/* ============================================================
   THE COMPLEXITY OF SIMPLICITY
   style.css — Single external stylesheet
   Palette: monochrome + ink navy accent
   Type: Playfair Display (headings) + Source Serif 4 (body)
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400;0,600;0,700;1,400;1,600&family=Source+Serif+4:ital,opsz,wght@0,8..60,300;0,8..60,400;0,8..60,600;1,8..60,300;1,8..60,400&family=DM+Sans:wght@300;400;500&display=swap');

/* ── CSS Variables ─────────────────────────────────────────── */
:root {
  --color-bg:           #fafaf8;
  --color-text:         #1a1a18;
  --color-text-light:   #555550;
  --color-text-lighter: #888880;
  --color-accent:       #1c3d6e;
  --color-accent-hover: #0f2548;
  --color-rule:         #d8d8d0;
  --color-rule-dark:    #a0a098;
  --color-tag-bg:       #eeeee8;
  --color-tag-text:     #444440;

  --font-display:  'Playfair Display', Georgia, serif;
  --font-body:     'Source Serif 4', Georgia, serif;
  --font-ui:       'DM Sans', Helvetica, Arial, sans-serif;

  --col-width:     740px;
  --col-padding:   1.5rem;

  --leading-tight: 1.25;
  --leading-body:  1.75;
}

/* ── Reset ─────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 18px; scroll-behavior: smooth; }

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-weight: 300;
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

a {
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color 0.15s ease;
}
a:hover { color: var(--color-accent-hover); }

/* ── Layout wrapper ────────────────────────────────────────── */
.site-wrapper {
  max-width: var(--col-width);
  margin: 0 auto;
  padding: 0 var(--col-padding);
}

/* ── HEADER / MASTHEAD ─────────────────────────────────────── */
.site-header {
  padding: 3.5rem 0 0;
  border-bottom: 2px solid var(--color-text);
  margin-bottom: 0;
}

.masthead {
  margin-bottom: 1.5rem;
}

.site-title {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 5vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
  color: var(--color-text);
  text-decoration: none;
}
.site-title:hover { color: var(--color-accent); }

.site-tagline {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  font-weight: 400;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-lighter);
  margin-top: 0.4rem;
}

/* ── NAV ───────────────────────────────────────────────────── */
.site-nav {
  display: flex;
  gap: 0;
  margin-top: 0;
}

.site-nav a {
  font-family: var(--font-ui);
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--color-text-light);
  padding: 0.65rem 1.1rem 0.65rem 0;
  margin-right: 1.2rem;
  border-top: 2px solid transparent;
  transition: color 0.15s ease, border-color 0.15s ease;
  position: relative;
  top: 2px; /* sits on top of header border */
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--color-accent);
  border-top-color: var(--color-accent);
}

/* ── MAIN CONTENT ──────────────────────────────────────────── */
.site-main {
  padding: 3rem 0 5rem;
}

/* ── SECTION LABEL ─────────────────────────────────────────── */
.section-label {
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-text-lighter);
  margin-bottom: 2rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--color-rule);
}

/* ── POST LIST (homepage & archive) ────────────────────────── */
.post-list {
  list-style: none;
}

.post-item {
  padding: 2rem 0;
  border-bottom: 1px solid var(--color-rule);
}
.post-item:first-child { padding-top: 0; }

.post-meta {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  margin-bottom: 0.45rem;
}

.post-date {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--color-accent);
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.post-tags {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
}

.tag {
  font-family: var(--font-ui);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  padding: 0.15rem 0.55rem;
  border-radius: 2px;
  text-decoration: none;
  transition: background 0.15s ease;
}
.tag:hover {
  background: var(--color-rule-dark);
  color: var(--color-text);
}

.post-title {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 600;
  line-height: var(--leading-tight);
  letter-spacing: -0.01em;
  margin-bottom: 0.6rem;
}

.post-title a {
  color: var(--color-text);
  text-decoration: none;
  transition: color 0.15s ease;
}
.post-title a:hover { color: var(--color-accent); }

.post-excerpt {
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.65;
  max-width: 64ch;
}

.read-more {
  display: inline-block;
  margin-top: 0.7rem;
  font-family: var(--font-ui);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-accent);
  text-decoration: none;
  border-bottom: 1px solid var(--color-accent);
  padding-bottom: 1px;
  transition: color 0.15s ease, border-color 0.15s ease;
}
.read-more:hover {
  color: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
}

/* ── ARCHIVE LINK ──────────────────────────────────────────── */
.archive-cta {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--color-rule);
  font-family: var(--font-ui);
  font-size: 0.8rem;
}
.archive-cta a {
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* ── ARCHIVE PAGE YEAR GROUPING ────────────────────────────── */
.archive-year {
  margin-top: 2.5rem;
}

