/* =====================================================
   [Your Name] — Personal Academic Website
   Design system: "paper & ink" — a muted academic palette
   with a periodic-table-style "element badge" (PHI / CHM /
   MTH) used as a cross-page wayfinding signature, grounded
   in the chemistry side of the site.
   ===================================================== */

:root {
  /* Color */
  --paper: #f0eee5;
  --paper-deep: #e4dfd0;
  --ink: #211f1a;
  --ink-muted: #6b6558;
  --oxblood: #6b2737;
  --oxblood-light: #8a4356;
  --slate: #35505a;
  --border: #d6d0bd;

  /* Type */
  --font-serif: 'Hoefler Text', 'Iowan Old Style', Georgia, 'Palatino Linotype', serif;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, 'SF Mono', 'Courier New', monospace;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 3.5rem;
  --space-xl: 5.5rem;

  --max-width: 980px;
}

/* Reset */
* { box-sizing: border-box; margin: 0; padding: 0; }

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

h1, h2, h3 {
  font-family: var(--font-serif);
  font-weight: 400;
  line-height: 1.2;
}

h1 { font-size: 2.6rem; }
h2 { font-size: 1.8rem; margin-bottom: var(--space-sm); }
h3 { font-size: 1.25rem; color: var(--oxblood); margin-bottom: var(--space-xs); }

p { margin-bottom: var(--space-sm); max-width: 68ch; }

a {
  color: var(--oxblood);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.15s ease, color 0.15s ease;
}
a:hover { border-bottom-color: currentColor; }

ul { list-style: none; }

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* ---------- Header / Nav ---------- */

.site-header {
  border-bottom: 1px solid var(--border);
  padding: var(--space-sm) 0;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-sm) var(--space-md);
}

.site-name {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  color: var(--ink);
  border-bottom: none;
}
.site-name:hover { color: var(--oxblood); }

.main-nav {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
  font-family: var(--font-mono);
}

.nav-link {
  font-size: 0.82rem;
  color: var(--ink-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  border-bottom: none;
  padding-bottom: 3px;
}
.nav-link:hover, .nav-link.current {
  color: var(--oxblood);
  border-bottom: 1px solid var(--oxblood);
}

/* ---------- Element badge (signature component) ----------
   Styled after a periodic table cell — used consistently
   across pages to mark Philosophy / Chemistry / Math content. */

.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  flex-shrink: 0;
  border: 1.5px solid var(--oxblood);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--oxblood);
  letter-spacing: 0.02em;
}

/* ---------- Page header ---------- */

.page-header {
  padding: var(--space-lg) 0 var(--space-md);
  border-bottom: 1px solid var(--border);
  margin-bottom: var(--space-lg);
  display: flex;
  gap: var(--space-sm);
  align-items: flex-start;
}

.page-header .heading-group { flex: 1; }

.eyebrow {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--slate);
  margin-bottom: var(--space-xs);
}

.page-intro { color: var(--ink-muted); font-size: 1.05rem; }

/* ---------- Home hero ---------- */

.hero {
  display: flex;
  gap: var(--space-lg);
  align-items: flex-start;
  padding: var(--space-xl) 0 var(--space-lg);
  flex-wrap: wrap;
}

.hero-photo {
  flex: 0 0 200px;
  width: 200px;
  height: 200px;
  border: 1px solid var(--border);
  border-radius: 4px;
  overflow: hidden;
}
.hero-photo img { width: 100%; height: 100%; object-fit: cover; }

.hero-text { flex: 1 1 380px; }
.hero-text h1 { margin-bottom: var(--space-xs); }

.tagline {
  font-size: 1.15rem;
  color: var(--ink-muted);
  margin-bottom: var(--space-sm);
}

.academic-info {
  display: inline-block;
  font-size: 0.95rem;
  padding: var(--space-xs) var(--space-sm);
  background-color: var(--paper-deep);
  border-left: 3px solid var(--oxblood);
  margin-bottom: var(--space-sm);
}

/* ---------- Fields of study ---------- */

.fields-section { padding: var(--space-lg) 0; border-top: 1px solid var(--border); }

.fields-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg) var(--space-md);
  margin-top: var(--space-md);
}

.field-card .badge { margin-bottom: var(--space-xs); }
.field-card p { font-size: 0.97rem; }
.learn-more { font-family: var(--font-mono); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.04em; }

