/* ===================================================================
   Hybrid Neural World Models site
   Light academic style. Mobile-first.
   Light cream paper background, warm dark text, serif body.
   =================================================================== */

:root {
  /* color palette */
  --bg:           #f7f3ea;
  --bg-band:     #efe9dc;
  --bg-card:    #fbf8f1;
  --rule:        #ddd2b8;
  --rule-soft:  #e6dec7;
  --ink:         #1a1814;
  --ink-soft:   #4a4438;
  --ink-mute:   #7a715f;
  --accent:     #a13b2b;       /* deep brick red */
  --accent-2:   #2a4f6e;       /* slate blue */
  --link:        #8b3324;
  --link-hover: #5e2117;
  --code-bg:    #2a261d;
  --code-ink:    #f1ead9;

  /* type scale: fluid */
  --fs-body:    clamp(1.0625rem, 0.95rem + 0.5vw, 1.1875rem); /* 17 - 19 */
  --fs-small:   clamp(0.9375rem, 0.87rem + 0.3vw, 1rem);
  --fs-h1:      clamp(2.1rem, 1.6rem + 3.2vw, 3.8rem);
  --fs-h2:      clamp(1.5rem, 1.2rem + 1.5vw, 2.2rem);
  --fs-h3:      clamp(1.2rem, 1.05rem + 0.8vw, 1.5rem);
  --fs-tag:     0.74rem;
  --fs-kicker:  0.78rem;

  /* rhythm */
  --leading:    1.65;
  --leading-tight: 1.25;
  --col-max:    42rem;          /* main reading column */
  --col-wide:   58rem;          /* wide figures */
  --pad-x:      max(1.25rem, env(safe-area-inset-left, 1.25rem));

  /* motion */
  --t-fast:     150ms cubic-bezier(.4,0,.2,1);
  --t-slow:     320ms cubic-bezier(.4,0,.2,1);
}

/* ---------- reset / base ---------- */

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

html {
  -webkit-text-size-adjust: 100%;
  -moz-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Source Serif 4", "Source Serif Pro", Georgia, "Times New Roman", serif;
  font-size: var(--fs-body);
  font-weight: 400;
  line-height: var(--leading);
  font-feature-settings: "kern" 1, "liga" 1, "calt" 1, "onum" 1;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img, video, picture, svg {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--link);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2.5px;
  text-decoration-color: rgba(139, 51, 36, 0.45);
  transition: color var(--t-fast), text-decoration-color var(--t-fast);
}
a:hover, a:focus-visible {
  color: var(--link-hover);
  text-decoration-color: currentColor;
}

button { font: inherit; cursor: pointer; }

::selection { background: rgba(161, 59, 43, 0.22); color: var(--ink); }

.skip {
  position: absolute;
  left: -9999px;
}
.skip:focus {
  position: fixed; left: 1rem; top: 1rem;
  z-index: 9999; padding: .6rem 1rem;
  background: var(--ink); color: var(--bg);
  border-radius: 4px;
}

/* ---------- container ---------- */

.container {
  width: 100%;
  max-width: var(--col-max);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}
.container.narrow { max-width: 36rem; }

/* ===================================================================
   HERO
   =================================================================== */

.hero {
  padding: clamp(2.5rem, 5vw + 1rem, 5rem) 0 clamp(1.5rem, 3vw, 3rem);
  border-bottom: 1px solid var(--rule);
  background:
    radial-gradient(ellipse at top, rgba(217, 196, 158, 0.18) 0%, transparent 60%),
    var(--bg);
}

.hero-meta {
  display: flex;
  align-items: center;
  gap: .65rem;
  margin-bottom: 1.5rem;
}
.logo-mark {
  height: 44px;
  width: auto;
  opacity: 0.95;
}
@media (min-width: 720px) {
  .logo-mark { height: 52px; }
}
.kicker {
  font-family: "Inter", system-ui, sans-serif;
  font-size: var(--fs-kicker);
  font-weight: 500;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ink-mute);
}

.hero-title {
  margin: 0 0 1rem;
  font-family: "Source Serif 4", Georgia, serif;
  font-size: var(--fs-h1);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.012em;
  color: var(--ink);
}
.hero-subtitle {
  display: inline-block;
  font-style: italic;
  font-weight: 400;
  color: var(--ink-soft);
}

