/* Variables */
:root {
  --bg: #fdfdfc;
  --fg: #1c1e21;
  --muted: #5c6470;
  --accent: #7c3aed;
  --accent-soft: #f0e9fd;
  --eclass: #d97706;
  --card: #ffffff;
  --border: #e3e5e8;
  --badge-pub: #0d7a4f;
  --badge-pub-bg: #e4f5ec;
  --badge-sub: #92600a;
  --badge-sub-bg: #fdf1da;
  --logo-scale: 8;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16181d;
    --fg: #e8eaed;
    --muted: #9aa3af;
    --accent: #b79bf5;
    --accent-soft: #2a2340;
    --eclass: #e8b45a;
    --card: #1e2127;
    --border: #31353c;
    --badge-pub: #6fd8a8;
    --badge-pub-bg: #17362a;
    --badge-sub: #ecc06a;
    --badge-sub-bg: #3a2e14;
  }
}

/* Base */
* { box-sizing: border-box; }
html { scroll-padding-top: 4rem; }
body {
  margin: 0;
  padding-top: 3.6rem;
  background: var(--bg);
  color: var(--fg);
  font: 17px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
.wrap { max-width: 46rem; margin: 0 auto; }
main { padding: 1rem 1.5rem 4rem; }
h2 {
  font-size: 1.35rem;
  margin: 3rem 0 1.25rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border);
  letter-spacing: -0.01em;
}
a { color: var(--accent); }
a:hover { text-decoration-thickness: 2px; }
code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  font-size: 0.82em;
  background: rgba(127, 131, 139, 0.15);
  padding: 0.08em 0.35em;
  border-radius: 5px;
}
p { margin: 0 0 1rem; }
.lead { font-size: 1.06rem; font-weight: 600; color: var(--fg); text-align: justify; }
.inline-logo { height: 2.25em; width: auto; vertical-align: -0.45em; }
.keyword, .keyword-alt {
  padding: 0.06em 0.5em;
  border-radius: 999px;
  font-weight: 500;
  white-space: nowrap;
  color: var(--accent);
  background: var(--accent-soft);
}
.keyword-alt {
  color: var(--badge-sub);
  background: var(--badge-sub-bg);
}

/* Work-in-progress banner */
.wip {
  position: fixed;
  top: 1.75rem;
  right: 0.9rem;
  transform: translateY(-50%);
  z-index: 10;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--badge-sub);
  background: var(--badge-sub-bg);
  border: 1px solid var(--badge-sub);
  border-radius: 999px;
  padding: 0.25rem 0.8rem;
  pointer-events: none;
}

/* Fixed top bar */
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 9;
  display: flex;
  align-items: center;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  padding: 0.55rem 1.5rem;
}
header .wrap {
  display: flex;
  align-items: center;
  width: 100%;
}
.topbar-logo {
  height: 2.4rem;
  width: auto;
}

/* Hero card */
.hero {
  position: relative;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2.25rem 1.75rem 2rem;
  margin: 2rem 0 2.5rem;
}
.hero > * { position: relative; z-index: 1; }
/* Amber halo flickers on outside the perimeter once the lamp lights up (~3s),
   using the same flicker as the e-class and text but capped at its subtle level. */
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  border-radius: inherit;
  pointer-events: none;
  box-shadow: 0 0 2.5rem 0.1rem var(--badge-sub-bg);
  opacity: 0;
  animation: heroGlow 0.28s 2.8s both;
}
@keyframes heroGlow {
  0% { opacity: 0; }
  30% { opacity: 0.55; }
  60% { opacity: 0; }
  100% { opacity: 0.55; }
}
/* #hero-logo-slot reserves the logo's box so injecting the SVG causes no layout shift */
#hero-logo-slot,
.hero-logo {
  display: block;
  height: calc(28px * var(--logo-scale));
  width: auto;
  max-width: 100%;
  margin: 0 auto 1.25rem;
}
/* In dark mode the wordmark and lamp outline are drawn in black; recolor to the
   foreground so they stay legible. The injected hero SVG is inline, so CSS reaches it. */
@media (prefers-color-scheme: dark) {
  .hero-logo [fill="rgb(0%, 0%, 0%)"] { fill: var(--fg); }
  .hero-logo [stroke="rgb(0%, 0%, 0%)"] { stroke: var(--fg); }
}

/* Lamp powers on bottom-to-top; then "Smart" fades in left-to-right. */
.hero-logo .lamp-bulb { animation: lampBulb 0.6s ease-out both; }
.hero-logo .lamp-edge,
.hero-logo .lamp-node {
  animation: lampFlicker 1.3s both;
  animation-delay: var(--d, 0s);
}
.hero-logo .lamp-eclass { animation: lampEclass 0.28s 2.8s both; }
.hero-logo .lamp-word use {
  opacity: 0;
  animation: lampEclass 0.28s 2.8s both;
}
@keyframes lampBulb { from { opacity: 0; } to { opacity: 1; } }
@keyframes lampFlicker {
  0%, 10% { opacity: 0; }
  18% { opacity: 1; }
  28% { opacity: 0.12; }
  40% { opacity: 1; }
  55% { opacity: 0.4; }
  70% { opacity: 1; }
  100% { opacity: 1; }
}
@keyframes lampEclass {
  0% { opacity: 0; }
  30% { opacity: 1; }
  60% { opacity: 0; }
  100% { opacity: 1; }
}
@media (prefers-reduced-motion: reduce) {
  .hero::after { animation: none; opacity: 0.55; }
  .hero-logo .lamp-bulb,
  .hero-logo .lamp-edge,
  .hero-logo .lamp-node,
  .hero-logo .lamp-eclass,
  .hero-logo .lamp-word use { animation: none; opacity: 1; }
}
.tagline {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--muted);
  text-align: center;
  margin: 0 auto;
  max-width: 34rem;
}
.hero hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 1.5rem 0 1.75rem;
}

