/* ─── tokens · Claude design system (verbatim) ───────────────────────── */
:root {
  --bg: #f5f4ed;
  --surface: #faf9f5;
  --surface-warm: #e8e6dc;

  --fg: #141413;
  --fg-2: #3d3d3a;
  --muted: #5e5d59;
  --meta: #87867f;

  --border: #f0eee6;
  --border-soft: #e8e6dc;

  --accent: #c96442;
  --accent-on: #faf9f5;
  --accent-hover: color-mix(in oklab, var(--accent), black 8%);
  --accent-active: color-mix(in oklab, var(--accent), black 14%);

  --success: #17a34a;
  --warn: #eab308;
  --danger: #b53333;

  --font-display: "Anthropic Serif", "Iowan Old Style", "Charter", Georgia, "Times New Roman", serif;
  --font-body: "Anthropic Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --font-mono: "Anthropic Mono", ui-monospace, "JetBrains Mono", "SF Mono", Menlo, monospace;

  --text-xs: 10px;
  --text-sm: 14px;
  --text-base: 16px;
  --text-lg: 20px;
  --text-xl: 25px;
  --text-2xl: 32px;
  --text-3xl: 52px;
  --text-4xl: 64px;

  --leading-body: 1.6;
  --leading-tight: 1.1;
  --tracking-display: 0em;

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-12: 48px;

  --section-y-desktop: 96px;
  --section-y-tablet: 64px;
  --section-y-phone: 48px;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-pill: 9999px;

  --elev-flat: none;
  --elev-ring: 0 0 0 1px var(--border);
  --elev-raised: rgba(0, 0, 0, 0.05) 0px 4px 24px;

  --focus-ring: 0 0 0 3px rgba(56, 152, 236, 0.3);

  --motion-fast: 150ms;
  --motion-base: 200ms;
  --ease-standard: cubic-bezier(0.2, 0, 0, 1);

  --container-max: 1200px;
  --container-gutter-desktop: 24px;
  --container-gutter-tablet: 16px;
  --container-gutter-phone: 12px;

  /* ── seed-compat aliases (so layout primitives resolve) ── */
  --accent-soft: color-mix(in oklch, var(--accent) 14%, transparent);
  --fg-soft: color-mix(in oklch, var(--fg) 6%, transparent);
  --fs-h1: clamp(48px, 6.4vw, 84px);
  --fs-h2: clamp(32px, 4vw, 52px);
  --fs-h3: 22px;
  --fs-lead: 19px;
  --fs-body: 16px;
  --fs-meta: 13px;
  --gap-xs: 8px;
  --gap-sm: 12px;
  --gap-md: 20px;
  --gap-lg: 32px;
  --gap-xl: 56px;
  --gap-2xl: 96px;
  --container: 1200px;
  --gutter: clamp(20px, 4vw, 32px);
  --radius: var(--radius-md);
}

/* ─── reset & base ───────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.55;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; }
p { text-wrap: pretty; }
h1, h2, h3, h4 { text-wrap: balance; }
::selection { background: color-mix(in oklch, var(--accent) 22%, transparent); color: var(--fg); }

/* ─── layout primitives ──────────────────────────────────────────────── */
.container {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.section { padding-block: clamp(56px, 10vw, var(--gap-2xl)); }
.section + .section { border-top: 1px solid var(--border); }
.stack { display: flex; flex-direction: column; }
.stack > * + * { margin-top: var(--gap-md); }
.row { display: flex; align-items: center; gap: var(--gap-md); }
.row-between { display: flex; align-items: center; justify-content: space-between; gap: var(--gap-md); }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--gap-lg); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--gap-lg); }
.grid-2-1 { display: grid; grid-template-columns: 2fr 1fr; gap: var(--gap-xl); align-items: start; }
.grid-1-2 { display: grid; grid-template-columns: 1fr 2fr; gap: var(--gap-xl); align-items: start; }
@media (max-width: 920px) {
  .grid-2, .grid-3, .grid-2-1, .grid-1-2 { grid-template-columns: 1fr; gap: var(--gap-lg); }
}

/* ─── type ───────────────────────────────────────────────────────────── */
.h1, h1 {
  font-family: var(--font-display);
  font-size: var(--fs-h1);
  font-weight: 500;
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin: 0;
}
.h2, h2 {
  font-family: var(--font-display);
  font-size: var(--fs-h2);
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: -0.015em;
  margin: 0;
}
.h3, h3 {
  font-size: var(--fs-h3);
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.005em;
  margin: 0;
}
.lead {
  font-size: var(--fs-lead);
  line-height: 1.6;
  color: var(--muted);
  max-width: 60ch;
  margin: 0;
}
.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 var(--gap-md);
}
.meta { font-family: var(--font-mono); font-size: var(--fs-meta); color: var(--muted); }
.num  { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