.authors {
  margin: 0 0 .35rem;
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(1.05rem, 0.95rem + 0.45vw, 1.25rem);
  color: var(--ink-soft);
}
.authors a {
  color: var(--ink-soft);
  text-decoration: none;
  border-bottom: 1px dotted var(--ink-mute);
  padding-bottom: 1px;
}
.authors a:hover { color: var(--accent); border-bottom-color: var(--accent); }
.authors .sep { color: var(--ink-mute); margin: 0 .35rem; }

.tagline {
  margin: 1.25rem 0 1.75rem;
  font-style: italic;
  color: var(--ink-soft);
  font-size: clamp(1.05rem, 0.95rem + 0.5vw, 1.25rem);
  line-height: 1.4;
  max-width: 32em;
}

.cta {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
}
.cta-btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .6rem 1.05rem;
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
  border-radius: 6px;
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--rule);
  transition: background var(--t-fast), border-color var(--t-fast), transform var(--t-fast);
}
.cta-btn:hover, .cta-btn:focus-visible {
  background: var(--bg-card);
  border-color: var(--ink-mute);
  color: var(--ink);
  text-decoration: none;
  transform: translateY(-1px);
}
.cta-btn.primary {
  background: var(--ink);
  color: var(--bg);
  border-color: var(--ink);
}
.cta-btn.primary:hover, .cta-btn.primary:focus-visible {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.cta-icon {
  font-family: "Inter", sans-serif;
  font-size: .85em;
  opacity: .8;
}

/* ===================================================================
   TABLE OF CONTENTS
   =================================================================== */

.toc {
  background: var(--bg-card);
  border-bottom: 1px solid var(--rule);
  padding: 1.75rem 0 2rem;
}
.toc-label {
  margin: 0 0 .9rem;
  font-family: "Inter", system-ui, sans-serif;
  font-size: var(--fs-kicker);
  font-weight: 600;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-mute);
}
.toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: none;
  column-gap: 2rem;
}
.toc-list > li {
  margin: 0 0 .35rem;
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.02rem;
  line-height: 1.4;
  break-inside: avoid;
}
.toc-list > li > a {
  display: inline-flex;
  align-items: baseline;
  gap: .5rem;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px dotted transparent;
  padding-bottom: 1px;
  transition: color var(--t-fast), border-color var(--t-fast);
}
.toc-list > li > a:hover,
.toc-list > li > a:focus-visible {
  color: var(--accent);
  border-bottom-color: var(--accent);
}
.toc-list .toc-num {
  display: inline-block;
  min-width: 1.5em;
  color: var(--ink-mute);
  font-family: "Inter", sans-serif;
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .04em;
  font-feature-settings: "tnum" 1;
  text-align: right;
}
.toc-list ol {
  list-style: none;
  margin: .3rem 0 .55rem 2.1rem;
  padding: 0;
}
.toc-list ol li {
  margin: 0;
  font-size: .94rem;
  line-height: 1.45;
  color: var(--ink-soft);
}
.toc-list ol li a {
  color: var(--ink-soft);
  text-decoration: none;
  border-bottom: 1px dotted transparent;
  padding-bottom: 1px;
  transition: color var(--t-fast), border-color var(--t-fast);
}
.toc-list ol li a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}
@media (min-width: 760px) {
  .toc-list { column-count: 2; }
}

html { scroll-padding-top: 1.5rem; }

/* ===================================================================
   MATH DISPLAY
   =================================================================== */

.math-display {
  margin: 1.5rem 0;
  padding: .2rem 0;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.math-boxed {
  background: var(--bg-card);
  border-left: 3px solid var(--accent);
  padding: .5rem 1rem .5rem 1.1rem;
  border-radius: 0 4px 4px 0;
}
mjx-container,
mjx-container[jax="SVG"] {
  font-size: 1em !important;
}
mjx-container[display="true"],
mjx-container[jax="SVG"][display="true"] {
  display: block !important;
  margin: 0 auto !important;
  overflow-x: auto;
  overflow-y: hidden;
  max-width: 100%;
  text-align: center;
}
mjx-container[display="true"] svg,
mjx-container[jax="SVG"][display="true"] svg {
  max-width: 100% !important;
  height: auto !important;
  display: inline-block;
}
mjx-container:not([display="true"]),
mjx-container[jax="SVG"]:not([display="true"]) {
  display: inline-block !important;
  margin: 0 !important;
  padding: 0 !important;
  vertical-align: baseline !important;
  line-height: 1 !important;
}
mjx-container:not([display="true"]) svg,
mjx-container[jax="SVG"]:not([display="true"]) svg {
  vertical-align: -0.18em;
}

/* ===================================================================
   DATA TABLES
   =================================================================== */

