin-top:32px;
}

.skip-link {
  position:absolute;
  left:12px;
  top:-100px;
  z-index:10;
  background:var(--ink);
  color:white;
  padding:12px 20px;
}

.skip-link:focus {
  top:12px;
  color:white;
}

/* Chrome */
.site-header {
  position:sticky;
  top:0;
  z-index:5;
  background:rgba(244,242,235,.97);
  border-bottom:1px solid var(--line);
}

.header-inner {
  max-width:1320px;
  min-height:88px;
  margin:auto;
  padding:16px clamp(24px,5.7vw,82px);
  display:flex;
  align-items:center;
  gap:32px;
}

.brand {
  display:inline-flex;
  align-items:center;
  font-size:1.35rem;
  font-weight:760;
  letter-spacing:-.065em;
  text-decoration:none;
  line-height:1;
  white-space:nowrap;
}

.brand>span:last-child {
  font-weight:400;
  letter-spacing:-.055em;
}

.brand-mark {
  display:inline-flex;
  align-items:flex-end;
  gap:3px;
  margin-right:11px;
  width:26px;
  height:24px;
  transform:skewY(-16deg);
}

.brand-mark i {
  width:6px;
  background:var(--green);
  height:15px;
}

.brand-mark i:nth-child(2) {
  height:22px;
}

.brand-mark i:nth-child(3) {
  height:17px;
  background:var(--accent);
}

.main-nav {
  margin-left:auto;
  display:flex;
  gap:29px;
  align-items:center;
}

.main-nav a {
  font-size:.78rem;
  font-weight:500;
  text-decoration:none;
  white-space:nowrap;
  min-height:44px;
  display:inline-flex;
  align-items:center;
  position:relative;
}

.main-nav a:hover:after,.main-nav a[aria-current]:after {
  content:'';
  position:absolute;
  bottom:7px;
  left:0;
  right:0;
  height:2px;
  background:var(--accent);
}

.header-contact {
  font-size:.75rem;
  font-weight:600;
  text-decoration:none;
  padding:10px 14px;
  border:1px solid var(--ink);
  white-space:nowrap;
  margin-left:4px;
  min-height:43px;
  display:inline-flex;
  align-items:center;
  gap:14px;
}

.site-footer {
  border-top:1px solid var(--line);
  padding-top:45px;
  padding-bottom:20px;
}

.footer-main {
  display:flex;
  justify-content:space-between;
  gap:30px;
}

.footer-main>div p {
  color:var(--muted);
  font-size:.8rem;
  margin-top:16px;
}

.footer-main nav {
  display:flex;
  flex-wrap:wrap;
  gap:25px;
  align-items:flex-start;
  padding-top:3px;
}

.footer-main nav a {
  font-size:.79rem;
  text-decoration:none;
  min-height:44px;
  display:inline-flex;
  gap:8px;
  align-items:center;
}

.footer-main nav a:hover {
  text-decoration:underline;
}

.footer-bottom {
  display:flex;
  justify-content:space-between;
  gap:20px;
  margin-top:45px;
  color:var(--muted);
  font-family:var(--mono);
  font-size:.62rem;
}

.footer-bottom p+p {
  margin:0;
}

/* Company home */
.hero {
  display:grid;
  grid-template-columns:1.12fr 1fr;
  gap:45px;
  align-items:center;
  padding-top:85px;
  padding-bottom:75px;
}

.hero h1 {
  font-size:clamp(2.6rem,4.15vw,4.05rem);
  line-height:1.13;
}

.hero-intro {
  font-size:1.04rem;
  line-height:1.7;
  max-width:540px;
  margin-top:26px;
  color:#3e4942;
}

.hero-support {
  font-size:.85rem;
  line-height:1.7;
  max-width:470px;
  color:var(--muted);
  margin-top:17px;
}

.hero-figure {
  background:#e9ede4;
  border:1px solid #d4dacd;
  margin-top:30px;
  min-width:0;
}

.figure-top {
  display:flex;
  justify-content:space-between;
  gap:15px;
  font-family:var(--mono);
  font-size:.56rem;
  letter-spacing:.06em;
  line-height:1.5;
}

.hero-figure .figure-top {
  padding:21px 22px 0;
}

.status-dot {
  white-space:nowrap;
}

.status-dot:before {
  content:'';
  width:5px;
  height:5px;
  background:var(--green);
  display:inline-block;
  margin-right:5px;
  border-radius:50%;
}

.hero-figure img {
  width:100%;
  margin-top:10px;
}

.hero-figure figcaption {
  border-top:1px solid #d4dacd;
  margin:0 22px;
  padding:17px 0;
  display:flex;
  flex-direction:column;
  gap:2px;
  font-size:.7rem;
}

