/* ============================================================
   EMBARC Lab — design system
   Minimal academic style: typography-first, white ground,
   a single Columbia-blue accent, generous whitespace.
   ============================================================ */

:root {
  /* color */
  --ink: #16181d;
  --ink-soft: #4b5563;
  --ink-faint: #8a93a0;
  --accent: #0b5cc4;        /* readable Columbia blue for links */
  --accent-deep: #08418a;
  --columbia: #b9d9eb;      /* official Columbia Blue, used as a tint */
  --wash: #f2f7fb;          /* pale blue wash for panels */
  --line: #e5e9ee;
  --bg: #ffffff;
  --gold: #8a6d1f;          /* award text */
  --gold-bg: #faf3dc;

  /* type */
  --serif: "Newsreader", "Source Serif 4", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --mono: "SF Mono", SFMono-Regular, ui-monospace, Menlo, Consolas, monospace;

  /* layout */
  --max: 1020px;
  --pad: 24px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-deep); text-decoration: underline; text-underline-offset: 3px; }

::selection { background: var(--columbia); color: var(--ink); }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 var(--pad); }

/* ---------------- navigation ---------------- */

.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: var(--max); margin: 0 auto; padding: 0 var(--pad);
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand {
  font-family: var(--serif);
  font-size: 22px; font-weight: 600; letter-spacing: 0.01em;
  color: var(--ink); text-decoration: none;
  display: flex; align-items: baseline; gap: 9px;
}
.brand:hover { text-decoration: none; color: var(--ink); }
.brand .brand-mark { color: var(--accent); }
.brand .brand-sub {
  font-family: var(--sans); font-size: 11.5px; font-weight: 500;
  color: var(--ink-faint); letter-spacing: 0.08em; text-transform: uppercase;
}
.nav-links { display: flex; gap: 26px; align-items: center; list-style: none; }
.nav-links a {
  font-size: 14.5px; font-weight: 500; color: var(--ink-soft);
  letter-spacing: 0.01em; padding: 4px 0;
  border-bottom: 2px solid transparent;
}
.nav-links a:hover { color: var(--ink); text-decoration: none; }
.nav-links a.active { color: var(--ink); border-bottom-color: var(--accent); }
.nav-toggle {
  display: none; background: none; border: 0; cursor: pointer;
  padding: 8px; color: var(--ink);
}
.nav-toggle svg { display: block; }

/* ---------------- page scaffolding ---------------- */

main { min-height: 60vh; }

.section { padding: 56px 0 8px; }
.section-head {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 16px; margin-bottom: 26px;
}
.eyebrow {
  font-size: 12px; font-weight: 600; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--accent);
  margin-bottom: 6px;
}
h1.page-title, .section-head h2 {
  font-family: var(--serif); font-weight: 600; letter-spacing: -0.01em;
  color: var(--ink);
}
.section-head h2 { font-size: 30px; line-height: 1.2; }
.section-head .more { font-size: 14px; white-space: nowrap; }

.page-head { padding: 64px 0 8px; }
h1.page-title { font-size: 42px; line-height: 1.15; margin-bottom: 14px; }
.page-lede { font-size: 17.5px; color: var(--ink-soft); }

/* ---------------- home hero ---------------- */

.hero { padding: 64px 0 30px; }
.hero-banner {
  width: 100%; aspect-ratio: 21 / 9; object-fit: cover; object-position: center 38%;
  border-radius: 12px; border: 1px solid var(--line);
  box-shadow: 0 12px 34px rgba(11, 92, 196, 0.10);
  margin-top: 42px;
}
@media (max-width: 820px) {
  .hero-banner { aspect-ratio: 16 / 10; margin-top: 28px; }
}
.hero h1 {
  font-family: var(--serif); font-weight: 500;
  font-size: clamp(34px, 5.4vw, 54px);
  line-height: 1.14; letter-spacing: -0.015em;
  margin-bottom: 22px;
}
.hero h1 em { font-style: italic; color: var(--accent); }
.hero p.lede {
  font-size: 18.5px; color: var(--ink-soft); line-height: 1.7;
}
.hero .hero-meta {
  margin-top: 10px; font-size: 14px; color: var(--ink-faint); letter-spacing: 0.02em;
}
.hero-actions { margin-top: 30px; display: flex; gap: 14px; flex-wrap: wrap; }

