/* ============================================================
   Erwin Lejeune — portfolio v2
   Hand-written. No framework, no build step.

   Colour comes from guilyx/branding — "Ink & Iris", a neutral-cool
   near-black under a periwinkle accent. The brand repo is the source
   of truth; if this file drifts from tokens/tokens.json, this file is
   wrong.

   The accent is the only saturated value in the system, so it is spent
   deliberately: mono labels and section keys, links, the one active
   control in a view, the mark, and focus rings. Not headings, not body
   copy, not gradients.
   ============================================================ */

/* ---------- tokens ---------- */

:root {
  --bg:        #0d0e12;   /* brand: color.bg       */
  --bg-soft:   #15171d;   /* brand: color.bgRaised */
  --bg-card:   #15171d;   /* brand: color.surface  */
  --line:      #252833;   /* brand: color.line     */
  --line-soft: #1b1e26;   /* derived: between surface and line, for quiet rules */

  --fg:        #e4e6ec;   /* brand: color.heading */
  --fg-dim:    #a5aab8;   /* brand: color.body    */
  --fg-faint:  #7c8291;   /* brand: color.muted   */

  /* color.faint (#555b69) is deliberately unused: it is documented as
     labels >= 14px only, and every mono key here sits around 11px. */

  --accent:      #8b95f0;                    /* brand: color.accent     */
  --accent-soft: rgba(139, 149, 240, .08);   /* brand: color.accentSoft */

  --sans: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  /* Brand mono is JetBrains Mono, but the shipped lockup SVG itself lists
     ui-monospace first, so the system face is on-brand and costs nothing. */
  --mono: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Consolas, monospace;

  --sidebar-w: 264px;
  --shell-max: 86rem;
  --radius: 10px;
  --ease: cubic-bezier(.4, 0, .2, 1);
}

/* Light theme is "Bone & Rust", the runner-up palette documented in
   brand/palette.md — the only light ground the brand actually defines.
   Using it beats inventing a light Ink & Iris: the iris accent drops to
   roughly 2:1 on a cream ground, and darkening it would fork the palette. */
html[data-theme="light"] {
  --bg:        #f5f3ee;
  --bg-soft:   #ffffff;
  --bg-card:   #ffffff;
  --line:      #dbd6cb;
  --line-soft: #e6e2d9;   /* derived, as above */

  --fg:        #1b1a17;
  --fg-dim:    #4b4842;
  --fg-faint:  #6f6b62;

  --accent:      #b0472b;
  --accent-soft: rgba(176, 71, 43, .08);
}

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

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

html { scroll-behavior: smooth; scroll-padding-top: 2rem; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3 { line-height: 1.2; margin: 0; font-weight: 700; letter-spacing: -.02em; }
p  { margin: 0 0 1rem; }
ul, ol { margin: 0; padding: 0; list-style: none; }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  padding: .6rem 1rem;
  background: var(--accent);
  color: var(--bg);
  font-weight: 700;
}
.skip-link:focus { left: 0; }

/* ---------- shell ---------- */

/* Sidebar + content are centred together, so wide screens get an even
   gutter on both sides instead of a wall of dead space on the right. */
.shell {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  max-width: var(--shell-max);
  margin-inline: auto;
  min-height: 100vh;
}

/* ---------- sidebar ---------- */

.sidebar {
  border-right: 1px solid var(--line);
  /* Transparent on desktop: once the shell is centred, a filled panel
     would show a hard edge on its left with nothing to explain it. */
  background: transparent;
  position: sticky;
  top: 0;
  align-self: start;
  height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 2rem 1.5rem;
}

.sidebar-top { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }

.brand { display: flex; align-items: center; gap: .8rem; color: inherit; }
.brand:hover { text-decoration: none; }

/* The swarm mark, inlined so currentColor resolves against the page.
   Rotation is 120deg about the centroid (16, 16.833) - the only interval
   at which the mark lands back on itself. */
.brand-mark {
  flex: none;
  width: 34px; height: 34px;
  color: var(--accent);
  transform-origin: 16px 16.833px;
  transition: transform .5s cubic-bezier(.645, .045, .355, 1);
}
.brand:hover .brand-mark { transform: rotate(120deg); }

.brand-text { display: flex; flex-direction: column; line-height: 1.3; }
.brand-text b { font-size: .95rem; }
.brand-text small { color: var(--fg-faint); font-size: .74rem; }