.hero-figure figcaption span:last-child {
  font-family:var(--mono);
  font-size:.52rem;
  color:var(--muted);
}

.intro-band {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:80px;
  padding-top:35px;
  padding-bottom:35px;
  border-top:1px solid var(--line);
  border-bottom:1px solid var(--line);
}

.intro-band p:first-child {
  font-family:var(--serif);
  font-size:1.7rem;
  line-height:1.3;
  letter-spacing:-.025em;
}

.intro-band p:last-child {
  font-size:.84rem;
  line-height:1.7;
  color:var(--muted);
  margin:0;
}

.section-heading {
  max-width:730px;
}

.section-heading>p:last-child:not(.eyebrow) {
  max-width:625px;
  margin-top:25px;
  font-size:.97rem;
  color:var(--muted);
}

.principles {
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:40px;
  margin-top:54px;
}

.principles article {
  border-top:1px solid var(--line);
  padding-top:22px;
}

.section-number {
  font-family:var(--mono);
  font-size:.66rem;
  color:var(--muted);
  display:block;
  margin-bottom:25px;
}

.principles h3 {
  font-size:1.08rem;
}

.principles p {
  margin-top:14px;
  font-size:.88rem;
  color:var(--muted);
  line-height:1.8;
}

.product-section {
  background:var(--dark);
  color:#f4f2eb;
}

.product-heading {
  display:flex;
  justify-content:space-between;
  align-items:flex-start;
  gap:24px;
}

.product-heading h2 {
  font-size:5.5rem;
  letter-spacing:-.055em;
}

.product-subtitle {
  font-family:var(--serif);
  font-size:1.65rem;
  line-height:1.3;
  margin-top:22px!important;
  letter-spacing:-.025em;
  color:#c6d3bf;
}

.status-pill {
  display:inline-flex;
  align-items:center;
  gap:9px;
  white-space:nowrap;
  border:1px solid currentColor;
  border-radius:30px;
  padding:7px 12px;
  font-family:var(--mono);
  font-size:.63rem;
  line-height:1.5;
  letter-spacing:.03em;
}

.status-pill:before {
  content:'';
  width:5px;
  height:5px;
  background:currentColor;
  border-radius:50%;
}

.product-heading>.status-pill {
  margin-top:45px;
  color:#ccd9c5;
}

.product-grid {
  display:grid;
  grid-template-columns:1fr 1.08fr;
  gap:65px;
  margin-top:43px;
  align-items:start;
}

.product-copy .lead {
  font-size:1.2rem;
  max-width:350px;
}

.product-copy>p:not(.lead) {
  font-size:.88rem;
  color:#c5cec5;
  line-height:1.8;
  margin-top:20px;
}

.product-copy .button {
  margin-top:28px;
}

.evidence-preview {
  background:#263e33;
  border:1px solid #4b5c4c;
  padding:26px 28px;
}

.evidence-preview .figure-top {
  color:#c3cfc0;
  font-size:.54rem;
}

.evidence-preview h3 {
  font-family:var(--serif);
  font-weight:400;
  font-size:1.6rem;
  line-height:1.4;
  letter-spacing:-.025em;
  margin-top:27px;
}

.mini-chart {
  display:grid;
  gap:22px;
  margin-top:30px;
  margin-bottom:25px;
}

.chart-row {
  display:grid;
  grid-template-columns:61px 1fr 76px;
  gap:10px;
  align-items:center;
  font-family:var(--mono);
  font-size:.78rem;
}

.chart-row small {
  font-size:.52rem;
  font-weight:400;
  color:#ced8c9;
}

.chart-row strong {
  font-weight:400;
  text-align:right;
  white-space:nowrap;
}

.chart-track {
  height:26px;
  background:#304b3c;
  position:relative;
  border-left:1px solid #92a98f;
}

.chart-track i {
  display:block;
  height:100%;
  background:#b8c99e;
}

.chart-row:last-child .chart-track i {
  background:#e4ba4b;
}

.chart-caption {
  border-top:1px solid #4b5c4c;
  padding-top:18px;
  color:#c4cfc1;
  font-size:.74rem;
  line-height:1.7;
}

.evidence-preview .text-link {
  margin-top:18px;
  font-size:.72rem;
}

.product-section a:focus-visible {
  outline-color:#efd07a;
}

.product-section .text-link:hover {
  color:#efd07a;
}

.product-note {
  display:flex;
  align-items:flex-start;
  gap:13px;
  margin-top:45px;
  padding-top:23px;
  border-top:1px solid #45584a;
}