.btn {
  display: inline-block; padding: 11px 22px; border-radius: 6px;
  font-size: 15px; font-weight: 550; letter-spacing: 0.01em;
  border: 1px solid transparent; transition: all 0.15s ease;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-deep); color: #fff; }
.btn-ghost { border-color: var(--line); color: var(--ink); background: #fff; }
.btn-ghost:hover { border-color: var(--ink-faint); color: var(--ink); }

.recruit-banner {
  margin-top: 44px;
  background: var(--wash);
  border: 1px solid #d8e8f4;
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  padding: 15px 20px;
  font-size: 15px; color: var(--ink);
  display: flex; gap: 10px; align-items: baseline; flex-wrap: wrap;
}
.recruit-banner strong { font-weight: 650; }
.recruit-banner .recruit-link { flex-basis: 100%; font-weight: 550; }

/* ---------------- research pillars ---------------- */

.pillars { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.pillar {
  border: 1px solid var(--line); border-radius: 10px;
  padding: 26px 26px 22px; background: #fff;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
  display: block; color: var(--ink);
}
.pillar:hover {
  text-decoration: none; color: var(--ink);
  border-color: #c4d6e6; box-shadow: 0 2px 14px rgba(11, 92, 196, 0.06);
}
.pillar .pillar-num {
  font-family: var(--mono); font-size: 12px; color: var(--accent);
  letter-spacing: 0.1em; margin-bottom: 12px;
}
.pillar h3 {
  font-family: var(--serif); font-size: 21px; font-weight: 600;
  line-height: 1.3; margin-bottom: 10px;
}
.pillar p { font-size: 14.5px; color: var(--ink-soft); line-height: 1.62; }

/* ---------------- research page ---------------- */

.research-block {
  padding: 40px 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 80px;
}
.research-figure-top { margin: 14px 0 34px; }
.research-pillars { margin-bottom: 48px; }
.research-block h2 {
  font-family: var(--serif); font-size: 27px; font-weight: 600;
  line-height: 1.25; margin-bottom: 6px;
}
.research-sub {
  font-size: 13px; font-weight: 600; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 12px;
}
.research-block .research-long { color: var(--ink-soft); margin-bottom: 16px; }
.keywords { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 20px; }
.keyword {
  font-size: 12.5px; font-weight: 550; color: var(--accent-deep);
  background: var(--wash); border: 1px solid #d8e8f4;
  padding: 3px 11px; border-radius: 999px;
}
.rep-pubs { border-left: 2px solid var(--line); padding-left: 18px; display: grid; gap: 10px; }
.rep-pub { font-size: 14.5px; line-height: 1.55; }
.rep-pub .rep-venue {
  font-family: var(--mono); font-size: 11.5px; color: var(--ink-faint);
  margin-left: 6px; white-space: nowrap;
}
.research-figure { margin: 34px 0 8px; }
.research-figure img { border: 1px solid var(--line); border-radius: 10px; }
.research-figure figcaption {
  font-size: 13px; color: var(--ink-faint); margin-top: 10px; text-align: center;
}