.nav { margin-top: 2.5rem; display: flex; flex-direction: column; flex: 1; min-height: 0; }

.nav > ul { display: flex; flex-direction: column; gap: .15rem; }

.nav a {
  display: flex;
  align-items: baseline;
  gap: .7rem;
  padding: .5rem .7rem;
  border-radius: 7px;
  color: var(--fg-dim);
  font-size: .92rem;
  font-weight: 500;
  border-left: 2px solid transparent;
  transition: color .18s var(--ease), background .18s var(--ease), border-color .18s var(--ease);
}
.nav a:hover { color: var(--fg); background: var(--line-soft); text-decoration: none; }

.nav a i {
  font-style: normal;
  font-family: var(--mono);
  font-size: .68rem;
  color: var(--fg-faint);
  transition: color .18s var(--ease);
}

.nav a.is-current {
  color: var(--accent);
  background: var(--accent-soft);
  border-left-color: var(--accent);
}
.nav a.is-current i { color: var(--accent); }

.sidebar-foot {
  margin-top: auto;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  gap: .9rem;
}

.social { display: flex; flex-wrap: wrap; gap: .35rem .9rem; }
.social a { font-size: .8rem; color: var(--fg-faint); }
.social a:hover { color: var(--accent); }

.theme-toggle {
  display: flex;
  align-items: center;
  gap: .5rem;
  align-self: flex-start;
  padding: .35rem .7rem .35rem .5rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--fg-faint);
  font: inherit;
  font-size: .76rem;
  cursor: pointer;
  transition: border-color .18s var(--ease), color .18s var(--ease);
}
.theme-toggle:hover { border-color: var(--accent); color: var(--fg); }

.theme-dot {
  width: 11px; height: 11px;
  border-radius: 50%;
  background: var(--accent);
}

.nav-toggle { display: none; }

/* ---------- main ---------- */

.main {
  width: 100%;
  max-width: 64rem;
  margin-inline: auto;
  padding: 0 clamp(1.25rem, 4vw, 3.5rem);
}

.section { padding: clamp(3rem, 6vw, 4.5rem) 0; border-bottom: 1px solid var(--line-soft); }
.section:last-child { border-bottom: 0; }

.section-title {
  display: flex;
  align-items: baseline;
  gap: .8rem;
  font-size: clamp(1.4rem, 3vw, 1.85rem);
  margin-bottom: 1rem;
}
.section-title i {
  font-style: normal;
  font-family: var(--mono);
  font-size: .82rem;
  font-weight: 400;
  color: var(--accent);
}
.section-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--line);
}

.section-lede { color: var(--fg-dim); max-width: 46rem; margin-bottom: 2rem; }

/* ---------- hero ---------- */

.hero { padding-top: clamp(4rem, 10vw, 7rem); }

.eyebrow {
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--fg-faint);
  letter-spacing: .04em;
  margin-bottom: 1.4rem;
}

.pulse {
  display: inline-block;
  width: 7px; height: 7px;
  margin-right: .15rem;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 2.6s infinite;
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 var(--accent-soft); }
  70%  { box-shadow: 0 0 0 8px transparent; }
  100% { box-shadow: 0 0 0 0 transparent; }
}

.hero h1 {
  font-size: clamp(2.1rem, 6vw, 3.4rem);
  letter-spacing: -.035em;
  margin-bottom: 1.5rem;
}
.hero h1 em {
  font-style: normal;
  color: var(--accent);
}

.lede { font-size: 1.08rem; color: var(--fg); max-width: 44rem; }
.lede b { color: var(--accent); font-weight: 500; }
.body { color: var(--fg-dim); max-width: 44rem; }

.facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1px;
  margin: 2.5rem 0;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.facts li {
  background: var(--bg-card);
  padding: 1rem 1.1rem;
  display: flex;
  flex-direction: column;
  gap: .15rem;
}
.facts b { font-size: .92rem; }
.facts span { font-size: .8rem; color: var(--fg-faint); }

.cta { display: flex; flex-wrap: wrap; gap: .75rem; }

.btn {
  display: inline-block;
  padding: .65rem 1.3rem;
  border: 1px solid var(--line);
  border-radius: 7px;
  color: var(--fg);
  font-size: .92rem;
  font-weight: 500;
  transition: border-color .18s var(--ease), background .18s var(--ease), transform .18s var(--ease);
}
.btn:hover { border-color: var(--accent); background: var(--accent-soft); text-decoration: none; transform: translateY(-1px); }

