/* ───────────────────────────────────────────────────────────────────────────
   Morgan Li — personal site
   Swiss / modern-minimal direction, vertical-nav locked in.
   ─────────────────────────────────────────────────────────────────────────── */

:root{
  --bg:#fafaf7;
  --bg-alt:#f0f0eb;
  --ink:#0a0a0a;
  --ink-2:#1a1a1a;
  --muted:#6e6e6e;
  --line:#0a0a0a;
  --line-soft:#dcdcd6;
  --accent:#0035ff;
  --accent-soft:#e0e6ff;

  --sans:"Manrope",ui-sans-serif,system-ui,-apple-system,sans-serif;
  --mono:"JetBrains Mono",ui-monospace,Menlo,monospace;

  --pad-x: clamp(24px, 5vw, 72px);
  --max: 1440px;
}
*,*::before,*::after{ box-sizing:border-box; }
html,body{ margin:0; padding:0; }
html{ scroll-behavior:smooth; scroll-padding-top: 80px; }
body{
  background: var(--bg); color: var(--ink);
  font-family: var(--sans); font-size: 17px; line-height: 1.5;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a{ color: inherit; }
::selection{ background: var(--accent); color: #fff; }

/* ── horizontal top nav (mobile fallback / unused on desktop) ────────────── */
.nav{
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav-inner{
  max-width: var(--max); margin: 0 auto;
  display:grid; grid-template-columns: 1fr auto 1fr; align-items: center;
  padding: 20px var(--pad-x); gap: 24px;
}
.brand{
  font-weight: 700; font-size: 17px; letter-spacing: -.01em;
  text-decoration: none; color: var(--ink);
  display: inline-flex; align-items: center; gap: 10px;
}
.nav-cta{
  background: var(--ink); color: var(--bg);
  padding: 10px 16px; border-radius: 999px;
  text-decoration: none; font-weight: 500; font-size: 14px;
  transition: background .2s;
}
.nav-cta:hover{ background: var(--accent); }

/* ── hero ────────────────────────────────────────────────────────────────── */
.hero{
  max-width: var(--max); margin: 0 auto;
  padding: clamp(60px, 10vw, 140px) var(--pad-x) clamp(80px, 12vw, 160px);
  position: relative;
}
.hero-grid{
  display: grid; grid-template-columns: 5fr 7fr; gap: 60px;
  align-items: end;
}
@media (max-width: 920px){ .hero-grid{ grid-template-columns: 1fr; gap: 32px; } }
.hero-eyebrow{
  display: flex; align-items: center; gap: 14px;
  font-family: var(--mono); font-size: 12px; letter-spacing: .04em;
  color: var(--muted); margin-bottom: 32px;
}
.hero-eyebrow .num{
  font-family: var(--sans); font-weight: 700; color: var(--ink);
  font-size: 13px;
}
.hero-eyebrow::before{
  content: ""; width: 28px; height: 1px; background: var(--ink);
}
.hero h1{
  margin: 0; padding: 0;
  font-size: clamp(64px, 11vw, 180px);
  font-weight: 700;
  line-height: .88; letter-spacing: -.045em;
  color: var(--ink);
}
.hero h1 span{ display: block; }
.hero h1 .blue{ color: var(--accent); }
.hero .right{
  display: flex; flex-direction: column; gap: 32px;
  padding-bottom: 12px;
}
.hero-lead{
  font-size: clamp(20px, 1.8vw, 26px);
  font-weight: 400; line-height: 1.4;
  max-width: 38ch;
  color: var(--ink-2);
  letter-spacing: -.005em;
  margin: 0;
}
.hero-meta{
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 20px 32px;
  padding-top: 28px;
  border-top: 1px solid var(--ink);
  font-size: 14px;
}
.hero-meta .k{
  font-family: var(--mono); font-size: 11.5px;
  color: var(--muted); text-transform: uppercase; letter-spacing: .08em;
  margin-bottom: 4px;
}
.hero-meta .v{ font-weight: 500; color: var(--ink); }

/* big counter ribbon */
.counters{
  max-width: var(--max); margin: 0 auto;
  padding: 0 var(--pad-x) 100px;
  display: grid; grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--ink);
}
@media (max-width: 720px){ .counters{ grid-template-columns: 1fr 1fr; } }
.counter{
  padding: 36px 24px 36px 0; border-right: 1px solid var(--line-soft);
}
.counter:last-child{ border-right: 0; }
.counter .n{
  font-size: clamp(40px, 5vw, 64px); font-weight: 700;
  letter-spacing: -.04em; line-height: 1; color: var(--ink);
}
.counter .n sup{ font-size: .35em; font-weight: 500; vertical-align: super; color: var(--muted); }
.counter .l{
  margin-top: 12px;
  font-family: var(--mono); font-size: 11.5px; color: var(--muted);
  text-transform: uppercase; letter-spacing: .08em;
  max-width: 22ch;
}