/* ─── chrome: nav + footer ───────────────────────────────────────────── */
.topnav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in oklch, var(--bg) 90%, transparent);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--border);
}
.topnav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: 16px;
  gap: var(--gap-md);
}
.topnav .logo {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--fg);
  display: inline-flex;
  align-items: baseline;
  gap: 4px;
}
.topnav .logo .dot { color: var(--accent); font-size: 22px; line-height: 0; }
.topnav nav { display: flex; gap: 28px; align-items: center; }
.topnav nav a {
  font-size: 14px;
  color: var(--muted);
  position: relative;
  padding-block: 4px;
  transition: color 150ms;
}
.topnav nav a:hover { color: var(--fg); }
.topnav nav a.is-active { color: var(--fg); }
.topnav nav a.is-active::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: -18px;
  height: 2px;
  background: var(--accent);
}
.topnav .nav-cta { margin-left: 8px; }
@media (max-width: 720px) {
  .topnav-inner { flex-wrap: wrap; padding-block: 12px; }
  .topnav nav { order: 3; flex-basis: 100%; gap: 18px; padding-top: 4px; }
  .topnav nav a.is-active::after { bottom: -6px; }
  .topnav .nav-cta { margin-left: 0; }
}
@media (max-width: 420px) {
  .topnav .logo { font-size: 18px; }
  .topnav .nav-cta { padding: 9px 14px; font-size: 13px; }
}

.pagefoot {
  padding-block: var(--gap-xl);
  color: var(--muted);
  font-size: 13px;
  border-top: 1px solid var(--border);
}
.pagefoot .row-between { flex-wrap: wrap; gap: var(--gap-md); }
.pagefoot .meta { font-size: 12px; letter-spacing: 0.04em; }

/* ─── buttons ────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 18px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: -0.005em;
  cursor: pointer;
  transition: transform 60ms, background 150ms, border-color 150ms, color 150ms;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--accent); color: var(--accent-on); border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent); }
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn-secondary { background: transparent; color: var(--fg); border-color: var(--border-soft); }
.btn-secondary:hover { border-color: var(--fg); background: var(--surface); }
.btn-ghost { background: transparent; color: var(--fg); border-color: transparent; padding-inline: 4px; }
.btn-ghost:hover { color: var(--accent); }
.btn-arrow::after { content: '→'; transition: transform 150ms; display: inline-block; }
.btn-arrow:hover::after { transform: translateX(3px); }
.btn-download::before { content: '↓'; font-family: var(--font-mono); font-size: 14px; transition: transform 150ms; display: inline-block; }
.btn-download:hover::before { transform: translateY(2px); }

/* ─── card ───────────────────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
}
.card-rule { background: transparent; border: 0; border-top: 1px solid var(--fg); padding: 24px 0 0; border-radius: 0; }

/* ─── tag ────────────────────────────────────────────────────────────── */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 5px 12px;
  background: transparent;
  color: var(--fg-2);
  border: 1px solid var(--border-soft);
  border-radius: 999px;
  font-size: 13px;
  letter-spacing: -0.005em;
  transition: border-color 150ms, color 150ms;
}
.tag:hover { border-color: var(--fg-2); }
.tag.is-accent {
  color: var(--accent);
  border-color: color-mix(in oklch, var(--accent) 26%, transparent);
  background: color-mix(in oklch, var(--accent) 6%, transparent);
}
.tag-list { display: flex; flex-wrap: wrap; gap: 8px; }
.tag-mono { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.04em; text-transform: uppercase; padding: 4px 10px; }

/* ─── HERO with portrait monogram ────────────────────────────────────── */
.hero-portrait {
  display: grid;
  grid-template-columns: 1.45fr 1fr;
  gap: clamp(40px, 7vw, 96px);
  align-items: center;
  padding-block: clamp(64px, 11vw, 140px);
}
@media (max-width: 920px) {
  .hero-portrait { grid-template-columns: 1fr; gap: var(--gap-xl); padding-block: clamp(48px, 12vw, 96px); }
}
.hero-portrait .eyebrow { margin-bottom: 24px; }
.hero-portrait h1 { margin-bottom: 28px; }
.hero-portrait .hero-bio {
  font-family: var(--font-display);
  font-size: clamp(20px, 1.9vw, 26px);
  line-height: 1.5;
  color: var(--fg-2);
  max-width: 28ch;
  margin: 0 0 36px;
}
.hero-portrait .hero-cta { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-portrait .hero-strap {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  margin-top: 32px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--meta);
}
.hero-portrait .hero-strap a { color: var(--muted); border-bottom: 1px solid transparent; transition: color 150ms, border-color 150ms; padding-bottom: 1px; }
.hero-portrait .hero-strap a:hover { color: var(--accent); border-bottom-color: var(--accent); }
.hero-portrait .hero-strap .dot { color: color-mix(in oklch, var(--meta) 50%, transparent); margin: 0 -8px; }