.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--bg); }
.btn-primary:hover { background: var(--accent); filter: brightness(1.08); }

/* ---------- timeline ---------- */

.timeline { display: flex; flex-direction: column; }

.tl-item {
  display: grid;
  grid-template-columns: 10.5rem minmax(0, 1fr);
  gap: 1.5rem;
  padding: 1.75rem 0;
  border-top: 1px solid var(--line-soft);
}
.tl-item:first-child { border-top: 0; padding-top: .5rem; }

.tl-when {
  font-family: var(--mono);
  font-size: .76rem;
  color: var(--fg-faint);
  padding-top: .3rem;
  letter-spacing: .01em;
}

.tl-what h3 { font-size: 1.05rem; margin-bottom: .15rem; }
.tl-what h3 .at { display: block; color: var(--accent); font-weight: 500; font-size: .98rem; }
.tl-where { font-size: .8rem; color: var(--fg-faint); margin-bottom: .7rem; }
.tl-what > p { color: var(--fg-dim); font-size: .94rem; }

.bullets { margin: .6rem 0 .9rem; display: flex; flex-direction: column; gap: .3rem; }
.bullets li {
  position: relative;
  padding-left: 1.1rem;
  font-size: .9rem;
  color: var(--fg-dim);
}
.bullets li::before {
  content: "";
  position: absolute;
  left: 0; top: .62em;
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--accent);
  opacity: .7;
}

.tags { display: flex; flex-wrap: wrap; gap: .35rem; }
.tags li {
  font-family: var(--mono);
  font-size: .68rem;
  padding: .18rem .5rem;
  border: 1px solid var(--line);
  border-radius: 4px;
  color: var(--fg-faint);
}

/* ---------- project filters + grid ---------- */

.filters { display: flex; flex-wrap: wrap; gap: .45rem; margin-bottom: 1.75rem; }

.chip {
  padding: .35rem .85rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--fg-dim);
  font: inherit;
  font-size: .82rem;
  cursor: pointer;
  transition: all .18s var(--ease);
}
.chip:hover { border-color: var(--accent); color: var(--fg); }
.chip.is-active {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
  font-weight: 500;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 20rem), 1fr));
  gap: 1rem;
}

.card {
  position: relative;
  padding: 1.25rem 1.25rem 1.1rem;
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  display: flex;
  flex-direction: column;
  gap: .55rem;
  transition: border-color .18s var(--ease), transform .18s var(--ease);
}
.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card[hidden] { display: none; }

.card h3 { font-size: .98rem; padding-right: 3rem; }
.card h3 a { color: var(--fg); }
.card:hover h3 a { color: var(--accent); }
.card h3 a::after {
  /* whole card is the click target */
  content: "";
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
}
.card p { margin: 0; font-size: .875rem; color: var(--fg-dim); flex: 1; }

.card-year {
  position: absolute;
  top: 1.25rem; right: 1.25rem;
  font-family: var(--mono);
  font-size: .68rem;
  color: var(--fg-faint);
}

.grid-empty { margin-top: 1.5rem; color: var(--fg-faint); font-size: .9rem; }

/* ---------- open source ---------- */

.oss { display: flex; flex-direction: column; }
.oss li {
  display: grid;
  grid-template-columns: 14rem minmax(0, 1fr);
  gap: 1.5rem;
  padding: .9rem 0;
  border-top: 1px solid var(--line-soft);
  align-items: baseline;
}
.oss li:first-child { border-top: 0; }
.oss li > a { font-weight: 500; font-size: .95rem; }
.oss li > span { color: var(--fg-dim); font-size: .875rem; }

/* ---------- writing ---------- */

.papers { display: flex; flex-direction: column; }
.papers li {
  display: grid;
  grid-template-columns: 7rem minmax(0, 1fr);
  gap: 1.5rem;
  padding: 1.5rem 0;
  border-top: 1px solid var(--line-soft);
}
.papers li:first-child { border-top: 0; padding-top: 0; }
.paper-year { font-family: var(--mono); font-size: .76rem; color: var(--fg-faint); padding-top: .3rem; }
.papers h3 { font-size: 1.02rem; margin-bottom: .5rem; }
.papers h3 a { color: var(--fg); }
.papers h3 a:hover { color: var(--accent); }
.papers p { margin: 0; color: var(--fg-dim); font-size: .9rem; }