/* ---------------- news ---------------- */

.news-list { display: grid; gap: 0; }
.news-item {
  display: grid; grid-template-columns: 92px 84px 1fr; gap: 16px;
  padding: 13px 0; border-bottom: 1px solid var(--line);
  font-size: 15px; align-items: baseline;
}
.news-item:last-child { border-bottom: 0; }
.news-date {
  font-family: var(--mono); font-size: 12.5px; color: var(--ink-faint);
  white-space: nowrap; letter-spacing: 0.02em;
}
.news-tag {
  font-size: 11px; font-weight: 650; letter-spacing: 0.08em;
  text-transform: uppercase; text-align: center;
  padding: 2px 0; border-radius: 4px;
  color: var(--accent-deep); background: var(--wash);
  align-self: start; margin-top: 2px;
}
.news-tag[data-tag="Award"] { color: var(--gold); background: var(--gold-bg); }
.news-tag[data-tag="Lab"] { color: #fff; background: var(--accent); }
.news-text { color: var(--ink); line-height: 1.6; }
.news-text b { font-weight: 600; }

/* ---------------- publications ---------------- */

.pub-controls {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  padding: 18px 0 6px;
}
.pub-filter {
  font-size: 13.5px; font-weight: 550; color: var(--ink-soft);
  background: #fff; border: 1px solid var(--line); border-radius: 999px;
  padding: 6px 15px; cursor: pointer; transition: all 0.12s ease;
  font-family: var(--sans);
}
.pub-filter:hover { border-color: var(--ink-faint); color: var(--ink); }
.pub-filter.active {
  background: var(--accent); border-color: var(--accent); color: #fff;
}
.pub-search {
  font-family: var(--sans); font-size: 13.5px; color: var(--ink);
  border: 1px solid var(--line); border-radius: 999px;
  padding: 6px 15px; width: 220px; background: #fff;
  transition: border-color 0.12s ease;
}
.pub-search:focus { outline: none; border-color: var(--accent); }
.pub-search::placeholder { color: var(--ink-faint); }
.pub-count { font-size: 13px; color: var(--ink-faint); margin-left: auto; }
.pub-empty { padding: 30px 0; color: var(--ink-faint); font-size: 15px; }

@media (max-width: 820px) {
  .pub-search { width: 100%; }
}

.pub-year {
  font-family: var(--serif); font-size: 24px; font-weight: 600;
  padding: 34px 0 4px; color: var(--ink);
  display: flex; align-items: center; gap: 14px;
}
.pub-year::after { content: ""; flex: 1; height: 1px; background: var(--line); }

.pub-item { padding: 16px 0; border-bottom: 1px solid #f0f2f5; }
.pub-item:last-child { border-bottom: 0; }
.pub-title {
  font-size: 16.5px; font-weight: 600; line-height: 1.45;
  color: var(--ink); margin-bottom: 3px;
}
.pub-title a { color: var(--ink); }
.pub-title a:hover { color: var(--accent-deep); }
.pub-authors { font-size: 14px; color: var(--ink-soft); line-height: 1.55; }
.pub-authors b { color: var(--ink); font-weight: 600; }
.pub-meta {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  margin-top: 7px; font-size: 13px;
}
.venue-badge {
  font-family: var(--mono); font-size: 11.5px; font-weight: 600;
  color: var(--accent-deep); background: var(--wash);
  border: 1px solid #d8e8f4; border-radius: 4px; padding: 1.5px 8px;
  letter-spacing: 0.02em; white-space: nowrap;
}
.award-badge {
  font-size: 12px; font-weight: 600; color: var(--gold);
  background: var(--gold-bg); border-radius: 4px; padding: 1.5px 9px;
}
.award-badge::before { content: "🏆 "; font-size: 11px; }
.pub-note { font-size: 12.5px; color: var(--ink-faint); font-style: italic; }
.pub-links { display: flex; flex-wrap: wrap; gap: 4px 12px; font-size: 13px; }
.pub-links a { font-weight: 550; }

.book-card {
  border: 1px solid var(--line); border-radius: 10px; padding: 22px 24px;
  margin-bottom: 16px;
}
.book-card h3 { font-family: var(--serif); font-size: 19px; font-weight: 600; margin-bottom: 4px; }
.book-card .book-meta { font-size: 13.5px; color: var(--ink-faint); margin-bottom: 8px; }
.book-card p { font-size: 14.5px; color: var(--ink-soft); }
.book-card .pub-links { margin-top: 8px; }

