/* ============================================================
   Design tokens
   ============================================================ */
:root {
  --paper:      #fbfaf7;   /* warm off-white, not cream */
  --paper-2:    #ffffff;
  --ink:        #1b1b1a;
  --ink-soft:   #555350;
  --ink-faint:  #8a8782;
  --rule:       #e6e3dc;
  --rule-soft:  #efece6;
  --accent:     #2a4b7c;   /* oxford-ish blue */
  --accent-2:   #11705f;   /* teal, used for the paper log */
  --code-bg:    #f3f1ea;

  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --sans:  "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono:  "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;

  --maxw: 1080px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper:     #16161a;
    --paper-2:   #1d1d22;
    --ink:       #e9e7e1;
    --ink-soft:  #b3b0a8;
    --ink-faint: #807d77;
    --rule:      #2d2d33;
    --rule-soft: #26262b;
    --accent:    #8fb3e6;
    --accent-2:  #5fc7af;
    --code-bg:   #24242a;
  }
}

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

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .15s ease, color .15s ease;
}
a:hover { border-bottom-color: var(--accent); }

h1, h2, h3, h4 {
  font-family: var(--serif);
  font-weight: 500;
  line-height: 1.2;
  color: var(--ink);
}

img { max-width: 100%; height: auto; }

code {
  font-family: var(--mono);
  font-size: .88em;
  background: var(--code-bg);
  padding: .12em .4em;
  border-radius: 4px;
}
pre {
  background: var(--code-bg);
  padding: 1rem 1.2rem;
  border-radius: 8px;
  overflow-x: auto;
  line-height: 1.5;
}
pre code { background: none; padding: 0; }

/* ============================================================
   Layout shell
   ============================================================ */
.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 4rem;
  align-items: start;
  padding-top: 3.5rem;
  padding-bottom: 4rem;
}

/* ---- Sidebar ---- */
.sidebar { position: sticky; top: 3.5rem; }

.avatar {
  width: 132px; height: 132px;
  border-radius: 50%;
  object-fit: cover;
  border: 1px solid var(--rule);
}
.avatar.placeholder {
  display: grid; place-items: center;
  background: var(--paper-2);
  color: var(--ink-faint);
  font-family: var(--serif);
  font-size: 2.6rem;
}

.sidebar .name {
  font-size: 1.7rem;
  margin: 1.1rem 0 .15rem;
  letter-spacing: -0.01em;
}
.sidebar .role {
  font-family: var(--mono);
  font-size: .78rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--accent-2);
  margin: 0 0 1.1rem;
}
.sidebar .meta {
  font-size: .92rem;
  color: var(--ink-soft);
  margin: 0 0 1.3rem;
}
.sidebar .meta span { display: block; }

.social { list-style: none; padding: 0; margin: 0; }
.social li { margin: .35rem 0; }
.social a {
  display: inline-flex; align-items: center; gap: .6rem;
  color: var(--ink-soft);
  font-size: .92rem;
  border: none;
}
.social a:hover { color: var(--accent); }
.social svg { width: 17px; height: 17px; flex: none; }

/* ---- Main column ---- */
.main { min-width: 0; }

.section { margin-bottom: 3.2rem; scroll-margin-top: 2rem; }
.section:last-child { margin-bottom: 0; }

.section-head {
  display: flex; align-items: baseline; gap: .6rem;
  margin: 0 0 1.3rem;
  padding-bottom: .5rem;
  border-bottom: 1px solid var(--rule);
}
.section-head h2 { font-size: 1.55rem; margin: 0; letter-spacing: -0.01em; }
.section-head .all-link {
  margin-left: auto;
  font-family: var(--mono);
  font-size: .76rem;
  letter-spacing: .04em;
  border: none;
}

.lead { font-size: 1.05rem; }
.lead p:first-child { margin-top: 0; }

/* facets row under bio */
.facets {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.4rem;
  margin-top: 1.8rem;
}
.facet h4 {
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .07em;
  text-transform: uppercase;
  color: var(--accent-2);
  margin: 0 0 .5rem;
}
.facet ul { margin: 0; padding-left: 1.1rem; }
.facet li { font-size: .88rem; color: var(--ink-soft); margin: .2rem 0; }

/* ---- Publications ---- */
.pub { padding: .2rem 0 1.1rem; border-bottom: 1px solid var(--rule-soft); margin-bottom: 1.1rem; }
.pub:last-child { border-bottom: none; margin-bottom: 0; }
.pub .venue {
  font-family: var(--mono);
  font-size: .73rem;
  letter-spacing: .05em;
  color: var(--ink-faint);
  text-transform: uppercase;
}
.pub h3 { font-size: 1.18rem; margin: .25rem 0 .35rem; }
.pub .authors { font-size: .92rem; color: var(--ink-soft); margin: 0 0 .55rem; }
.pub .authors strong { color: var(--ink); font-weight: 600; }
.pub-links a {
  font-family: var(--mono);
  font-size: .76rem;
  margin-right: .9rem;
  border: none;
  color: var(--accent);
}
.pub-links a:hover { text-decoration: underline; }