/* ---------- education ---------- */

.edu { display: flex; flex-direction: column; margin-bottom: 3rem; }
.edu li {
  display: grid;
  grid-template-columns: 7rem minmax(0, 1fr);
  gap: 1.5rem;
  padding: 1.35rem 0;
  border-top: 1px solid var(--line-soft);
}
.edu li:first-child { border-top: 0; padding-top: 0; }
.edu-when { font-family: var(--mono); font-size: .76rem; color: var(--fg-faint); padding-top: .3rem; }
.edu h3 { font-size: 1rem; margin-bottom: .1rem; }
.edu-where { font-size: .82rem; color: var(--accent); margin-bottom: .5rem; }
.edu p:last-child { margin: 0; color: var(--fg-dim); font-size: .9rem; }

.odds {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.odds > div { background: var(--bg-card); padding: 1.2rem 1.3rem; }
.odds h3 {
  font-family: var(--mono);
  font-size: .7rem;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--accent);
  margin-bottom: .7rem;
}
.odds ul { display: flex; flex-direction: column; gap: .3rem; }
.odds li { font-size: .875rem; color: var(--fg-dim); }

/* ---------- contact ---------- */

.contact { display: flex; flex-direction: column; max-width: 34rem; }
.contact li {
  display: grid;
  grid-template-columns: 6.5rem minmax(0, 1fr);
  gap: 1rem;
  padding: .7rem 0;
  border-top: 1px solid var(--line-soft);
  font-size: .93rem;
}
.contact li:first-child { border-top: 0; }
.contact span { font-family: var(--mono); font-size: .74rem; color: var(--fg-faint); padding-top: .18rem; }

.foot {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line-soft);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: .5rem;
}
.foot p { margin: 0; font-size: .78rem; color: var(--fg-faint); }

/* ---------- responsive ---------- */

@media (max-width: 900px) {
  .shell { grid-template-columns: 1fr; }

  .sidebar {
    position: sticky;
    top: 0;
    z-index: 20;
    height: auto;
    padding: 1rem 1.25rem;
    border-right: 0;
    border-bottom: 1px solid var(--line);
    backdrop-filter: blur(10px);
    background: color-mix(in srgb, var(--bg-soft) 88%, transparent);
  }

  .nav-toggle {
    display: block;
    width: 40px; height: 40px;
    padding: 0;
    border: 1px solid var(--line);
    border-radius: 7px;
    background: transparent;
    cursor: pointer;
    position: relative;
  }
  .nav-toggle span,
  .nav-toggle span::before,
  .nav-toggle span::after {
    content: "";
    position: absolute;
    left: 50%;
    width: 17px; height: 1.5px;
    background: var(--fg);
    transform: translateX(-50%);
    transition: transform .22s var(--ease), opacity .22s var(--ease);
  }
  .nav-toggle span { top: 50%; margin-top: -.75px; }
  .nav-toggle span::before { left: 0; transform: none; top: -5px; }
  .nav-toggle span::after  { left: 0; transform: none; top:  5px; }

  .nav-toggle[aria-expanded="true"] span { background: transparent; }
  .nav-toggle[aria-expanded="true"] span::before { top: 0; transform: rotate(45deg); }
  .nav-toggle[aria-expanded="true"] span::after  { top: 0; transform: rotate(-45deg); }

  .nav {
    display: none;
    margin-top: 1rem;
    max-height: calc(100vh - 6rem);
    overflow-y: auto;
  }
  .nav.is-open { display: flex; }

  .sidebar-foot { margin-top: 1.25rem; }

  .main { padding-inline: 1.25rem; }

  .tl-item, .papers li, .edu li, .oss li {
    grid-template-columns: 1fr;
    gap: .4rem;
  }
  .tl-when, .paper-year, .edu-when { padding-top: 0; }
  .oss li { gap: .2rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
}

@media print {
  .sidebar, .filters, .cta { display: none; }
  .shell { grid-template-columns: 1fr; }
  body { background: #fff; color: #000; }
  .card, .facts li, .odds > div { break-inside: avoid; }
}