.product-note .small-square {
  flex:none;
  margin:8px 0 0;
}

.product-note p {
  font-size:.7rem;
  color:#c4cfc1;
  max-width:940px;
  line-height:1.7;
}

.founder-section {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:70px;
}

.founder-copy {
  padding-top:50px;
}

.founder-copy .lead {
  font-size:1.3rem;
}

.founder-copy>p:not(.lead) {
  font-size:.89rem;
  color:var(--muted);
}

.founder-copy .text-link {
  margin-top:20px;
  font-size:.78rem;
}

.founder-copy .affiliation-note {
  font-size:.69rem!important;
  margin-top:20px;
  max-width:430px;
}

.direction-note {
  margin-top:35px;
  padding-top:26px;
  border-top:1px solid var(--line);
}

.direction-note h3 {
  font-size:1rem;
}

.direction-note p {
  font-size:.87rem;
  color:var(--muted);
  margin-top:14px;
}

.learning-section {
  background:#e9ece3;
}

.learning-heading {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:70px;
}

.learning-heading>div:last-child {
  padding-top:47px;
  font-size:.88rem;
  color:var(--muted);
}

.learning-heading .text-link {
  margin-top:24px;
  color:var(--ink);
  font-size:.78rem;
}

.selected-learning {
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:25px;
  margin-top:50px;
}

.learning-card {
  display:flex;
  flex-direction:column;
  position:relative;
  padding:22px;
  background:var(--paper);
  border:1px solid #d3d9cc;
  transition:border-color .15s;
}

.learning-card:hover {
  border-color:#75836d;
}

.learning-card:focus-within {
  outline:3px solid var(--green);
  outline-offset:3px;
}

.card-meta {
  display:flex;
  justify-content:space-between;
  align-items:flex-start;
  gap:12px;
  font-family:var(--mono);
  font-size:.55rem;
  color:var(--muted);
  margin-bottom:25px;
  line-height:1.5;
}

.learning-card h3 {
  font-weight:550;
  font-size:1.07rem;
  line-height:1.5;
  letter-spacing:-.025em;
}

.learning-card h3 a {
  text-decoration:none;
}

.learning-card h3 a:after {
  content:'';
  position:absolute;
  inset:0;
}

.learning-card h3 a:focus-visible {
  outline:none;
}

.learning-card>p {
  font-size:.77rem;
  color:var(--muted);
  line-height:1.75;
  margin-top:15px;
  margin-bottom:30px;
}

.card-end {
  margin-top:auto;
  display:flex;
  justify-content:space-between;
  font-size:.69rem;
  font-weight:500;
  border-top:1px solid var(--line);
  padding-top:15px;
}

.card-end span {
  font-size:1rem;
}

.learning-footnote {
  font-size:.7rem;
  line-height:1.8;
  color:var(--muted);
  max-width:810px;
  margin-top:24px;
}

.contact-section {
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:50px;
  padding-top:100px;
  padding-bottom:100px;
}

.contact-section>div>p:last-child {
  font-size:.9rem;
  color:var(--muted);
  margin-top:23px;
}

.contact-email {
  font-family:var(--serif);
  font-size:clamp(1.35rem,2.2vw,2.05rem);
  text-decoration:none;
  border-bottom:1px solid var(--ink);
  padding:10px 0;
  letter-spacing:-.035em;
  display:flex;
  gap:25px;
  align-items:center;
  white-space:nowrap;
}

.contact-email span {
  font-family:var(--sans);
  font-size:1.6rem;
}

/* Product and learning pages */
.page-hero {
  padding-top:75px;
  padding-bottom:65px;
}

.page-hero h1 {
  max-width:950px;
}

.page-hero>.eyebrow {
  margin-bottom:27px;
}

.page-intro {
  max-width:700px;
  margin-top:27px;
  font-size:1.07rem;
  color:var(--muted);
  line-height:1.8;
}

.title-with-status {
  display:flex;
  align-items:center;
  gap:32px;
}

.title-with-status h1 {
  font-size:5.7rem;
}

.title-with-status .status-pill {
  color:var(--green);
}

.page-deck {
  font-family:var(--serif);
  font-size:clamp(2rem,3.5vw,3.1rem);
  line-height:1.28;
  letter-spacing:-.04em;
  margin-top:25px;
}

.raildyn-overview {
  padding-top:55px;
  padding-bottom:75px;
  border-top:1px solid var(--line);
}