/* ── sections ────────────────────────────────────────────────────────────── */
.sec{
  max-width: var(--max); margin: 0 auto;
  padding: clamp(80px, 10vw, 140px) var(--pad-x);
  border-top: 1px solid var(--ink);
}
.sec-head{
  display: grid; grid-template-columns: 1fr 3fr; gap: 60px;
  margin-bottom: 80px;
}
@media (max-width: 820px){ .sec-head{ grid-template-columns: 1fr; gap: 16px; margin-bottom: 48px; } }
.sec-eyebrow{
  font-family: var(--mono); font-size: 12px;
  color: var(--muted); letter-spacing: .04em;
  display: flex; align-items: baseline; gap: 12px;
  padding-top: 16px;
}
.sec-eyebrow .num{
  font-family: var(--sans); font-weight: 700; color: var(--ink);
  font-size: 28px; letter-spacing: -.02em;
}
.sec h2{
  margin: 0;
  font-size: clamp(40px, 6vw, 84px); font-weight: 700;
  letter-spacing: -.035em; line-height: .95;
  max-width: 18ch;
}
.sec h2 .blue{ color: var(--accent); }

/* ── about ───────────────────────────────────────────────────────────────── */
.about-grid{ display:grid; grid-template-columns: 1fr 2fr; gap: 60px; }
@media (max-width: 820px){ .about-grid{ grid-template-columns: 1fr; gap: 32px; } }
.about-grid .pre{ font-family: var(--mono); font-size: 12px; color: var(--muted); letter-spacing: .04em; text-transform: uppercase; }
.about-grid p{
  margin: 0 0 24px; font-size: clamp(20px, 1.6vw, 24px); line-height: 1.45;
  letter-spacing: -.005em; max-width: 50ch;
}
.about-grid p:last-child{ margin-bottom: 0; }
.about-facts{
  margin-top: 56px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px;
  padding-top: 32px; border-top: 1px solid var(--line-soft);
  grid-column: 1 / -1;
}
@media (max-width: 720px){ .about-facts{ grid-template-columns: 1fr 1fr; } }
.fact .k{ font-family: var(--mono); font-size: 11.5px; color: var(--muted); text-transform: uppercase; letter-spacing: .08em; margin-bottom: 6px; }
.fact .v{ font-size: 17px; font-weight: 500; }

/* ── skills ──────────────────────────────────────────────────────────────── */
.skills{
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 0;
}
@media (max-width: 820px){ .skills{ grid-template-columns: 1fr; } }
.skill-cat{
  display: grid; grid-template-columns: 180px 1fr; gap: 32px;
  padding: 28px 0; border-top: 1px solid var(--line-soft);
  align-items: start;
}
.skill-cat:nth-child(-n+2){ border-top: 1px solid var(--ink); }
.skill-cat .h{
  font-weight: 700; font-size: 16px; letter-spacing: -.005em;
}
.skill-cat .h small{
  display: block; font-family: var(--mono); font-size: 11px;
  color: var(--muted); font-weight: 400; margin-top: 4px; letter-spacing: .04em;
}
.skill-cat .list{
  display: flex; flex-wrap: wrap; gap: 8px 12px;
}
.skill-cat .list span{
  font-size: 15px; color: var(--ink); position: relative; padding-right: 12px;
}
.skill-cat .list span::after{
  content: "·"; color: var(--muted); position: absolute; right: 2px;
}
.skill-cat .list span:last-child::after{ display:none; }

/* gap between columns */
.skills .skill-cat:nth-child(odd){ padding-right: 32px; }
.skills .skill-cat:nth-child(even){ padding-left: 32px; border-left: 1px solid var(--line-soft); }
@media (max-width: 820px){
  .skills .skill-cat:nth-child(odd){ padding-right: 0; }
  .skills .skill-cat:nth-child(even){ padding-left: 0; border-left: 0; }
}