/* ---------------- selected pubs (home) ---------------- */

.sel-pubs { display: grid; gap: 0; }

/* ---------------- people ---------------- */

.pi-card {
  display: grid; grid-template-columns: 240px 1fr; gap: 40px;
  padding: 10px 0 26px; align-items: start;
}
.pi-photo img {
  border-radius: 10px; aspect-ratio: 4 / 5; object-fit: cover;
  border: 1px solid var(--line);
}
.pi-name { font-family: var(--serif); font-size: 28px; font-weight: 600; margin-bottom: 2px; }
.pi-role { font-size: 15px; color: var(--ink-soft); margin-bottom: 14px; }
.pi-bio p { font-size: 15px; color: var(--ink-soft); margin-bottom: 12px; }
.pi-links { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 14px; margin-top: 6px; }
.pi-email { font-family: var(--mono); font-size: 13.5px; color: var(--ink-soft); margin-top: 8px; }
.pi-office { font-family: var(--mono); font-size: 13.5px; color: var(--ink-soft); margin-top: 3px; }

.people-group { padding: 26px 0 6px; }
.people-group h2 {
  font-family: var(--serif); font-size: 23px; font-weight: 600; margin-bottom: 18px;
  display: flex; align-items: center; gap: 14px;
}
.people-group h2::after { content: ""; flex: 1; height: 1px; background: var(--line); }
.people-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(210px, 1fr)); gap: 20px; }
.person {
  border: 1px solid var(--line); border-radius: 10px; padding: 18px;
  text-align: center;
}
.person .avatar {
  width: 96px; height: 96px; border-radius: 50%; object-fit: cover;
  margin: 0 auto 12px; border: 1px solid var(--line);
}
.person .monogram {
  width: 96px; height: 96px; border-radius: 50%;
  margin: 0 auto 12px; background: var(--wash); color: var(--accent);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--serif); font-size: 32px; font-weight: 600;
}
.person h3 { font-size: 16px; font-weight: 600; }
.person .person-role { font-size: 13px; color: var(--ink-faint); margin: 2px 0 6px; }
.person .person-note {
  font-size: 12px; color: var(--accent-deep); background: var(--wash);
  border-radius: 999px; padding: 2px 10px; display: inline-block; margin: -2px 0 6px;
}
.person .person-edu { font-size: 12.5px; color: var(--ink-faint); margin-bottom: 6px; }
.person .person-interests { font-size: 13px; color: var(--ink-soft); }
.person .person-links { margin-top: 8px; font-size: 13px; display: flex; justify-content: center; gap: 10px; flex-wrap: wrap; }

.group-note { font-size: 14px; color: var(--ink-faint); margin: -8px 0 16px; }

.table-scroll { overflow-x: auto; }
.mentee-table {
  width: 100%; border-collapse: collapse; font-size: 13.5px;
}
.mentee-table th {
  text-align: left; font-size: 11px; font-weight: 650; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--ink-faint);
  padding: 8px 10px 8px 0; border-bottom: 1px solid var(--line);
  white-space: nowrap;
}
.mentee-table td {
  padding: 9px 10px 9px 0; border-bottom: 1px solid #f0f2f5;
  vertical-align: top; color: var(--ink-soft); line-height: 1.5;
  white-space: nowrap;
}
.mentee-table th:last-child, .mentee-table td:last-child { padding-right: 0; }
.mentee-table tr:last-child td { border-bottom: 0; }
.mentee-table .mentee-name { font-weight: 600; color: var(--ink); }
.mentee-table .mentee-years {
  font-family: var(--mono); font-size: 11.5px; color: var(--ink-faint);
}
.mentee-table .mentee-highlight { font-size: 12px; }