.table-figure {
  margin: 1.6rem 0 1.8rem;
}
.table-figure .data-table {
  width: 100%;
  border-collapse: collapse;
  font-family: "Inter", system-ui, sans-serif;
  font-size: .88rem;
  line-height: 1.45;
  color: var(--ink);
  background: var(--bg-card);
  border: 1px solid var(--rule);
  border-radius: 6px;
  overflow: hidden;
}
.data-table thead th {
  background: var(--rule-soft);
  color: var(--ink);
  font-weight: 600;
  text-align: left;
  padding: .55rem .7rem;
  border-bottom: 1px solid var(--rule);
  font-feature-settings: "tnum" 1;
}
.data-table tbody th {
  font-weight: 600;
  text-align: left;
  padding: .5rem .7rem;
  border-right: 1px solid var(--rule);
  background: rgba(0,0,0,.02);
  vertical-align: middle;
  white-space: nowrap;
}
.data-table tbody td {
  padding: .45rem .7rem;
  border-top: 1px solid var(--rule-soft);
  font-feature-settings: "tnum" 1;
  color: var(--ink-soft);
}
.data-table tbody td:first-of-type { font-weight: 500; color: var(--ink); }
.data-table tbody tr:hover td,
.data-table tbody tr:hover th { background: rgba(161, 59, 43, 0.04); }

.table-figure .caption {
  margin-top: .65rem;
}

/* mobile: let tables scroll horizontally */
@media (max-width: 720px) {
  .table-figure {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    margin-left: calc(-1 * var(--pad-x));
    margin-right: calc(-1 * var(--pad-x));
    padding: 0 var(--pad-x);
  }
  .table-figure .data-table {
    min-width: 32rem;
    font-size: .82rem;
  }
  .table-figure .caption {
    padding: 0 var(--pad-x);
  }
}

/* ===================================================================
   SECTIONS
   =================================================================== */

.section {
  padding: clamp(2.25rem, 4vw + 1rem, 4.5rem) 0;
}
.section + .section { padding-top: clamp(2rem, 4vw, 4rem); }
.section-lede { padding-top: clamp(1.5rem, 3vw, 3rem); }

.section-band {
  background: var(--bg-band);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.section-title {
  margin: 0 0 1.25rem;
  font-family: "Source Serif 4", Georgia, serif;
  font-size: var(--fs-h2);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.008em;
  color: var(--ink);
  position: relative;
  padding-top: .25rem;
}
.section-title::before {
  content: "";
  display: block;
  width: 2.5rem;
  height: 2px;
  background: var(--accent);
  margin-bottom: .9rem;
  border-radius: 2px;
}

p { margin: 0 0 1.1em; }
p:last-child { margin-bottom: 0; }

.lede {
  font-size: clamp(1.15rem, 1.05rem + 0.5vw, 1.35rem);
  line-height: 1.5;
  color: var(--ink);
  font-style: italic;
  margin: 1.5rem 0 1.5rem;
  padding-left: 1rem;
  border-left: 3px solid var(--accent);
}

em { font-style: italic; }
strong { font-weight: 600; color: var(--ink); }

.plain-list {
  list-style: none;
  margin: 0 0 1.2em;
  padding: 0;
}
.plain-list li {
  position: relative;
  padding: .35rem 0 .55rem 1.4rem;
  border-bottom: 1px dashed var(--rule-soft);
}
.plain-list li:last-child { border-bottom: none; }
.plain-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.15em;
  width: .55rem;
  height: 2px;
  background: var(--accent);
}

.mode-list li { padding-left: 0; }
.mode-list li::before { display: none; }
.mode-tag {
  display: inline-block;
  font-family: "Inter", system-ui, sans-serif;
  font-size: var(--fs-tag);
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--bg);
  background: var(--accent);
  padding: .15rem .55rem;
  border-radius: 3px;
  margin-right: .6rem;
  vertical-align: 2px;
}

/* ===================================================================
   ENV BLOCKS
   =================================================================== */

.env { border-top: 1px solid var(--rule-soft); }
.env:first-of-type { border-top: none; }
.env-tag {
  font-family: "Inter", system-ui, sans-serif;
  font-size: var(--fs-tag);
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 .4rem;
}
.env-title {
  margin: 0 0 1rem;
  font-family: "Source Serif 4", Georgia, serif;
  font-size: var(--fs-h3);
  font-weight: 600;
  font-style: italic;
  color: var(--ink);
  line-height: 1.2;
}

/* ===================================================================
   FIGURES
   =================================================================== */