.raildyn-overview h2 {
  max-width:560px;
}

.raildyn-overview .principles {
  margin-top:36px;
}

.reference-section {
  background:#e9ece3;
}

.reference-section h2 {
  max-width:850px;
}

.reference-intro {
  max-width:790px;
  font-size:.97rem;
  color:var(--muted);
  margin-top:24px;
}

.reference-grid {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:65px;
  margin-top:50px;
  align-items:center;
}

.model-figure {
  border:1px solid #cad3c4;
  background:#f0f1e9;
  align-self:start;
}

.model-figure img {
  width:100%;
}

.model-figure figcaption {
  font-size:.66rem;
  color:var(--muted);
  padding:16px 20px;
  border-top:1px solid #cad3c4;
}

.model-specs {
  margin:20px 0 0;
  font-size:.79rem;
}

.model-specs>div {
  padding:10px 0;
  border-top:1px solid #cdd4c7;
  display:grid;
  grid-template-columns:.95fr 1.3fr;
  gap:15px;
}

.model-specs dt {
  color:var(--muted);
}

.model-specs dd {
  margin:0;
}

.results-heading {
  display:flex;
  align-items:baseline;
  justify-content:space-between;
  gap:25px;
  margin-top:55px;
  margin-bottom:18px;
}

.results-heading p {
  font-size:.72rem;
  color:var(--muted);
}

.table-scroll {
  overflow-x:auto;
  border:1px solid #c5cebd;
  background:var(--paper);
}

.results-table {
  border-collapse:collapse;
  width:100%;
  font-size:.89rem;
  min-width:530px;
  font-variant-numeric:tabular-nums;
}

.results-table caption {
  text-align:left;
  font-size:.68rem;
  padding:14px 20px;
  border-bottom:1px solid #c5cebd;
  color:var(--muted);
}

.results-table th,.results-table td {
  padding:18px 20px;
  text-align:right;
}

.results-table th:first-child {
  text-align:left;
}

.results-table thead {
  font-size:.74rem;
}

.results-table thead th {
  font-weight:500;
  line-height:1.6;
}

.results-table thead span {
  font-weight:400;
  color:var(--muted);
  font-size:.65rem;
}

.results-table tbody tr {
  border-top:1px solid #c5cebd;
}

.results-table tbody th {
  font-weight:500;
}

.results-table tbody tr:last-child {
  background:#dfe6d8;
}

.result-reading {
  font-size:.8rem;
  max-width:850px;
  margin-top:18px;
  color:var(--muted);
}

.evidence-notes {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:50px;
  margin-top:40px;
  padding-top:25px;
  border-top:1px solid #c5cebd;
}

.evidence-notes h3 {
  font-size:.9rem;
}

.evidence-notes p {
  font-size:.76rem;
  line-height:1.75;
  color:var(--muted);
  margin-top:12px;
}

.evidence-notes code {
  font-size:.69rem;
  color:var(--ink);
  overflow-wrap:anywhere;
}

.raildyn-direction {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:70px;
}

.raildyn-direction>div:last-child {
  padding-top:48px;
}

.raildyn-direction p:not(.lead):not(.eyebrow) {
  font-size:.91rem;
  color:var(--muted);
}

.attribution-box {
  padding-top:30px;
  padding-bottom:30px;
  border-top:1px solid var(--line);
  border-bottom:1px solid var(--line);
}

.attribution-box h2 {
  font-family:var(--sans);
  font-size:1rem;
  font-weight:600;
  letter-spacing:-.02em;
}

.attribution-box p {
  font-size:.81rem;
  color:var(--muted);
  margin-top:14px;
  max-width:1000px;
}

.library-section {
  padding-top:45px;
  padding-bottom:90px;
  border-top:1px solid var(--line);
}

.library-top {
  display:flex;
  align-items:end;
  justify-content:space-between;
  gap:35px;
}

.library-top .eyebrow {
  margin-bottom:16px;
}

.library-top h2 {
  font-size:2.4rem;
}

.library-search {
  min-width:250px;
}

.library-search label {
  display:block;
  font-size:.74rem;
  font-weight:600;
  margin-bottom:7px;
}

.library-search input {
  width:100%;
  padding:10px 12px;
  border:1px solid #8a9583;
  border-radius:0;
  background:var(--white);
  font-size:.86rem;
  color:var(--ink);
}

.library-search p {
  font-family:var(--mono);
  font-size:.64rem;
  color:var(--muted);
  margin-top:7px;
}

.archive-note {
  font-size:.8rem;
  color:var(--muted);
  max-width:930px;
  line-height:1.8;
  margin-top:30px;
  margin-bottom:34px;
}

