@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Source+Serif+4:ital,opsz,wght@0,8..60,400;0,8..60,600;1,8..60,400&family=JetBrains+Mono:wght@400;500&display=swap');

/* ---------------------------------------------------------------- tokens */
:root {
  color-scheme: light dark;

  --font-ui: 'Inter', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-body: 'Source Serif 4', Georgia, 'Times New Roman', serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;

  --bg: #fbfaf7;
  --surface: #ffffff;
  --text: #1d1d1f;
  --text-muted: #6b6b70;
  --border: #e6e3dc;
  --accent: #5e2b8a;
  --accent-soft: color-mix(in srgb, var(--accent) 10%, transparent);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 4px 16px rgba(0, 0, 0, 0.04);

  --radius: 8px;
  --measure: 42rem;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 1rem;
  --space-4: 1.5rem;
  --space-5: 2.5rem;
  --space-6: 4rem;
}

/* Dark tokens: follow the system unless the toggle picked a theme. */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #121417;
    --surface: #191c20;
    --text: #e6e6e6;
    --text-muted: #9a9ca3;
    --border: #2a2e34;
    --accent: #ad8af8;
    --accent-soft: color-mix(in srgb, var(--accent) 10%, transparent);
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 4px 16px rgba(0, 0, 0, 0.2);
  }
}

:root[data-theme="dark"] {
  --bg: #121417;
  --surface: #191c20;
  --text: #e6e6e6;
  --text-muted: #9a9ca3;
  --border: #2a2e34;
  --accent: #ad8af8;
  --accent-soft: color-mix(in srgb, var(--accent) 10%, transparent);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 4px 16px rgba(0, 0, 0, 0.2);
}

:root[data-theme="light"] { color-scheme: light; }
:root[data-theme="dark"]  { color-scheme: dark; }

/* ---------------------------------------------------------------- base */
* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.wrap {
  max-width: var(--measure);
  margin: 0 auto;
  padding: var(--space-4) var(--space-4) var(--space-5);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
  animation: rise 0.35s ease-out both;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(6px); }
}

@media (prefers-reduced-motion: reduce) {
  main { animation: none; }
  *, *::before, *::after { transition: none !important; }
}

h1, h2, h3, h4 {
  font-family: var(--font-ui);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.25;
  color: var(--text);
  text-wrap: balance;
}

p { text-wrap: pretty; }

a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-decoration-color: color-mix(in srgb, var(--accent) 35%, transparent);
  text-underline-offset: 3px;
  transition: text-decoration-color 0.15s, color 0.15s, background-color 0.15s, border-color 0.15s;
}

a:hover { text-decoration-color: currentColor; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

::selection { background: var(--accent); color: var(--bg); }

code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--accent-soft);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

/* ---------------------------------------------------------------- header */
.site-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
  padding-bottom: var(--space-3);
  margin-bottom: var(--space-6);
  border-bottom: 1px solid var(--border);
  font-family: var(--font-ui);
}

.site-name {
  font-weight: 600;
  font-size: 1rem;
  letter-spacing: -0.01em;
  color: var(--text);
  text-decoration: none;
}

.site-name:hover { color: var(--accent); }

.header ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-4);
  margin: 0;
  padding: 0;
}

.header a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  padding: var(--space-1) 0;
  border-bottom: 2px solid transparent;
}

.header a:hover { color: var(--text); }

.header a[aria-current="page"] {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.site-header .header { margin-left: auto; }

.theme-toggle {
  font: inherit;
  font-size: 1rem;
  line-height: 1;
  width: 2rem;
  height: 2rem;
  display: inline-grid;
  place-items: center;
  color: var(--text-muted);
  background: none;
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}

.theme-toggle:hover {
  color: var(--accent);
  border-color: var(--border);
}

/* ---------------------------------------------------------------- page titles */
.page-title {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  margin: 0 0 var(--space-5);
}

.section {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin: var(--space-5) 0 var(--space-4);
}

/* ---------------------------------------------------------------- home */
.hero h1 {
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin: 0 0 var(--space-2);
}

.tagline {
  font-family: var(--font-ui);
  font-size: 1rem;
  color: var(--text-muted);
  margin: 0 0 var(--space-5);
}

.intro {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin: 0 0 var(--space-5);
}