.figure {
  margin: 1.6rem 0 1.8rem;
  padding: 0;
}

.figure .media,
.figure img {
  width: 100%;
  border-radius: 6px;
  background: #111;
  display: block;
  border: 1px solid var(--rule);
}

.figure-zoom {
  display: block;
  cursor: zoom-in;
  -webkit-tap-highlight-color: rgba(161, 59, 43, 0.18);
  transition: transform var(--t-fast);
}
.figure-zoom:hover img {
  border-color: var(--accent);
}
.figure-zoom:active {
  transform: scale(0.995);
}

.figure-pair .media,
.figure-pair img {
  max-width: 28rem;
  margin: 0 auto;
}

.figure-wide {
  max-width: var(--col-wide);
  margin-left: auto;
  margin-right: auto;
}
.figure-wide img {
  border-radius: 6px;
}

.figure-bleed {
  margin: 1.25rem 0 2.25rem;
}

.caption {
  margin: .65rem 0 0;
  padding: 0 .25rem;
  color: var(--ink-mute);
  font-size: var(--fs-small);
  font-style: italic;
  line-height: 1.45;
  text-align: left;
}

/* ===================================================================
   BIBTEX + RESOURCES
   =================================================================== */

.bibtex {
  background: var(--code-bg);
  color: var(--code-ink);
  padding: 1rem 1.1rem;
  border-radius: 6px;
  font-family: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.86rem;
  line-height: 1.55;
  overflow-x: auto;
  margin: 0 0 2rem;
  border: 1px solid #1f1c16;
  -webkit-overflow-scrolling: touch;
}
.bibtex code {
  background: none; padding: 0; color: inherit;
  font: inherit;
}

.resource-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: .75rem;
  margin-top: 1rem;
}
.resource {
  display: flex;
  flex-direction: column;
  gap: .25rem;
  padding: .9rem 1rem;
  background: var(--bg-card);
  border: 1px solid var(--rule);
  border-radius: 6px;
  text-decoration: none;
  color: var(--ink);
  transition: border-color var(--t-fast), transform var(--t-fast), background var(--t-fast);
}
.resource:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
  background: #fffaf0;
  text-decoration: none;
}
.resource-label {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ink);
}
.resource-meta {
  font-family: "Inter", system-ui, sans-serif;
  font-size: 0.85rem;
  color: var(--ink-mute);
}

/* ===================================================================
   FOOTER
   =================================================================== */

.site-footer {
  margin-top: 3rem;
  padding: 2.5rem 0 3rem;
  border-top: 1px solid var(--rule);
  background: var(--bg-card);
  color: var(--ink-mute);
  text-align: center;
}
.site-footer .container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .75rem;
}
.footer-logo {
  height: 36px;
  width: auto;
  opacity: 0.72;
}
.footer-copy {
  margin: 0;
  font-size: var(--fs-small);
  color: var(--ink-soft);
}
.footer-copy a {
  color: var(--ink-soft);
  text-decoration: underline;
  text-decoration-color: rgba(74, 68, 56, 0.4);
}
.footer-year {
  margin: 0;
  font-family: "Inter", sans-serif;
  font-size: 0.8rem;
  letter-spacing: .1em;
  color: var(--ink-mute);
}

/* ===================================================================
   RESPONSIVE
   =================================================================== */

@media (min-width: 640px) {
  .resource-row { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 720px) {
  .figure-bleed { margin-left: -2rem; margin-right: -2rem; }
  .figure-bleed .media { border-radius: 8px; }
  .figure-wide { margin-left: -2rem; margin-right: -2rem; max-width: calc(var(--col-max) + 4rem); }
}

@media (min-width: 960px) {
  :root {
    --pad-x: 1.5rem;
  }
  .figure-bleed { margin-left: -4rem; margin-right: -4rem; }
  .figure-wide  { margin-left: -6rem; margin-right: -6rem; max-width: calc(var(--col-max) + 12rem); }
}

@media (min-width: 1100px) {
  .figure-wide { margin-left: -8rem; margin-right: -8rem; max-width: calc(var(--col-max) + 16rem); }
}

/* keep figure captions readable when figure goes outside main column */
@media (min-width: 720px) {
  .figure-bleed .caption,
  .figure-wide  .caption {
    max-width: var(--col-max);
    margin-left: auto;
    margin-right: auto;
  }
}

/* reduce motion respects */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* tiny phone tweaks */
@media (max-width: 380px) {
  :root { --pad-x: 1rem; }
  .cta-btn { padding: .55rem .85rem; font-size: 0.9rem; }
  .hero-meta .kicker { font-size: 0.72rem; }
}