/* ── projects ────────────────────────────────────────────────────────────── */
.filter-row{
  display: flex; gap: 6px; flex-wrap: wrap; align-items: center;
  margin-bottom: 48px;
}
.filter-row .lbl{
  font-family: var(--mono); font-size: 11.5px; color: var(--muted);
  text-transform: uppercase; letter-spacing: .08em; margin-right: 8px;
}
.chip{
  cursor: pointer; appearance: none; background: transparent;
  color: var(--ink); border: 1px solid var(--line-soft);
  padding: 8px 14px; border-radius: 999px;
  font-family: var(--sans); font-size: 14px; font-weight: 500;
  transition: all .15s;
}
.chip:hover{ border-color: var(--ink); }
.chip[data-on="1"]{ background: var(--ink); color: var(--bg); border-color: var(--ink); }
.chip .ct{ opacity: .55; margin-left: 4px; font-variant-numeric: tabular-nums; }
.chip[data-on="1"] .ct{ opacity: .8; }

.projects-grid{ display: grid; grid-template-columns: repeat(12, 1fr); gap: 24px; }

.project{
  grid-column: span 6;
  position: relative;
  padding: 36px 32px;
  background: var(--bg-alt);
  border-radius: 4px;
  display: flex; flex-direction: column;
  transition: transform .25s, background .25s;
  text-decoration: none; color: var(--ink);
}
.project:hover{ transform: translateY(-3px); background: #e8e8e2; }
.project[data-color="ink"]{ background: var(--ink); color: var(--bg); }
.project[data-color="ink"]:hover{ background: #000; }
.project[data-color="green"]{ background: var(--accent); color: #fff; }
.project[data-color="green"]:hover{ background: #0028cc; }

/* media slot — sits flush with project edges, above the top bar */
.project .media{
  position: relative;
  margin: -36px -32px 28px;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: #0c0c08;
  border-bottom: 1px solid color-mix(in srgb, currentColor 18%, transparent);
}
.project .media img{
  width: 100%; height: 100%; object-fit: cover;
  display: block;
  transition: transform .6s cubic-bezier(.2,.6,.2,1);
}
.project:hover .media img{ transform: scale(1.03); }
.project .media .badge{
  position: absolute; top: 12px; left: 12px;
  font-family: var(--mono); font-size: 10.5px;
  letter-spacing: .08em; text-transform: uppercase;
  background: rgba(0,0,0,.72); color: #fff;
  padding: 5px 10px; border-radius: 999px;
  display: inline-flex; gap: 6px; align-items: center;
  backdrop-filter: blur(6px);
}
.project .media .badge i{
  width: 6px; height: 6px; border-radius: 50%; background: #ff5b2e;
  display: inline-block;
}

.project:nth-of-type(5n+1){ grid-column: span 8; }
.project:nth-of-type(5n+2){ grid-column: span 4; }
.project:nth-of-type(5n+3){ grid-column: span 4; }
.project:nth-of-type(5n+4){ grid-column: span 8; }
.project:nth-of-type(5n+5){ grid-column: span 6; }

@media (max-width: 820px){
  .project, .project:nth-of-type(n){ grid-column: span 12; }
}

.project .top{
  display: flex; justify-content: space-between; align-items: baseline;
  margin-bottom: 24px;
  font-family: var(--mono); font-size: 11.5px;
  text-transform: uppercase; letter-spacing: .08em;
  opacity: .65;
}
.project h3{
  margin: 0 0 12px; font-size: clamp(24px, 2.4vw, 36px);
  font-weight: 700; letter-spacing: -.025em; line-height: 1.05;
  /* Long compound titles like "RogueTechPerfFixes" have no native break
     opportunities; allow them to wrap inside narrow span-4 cards. */
  overflow-wrap: anywhere;
  hyphens: auto;
}
.project .sub{
  margin: 0 0 28px; font-size: 16px; line-height: 1.45;
  opacity: .85; max-width: 50ch;
}
.project .hl{
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 20px; padding: 20px 0;
  border-top: 1px solid currentColor; border-bottom: 1px solid currentColor;
  border-color: color-mix(in srgb, currentColor 25%, transparent);
  margin-bottom: 20px;
}
.project .hl .h{ font-size: clamp(20px, 1.6vw, 26px); font-weight: 700; letter-spacing: -.02em; line-height: 1; }
.project .hl .l{
  margin-top: 6px; font-family: var(--mono); font-size: 10.5px;
  opacity: .7; text-transform: uppercase; letter-spacing: .06em;
}
.project .body p{ margin: 0 0 10px; font-size: 14.5px; line-height: 1.55; opacity: .92; }
.project .tags{ display: flex; flex-wrap: wrap; gap: 6px; margin-top: auto; padding-top: 24px; }
.project .tags span{
  font-family: var(--mono); font-size: 10.5px;
  padding: 4px 10px; border-radius: 999px;
  border: 1px solid color-mix(in srgb, currentColor 25%, transparent);
  text-transform: uppercase; letter-spacing: .06em;
}