/* ---- Timeline (education / experience) ---- */
.timeline { list-style: none; margin: 0; padding: 0; }
.timeline li {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 1rem;
  padding: .55rem 0;
  border-bottom: 1px solid var(--rule-soft);
}
.timeline li:last-child { border-bottom: none; }
.timeline .when {
  font-family: var(--mono);
  font-size: .8rem;
  color: var(--ink-faint);
  padding-top: .12rem;
}
.timeline .what { color: var(--ink-soft); }
.timeline .what strong { color: var(--ink); }

/* ============================================================
   Paper reading log — the signature element
   ============================================================ */
.paperlog { list-style: none; margin: 0; padding: 0; position: relative; }
.paperlog::before {
  content: ""; position: absolute;
  left: 6px; top: 6px; bottom: 6px;
  width: 2px; background: var(--rule);
}
.entry { position: relative; padding: 0 0 1.6rem 2.2rem; }
.entry:last-child { padding-bottom: 0; }
.entry::before {
  content: ""; position: absolute; left: 0; top: 7px;
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--accent-2);
}
.entry .date {
  font-family: var(--mono);
  font-size: .74rem;
  letter-spacing: .04em;
  color: var(--ink-faint);
}
.entry h3 { font-size: 1.12rem; margin: .15rem 0 .3rem; }
.entry h3 a { color: var(--ink); border: none; }
.entry h3 a:hover { color: var(--accent); }
.entry .gist { font-size: .94rem; color: var(--ink-soft); margin: 0 0 .55rem; }

.tags { display: flex; flex-wrap: wrap; gap: .4rem; align-items: center; }
.tag {
  font-family: var(--mono);
  font-size: .68rem;
  letter-spacing: .03em;
  color: var(--accent-2);
  background: color-mix(in srgb, var(--accent-2) 11%, transparent);
  padding: .12rem .5rem;
  border-radius: 999px;
}
.rating { font-family: var(--mono); font-size: .74rem; color: var(--ink-faint); margin-left: auto; }
.rating .star { color: #d4a017; }

/* ---- Blog list ---- */
.postlist { list-style: none; margin: 0; padding: 0; }
.postlist li {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 1.2rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--rule-soft);
}
.postlist .when { font-family: var(--mono); font-size: .78rem; color: var(--ink-faint); padding-top: .2rem; }
.postlist h3 { font-size: 1.18rem; margin: 0 0 .3rem; }
.postlist .excerpt { font-size: .92rem; color: var(--ink-soft); margin: 0; }

/* ============================================================
   Article (post + paper) pages
   ============================================================ */
.article { max-width: 720px; margin: 0 auto; padding: 3.5rem 1.5rem 4rem; }
.article .back {
  font-family: var(--mono); font-size: .78rem; border: none;
  display: inline-block; margin-bottom: 2rem;
}
.article-head { margin-bottom: 2.2rem; padding-bottom: 1.4rem; border-bottom: 1px solid var(--rule); }
.article-head .date {
  font-family: var(--mono); font-size: .76rem; letter-spacing: .04em;
  color: var(--ink-faint); text-transform: uppercase;
}
.article-head h1 { font-size: 2.1rem; margin: .4rem 0 .6rem; letter-spacing: -0.015em; }
.article-content { font-size: 1.06rem; line-height: 1.75; }
.article-content h2 { font-size: 1.5rem; margin: 2.2rem 0 .8rem; }
.article-content h3 { font-size: 1.22rem; margin: 1.8rem 0 .6rem; }
.article-content blockquote {
  margin: 1.4rem 0; padding: .4rem 0 .4rem 1.3rem;
  border-left: 3px solid var(--accent-2);
  color: var(--ink-soft); font-style: italic;
}
.article-content a { border-bottom: 1px solid color-mix(in srgb, var(--accent) 40%, transparent); }

/* paper-specific meta block */
.paper-meta {
  display: grid; grid-template-columns: max-content 1fr; gap: .35rem 1.2rem;
  font-size: .92rem; margin: 1.4rem 0;
  padding: 1.1rem 1.3rem; background: var(--paper-2);
  border: 1px solid var(--rule); border-radius: 10px;
}
.paper-meta dt { font-family: var(--mono); font-size: .74rem; text-transform: uppercase; letter-spacing: .05em; color: var(--ink-faint); padding-top: .15rem; }
.paper-meta dd { margin: 0; color: var(--ink-soft); }
.paper-meta dd a { border: none; color: var(--accent); }

/* ============================================================
   Footer
   ============================================================ */
.site-footer {
  border-top: 1px solid var(--rule);
  padding: 1.6rem 0;
  font-family: var(--mono);
  font-size: .76rem;
  color: var(--ink-faint);
  text-align: center;
}
.site-footer a { color: var(--ink-faint); border: none; }
.site-footer a:hover { color: var(--accent); }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 820px) {
  body { font-size: 16px; }
  .layout { grid-template-columns: 1fr; gap: 2.4rem; padding-top: 2.4rem; }
  .sidebar { position: static; text-align: center; }
  .sidebar .meta span, .social { display: inline-flex; }
  .social { flex-wrap: wrap; gap: .4rem 1.2rem; justify-content: center; }
  .social a { font-size: .88rem; }
  .facets { grid-template-columns: 1fr; gap: 1rem; }
  .timeline li, .postlist li { grid-template-columns: 1fr; gap: .2rem; }
  .timeline .when { padding-top: 0; }
}

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