/* portrait card (monogram block) */
.portrait {
  aspect-ratio: 4 / 5;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background:
    radial-gradient(circle at 28% 22%, color-mix(in oklch, var(--accent) 28%, transparent) 0%, transparent 55%),
    radial-gradient(circle at 76% 78%, color-mix(in oklch, var(--fg) 18%, transparent) 0%, transparent 55%),
    linear-gradient(160deg, var(--surface) 0%, var(--surface-warm) 100%);
  position: relative;
  overflow: hidden;
  box-shadow: rgba(0, 0, 0, 0.04) 0 1px 0 inset, rgba(0, 0, 0, 0.06) 0 16px 40px -8px;
}
.portrait::before {
  content: 'ZX';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -52%);
  font-family: var(--font-display);
  font-size: clamp(140px, 18vw, 240px);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.05em;
  color: color-mix(in oklch, var(--fg) 84%, transparent);
}
.portrait::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    repeating-linear-gradient(0deg, transparent 0 41px, color-mix(in oklch, var(--fg) 3%, transparent) 41px 42px);
  pointer-events: none;
  opacity: 0.4;
}
.portrait .label-top, .portrait .label-bot {
  position: absolute;
  left: 22px;
  right: 22px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--muted);
  z-index: 1;
}
.portrait .label-top { top: 20px; color: var(--meta); }
.portrait .label-bot { bottom: 20px; }
.portrait .label-bot .right { color: var(--meta); font-size: 10px; }

/* ─── ABOUT prose ────────────────────────────────────────────────────── */
.about-prose p {
  max-width: 50ch;
  margin: 0 0 22px;
}
.about-prose p:first-child {
  font-family: var(--font-display);
  font-size: clamp(22px, 2.4vw, 28px);
  font-weight: 400;
  line-height: 1.45;
  letter-spacing: -0.005em;
  color: var(--fg);
}
.about-prose p:not(:first-child) {
  font-size: 16px;
  line-height: 1.7;
  color: var(--muted);
}
.about-prose .signoff {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--meta);
  margin-top: 32px;
}

/* fact card */
.fact-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  box-shadow: var(--elev-raised);
}
.fact-card .fact-title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--accent);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}
.fact-card .fact-title .ver { color: var(--meta); font-size: 10px; }
.fact-row {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 16px;
  align-items: baseline;
}
@media (max-width: 480px) {
  .fact-row { grid-template-columns: 1fr; gap: 4px; }
}
.fact-row .label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--meta);
}
.fact-row .value {
  color: var(--fg);
  font-size: 15px;
  line-height: 1.45;
}
.fact-row .value a {
  border-bottom: 1px solid var(--border-soft);
  transition: color 150ms, border-color 150ms;
}
.fact-row .value a:hover { color: var(--accent); border-bottom-color: var(--accent); }
.fact-row .value.mono { font-family: var(--font-mono); font-size: 13px; letter-spacing: -0.01em; }

/* ─── nav cards (quick links to sub-pages) ───────────────────────────── */
.nav-card-link { color: inherit; display: block; }
.nav-card {
  display: flex;
  flex-direction: column;
  gap: 16px;
  border-top: 1px solid var(--fg);
  padding: 28px 0 8px;
  height: 100%;
  transition: padding-left 250ms var(--ease-standard);
}
.nav-card-link:hover .nav-card { padding-left: 4px; }
.nav-card .nav-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.10em;
  color: var(--meta);
  transition: color 200ms var(--ease-standard);
}
.nav-card-link:hover .nav-card .nav-num { color: var(--accent); }
.nav-card h3 {
  font-family: var(--font-display);
  font-size: clamp(26px, 2.6vw, 32px);
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--fg);
}
.nav-card p {
  color: var(--muted);
  font-size: 15px;
  margin: 0;
  line-height: 1.6;
  max-width: 36ch;
}
.nav-card .nav-link {
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--fg);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 8px;
  transition: color 150ms;
}
.nav-card .nav-link::after {
  content: '→';
  transition: transform 200ms var(--ease-standard);
  display: inline-block;
}
.nav-card-link:hover .nav-link { color: var(--accent); }
.nav-card-link:hover .nav-link::after { transform: translateX(4px); }