/* ── experience ──────────────────────────────────────────────────────────── */
.xp-list{ list-style: none; margin: 0; padding: 0; }
.xp{
  display: grid; grid-template-columns: 200px 1fr 2fr; gap: 48px;
  padding: 36px 0; border-top: 1px solid var(--line-soft); align-items: start;
}
.xp:first-child{ border-top: 1px solid var(--ink); }
.xp:last-child{ border-bottom: 1px solid var(--line-soft); }
@media (max-width: 820px){ .xp{ grid-template-columns: 1fr; gap: 16px; } }
.xp .dates{
  font-family: var(--mono); font-size: 13px; color: var(--ink);
  font-weight: 500; padding-top: 6px;
}
.xp .where h3{
  margin: 0 0 6px; font-size: clamp(20px, 1.8vw, 26px);
  font-weight: 700; letter-spacing: -.02em; line-height: 1.1;
}
.xp .where .loc{ font-size: 13px; color: var(--muted); margin-bottom: 8px; font-family: var(--mono); letter-spacing: .04em; }
.xp .where .role{ color: var(--accent); font-weight: 500; font-size: 15px; }
.xp ul{ list-style: none; margin: 0; padding: 0; }
.xp ul li{
  padding: 6px 0;
  font-size: 15.5px; line-height: 1.55;
}
.xp ul li + li{ border-top: 1px solid var(--line-soft); padding-top: 12px; margin-top: 6px; }

.edu{
  margin-top: 80px; padding-top: 28px;
  border-top: 1px solid var(--ink);
}
.edu h4{
  margin: 0 0 24px;
  font-family: var(--mono); font-size: 11.5px;
  color: var(--muted); text-transform: uppercase; letter-spacing: .08em;
}
.edu-grid{ display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
@media (max-width: 720px){ .edu-grid{ grid-template-columns: 1fr; } }
.edu-item{
  padding: 20px 0; display: grid; grid-template-columns: 1fr auto; gap: 8px 24px;
  border-top: 1px solid var(--line-soft);
}
.edu-item .p{ font-weight: 700; font-size: 18px; letter-spacing: -.01em; }
.edu-item .s{ color: var(--muted); font-size: 14px; }
.edu-item .d{ font-family: var(--mono); font-size: 12px; color: var(--ink); text-align: right; }
.edu-item .n{ color: var(--accent); font-family: var(--mono); font-size: 11.5px; grid-column: 1 / -1; text-transform: uppercase; letter-spacing: .08em; }

/* ── writing ─────────────────────────────────────────────────────────────── */
.writing-list{
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 0;
  border-top: 1px solid var(--ink);
}
@media (max-width: 820px){ .writing-list{ grid-template-columns: 1fr; } }
.post{
  padding: 36px 32px;
  border-bottom: 1px solid var(--line-soft);
  display: flex; flex-direction: column; gap: 14px;
  text-decoration: none; color: var(--ink);
  transition: background .2s;
  cursor: pointer;
}
.post:hover{ background: var(--bg-alt); }
.post:nth-child(odd){ border-right: 1px solid var(--line-soft); }
@media (max-width: 820px){ .post:nth-child(odd){ border-right: 0; } }
.post .kicker{
  font-family: var(--mono); font-size: 11.5px; color: var(--muted);
  text-transform: uppercase; letter-spacing: .08em;
  display: flex; justify-content: space-between; align-items: baseline;
}
.post .kicker .arr{ color: var(--accent); transition: transform .25s; }
.post:hover .kicker .arr{ transform: translate(3px, -3px); }
.post h3{
  margin: 0; font-size: clamp(22px, 2vw, 30px);
  font-weight: 700; letter-spacing: -.025em; line-height: 1.1;
  max-width: 22ch;
}
.post p{ margin: 0; font-size: 16px; line-height: 1.5; color: var(--ink-2); max-width: 52ch; }
.post .meta{ font-family: var(--mono); font-size: 11.5px; color: var(--muted); margin-top: auto; padding-top: 8px; }