.library-grid {
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:22px;
}

.library-grid .learning-card {
  background:#e9ece3;
}

.empty-results {
  font-size:1.1rem;
  padding:60px 0;
}

.episode-page {
  padding-top:40px;
  padding-bottom:80px;
}

.breadcrumbs {
  display:flex;
  gap:13px;
  font-size:.72rem;
  color:var(--muted);
}

.breadcrumbs a {
  min-height:40px;
  display:inline-flex;
  align-items:center;
}

.breadcrumbs span {
  line-height:40px;
}

.episode-header {
  margin-top:40px;
  max-width:950px;
}

.episode-header h1 {
  font-family:var(--sans);
  font-weight:500;
  font-size:clamp(2rem,4.3vw,3.6rem);
  letter-spacing:-.045em;
  line-height:1.23;
}

.episode-summary {
  font-size:1.04rem;
  color:var(--muted);
  margin-top:25px;
  line-height:1.8;
  max-width:880px;
}

.episode-meta {
  display:flex;
  gap:25px;
  font-family:var(--mono);
  font-size:.64rem;
  margin-top:23px;
  color:var(--muted);
}

.episode-body {
  display:grid;
  grid-template-columns:1.05fr 1fr;
  gap:50px;
  margin-top:45px;
  border-top:1px solid var(--line);
  padding-top:35px;
}

.watch-panel {
  background:#e4eadd;
  padding:28px;
  display:flex;
  align-items:flex-start;
  gap:25px;
}

.play-symbol {
  border:1px solid #b6c3ad;
  border-radius:50%;
  width:45px;
  height:45px;
  flex:none;
  display:grid;
  place-items:center;
  font-size:.7rem;
  color:var(--green);
  padding-left:2px;
}

.watch-panel h2,.source-note h2 {
  font-family:var(--sans);
  font-size:1.14rem;
  letter-spacing:-.025em;
  font-weight:600;
}

.watch-panel p {
  font-size:.83rem;
  margin-top:16px;
  color:var(--muted);
}

.watch-panel .button {
  margin-top:25px;
  font-size:.78rem;
}

.source-note {
  padding-top:10px;
}

.source-note>p {
  font-size:.83rem;
  color:var(--muted);
  margin-top:16px;
}

.source-note .text-link {
  font-size:.8rem;
  margin-top:18px;
  display:inline;
  line-height:1.8;
  overflow-wrap:anywhere;
}

.source-note .small-text {
  font-size:.72rem;
  margin-top:25px;
}

.return-link {
  margin-top:40px;
  font-size:.8rem;
}

.not-found {
  min-height:60vh;
}

/* Responsive behavior */
@media(min-width:1600px) {
  .hero {
    padding-top:100px;
    padding-bottom:90px;
  }

}

@media(max-width:1050px) {
  .header-inner {
    gap:22px;
  }

  .main-nav {
    gap:22px;
  }

  .header-contact {
    margin-left:0;
  }

  .hero {
    gap:30px;
  }

  .hero h1 {
    font-size:3rem;
  }

  .hero .eyebrow {
    font-size:.59rem;
  }

  .hero-figure .figure-top {
    flex-direction:column;
    gap:5px;
  }

  .product-grid {
    gap:35px;
  }

  .evidence-preview {
    padding:23px;
  }

  .founder-section,.learning-heading,.raildyn-direction,.reference-grid {
    gap:45px;
  }

  .principles {
    gap:27px;
  }

  .selected-learning {
    gap:18px;
  }

  .learning-card {
    padding:20px;
  }

  .contact-section {
    gap:30px;
  }

  .contact-email {
    font-size:1.6rem;
    gap:14px;
  }

  .hero .actions {
    gap:20px;
  }

  .hero .button {
    gap:20px;
  }

}

@media(max-width:800px) {
  html {
    scroll-padding-top:120px;
  }

  .header-inner {
    flex-wrap:wrap;
    gap:3px 20px;
    padding-top:16px;
    padding-bottom:8px;
    min-height:90px;
  }

  .brand {
    font-size:1.25rem;
  }

  .brand-mark {
    height:21px;
  }

  .header-contact {
    margin-left:auto;
    font-size:.67rem;
    min-height:35px;
    padding:6px 10px;
  }

  .main-nav {
    order:3;
    width:100%;
    margin-left:0;
    justify-content:space-between;
    gap:20px;
  }

  .main-nav a {
    font-size:.73rem;
    min-height:36px;
  }

  .main-nav a:hover:after,.main-nav a[aria-current]:after {
    bottom:2px;
  }

  .hero {
    grid-template-columns:1fr;
    gap:35px;
    padding-top:52px;
    padding-bottom:50px;
  }

