/* =====================================================================
   Design tokens
   ===================================================================== */
:root {
  --paper: #FAFAF8;
  --ink: #16233F;
  --ink-soft: #4C5B77;
  --blueprint: #2D5F8A;
  --blueprint-soft: #D3DDE6;
  --accent: #E8590C;
  --accent-soft: rgba(232, 89, 12, 0.10);
  --line: #C7D1DB;

  --font-display: "IBM Plex Sans", sans-serif;
  --font-body: "IBM Plex Sans", sans-serif;
  --font-mono: "IBM Plex Mono", monospace;

  --maxw: 980px;
  --topbar-h: 68px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--blueprint); text-decoration: none; }
a:hover { color: var(--accent); }
a:focus-visible, button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Faint blueprint grid, fixed behind everything */
.grid-overlay {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    linear-gradient(var(--blueprint-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--blueprint-soft) 1px, transparent 1px);
  background-size: 32px 32px;
  opacity: 0.35;
  mask-image: linear-gradient(to bottom, black, black 40%, transparent 92%);
}

/* =====================================================================
   Top bar / navigation
   ===================================================================== */
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(250, 250, 248, 0.9);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line);
}

.topbar__inner {
  max-width: var(--maxw);
  margin: 0 auto;
  height: var(--topbar-h);
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.topbar__mark {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  flex-shrink: 0;
}
.mark__glyph {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--ink);
  border: 1.5px solid var(--ink);
  padding: 0.15rem 0.4rem;
}
.mark__label {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  color: var(--ink-soft);
  display: none;
}
@media (min-width: 640px) { .mark__label { display: inline; } }

.tabs {
  display: flex;
  gap: 0.25rem;
  overflow-x: auto;
}
.tab {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  background: none;
  border: none;
  color: var(--ink-soft);
  padding: 0.5rem 0.7rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  transition: color 0.15s ease, border-color 0.15s ease;
}
.tab__num { color: var(--blueprint); font-weight: 600; }
.tab:hover { color: var(--ink); }
.tab.is-active {
  color: var(--ink);
  border-bottom-color: var(--accent);
}
.tab.is-active .tab__num { color: var(--accent); }

.navtoggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 32px;
  height: 32px;
  background: none;
  border: 1px solid var(--line);
  cursor: pointer;
}
.navtoggle span {
  display: block;
  height: 2px;
  background: var(--ink);
  margin: 0 6px;
}

@media (max-width: 720px) {
  .tabs {
    position: fixed;
    top: var(--topbar-h);
    left: 0; right: 0;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    padding: 0.5rem 1.5rem 1rem;
    display: none;
  }
  .tabs.is-open { display: flex; }
  .tab { border-bottom: none; border-left: 2px solid transparent; padding: 0.6rem 0.5rem; }
  .tab.is-active { border-left-color: var(--accent); border-bottom-color: transparent; }
  .navtoggle { display: flex; }
}

/* =====================================================================
   Layout shell
   ===================================================================== */
main {
  position: relative;
  z-index: 1;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 3rem 1.5rem 5rem;
}

.panel[hidden] { display: none; }
.panel {
  scroll-margin-top: calc(var(--topbar-h) + 1rem);
}
.section-title {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 600;
  margin: 0 0 0.5rem;
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
}
.section-title__num {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 500;
}
.section-intro {
  color: var(--ink-soft);
  max-width: 60ch;
  margin: 0 0 2rem;
}

/* =====================================================================
   Hero / title block (About)
   ===================================================================== */
.hero {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 2.5rem;
  align-items: start;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--line);
  margin-bottom: 2.5rem;
}
@media (max-width: 800px) {
  .hero { grid-template-columns: 1fr; }
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--blueprint);
  margin: 0 0 0.75rem;
}
.hero__intro h1 {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 5vw, 3.2rem);
  font-weight: 700;
  margin: 0 0 1rem;
  line-height: 1.05;
  letter-spacing: -0.01em;
}
.hero__thesis {
  font-size: 1.1rem;
  color: var(--ink-soft);
  max-width: 46ch;
  margin: 0 0 1.75rem;
}
.hero__actions { display: flex; flex-wrap: wrap; gap: 0.75rem; }

.btn {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  padding: 0.7rem 1.1rem;
  border: 1.5px solid var(--ink);
  display: inline-block;
  transition: transform 0.12s ease, background 0.15s ease, color 0.15s ease;
}
.btn--primary { background: var(--ink); color: var(--paper); }
.btn--primary:hover { background: var(--accent); border-color: var(--accent); color: #fff; transform: translateY(-1px); }
.btn--ghost { background: transparent; color: var(--ink); }
.btn--ghost:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }

.titleblock {
  width: 100%;
  border-collapse: collapse;
  border: 1.5px solid var(--ink);
  font-size: 0.85rem;
}
.titleblock th, .titleblock td {
  text-align: left;
  padding: 0.55rem 0.7rem;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
.titleblock tr:last-child th, .titleblock tr:last-child td { border-bottom: none; }
.titleblock th {
  font-family: var(--font-mono);
  font-weight: 500;
  color: var(--ink-soft);
  width: 32%;
  border-right: 1px solid var(--line);
  text-transform: uppercase;
  font-size: 0.72rem;
  letter-spacing: 0.05em;
}
.titleblock td { font-family: var(--font-body); color: var(--ink); }
.titleblock--compact { font-size: 0.8rem; }

/* Dimension-line stat callouts */
.measure {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  margin-bottom: 3rem;
}
@media (max-width: 700px) { .measure { grid-template-columns: repeat(2, 1fr); } }

.measure__item { text-align: center; }
.measure__line {
  display: block;
  height: 1px;
  background: var(--blueprint);
  margin-bottom: 0.6rem;
  position: relative;
}
.measure__line::before, .measure__line::after {
  content: "";
  position: absolute;
  top: -3px;
  width: 1px;
  height: 7px;
  background: var(--blueprint);
}
.measure__line::before { left: 0; }
.measure__line::after { right: 0; }
.measure__value {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.5rem;
  color: var(--ink);
}
.measure__label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--ink-soft);
  margin-top: 0.2rem;
  letter-spacing: 0.02em;
}

.about-body p { max-width: 68ch; color: var(--ink); }
.about-body p:not(:last-child) { margin-bottom: 1.1rem; }

/* =====================================================================
   Research
   ===================================================================== */
.projects {
  display: grid;
  gap: 1.5rem;
}
.project {
  border: 1px solid var(--line);
  padding: 1.5rem 1.75rem;
  position: relative;
  transition: border-color 0.15s ease;
}
.project:hover { border-color: var(--blueprint); }
.project__fig {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--accent);
  letter-spacing: 0.05em;
  margin: 0 0 0.5rem;
}
.project h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
}
.project p { margin: 0 0 0.75rem; color: var(--ink-soft); max-width: 62ch; }
.project__tags { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-bottom: 0.9rem !important; }
.project__tags span {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--blueprint);
  background: var(--accent-soft);
  background: rgba(45, 95, 138, 0.08);
  padding: 0.2rem 0.5rem;
  border-radius: 2px;
}
.project__link { font-family: var(--font-mono); font-size: 0.82rem; }

/* =====================================================================
   Publications
   ===================================================================== */
.pubs { list-style: none; margin: 0; padding: 0; }
.pub {
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--line);
}
.pub:first-child { padding-top: 0; }
.pub__meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
  margin: 0 0 0.4rem;
  letter-spacing: 0.03em;
}
.pub__title {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  margin: 0 0 0.35rem;
}
.pub__authors { color: var(--ink-soft); margin: 0 0 0.6rem; font-size: 0.92rem; }
.pub__links { display: flex; gap: 1rem; margin: 0; }
.pub__links a { font-family: var(--font-mono); font-size: 0.8rem; }

/* =====================================================================
   Teaching
   ===================================================================== */
.teaching-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}
.teaching-table th, .teaching-table td {
  text-align: left;
  padding: 0.75rem 0.5rem;
  border-bottom: 1px solid var(--line);
}
.teaching-table th {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-soft);
  font-weight: 500;
}

/* =====================================================================
   CV / datasheet
   ===================================================================== */
.datasheet {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  align-items: start;
}
@media (max-width: 700px) { .datasheet { grid-template-columns: 1fr; } }

/* =====================================================================
   Contact
   ===================================================================== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
@media (max-width: 600px) { .contact-grid { grid-template-columns: 1fr; } }

.contact-item {
  background: var(--paper);
  padding: 1.4rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  transition: background 0.15s ease;
}
.contact-item:not(.contact-item--static):hover { background: var(--accent-soft); }
.contact-item__label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-soft);
}
.contact-item__value { color: var(--ink); font-size: 0.95rem; word-break: break-word; }

/* =====================================================================
   Footer
   ===================================================================== */
.footer {
  position: relative;
  z-index: 1;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 1.5rem 1.5rem 3rem;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--ink-soft);
}
.footer__rev { color: var(--blueprint); }

/* =====================================================================
   Reduced motion
   ===================================================================== */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}