/* ── interests ───────────────────────────────────────────────────────────── */
.interests{
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 0;
  border-top: 1px solid var(--ink);
}
@media (max-width: 820px){ .interests{ grid-template-columns: 1fr 1fr; } }
@media (max-width: 540px){ .interests{ grid-template-columns: 1fr; } }
.interest{
  padding: 32px 28px; border-bottom: 1px solid var(--line-soft);
  border-right: 1px solid var(--line-soft);
  display: flex; flex-direction: column; gap: 12px;
}
.interest:nth-child(3n){ border-right: 0; }
.interest .icon{
  font-size: 28px; line-height: 1; font-weight: 700; color: var(--accent);
}
.interest h4{ margin: 0; font-size: 20px; font-weight: 700; letter-spacing: -.015em; }
.interest p{ margin: 0; font-size: 14.5px; color: var(--muted); line-height: 1.5; }

/* ── footer ──────────────────────────────────────────────────────────────── */
.footer{
  background: var(--ink); color: var(--bg);
  margin-top: 0;
}
.footer-inner{
  max-width: var(--max); margin: 0 auto;
  padding: clamp(80px, 10vw, 140px) var(--pad-x) 40px;
}
.footer h2{
  margin: 0;
  font-size: clamp(48px, 9vw, 160px);
  font-weight: 700; line-height: .9; letter-spacing: -.045em;
}
.footer h2 .blue{ color: #5d80ff; }
.footer .lead{
  margin: 40px 0 0; font-size: clamp(18px, 1.6vw, 22px);
  max-width: 40ch; color: color-mix(in srgb, var(--bg) 75%, transparent);
  line-height: 1.45;
}
.footer-grid{
  margin-top: 80px; padding-top: 40px;
  border-top: 1px solid color-mix(in srgb, var(--bg) 25%, transparent);
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px;
}
@media (max-width: 720px){ .footer-grid{ grid-template-columns: 1fr; } }
.footer-grid .lbl{
  font-family: var(--mono); font-size: 11.5px;
  color: color-mix(in srgb, var(--bg) 55%, transparent);
  text-transform: uppercase; letter-spacing: .08em; margin-bottom: 14px;
}
.footer-grid a{
  display: block; color: var(--bg); text-decoration: none;
  padding: 4px 0; font-size: 17px;
  transition: color .15s;
}
.footer-grid a:hover{ color: #5d80ff; }
.footer-foot{
  margin-top: 80px; padding-top: 28px;
  border-top: 1px solid color-mix(in srgb, var(--bg) 15%, transparent);
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  font-family: var(--mono); font-size: 11.5px;
  color: color-mix(in srgb, var(--bg) 50%, transparent);
  text-transform: uppercase; letter-spacing: .04em;
}

/* ── vertical nav (locked in as default) ─────────────────────────────────── */
body{ padding-left: 240px; }
.v-nav{
  display: flex; flex-direction: column;
  position: fixed; top: 0; bottom: 0; left: 0; width: 240px;
  z-index: 60;
  padding: 32px 28px;
  background: var(--bg);
  border-right: 1px solid var(--ink);
}

.v-nav .brand{
  text-decoration: none; color: var(--ink);
  display: block; padding-bottom: 24px;
  border-bottom: 1px solid var(--line-soft);
}
.v-nav .brand .dot{
  display: inline-block; width: 14px; height: 14px;
  background: var(--accent); border-radius: 50%;
  margin-bottom: 14px;
}
.v-nav .brand .name{
  font-family: var(--sans); font-weight: 700;
  font-size: 22px; line-height: 1.05; letter-spacing: -.02em;
  color: var(--ink);
}
.v-nav .brand .role{
  margin-top: 4px;
  font-family: var(--mono); font-size: 11.5px;
  color: var(--muted); letter-spacing: .04em;
  text-transform: uppercase;
}

.v-nav .v-eyebrow{
  margin-top: 28px; margin-bottom: 8px;
  font-family: var(--mono); font-size: 10.5px;
  color: var(--muted); text-transform: uppercase; letter-spacing: .12em;
}