.archive-year-label {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 400;
  font-style: italic;
  color: var(--color-rule-dark);
  margin-bottom: 0.5rem;
}

.archive-list {
  list-style: none;
}

.archive-list li {
  display: grid;
  grid-template-columns: 7rem 1fr;
  gap: 1rem;
  align-items: baseline;
  padding: 0.55rem 0;
  border-bottom: 1px solid var(--color-rule);
}

.archive-list .a-date {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  color: var(--color-accent);
  white-space: nowrap;
}

.archive-list .a-title {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.3;
}

.archive-list .a-title a {
  color: var(--color-text);
  text-decoration: none;
}
.archive-list .a-title a:hover { color: var(--color-accent); }

/* ── SINGLE ARTICLE ────────────────────────────────────────── */
.article-header {
  margin-bottom: 2.5rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--color-rule);
}

.article-header .post-meta {
  margin-bottom: 1rem;
}

.article-title {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 1.2rem;
}

.article-lede {
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-style: italic;
  color: var(--color-text-light);
  line-height: 1.7;
  border-left: 3px solid var(--color-accent);
  padding-left: 1.2rem;
  margin-top: 1.2rem;
}

/* Article body typography */
.article-body {
  font-size: 1rem;
  line-height: var(--leading-body);
}

.article-body p {
  margin-bottom: 1.4rem;
  max-width: 68ch;
}

.article-body h2 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.2;
  color: var(--color-text);
  margin: 2.5rem 0 0.9rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-rule);
}

.article-body h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  font-style: italic;
  color: var(--color-text);
  margin: 2rem 0 0.6rem;
}

.article-body ul,
.article-body ol {
  padding-left: 1.5rem;
  margin-bottom: 1.4rem;
  max-width: 64ch;
}

.article-body li {
  margin-bottom: 0.4rem;
  line-height: 1.65;
}

.article-body strong { font-weight: 600; color: var(--color-text); }

.article-body em { font-style: italic; }

.article-body a {
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

.article-body blockquote {
  border-left: 3px solid var(--color-accent);
  margin: 1.8rem 0;
  padding: 0.2rem 0 0.2rem 1.2rem;
  font-style: italic;
  color: var(--color-text-light);
  font-size: 1.05rem;
  max-width: 60ch;
}

/* numbered list styling */
.article-body ol { list-style: decimal; }

/* ── ARTICLE FOOTER ────────────────────────────────────────── */
.article-footer {
  margin-top: 3.5rem;
  padding-top: 1.5rem;
  border-top: 2px solid var(--color-text);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.back-link {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--color-text-light);
  transition: color 0.15s ease;
}
.back-link:hover { color: var(--color-accent); }

.article-footer .post-tags { justify-content: flex-end; }

/* ── ABOUT PAGE ────────────────────────────────────────────── */
.about-body {
  display: grid;
  gap: 3rem;
}

.about-intro {
  font-family: var(--font-body);
  font-size: 1.05rem;
  line-height: var(--leading-body);
}

.about-intro p { margin-bottom: 1.2rem; max-width: 66ch; }

.about-section h2 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-rule);
}

.edu-item {
  margin-bottom: 1.4rem;
}

.edu-item .degree {
  font-family: var(--font-ui);
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--color-text);
}

.edu-item .institution {
  font-family: var(--font-ui);
  font-size: 0.85rem;
  color: var(--color-text-light);
}

.edu-item .year {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  color: var(--color-accent);
  margin-top: 0.1rem;
}

.orcid-link {
  font-family: var(--font-ui);
  font-size: 0.85rem;
}

/* ── FOOTER ────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--color-rule);
  padding: 2rem 0 3rem;
  margin-top: 2rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-copy {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  color: var(--color-text-lighter);
}

.footer-nav {
  display: flex;
  gap: 1.5rem;
}

.footer-nav a {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  color: var(--color-text-lighter);
  text-decoration: none;
  letter-spacing: 0.04em;
  transition: color 0.15s ease;
}
.footer-nav a:hover { color: var(--color-accent); }

/* ── RESPONSIVE ────────────────────────────────────────────── */
@media (max-width: 600px) {
  html { font-size: 16px; }

  .site-header { padding-top: 2rem; }

  .site-title { font-size: 1.6rem; }

  .site-nav a {
    font-size: 0.72rem;
    margin-right: 0.8rem;
    padding-right: 0;
  }

  .archive-list li {
    grid-template-columns: 1fr;
    gap: 0.2rem;
  }

  .archive-list .a-date { font-size: 0.7rem; }

  .article-footer {
    flex-direction: column;
    align-items: flex-start;
  }
  .article-footer .post-tags { justify-content: flex-start; }

  .footer-inner { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 400px) {
  :root { --col-padding: 1rem; }
}