/* ─── contact strip ──────────────────────────────────────────────────── */
.contact-strip {
  text-align: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: clamp(48px, 8vw, 96px) clamp(28px, 5vw, 80px);
  box-shadow: rgba(0, 0, 0, 0.04) 0 1px 24px;
}
.contact-strip h2 {
  max-width: 22ch;
  margin: 0 auto var(--gap-md);
}
.contact-strip .lead { margin: 0 auto var(--gap-lg); max-width: 48ch; }
.contact-strip .email-link {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: clamp(15px, 1.6vw, 19px);
  letter-spacing: -0.01em;
  color: var(--accent);
  border-bottom: 1px solid color-mix(in oklch, var(--accent) 32%, transparent);
  padding-bottom: 2px;
  transition: color 150ms, border-color 150ms;
}
.contact-strip .email-link:hover {
  color: var(--accent-hover);
  border-bottom-color: var(--accent);
}
.contact-strip .links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-top: 28px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--meta);
  flex-wrap: wrap;
}
.contact-strip .links a { color: var(--muted); transition: color 150ms; }
.contact-strip .links a:hover { color: var(--accent); }
.contact-strip .links .sep { color: color-mix(in oklch, var(--meta) 50%, transparent); }

/* ─── TIMELINE (education & experience pages) ────────────────────────── */
.timeline { border-top: 1px solid var(--fg); }
.tl-row {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: var(--gap-lg);
  padding: 44px 0;
  border-bottom: 1px solid var(--border);
  align-items: start;
}
@media (max-width: 760px) {
  .tl-row { grid-template-columns: 1fr; gap: 12px; padding: 32px 0; }
}
.tl-side {
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.tl-logo {
  width: 76px;
  height: 76px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: rgba(0, 0, 0, 0.03) 0 1px 2px;
}
.tl-logo img {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
  display: block;
}
@media (max-width: 760px) {
  .tl-side { flex-direction: row; align-items: center; gap: 14px; }
}
.tl-date {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--accent);
  text-transform: uppercase;
  padding-top: 8px;
}
.tl-side .tl-date { padding-top: 0; }
.tl-body h3 {
  font-family: var(--font-display);
  font-size: clamp(22px, 2.2vw, 30px);
  font-weight: 500;
  letter-spacing: -0.005em;
  line-height: 1.2;
  color: var(--fg);
  margin: 0 0 6px;
}
.tl-body .tl-org {
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--muted);
  margin: 0 0 18px;
  line-height: 1.5;
}
.tl-body .tl-org strong { color: var(--fg-2); font-weight: 600; }
.tl-body .tl-org .sep { color: color-mix(in oklch, var(--meta) 50%, transparent); margin: 0 6px; }
.tl-body p {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 15.5px;
  line-height: 1.65;
  max-width: 64ch;
}
.tl-body ul {
  margin: 6px 0 0;
  padding-left: 18px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.65;
  max-width: 64ch;
}
.tl-body ul li { margin-bottom: 8px; }
.tl-body ul li::marker { color: var(--accent); }
.tl-body .tl-tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 18px; }

/* page-header (small hero for sub-pages) */
.page-header {
  padding-block: clamp(56px, 9vw, 128px) clamp(40px, 6vw, 56px);
}
.page-header .eyebrow { margin-bottom: 16px; }
.page-header h1 { margin-bottom: 24px; max-width: 18ch; }
.page-header .lead { max-width: 56ch; }
.page-header .meta-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 32px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--meta);
}
.page-header .meta-strip .dot { color: color-mix(in oklch, var(--meta) 50%, transparent); }

/* next-page strip at the bottom of sub-pages */
.next-strip {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--gap-lg);
  border-top: 1px solid var(--fg);
  padding-top: 36px;
  margin-top: 32px;
}
@media (max-width: 720px) { .next-strip { grid-template-columns: 1fr; } }
.next-strip a { display: flex; flex-direction: column; gap: 8px; padding-block: 8px; }
.next-strip .right { text-align: right; align-items: flex-end; }
.next-strip .label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--meta);
}
.next-strip h3 {
  font-family: var(--font-display);
  font-size: clamp(24px, 2.4vw, 30px);
  font-weight: 500;
  letter-spacing: -0.005em;
  color: var(--fg);
  transition: color 150ms;
}
.next-strip a:hover h3 { color: var(--accent); }
.next-strip .left h3::before { content: '← '; }
.next-strip .right h3::after { content: ' →'; }

/* ── print ── */
@media print {
  .topnav, .pagefoot, .next-strip, .contact-strip .links { display: none !important; }
  body { background: white; color: black; }
  .portrait { display: none; }
  .hero-portrait { grid-template-columns: 1fr; padding-block: 24px; }
}