.v-nav .v-links{
  display: flex; flex-direction: column; gap: 0; flex: 1;
}
.v-nav .v-links a{
  color: var(--ink); text-decoration: none;
  font-family: var(--sans); font-size: 15px; font-weight: 500;
  padding: 11px 0; border-bottom: 1px solid var(--line-soft);
  display: flex; align-items: baseline; gap: 12px;
  position: relative;
  transition: color .15s, padding-left .2s;
}
.v-nav .v-links a .n{
  font-family: var(--mono); font-size: 11px; letter-spacing: .08em;
  color: var(--muted); min-width: 18px;
}
.v-nav .v-links a::before{
  content: ""; position: absolute; left: -28px; top: 50%;
  width: 0; height: 1px; background: var(--accent);
  transform: translateY(-50%);
  transition: width .2s cubic-bezier(.2,.6,.2,1);
}
.v-nav .v-links a:hover,
.v-nav .v-links a[aria-current="true"]{
  color: var(--accent); padding-left: 8px;
}
.v-nav .v-links a:hover::before,
.v-nav .v-links a[aria-current="true"]::before{ width: 24px; left: -4px; }
.v-nav .v-links a:hover .n,
.v-nav .v-links a[aria-current="true"] .n{ color: var(--accent); }

.v-nav .v-foot{
  padding-top: 20px;
  border-top: 1px solid var(--line-soft);
  display: flex; flex-direction: column; gap: 4px;
}
.v-nav .v-foot .avail{
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--mono); font-size: 11px; letter-spacing: .04em;
  color: var(--ink); text-transform: uppercase;
  margin-bottom: 14px;
}
.v-nav .v-foot .avail i{
  width: 7px; height: 7px; border-radius: 50%; background: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
  animation: pulse 2.2s infinite;
}
@keyframes pulse{ 0%,100%{opacity:1} 50%{opacity:.45} }
.v-nav .v-foot .lbl{
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .12em;
  color: var(--muted); text-transform: uppercase; margin-bottom: 6px;
}
.v-nav .v-foot a{
  color: var(--ink); text-decoration: none;
  font-family: var(--sans); font-size: 13.5px; padding: 3px 0;
  transition: color .15s;
}
.v-nav .v-foot a:hover{ color: var(--accent); }

/* mobile fallback for vertical nav */
.v-nav-mobile{ display: none; }
@media (max-width: 920px){
  body{ padding-left: 0; }
  .v-nav{ display: none; }
  .v-nav-mobile{
    display: flex; position: sticky; top: 0; z-index: 50;
    background: color-mix(in srgb, var(--bg) 88%, transparent);
    -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--ink);
    padding: 16px var(--pad-x);
    align-items: center; justify-content: space-between;
  }
  .v-nav-mobile .brand{
    font-weight: 700; font-size: 17px; letter-spacing: -.01em;
    text-decoration: none; color: var(--ink);
    display: inline-flex; align-items: center; gap: 10px;
  }
  .v-nav-mobile .brand::before{
    content: ""; width: 12px; height: 12px;
    background: var(--accent); border-radius: 50%;
  }
  .v-nav-mobile .nav-cta{
    background: var(--ink); color: var(--bg);
    padding: 8px 14px; border-radius: 999px;
    text-decoration: none; font-weight: 500; font-size: 13px;
  }
}

/* reveal */
.reveal{ opacity:0; transform: translateY(14px); transition: opacity .7s, transform .7s cubic-bezier(.2,.6,.2,1); }
.reveal.in{ opacity: 1; transform: none; }

/* ── research project: animated vector-space viz ─────────────────────────── */
/* Two alternating scenes inside the project's media slot. Conveys the core
   research finding: vector subtraction (play − game) ≠ orthogonal negation
   (play ⟂ game). The first destroys 'play'; the second preserves it. */
.project .media .research-viz{
  width: 100%; height: 100%; display: block;
  background: #0a0a0a;
}
.research-viz .rv-lbl{
  font-family: "JetBrains Mono", ui-monospace, Menlo, monospace;
  font-size: 11px;
  fill: rgba(250,250,247,0.78);
}
.research-viz .rv-bold       { font-weight: 600; font-size: 12px; letter-spacing: 0.06em; }
.research-viz .rv-tiny       { font-size: 8.5px; fill: rgba(250,250,247,0.55); letter-spacing: 0.02em; }
.research-viz .rv-dim        { fill: rgba(250,250,247,0.7); }
.research-viz .rv-cobalt     { fill: #5d80ff; }
.research-viz .rv-cobalt-sub { fill: rgba(149,170,255,0.85); font-size: 10px; }
.research-viz .rv-warn       { fill: #ff7b50; }
.research-viz .rv-warn-sub   { fill: rgba(255,150,115,0.85); font-size: 10px; }
.research-viz .rv-foot       {
  fill: rgba(250,250,247,0.42); font-size: 9.5px;
  letter-spacing: 0.12em; text-transform: uppercase;
}