  .hero-copy {
    max-width:670px;
  }

  .hero h1 {
    font-size:clamp(2.9rem,6.5vw,4rem);
    max-width:620px;
  }

  .hero .eyebrow {
    font-size:.65rem;
  }

  .hero-intro {
    font-size:1.04rem;
  }

  .hero-support {
    max-width:580px;
  }

  .hero-figure {
    margin-top:0;
    max-width:640px;
    width:100%;
    justify-self:center;
  }

  .hero-figure .figure-top {
    flex-direction:row;
  }

  .hero-figure img {
    max-height:350px;
    object-fit:contain;
  }

  .hero-figure figcaption {
    flex-direction:row;
    justify-content:space-between;
    align-items:baseline;
    gap:20px;
  }

  .intro-band {
    gap:35px;
  }

  .intro-band p:first-child {
    font-size:1.5rem;
  }

  .intro-band p:last-child {
    font-size:.78rem;
  }

  .section-space {
    padding-top:65px;
    padding-bottom:65px;
  }

  .principles {
    gap:25px;
  }

  .principles h3 {
    font-size:.95rem;
  }

  .principles p {
    font-size:.8rem;
  }

  .section-number {
    margin-bottom:18px;
  }

  .product-grid {
    grid-template-columns:1fr;
    gap:35px;
  }

  .product-copy .lead {
    max-width:none;
  }

  .product-copy p {
    max-width:680px;
  }

  .product-heading h2 {
    font-size:4.6rem;
  }

  .evidence-preview {
    padding:28px;
    max-width:700px;
  }

  .evidence-preview .figure-top {
    font-size:.6rem;
  }

  .chart-row {
    grid-template-columns:70px 1fr 85px;
    font-size:.88rem;
    gap:14px;
  }

  .chart-track {
    height:29px;
  }

  .founder-section,.raildyn-direction {
    grid-template-columns:1fr;
    gap:25px;
  }

  .founder-copy,.raildyn-direction>div:last-child {
    padding-top:0;
  }

  .founder-copy>p:not(.lead) {
    font-size:.93rem;
  }

  .founder-copy .affiliation-note {
    max-width:none;
  }

  .learning-heading {
    grid-template-columns:1fr;
    gap:20px;
  }

  .learning-heading>div:last-child {
    padding-top:0;
    max-width:620px;
  }

  .learning-heading .text-link {
    margin-top:18px;
  }

  .selected-learning {
    grid-template-columns:1fr;
    gap:15px;
    margin-top:33px;
  }

  .selected-learning .learning-card {
    padding:24px;
    display:grid;
    grid-template-columns:1fr 1fr;
    column-gap:25px;
  }

  .selected-learning .card-meta {
    grid-column:1/-1;
    margin-bottom:16px;
  }

  .selected-learning .learning-card h3 {
    font-size:1.1rem;
    grid-column:1;
  }

  .selected-learning .learning-card>p {
    grid-column:2;
    grid-row:2/4;
    margin-top:0;
    font-size:.81rem;
    margin-bottom:5px;
  }

  .selected-learning .card-end {
    grid-column:1;
    margin-top:25px;
  }

  .contact-section {
    padding-top:65px;
    padding-bottom:65px;
    flex-direction:column;
    align-items:flex-start;
    gap:30px;
  }

  .contact-email {
    font-size:1.85rem;
  }

  .footer-main {
    gap:25px;
    flex-direction:column;
  }

  .footer-main nav {
    gap:25px;
  }

  .footer-bottom {
    margin-top:25px;
  }

  .page-hero {
    padding-top:50px;
    padding-bottom:50px;
  }

  .title-with-status h1 {
    font-size:4.8rem;
  }

  .page-intro {
    font-size:1rem;
  }

  .reference-grid {
    gap:25px;
  }

  .reference-grid h3 {
    font-size:1rem;
  }

  .model-specs {
    font-size:.72rem;
  }

  .model-specs>div {
    grid-template-columns:1fr;
    padding:6px 0;
    gap:0;
  }

  .results-heading {
    align-items:flex-start;
    flex-direction:column;
    gap:5px;
  }

  .evidence-notes {
    gap:30px;
  }

  .library-grid {
    grid-template-columns:repeat(2,1fr);
  }

  .library-top {
    align-items:flex-start;
    flex-direction:column;
    gap:25px;
  }

  .library-search {
    width:100%;
  }

  .episode-body {
    grid-template-columns:1fr;
    gap:28px;
  }

  .watch-panel {
    padding:28px;
  }

  .episode-page {
    padding-top:27px;
  }

}

@media(max-width:500px) {
  .section-shell {
    padding-left:24px;
    padding-right:24px;
  }

