:root {
  --navy: #06182e;
  --navy2: #0c355f;
  --blue: #1267a8;
  --cyan: #6bc3cf;
  --ink: #17202a;
  --muted: #667085;
  --line: #e3e9ef;
  --soft: #f5f8fb;
  --panel: #0a1624;
  --panel2: #0d1d2e;
  --panel-line: rgba(255,255,255,.25);
  --max: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--ink);
  background: #fff;
  line-height: 1.62;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  color: #fff;
  background: rgba(6,24,46,.97);
}

.nav {
  max-width: var(--max);
  min-height: 78px;
  margin: 0 auto;
  padding: 0 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
}

.brand {
  font-size: 20px;
  font-weight: 800;
  line-height: 1.15;
}

.brand small {
  display: block;
  margin-top: 5px;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: .13em;
  text-transform: uppercase;
  opacity: .68;
}

.menu {
  display: flex;
  gap: 24px;
  font-size: 12px;
  font-weight: 800;
}

.menu a {
  padding: 28px 0 24px;
  opacity: .76;
  border-bottom: 3px solid transparent;
}

.menu a:hover,
.menu a.active {
  opacity: 1;
  border-bottom-color: #fff;
}

.container {
  max-width: var(--max);
  margin: 0 auto;
  padding-left: 28px;
  padding-right: 28px;
}

.section {
  padding-top: 72px;
  padding-bottom: 72px;
}

.page-head {
  background: linear-gradient(115deg, #f8fafc, #edf5fa);
  border-bottom: 1px solid var(--line);
}

.page-head .container {
  padding-top: 45px;
  padding-bottom: 45px;
}

.page-head h1 {
  margin: 5px 0 0;
  font-size: 42px;
}

.breadcrumb {
  color: var(--muted);
  font-size: 12px;
}

.kicker {
  color: var(--blue);
  font-size: 11px;
  font-weight: 900;
  letter-spacing: .17em;
  text-transform: uppercase;
}

h1, h2, h3 {
  letter-spacing: -.02em;
}

h2 {
  margin: 8px 0 12px;
  font-size: 34px;
  line-height: 1.2;
}

.lead {
  max-width: 800px;
  color: var(--muted);
  font-size: 17px;
}

/* Home hero */
.home-hero {
  position: relative;
  min-height: 690px;
  overflow: hidden;
  display: flex;
  align-items: center;
  color: #fff;
  background:
    radial-gradient(circle at 18% 42%, rgba(66,183,189,.25), transparent 28%),
    radial-gradient(circle at 69% 34%, rgba(89,94,207,.28), transparent 27%),
    radial-gradient(circle at 56% 76%, rgba(63,146,180,.22), transparent 25%),
    linear-gradient(120deg, #04080d, #081422 58%, #04080d);
}

.hero-particles {
  position: absolute;
  inset: 0;
  opacity: .6;
  background-image:
    radial-gradient(circle at 15% 25%, rgba(87,218,213,.8) 0 1px, transparent 1.5px),
    radial-gradient(circle at 34% 51%, rgba(92,200,224,.65) 0 1px, transparent 1.5px),
    radial-gradient(circle at 57% 29%, rgba(115,117,255,.75) 0 1px, transparent 1.5px),
    radial-gradient(circle at 73% 63%, rgba(78,171,219,.55) 0 1px, transparent 1.5px);
  background-size: 24px 24px, 29px 29px, 31px 31px, 26px 26px;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 840px;
  margin: 0 auto;
  padding: 110px 28px 120px;
  text-align: center;
}

.hero-eyebrow {
  margin-bottom: 28px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .08em;
}

.home-hero h1 {
  margin: 0 0 22px;
  font-size: 60px;
  line-height: 1.05;
}

.hero-intro {
  max-width: 780px;
  margin: 0 auto;
  color: rgba(255,255,255,.84);
  font-size: 18px;
  line-height: 1.75;
}

.hero-intro strong {
  color: #fff;
}

/* Quick links */
.quick-links {
  background: #fff;
}

.quick-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0,1fr));
  gap: 20px;
  margin-top: 28px;
}

.quick-card {
  min-height: 200px;
  padding: 30px 28px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
  box-shadow: 0 8px 24px rgba(15,23,42,.045);
  transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}

.quick-card:hover {
  transform: translateY(-5px);
  border-color: #cbd9e5;
  box-shadow: 0 14px 30px rgba(15,23,42,.08);
}