/* the two scenes alternate via opacity */
.research-viz .rv-scene{ opacity: 0; }
.research-viz .rv-scene-a{ animation: rv-scene-a 10s ease-in-out infinite; }
.research-viz .rv-scene-b{ animation: rv-scene-b 10s ease-in-out infinite; }

@keyframes rv-scene-a{
  0%, 3%    { opacity: 0; }
  9%, 42%   { opacity: 1; }
  48%, 100% { opacity: 0; }
}
@keyframes rv-scene-b{
  0%, 49%   { opacity: 0; }
  56%, 92%  { opacity: 1; }
  98%, 100% { opacity: 0; }
}

/* draw-in: result vectors extend from the origin when their scene becomes
   visible. Path lengths roughly match the on-screen lengths (≈85 and ≈72). */
.research-viz .rv-vec-naive{
  stroke-dasharray: 90;
  stroke-dashoffset: 90;
  animation: rv-draw-a 10s ease-in-out infinite;
}
.research-viz .rv-vec-ortho{
  stroke-dasharray: 78;
  stroke-dashoffset: 78;
  animation: rv-draw-b 10s ease-in-out infinite;
}
@keyframes rv-draw-a{
  0%, 9%    { stroke-dashoffset: 90; }
  20%, 42%  { stroke-dashoffset: 0; }
  48%, 100% { stroke-dashoffset: 90; }
}
@keyframes rv-draw-b{
  0%, 56%   { stroke-dashoffset: 78; }
  66%, 92%  { stroke-dashoffset: 0; }
  98%, 100% { stroke-dashoffset: 78; }
}

@media (prefers-reduced-motion: reduce){
  .research-viz .rv-scene-a,
  .research-viz .rv-scene-b{ animation: none; }
  .research-viz .rv-scene-a{ opacity: 0; }       /* hide naive — its title card would clash with ortho's */
  .research-viz .rv-scene-b{ opacity: 1; }
  .research-viz .rv-vec-naive,
  .research-viz .rv-vec-ortho{ animation: none; stroke-dashoffset: 0; }
}

/* ── article pages (writing/*.html) ──────────────────────────────────────── */
.article-main{
  max-width: 760px;
  margin: 0 auto;
  padding: clamp(48px, 6vw, 96px) var(--pad-x) 120px;
}

.back-link{
  font-family: var(--mono); font-size: 12px; letter-spacing: .04em;
  color: var(--muted); text-decoration: none;
  display: inline-flex; align-items: center; gap: 8px;
  margin-bottom: 72px;
  text-transform: uppercase;
  transition: color .15s, gap .2s;
}
.back-link::before{ content: "\2190"; transition: transform .2s; display: inline-block; }
.back-link:hover{ color: var(--accent); gap: 12px; }
.back-link:hover::before{ transform: translateX(-3px); }

.article-head{
  margin-bottom: 56px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--ink);
}
.article-kicker{
  font-family: var(--mono); font-size: 12px;
  color: var(--accent);
  text-transform: uppercase; letter-spacing: .08em;
  margin-bottom: 28px;
}
.article-head h1{
  margin: 0 0 36px;
  font-size: clamp(34px, 5.2vw, 60px);
  font-weight: 700;
  letter-spacing: -.03em;
  line-height: 1.05;
  max-width: 18ch;
  color: var(--ink);
}
.article-meta{
  display: flex; gap: 28px;
  font-family: var(--mono); font-size: 12px;
  color: var(--muted);
  letter-spacing: .08em; text-transform: uppercase;
}
.article-meta span + span::before{
  content: "\00B7"; color: var(--line-soft);
  margin-right: 28px; margin-left: 0;
}

/* body typography ── editorial, ~70ch line length, generous rhythm */
.article-body{
  font-size: 17.5px;
  line-height: 1.65;
  color: var(--ink-2);
}
.article-body > * + *{ margin-top: 1.4em; }
.article-body .lede{
  font-size: clamp(20px, 2vw, 23px);
  line-height: 1.5;
  letter-spacing: -.005em;
  color: var(--ink);
  font-weight: 400;
  margin-bottom: 1.8em;
}
.article-body p{ margin: 0; max-width: 68ch; }
.article-body h2{
  margin: 64px 0 20px;
  font-size: clamp(24px, 2.4vw, 30px);
  font-weight: 700;
  letter-spacing: -.02em;
  line-height: 1.2;
  color: var(--ink);
  display: flex; align-items: baseline; gap: 14px;
}
.article-body h2::before{
  content: counter(art-h2, decimal-leading-zero);
  counter-increment: art-h2;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: .04em;
}
.article-body{ counter-reset: art-h2; }
.article-body h3{
  margin: 40px 0 12px;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -.015em;
  color: var(--ink);
}
.article-body a:not(.back-link){
  color: var(--accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  text-decoration-color: rgba(0,53,255,.35);
  transition: text-decoration-color .15s;
}
.article-body a:not(.back-link):hover{ text-decoration-color: var(--accent); }