  .header-inner {
    padding-left:24px;
    padding-right:24px;
  }

  .hero h1 {
    font-size:2.75rem;
    line-height:1.12;
  }

  .hero .eyebrow {
    font-size:.56rem;
    letter-spacing:.09em;
    white-space:normal;
  }

  .hero-intro {
    font-size:.95rem;
    line-height:1.75;
  }

  .hero-support {
    font-size:.8rem;
  }

  .hero .actions {
    gap:20px;
  }

  .hero .button {
    gap:25px;
  }

  .hero .text-link {
    font-size:.77rem;
  }

  .hero-figure .figure-top {
    padding:18px 17px 0;
    font-size:.48rem;
    gap:7px;
  }

  .hero-figure figcaption {
    margin:0 17px;
    flex-direction:column;
    gap:3px;
    font-size:.65rem;
  }

  .hero-figure figcaption span:last-child {
    font-size:.48rem;
  }

  .hero-figure img {
    margin-top:0;
  }

  .intro-band {
    grid-template-columns:1fr;
    gap:17px;
    padding-top:28px;
    padding-bottom:28px;
  }

  .intro-band p:first-child {
    max-width:270px;
    font-size:1.6rem;
  }

  .intro-band p:last-child {
    font-size:.81rem;
  }

  .section-space {
    padding-top:55px;
    padding-bottom:55px;
  }

  h2 {
    font-size:2.35rem;
  }

  .eyebrow {
    font-size:.61rem;
    margin-bottom:20px;
  }

  .section-heading>p:last-child:not(.eyebrow) {
    font-size:.88rem;
    margin-top:20px;
  }

  .principles {
    grid-template-columns:1fr;
    gap:26px;
    margin-top:32px;
  }

  .principles article {
    padding-top:17px;
  }

  .principles h3 {
    font-size:1.04rem;
  }

  .principles p {
    font-size:.85rem;
    margin-top:10px;
  }

  .section-number {
    margin-bottom:12px;
    font-size:.6rem;
  }

  .product-heading {
    gap:15px;
    flex-wrap:wrap;
  }

  .product-heading h2 {
    font-size:4.5rem;
  }

  .product-subtitle {
    font-size:1.55rem;
    margin-top:17px!important;
  }

  .product-heading>.status-pill {
    margin-top:6px;
  }

  .product-grid {
    margin-top:30px;
  }

  .product-copy .lead {
    font-size:1.2rem;
  }

  .product-copy>p:not(.lead) {
    font-size:.86rem;
  }

  .evidence-preview {
    padding:20px 18px;
  }

  .evidence-preview .figure-top {
    font-size:.49rem;
    gap:10px;
  }

  .evidence-preview h3 {
    font-size:1.4rem;
    margin-top:22px;
  }

  .chart-row {
    grid-template-columns:54px 1fr 63px;
    gap:8px;
    font-size:.71rem;
  }

  .chart-row small {
    font-size:.46rem;
  }

  .chart-track {
    height:24px;
  }

  .mini-chart {
    gap:20px;
    margin-top:25px;
  }

  .chart-caption {
    font-size:.67rem;
  }

  .evidence-preview .text-link {
    font-size:.67rem;
  }

  .product-note {
    margin-top:28px;
  }

  .product-note p {
    font-size:.65rem;
  }

  .founder-copy .lead {
    font-size:1.14rem;
  }

  .founder-copy>p:not(.lead) {
    font-size:.86rem;
  }

  .selected-learning .learning-card {
    display:flex;
    padding:23px;
  }

  .selected-learning .learning-card h3 {
    font-size:1.04rem;
  }

  .selected-learning .learning-card>p {
    margin-top:13px;
    margin-bottom:20px;
    font-size:.78rem;
  }

  .selected-learning .card-end {
    margin-top:auto;
  }

  .learning-heading>div:last-child {
    font-size:.85rem;
  }

  .contact-section {
    padding-top:55px;
    padding-bottom:55px;
    gap:22px;
  }

  .contact-section>div>p:last-child {
    font-size:.84rem;
  }

  .contact-email {
    font-size:1.55rem;
    gap:14px;
    white-space:normal;
    overflow-wrap:anywhere;
  }

  .contact-email span {
    font-size:1.25rem;
  }

  .footer-main nav {
    gap:10px 24px;
  }

  .footer-bottom {
    flex-direction:column;
    gap:7px;
    font-size:.59rem;
  }