/* Figures */
.fig-run {
  margin: 0.5rem auto 1.75rem;
  max-width: 27rem;
}
.fig-run img {
  display: block;
  width: 100%;
  height: auto;
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.9rem 1.1rem;
}
.fig-run figcaption { display: none; }
.fig-run.fig-wide { max-width: 42rem; }

/* Diagrams (SVG illustrations and animations) */
@keyframes march {
  to { stroke-dashoffset: -15.5; }
}
@keyframes flow {
  to { stroke-dashoffset: -100; }
}
.diagram .packet path {
  fill: none;
  stroke: var(--eclass);
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-dasharray: 12 88;
  animation: flow 1.2s linear infinite;
  animation-play-state: paused;
  visibility: hidden;
}
.extension:hover .packet path {
  animation-play-state: running;
  visibility: visible;
}
.extension:hover .eclass {
  animation: march 1.8s linear infinite;
}
@media (prefers-reduced-motion: reduce) {
  .diagram .packet { display: none; }
  .extension:hover .eclass { animation: none; }
}
.diagram .eclass {
  fill: none;
  stroke: var(--eclass);
  stroke-width: 2.5;
  stroke-dasharray: 5 4;
  stroke-dashoffset: 2.5;
  stroke-linecap: round;
}
.diagram .enode { fill: var(--eclass); }
.diagram .edge { stroke: var(--muted); stroke-width: 2.5; fill: none; }
.diagram .vbox {
  fill: var(--badge-sub-bg);
  stroke: var(--badge-sub);
  stroke-width: 2;
}
.diagram .vlabel {
  font: 12px ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  fill: var(--fg);
}
.diagram .fg { stroke: var(--fg); stroke-width: 3; stroke-linecap: round; }

/* Semantic extensions: two-column grid of cards */
.extensions {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-bottom: 1rem;
}
.extension {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem 1.35rem;
}
.extension h3 {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin: 0 0 0.5rem;
  font-size: 1.08rem;
}
.extension-icon {
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  flex-shrink: 0;
  border-radius: 8px;
  color: var(--accent);
  background: var(--accent-soft);
}
.extension-icon svg { width: 1.2rem; height: 1.2rem; }
.extension p { margin: 0; color: var(--muted); font-size: 0.95rem; text-align: justify; }
.extension-img { width: 100%; max-width: 270px; height: auto; align-self: center; }
.ext-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: auto;
}
.ext-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  flex: 1 1 0;
  min-width: 7rem;
  padding: 0.4rem 0.9rem;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  text-align: center;
  text-decoration: none;
  color: var(--bg);
  background: var(--accent);
  border: 1px solid transparent;
  transition: opacity 0.15s ease, border-color 0.15s ease;
}
.ext-btn:hover { opacity: 0.88; }
.ext-btn.is-disabled {
  flex: 0 1 auto;
  min-width: 10rem;
  color: var(--muted);
  background: transparent;
  border: 1px dashed var(--border);
  cursor: default;
  pointer-events: none;
}
/* Secondary artifact button: matches the primary button's size, sits beside it */
.ext-btn-artifact {
  color: var(--fg);
  background: transparent;
  border: 1px solid var(--border);
}
.ext-btn-artifact:hover { opacity: 1; border-color: var(--accent); }
.artifact-icon { width: 1.1em; height: 1.1em; flex-shrink: 0; }
@media (max-width: 40rem) {
  .extensions { grid-template-columns: 1fr; }
}

/* Publications */
.publication {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.15rem 1.35rem;
  margin-bottom: 1rem;
}
.publication h3 { margin: 0 0 0.3rem; font-size: 1.08rem; line-height: 1.4; }
.publication .authors { color: var(--fg); font-size: 0.95rem; margin: 0 0 0.15rem; }
.publication .venue { color: var(--muted); font-size: 0.9rem; margin: 0 0 0.6rem; }
.badge {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  border-radius: 999px;
  padding: 0.12rem 0.6rem;
  margin-bottom: 0.55rem;
}
.badge.published { color: var(--badge-pub); background: var(--badge-pub-bg); }
.links { font-size: 0.92rem; }
.links a { margin-right: 1rem; font-weight: 500; }
details { margin-top: 0.6rem; font-size: 0.93rem; }
details summary {
  cursor: pointer;
  color: var(--muted);
  font-weight: 500;
  user-select: none;
}
details p { margin: 0.5rem 0 0; color: var(--muted); }

/* Read-more button (links to the background subpage) */
.readmore-wrap {
  text-align: center;
  margin: 0 0 2.5rem;
}
.readmore-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.6rem 1.35rem;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid transparent;
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.readmore-btn:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
}

/* Subpage helpers */
.backlink { font-size: 0.92rem; }
.page-title {
  font-size: 1.7rem;
  margin: 0.5rem 0 1rem;
  letter-spacing: -0.01em;
}

/* Credits logos */
.credit-logos {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  margin: 1.25rem 0 0.5rem;
}
.credit-logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 1.25rem;
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.credit-logo:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}
.credit-logo img {
  display: block;
  height: 40px;
  width: auto;
}

/* Footer */
footer {
  border-top: 1px solid var(--border);
  background: linear-gradient(to top, rgba(127, 131, 139, 0.04), rgba(127, 131, 139, 0) 55%);
  color: var(--muted);
  font-size: 0.88rem;
  padding: 1.5rem;
  text-align: center;
}
footer a { color: var(--muted); }