.join-cta-card {
  background: var(--wash); border: 1px solid #d8e8f4; border-radius: 10px;
  padding: 26px 28px; margin: 26px 0;
}
.join-cta-card h3 { font-family: var(--serif); font-size: 21px; font-weight: 600; margin-bottom: 8px; }
.join-cta-card p { font-size: 15px; color: var(--ink-soft); }
.join-cta-card .btn { margin-top: 14px; }

/* ---------------- join page ---------------- */

.join-section { padding: 30px 0 4px; }
.join-section h2 {
  font-family: var(--serif); font-size: 25px; font-weight: 600; margin-bottom: 12px;
}
.join-section p, .join-section li { font-size: 15.5px; color: var(--ink-soft); }
.join-section p { margin-bottom: 12px; }
.join-section ul { padding-left: 22px; margin-bottom: 12px; }
.join-section li { margin-bottom: 7px; }
.join-section li::marker { color: var(--accent); }

.role-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin: 8px 0 12px; }
.role-card { border: 1px solid var(--line); border-radius: 10px; padding: 22px 24px; }
.role-card h3 { font-family: var(--serif); font-size: 19px; font-weight: 600; margin-bottom: 8px; }
.role-card p { font-size: 14.5px; color: var(--ink-soft); margin-bottom: 8px; }
.role-card .role-how { font-size: 13.5px; color: var(--ink); background: var(--wash); border-radius: 6px; padding: 9px 13px; }
.role-card .role-how b { font-weight: 600; }

.callout {
  border-left: 3px solid var(--accent); background: var(--wash);
  border-radius: 0 8px 8px 0; padding: 14px 18px; margin: 16px 0;
  font-size: 14.5px; color: var(--ink);
}
.callout code, .mono { font-family: var(--mono); font-size: 0.92em; background: #e8f0f8; border-radius: 4px; padding: 1px 6px; }

/* ---------------- footer ---------------- */

.footer {
  margin-top: 80px; border-top: 1px solid var(--line);
  background: #fafbfc;
  padding: 42px 0 34px;
}
.footer-inner {
  max-width: var(--max); margin: 0 auto; padding: 0 var(--pad);
  display: flex; justify-content: space-between; gap: 30px; flex-wrap: wrap;
}
.footer h4 {
  font-family: var(--serif); font-size: 18px; font-weight: 600; margin-bottom: 6px;
}
.footer p { font-size: 13.5px; color: var(--ink-soft); line-height: 1.7; }
.footer .footer-links { display: flex; gap: 18px; flex-wrap: wrap; font-size: 13.5px; margin-top: 8px; }
.footer .footer-note { font-size: 12.5px; color: var(--ink-faint); margin-top: 16px; }

/* ---------------- responsive ---------------- */

@media (max-width: 820px) {
  .pillars { grid-template-columns: 1fr; }
  .role-cards { grid-template-columns: 1fr; }
  .pi-card { grid-template-columns: 1fr; gap: 24px; }
  .pi-photo { max-width: 240px; }

  .nav-toggle { display: block; }
  .nav-links {
    display: none;
    position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; gap: 0; align-items: stretch;
    background: #fff; border-bottom: 1px solid var(--line);
    padding: 8px 0;
    box-shadow: 0 12px 24px rgba(20, 30, 40, 0.07);
  }
  .nav-links.open { display: flex; }
  .nav-links a {
    padding: 13px var(--pad); border-bottom: 0; font-size: 15.5px;
  }
  .nav-links a.active { background: var(--wash); border-bottom: 0; }

  .hero { padding: 56px 0 20px; }
  .news-item { grid-template-columns: 84px 1fr; }
  .news-item .news-tag { display: none; }
  h1.page-title { font-size: 34px; }
}

@media (max-width: 480px) {
  .brand .brand-sub { display: none; }
  .news-item { grid-template-columns: 76px 1fr; gap: 12px; }
}

/* ---------------- print ---------------- */
@media print {
  .nav, .footer, .hero-actions, .pub-controls { display: none; }
}