.intro p { margin: 0; }

.portrait {
  flex: none;
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  border: 1px solid var(--border);
}

.portrait.clickable { cursor: pointer; }
.portrait.clickable:active { transform: scale(0.96); }

.contact {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  padding: 0;
  margin: 0;
}

.contact a {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text);
  text-decoration: none;
  padding: 0.4rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
}

.contact a:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ---------------------------------------------------------------- project / note cards */
.project {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-4);
  margin: 0 0 var(--space-3);
  transition: border-color 0.15s, box-shadow 0.15s, transform 0.15s;
}

.project:hover {
  border-color: color-mix(in srgb, var(--accent) 55%, var(--border));
  box-shadow: var(--shadow);
  transform: translateY(-1px);
}

.project-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-1) var(--space-3);
  margin: 0 0 var(--space-2);
}

.project h3 {
  font-size: 1.125rem;
  margin: 0;
}

.project h3 a { color: var(--text); text-decoration: none; }
.project h3 a:hover { color: var(--accent); }

.project p { margin: 0 0 var(--space-3); }
.project p:last-child { margin-bottom: 0; }

.project .repo,
.project .dates {
  font-family: var(--font-ui);
  font-size: 0.8125rem;
  font-weight: 500;
  white-space: nowrap;
}

.project .repo { text-decoration: none; }
.project .repo:hover { text-decoration: underline; }

.arr {
  display: inline-block;
  transition: transform 0.15s;
}

a:hover .arr { transform: translate(2px, -2px); }
.project .dates { color: var(--text-muted); }

.project .links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin: 0;
  padding: 0;
}

.tags li {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 0.15rem 0.6rem;
  border-radius: 999px;
}

.empty {
  font-family: var(--font-ui);
  font-size: 0.9375rem;
  color: var(--text-muted);
  background: var(--surface);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: var(--space-3) var(--space-4);
  margin: 0 0 var(--space-4);
}

/* ---------------------------------------------------------------- resume */
.download {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-ui);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--bg);
  background: var(--accent);
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
}

.download:hover { filter: brightness(1.1); }

.resume-lead {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  margin: 0 0 var(--space-4);
  color: var(--text-muted);
}

.timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}

.timeline li {
  display: grid;
  grid-template-columns: 9.5rem minmax(0, 1fr);
  gap: var(--space-4);
  padding: var(--space-3) 0;
  border-top: 1px solid var(--border);
}

.timeline li:last-child { border-bottom: 1px solid var(--border); }

.timeline .when {
  font-family: var(--font-ui);
  font-size: 0.8125rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  padding-top: 0.2rem;
}

.timeline .where {
  display: block;
  font-family: var(--font-ui);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
}

.timeline .what {
  display: block;
  margin-top: var(--space-1);
}

.timeline strong { font-weight: 600; }

/* ---------------------------------------------------------------- notes */
.back {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: 0.875rem;
  color: var(--text-muted);
  text-decoration: none;
  margin: 0 0 var(--space-4);
}

.back:hover { color: var(--accent); }

.note-body h1 { font-size: 2rem; font-weight: 700; letter-spacing: -0.025em; margin: 0 0 var(--space-2); }
.note-body h2 { font-size: 1.5rem; margin: var(--space-5) 0 var(--space-3); }
.note-body h3 { font-size: 1.25rem; margin: var(--space-5) 0 var(--space-2); }
.note-body h4 { font-size: 1.05rem; margin: var(--space-4) 0 var(--space-2); }

.note-body .subtitle {
  font-family: var(--font-ui);
  font-size: 0.875rem;
  color: var(--text-muted);
  margin: 0 0 var(--space-5);
}

.note-body p { margin: 0 0 var(--space-4); }

.note-body ul,
.note-body ol { margin: 0 0 var(--space-4); padding-left: 1.4em; }
.note-body li { margin: 0 0 var(--space-2); }

.note-body hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: var(--space-5) 0;
}

.note-body img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 0 auto var(--space-4);
  border-radius: var(--radius);
}

.note-body pre {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-3) var(--space-4);
  overflow-x: auto;
  margin: 0 0 var(--space-4);
  line-height: 1.5;
}

.note-body pre code {
  background: none;
  padding: 0;
  font-size: 0.8125rem;
}

