/* ============================================================
   style.css  —  Shared styles for all pages
   ============================================================ */

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

:root {
  --ink:        #1a1a18;
  --ink-soft:   #4a4a44;
  --ink-muted:  #888880;
  --paper:      #faf9f6;
  --paper-warm: #f3f1ec;
  --rule:       #e0ddd6;
  --accent:     #2d5a3d;
  --accent-bg:  #e8f0ea;
  --link:       #1a3d6b;
  --max:        780px;
  --serif:      'EB Garamond', Georgia, serif;
  --sans:       'Instrument Sans', system-ui, sans-serif;
  --mono:       'DM Mono', monospace;
}

html { scroll-behavior: smooth; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.75;
}

/* ── Navigation ─────────────────────────────────────────── */

nav {
  position: sticky;
  top: 0;
  background: var(--paper);
  border-bottom: 1px solid var(--rule);
  z-index: 100;
  padding: 0 2rem;
}

.nav-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 52px;
  position: relative;
}

.nav-name {
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  gap: 1.6rem;
  list-style: none;
  flex-wrap: nowrap;
  align-items: center;
}

.nav-links a {
  font-family: var(--sans);
  font-size: 13px;
  color: var(--ink-soft);
  text-decoration: none;
  letter-spacing: 0.02em;
  transition: color 0.15s;
}

.nav-links a:hover,
.nav-links a.active { color: var(--ink); }
.nav-links a.active { border-bottom: 1px solid var(--ink); }

/* ── Hamburger button ───────────────────────────────────── */

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  border-radius: 3px;
  transition: background 0.15s;
  flex-shrink: 0;
}
.nav-toggle:hover { background: var(--paper-warm); }
.nav-toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--ink-soft);
  transition: transform 0.25s, opacity 0.2s, width 0.2s;
  transform-origin: center;
}
.nav-toggle.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; width: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ── Page wrapper ───────────────────────────────────────── */

.page {
  max-width: var(--max);
  margin: 0 auto;
  padding: 5rem 2rem 6rem;
}

/* ── Section label ──────────────────────────────────────── */

.section-label {
  font-family: var(--sans);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 2.5rem;
}

/* ── Buttons ────────────────────────────────────────────── */

.btn {
  display: inline-block;
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 500;
  padding: 8px 18px;
  border-radius: 3px;
  text-decoration: none;
  transition: all 0.15s;
  letter-spacing: 0.02em;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
  border: 1px solid var(--accent);
}
.btn-primary:hover { opacity: 0.88; }
.btn-secondary {
  background: transparent;
  color: var(--ink-soft);
  border: 1px solid var(--rule);
}
.btn-secondary:hover { border-color: var(--ink-muted); color: var(--ink); }

/* ── Footer ─────────────────────────────────────────────── */

footer {
  max-width: var(--max);
  margin: 0 auto;
  padding: 2rem 2rem 4rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-family: var(--sans);
  font-size: 12px;
  color: var(--ink-muted);
  border-top: 1px solid var(--rule);
}

/* ── Shared list row (education, cv, etc.) ──────────────── */

.row-item {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 0 1.5rem;
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--rule);
}
.row-item:last-child { border-bottom: none; }
.row-year {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-muted);
  padding-top: 3px;
  white-space: nowrap;
}
.row-title {
  font-size: 17px;
  font-weight: 500;
  margin-bottom: 0.15rem;
}
.row-sub {
  font-family: var(--sans);
  font-size: 13.5px;
  color: var(--ink-soft);
}
.row-detail {
  font-family: var(--sans);
  font-size: 12.5px;
  color: var(--ink-muted);
  margin-top: 0.2rem;
}

/* ── Skill tags ─────────────────────────────────────────── */

.skills-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.skill-tag {
  font-family: var(--mono);
  font-size: 12px;
  background: var(--paper-warm);
  color: var(--ink-soft);
  padding: 4px 10px;
  border-radius: 2px;
  border: 1px solid var(--rule);
}

/* ── Research tag badge ─────────────────────────────────── */

.res-tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: 11px;
  background: var(--accent-bg);
  color: var(--accent);
  padding: 2px 8px;
  border-radius: 2px;
  margin-bottom: 0.6rem;
  letter-spacing: 0.04em;
}

/* ── Divider items (research, publications, blog) ───────── */

.divider-item {
  padding: 1.6rem 0;
  border-bottom: 1px solid var(--rule);
}
.divider-item:last-child { border-bottom: none; }

/* ============================================================
   RESPONSIVE BREAKPOINTS
   ============================================================ */

/* ── Tablet (769px – 900px): tighten nav gaps ───────────── */
@media (max-width: 900px) {
  .nav-links { gap: 1.1rem; }
  .nav-links a { font-size: 12px; }
}

/* ── Mobile nav hamburger at 700px ─────────────────────── */
@media (max-width: 700px) {

  nav { padding: 0 1.2rem; }

  .nav-toggle { display: flex; }

  .nav-links {
    display: none;
    position: absolute;
    top: calc(100% + 1px);
    left: -1.2rem;
    right: -1.2rem;
    background: var(--paper);
    border-bottom: 1px solid var(--rule);
    flex-direction: column;
    gap: 0;
    padding: 0.5rem 0 0.8rem;
    box-shadow: 0 6px 20px rgba(0,0,0,0.07);
    z-index: 200;
  }

  .nav-links.open { display: flex; }

  .nav-links li { width: 100%; }

  .nav-links a {
    display: block;
    padding: 0.65rem 1.8rem;
    font-size: 14px;
    border-bottom: none !important;
  }

  .nav-links a.active {
    border-bottom: none !important;
    color: var(--ink);
    font-weight: 500;
  }
}

/* ── General mobile (<=600px) ───────────────────────────── */
@media (max-width: 600px) {

  body { font-size: 17px; }

  .page { padding: 3rem 1.2rem 4rem; }

  .row-item { grid-template-columns: 1fr; gap: 0.2rem; }

  .btn { font-size: 12px; padding: 7px 14px; }

  footer {
    padding: 1.5rem 1.2rem 3rem;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.25rem;
  }
}

/* ── Print ──────────────────────────────────────────────── */

@media print {
  body { background: white; color: black; }
  nav, footer, #js-cv-dl { display: none !important; }
  .page { max-width: 800px; margin: auto; padding: 0; }
  .cv-block { page-break-inside: avoid; }
  .cv-heading { border-bottom: 1px solid #ccc; }
  * { -webkit-print-color-adjust: exact !important; print-color-adjust: exact !important; }
}

@page { margin: 20mm; }