.article-body code{
  font-family: var(--mono);
  font-size: .87em;
  background: var(--bg-alt);
  padding: 2px 6px;
  border-radius: 3px;
  color: var(--ink);
}
.article-body pre{
  background: var(--ink);
  color: #e6e6df;
  padding: 22px 26px;
  border-radius: 4px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.6;
  overflow-x: auto;
  margin: 28px 0;
  max-width: 100%;
  scrollbar-width: thin;
  scrollbar-color: rgba(250,250,247,.2) transparent;
}
.article-body pre code{
  background: transparent;
  padding: 0;
  color: inherit;
  font-size: inherit;
  border-radius: 0;
}
/* lightweight token colors for spans inside <pre><code> */
.article-body pre .c { color: #7a7a72; }   /* comment */
.article-body pre .k { color: #ff7b50; }   /* keyword */
.article-body pre .s { color: #95aaff; }   /* string */
.article-body pre .n { color: #fafaf7; }   /* normal */

.article-body blockquote{
  margin: 32px 0;
  padding: 4px 0 4px 24px;
  border-left: 2px solid var(--accent);
  font-size: 19px;
  line-height: 1.5;
  color: var(--ink);
  font-style: italic;
  max-width: 64ch;
}
.article-body ul, .article-body ol{
  margin: 20px 0;
  padding-left: 22px;
  max-width: 68ch;
}
.article-body li{ margin: 6px 0; }
.article-body li::marker{ color: var(--accent); }
.article-body strong{ font-weight: 700; color: var(--ink); }
.article-body em{ font-style: italic; }
.article-body hr{
  border: 0;
  border-top: 1px solid var(--line-soft);
  margin: 48px 0;
}

/* results table — used in the negation article */
.article-body table{
  width: 100%; max-width: 68ch;
  border-collapse: collapse;
  margin: 28px 0;
  font-size: 15px;
}
.article-body thead th{
  text-align: left;
  font-family: var(--mono);
  font-size: 11.5px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--muted);
  padding: 10px 14px 10px 0;
  border-bottom: 1px solid var(--ink);
}
.article-body tbody td{
  padding: 12px 14px 12px 0;
  border-bottom: 1px solid var(--line-soft);
  font-variant-numeric: tabular-nums;
}
.article-body tbody tr:last-child td{ border-bottom: 1px solid var(--ink); }
.article-body td.hi{ color: var(--accent); font-weight: 600; }
.article-body td.lo{ color: #c0451a; font-weight: 600; }

/* simple math notation */
.math-block{
  display: block;
  text-align: center;
  font-family: "Cambria","Georgia",serif;
  font-size: 18px;
  font-style: italic;
  color: var(--ink);
  margin: 26px 0;
  letter-spacing: .01em;
}
.math-inline{
  font-family: "Cambria","Georgia",serif;
  font-style: italic;
  font-size: 1em;
}

/* article footer nav */
.article-nav{
  margin-top: 96px;
  padding-top: 36px;
  border-top: 1px solid var(--ink);
}
.article-nav a{
  text-decoration: none;
  color: var(--ink);
  display: flex; flex-direction: column; gap: 10px;
  padding: 24px 0;
  transition: color .15s, transform .2s;
}
.article-nav a:hover{ color: var(--accent); }
.article-nav .nav-kicker{
  font-family: var(--mono); font-size: 11.5px;
  color: var(--muted);
  text-transform: uppercase; letter-spacing: .08em;
  display: inline-flex; align-items: center; gap: 8px;
  transition: gap .2s, color .15s;
}
.article-nav a:hover .nav-kicker{ color: var(--accent); gap: 12px; }
.article-nav .nav-title{
  font-size: clamp(20px, 2vw, 26px);
  font-weight: 700;
  letter-spacing: -.02em;
  line-height: 1.2;
  max-width: 28ch;
}

/* mobile tweaks */
@media (max-width: 920px){
  .article-main{ padding-top: 24px; }
}

@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior: auto; }
  .reveal{ opacity: 1; transform: none; transition: none; }
  *{ animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
}