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--border);
  margin-top: var(--space-xl);
  padding: var(--space-lg) 0;
  background-color: var(--paper-deep);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.footer-links { display: flex; gap: var(--space-md); font-family: var(--font-mono); font-size: 0.85rem; }

.footer-note {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--ink-muted);
}

/* ---------- Research page ---------- */

.chemical-group { margin-bottom: var(--space-md); }

.chemical-group-label {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--slate);
  margin-bottom: var(--space-sm);
}

.chemical-row { display: grid; gap: var(--space-sm); }
.chemical-row.core { grid-template-columns: repeat(3, 1fr); }
.chemical-row.complementary { grid-template-columns: repeat(5, 1fr); }

.chemical-card {
  border: 1px solid var(--border);
  border-radius: 4px;
  overflow: hidden;
  background: #fff;
}
.chemical-card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-bottom: 1px solid var(--border);
}
.chemical-card .label {
  padding: var(--space-xs);
  font-size: 0.82rem;
  text-align: center;
}

.interaction-note {
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--slate);
  margin: var(--space-sm) 0;
}

.research-writeup { padding: var(--space-md) 0; border-top: 1px solid var(--border); }

/* ---------- Academics page ---------- */

.academic-block { padding: var(--space-lg) 0; display: flex; gap: var(--space-md); }
.academic-block.primary { border-bottom: 1px solid var(--border); }
.academic-block.secondary { opacity: 0.94; }

.academic-block .badge { margin-top: 0.3rem; }
.academic-block .block-content { flex: 1; }

.role-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 2px 8px;
  border: 1px solid var(--slate);
  color: var(--slate);
  border-radius: 3px;
  margin-bottom: var(--space-sm);
}

.subsection { margin-top: var(--space-md); }
.subsection h4 {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-muted);
  margin-bottom: var(--space-xs);
  font-weight: 600;
}

.closing-note {
  padding: var(--space-lg) 0;
  border-top: 1px solid var(--border);
  font-style: italic;
  color: var(--ink-muted);
}

/* ---------- CV page ---------- */

.cv-download {
  text-align: center;
  padding: var(--space-md);
  margin-bottom: var(--space-lg);
  background-color: var(--paper-deep);
  border: 1px solid var(--border);
  border-radius: 4px;
}

.btn {
  display: inline-block;
  padding: 0.65rem 1.6rem;
  background-color: var(--oxblood);
  color: var(--paper);
  border-bottom: none;
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.btn:hover { background-color: var(--oxblood-light); border-bottom: none; }

.coursework-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.coursework-col .badge { margin-bottom: var(--space-xs); }

.coursework-list li {
  padding: var(--space-xs) 0;
  border-bottom: 1px dotted var(--border);
  font-size: 0.95rem;
}

.cv-section { padding: var(--space-md) 0; border-top: 1px solid var(--border); }

/* ---------- Responsive ---------- */

@media (max-width: 800px) {
  .chemical-row.complementary { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 700px) {
  .header-inner { flex-direction: column; align-items: flex-start; }
  .hero { flex-direction: column; }
  .fields-grid { grid-template-columns: 1fr; }
  .chemical-row.core { grid-template-columns: repeat(3, 1fr); }
  .chemical-row.complementary { grid-template-columns: repeat(2, 1fr); }
  .coursework-grid { grid-template-columns: 1fr; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
  .page-header { flex-direction: column; }
  .academic-block { flex-direction: column; }
}

@media (max-width: 460px) {
  h1 { font-size: 2.1rem; }
  .chemical-row.core { grid-template-columns: 1fr 1fr; }
  .chemical-row.complementary { grid-template-columns: 1fr 1fr; }
}

.popup-overlay {
  display: none; /* Hidden by default */
  position: fixed;
  z-index: 1000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0,0,0,0.5); /* Semi-transparent black */
  justify-content: center;
  align-items: center;
}

.popup-content {
  background-color: white;
  padding: 20px;
  border-radius: 8px;
  position: relative;
  max-width: 500px;
  width: 100%;
}

.close-btn {
  position: absolute;
  top: 10px;
  right: 15px;
  font-size: 24px;
  font-weight: bold;
  cursor: pointer;
}