  .footer-main>div p {
    font-size:.75rem;
  }

  .title-with-status {
    flex-wrap:wrap;
    gap:18px;
  }

  .title-with-status h1 {
    font-size:4.4rem;
  }

  .page-deck {
    font-size:2.1rem;
    margin-top:26px;
  }

  .page-intro {
    font-size:.9rem;
  }

  .page-hero h1 {
    font-size:2.9rem;
  }

  .page-hero .title-with-status h1 {
    font-size:4.4rem;
  }

  .page-hero .actions {
    gap:23px;
    align-items:flex-start;
    flex-direction:column;
  }

  .reference-grid {
    grid-template-columns:1fr;
    margin-top:30px;
  }

  .model-specs {
    font-size:.76rem;
  }

  .model-specs>div {
    grid-template-columns:1fr 1.35fr;
    padding:10px 0;
    gap:15px;
  }

  .reference-intro {
    font-size:.86rem;
  }

  .results-heading {
    margin-top:35px;
  }

  .results-heading h3 {
    font-size:1rem;
  }

  .results-heading p {
    font-size:.66rem;
  }

  .results-table {
    min-width:515px;
  }

  .results-table th,.results-table td {
    padding:15px 16px;
  }

  .result-reading {
    font-size:.72rem;
  }

  .evidence-notes {
    grid-template-columns:1fr;
    gap:26px;
    margin-top:30px;
  }

  .evidence-notes p {
    font-size:.73rem;
  }

  .raildyn-direction .lead {
    font-size:1.17rem;
  }

  .raildyn-direction p:not(.lead):not(.eyebrow) {
    font-size:.86rem;
  }

  .attribution-box h2 {
    font-size:.92rem;
  }

  .attribution-box p {
    font-size:.76rem;
  }

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

  .library-top h2 {
    font-size:2.1rem;
  }

  .library-section {
    padding-top:32px;
    padding-bottom:55px;
  }

  .archive-note {
    font-size:.75rem;
    margin-top:23px;
  }

  .episode-header {
    margin-top:28px;
  }

  .episode-header h1 {
    font-size:2.15rem;
    line-height:1.25;
  }

  .episode-summary {
    font-size:.91rem;
    line-height:1.8;
  }

  .episode-meta {
    font-size:.58rem;
    gap:20px;
  }

  .watch-panel {
    padding:22px;
    gap:16px;
    flex-direction:column;
  }

  .play-symbol {
    width:37px;
    height:37px;
  }

  .source-note>p {
    font-size:.8rem;
  }

  .source-note .small-text {
    font-size:.7rem;
  }

  .episode-body {
    margin-top:30px;
    padding-top:25px;
  }

  .watch-panel .button {
    font-size:.74rem;
  }

  .episode-page {
    padding-bottom:55px;
  }

}

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

  *,*:before,*:after {
    transition:none!important;
    animation:none!important;
  }

}

/* Keep evidence labels readable at every viewport. */
.figure-top,.hero-figure .figure-top,.evidence-preview .figure-top,.card-meta,.eyebrow,.hero .eyebrow,.status-pill,.section-number,.footer-bottom,.library-search p,.episode-meta {
  font-size:.6875rem;
}

.figure-top,.hero-figure .figure-top,.evidence-preview .figure-top {
  flex-wrap:wrap;
  row-gap:5px;
}

.hero-figure figcaption span:last-child,.model-figure figcaption,.chart-row small,.product-note p,.chart-caption,.learning-footnote {
  font-size:.6875rem;
}

.chart-row {
  font-size:.8125rem;
}

.chart-row small {
  line-height:1.4;
}

.chart-row>span {
  line-height:1.5;
}

.table-hint {
  font-size:.75rem;
  color:var(--muted);
  margin:0 0 10px;
}

@media(max-width:500px) {
  .hero-figure .figure-top {
    padding-left:17px;
    padding-right:17px;
  }

  .hero .eyebrow {
    letter-spacing:.065em;
  }

  .evidence-preview .figure-top {
    flex-direction:column;
  }

  .chart-row {
    grid-template-columns:55px 1fr 72px;
    gap:8px;
  }

  .card-meta {
    gap:10px;
  }

  .status-dot {
    white-space:normal;
  }

}

/* Provenance, caveats and table notes stay at a readable size on small screens. */
.evidence-notes p,.results-heading p,.result-reading,.source-note .small-text,.attribution-box p,.product-note p,.chart-caption,.learning-footnote,.model-figure figcaption,.table-hint {
  font-size:.8125rem;
}

.founder-copy .affiliation-note {
  font-size:.8125rem!important;
}