.note-body blockquote {
  border-left: 3px solid var(--accent);
  margin: 0 0 var(--space-4);
  padding: var(--space-1) 0 var(--space-1) var(--space-4);
  color: var(--text-muted);
  font-style: italic;
}

.note-body blockquote p:last-child { margin-bottom: 0; }

/* Heading permalinks, added by notes.js */
.note-body h2,
.note-body h3 { position: relative; scroll-margin-top: var(--space-4); }

.note-body .anchor {
  position: absolute;
  left: -1.1em;
  padding-right: 0.3em;
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 400;
  opacity: 0;
  transition: opacity 0.15s;
}

.note-body h2:hover .anchor,
.note-body h3:hover .anchor,
.note-body .anchor:focus-visible { opacity: 1; }
.note-body .anchor:hover { color: var(--accent); }

/* Math (KaTeX) */
.note-body .katex { font-size: 1.05em; }
.note-body .math-display {
  overflow-x: auto;
  overflow-y: hidden;
  margin: 0 0 var(--space-4);
  padding: var(--space-1) 0;
}

/* Syntax highlighting (highlight.js classes, site colors) */
:root {
  --hl-keyword: #8a3ab9;
  --hl-string: #2f7d4f;
  --hl-number: #b35c00;
  --hl-comment: #8b8b90;
  --hl-title: #2b5d8a;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --hl-keyword: #c792ea;
    --hl-string: #9ece6a;
    --hl-number: #ff9e64;
    --hl-comment: #7a7e87;
    --hl-title: #7aa2f7;
  }
}

:root[data-theme="dark"] {
  --hl-keyword: #c792ea;
  --hl-string: #9ece6a;
  --hl-number: #ff9e64;
  --hl-comment: #7a7e87;
  --hl-title: #7aa2f7;
}

.hljs-keyword, .hljs-built_in, .hljs-literal, .hljs-meta { color: var(--hl-keyword); }
.hljs-string, .hljs-regexp                               { color: var(--hl-string); }
.hljs-number, .hljs-params                               { color: var(--hl-number); }
.hljs-comment, .hljs-quote                               { color: var(--hl-comment); font-style: italic; }
.hljs-title, .hljs-title.function_, .hljs-type           { color: var(--hl-title); }

/* ---------------------------------------------------------------- footer */
.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
  margin-top: var(--space-6);
  padding-top: var(--space-4);
  border-top: 1px solid var(--border);
  font-family: var(--font-ui);
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.site-footer ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin: 0;
  padding: 0;
}

.site-footer a { color: var(--text-muted); text-decoration: none; }
.site-footer a:hover { color: var(--accent); }

/* ---------------------------------------------------------------- small screens */
@media (max-width: 36rem) {
  body { font-size: 17px; }
  .wrap { padding: var(--space-3) var(--space-3) var(--space-4); }
  .site-header { margin-bottom: var(--space-5); }
  .site-header .theme-toggle { margin-left: auto; }
  .site-header .header { order: 3; flex-basis: 100%; margin-left: 0; }
  .hero h1 { font-size: 2rem; }
  .page-title, .note-body h1 { font-size: 1.625rem; }
  .intro { flex-direction: column; align-items: flex-start; }
  .timeline li { grid-template-columns: 1fr; gap: var(--space-1); }
  .note-body .anchor { display: none; }
}

/* ---------------------------------------------------------------- print */
@media print {
  :root {
    --bg: #fff; --surface: #fff; --text: #000; --text-muted: #444;
    --border: #ccc; --accent: #000;
  }

  body { font-size: 11pt; background: #fff; color: #000; }
  .wrap { max-width: none; padding: 0; min-height: 0; }
  main { animation: none; }

  .site-header, .site-footer, .theme-toggle, .download, .back { display: none; }

  .page-title { margin-bottom: 1rem; }
  .resume-lead { display: none; }
  .section { margin: 1.25rem 0 0.5rem; }
  .timeline li { padding: 0.5rem 0; break-inside: avoid; }
  .project { break-inside: avoid; box-shadow: none; transform: none; }

  .timeline a::after,
  .note-body a[href^="http"]::after { content: " (" attr(href) ")"; font-size: 0.85em; }
}