.quick-number {
  margin-bottom: 30px;
  color: var(--blue);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: .12em;
}

.quick-card h3 {
  margin: 0 0 9px;
  font-size: 24px;
}

.quick-card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.quick-arrow {
  margin-top: 22px;
  color: var(--blue);
  font-size: 13px;
  font-weight: 800;
}

/* News */
.news-section {
  background: var(--soft);
}

.news-list {
  margin-top: 28px;
  border-top: 1px solid var(--line);
}

.news-item {
  padding: 22px 0;
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 24px;
  border-bottom: 1px solid var(--line);
}

.news-date {
  color: var(--blue);
  font-size: 12px;
  font-weight: 800;
}

.news-title {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
}

.news-text {
  margin-top: 4px;
  color: var(--muted);
  font-size: 13px;
}

/* Reveal */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity .7s ease, transform .7s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Research themes */
.research-overview {
  display: grid;
  grid-template-columns: repeat(3, minmax(0,1fr));
  gap: 22px;
  margin-top: 36px;
}

.research-theme {
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: 0 10px 28px rgba(15,23,42,.05);
}

.research-theme-visual {
  height: 190px;
  background: #0f2a46;
}

.research-theme-visual svg {
  width: 100%;
  height: 100%;
  display: block;
}

.research-theme-body {
  padding: 25px 24px 27px;
}

.research-theme-body h3 {
  margin: 4px 0 10px;
  font-size: 22px;
  line-height: 1.28;
}

.research-theme-body p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.theme-points {
  margin-top: 17px;
  padding-left: 18px;
  color: #3f4c59;
  font-size: 13px;
}

.theme-points li + li {
  margin-top: 5px;
}

/* PI */
.pi {
  display: grid;
  grid-template-columns: 285px 1fr;
  gap: 52px;
  align-items: start;
}

.pi-photo {
  width: 285px;
  height: 356px;
  object-fit: cover;
  object-position: center top;
  border: 1px solid var(--line);
  border-radius: 7px;
  box-shadow: 0 12px 30px rgba(17,24,39,.08);
}

.pi h2 {
  margin-top: 4px;
  margin-bottom: 10px;
  font-size: 37px;
}

.pi-contact {
  color: var(--muted);
  font-size: 14px;
}

.profile-links {
  margin: 16px 0 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
}

.profile-link {
  padding: 7px 11px;
  color: var(--blue);
  font-size: 12px;
  font-weight: 800;
  border: 1px solid #d7e1ea;
  border-radius: 6px;
}

.orcid-dot {
  display: inline-flex;
  width: 19px;
  height: 19px;
  margin-right: 6px;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 10px;
  background: #a6ce39;
  border-radius: 50%;
}

.cv-row {
  display: grid;
  grid-template-columns: 132px 1fr;
  gap: 15px;
  padding: 9px 0;
  font-size: 14px;
  border-bottom: 1px solid var(--line);
}

/* Members */
.members-dark {
  color: #fff;
  background: var(--panel);
}

.members-dark.alt {
  background: var(--panel2);
}

.members-dark .kicker {
  color: #81d0db;
}

.members-dark h2 {
  color: #fff;
}

.member-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0,1fr));
  column-gap: 40px;
  row-gap: 0;
  margin-top: 24px;
}

.member-row {
  min-height: 240px;
  padding: 28px 0;
  display: grid;
  grid-template-columns: 132px 1fr;
  gap: 24px;
  align-items: start;
  border-top: 1px dotted var(--panel-line);
}

.member-photo {
  width: 120px;
  height: 120px;
  object-fit: cover;
  object-position: center top;
  background: #1d2834;
  border-radius: 50%;
}

.member-badge {
  display: inline-block;
  margin-bottom: 7px;
  padding: 3px 9px;
  color: #fff;
  font-size: 11px;
  font-weight: 800;
  background: #5d6670;
}

.member-name {
  margin: 0 0 5px;
  color: #fff;
  font-size: 21px;
}

.member-role {
  margin-bottom: 10px;
  color: #c7d5e1;
  font-size: 12.5px;
}

.member-history {
  margin-bottom: 10px;
  color: #b9c8d5;
  font-size: 11.8px;
  line-height: 1.5;
}

.member-history div + div {
  margin-top: 4px;
}

.member-email {
  margin-bottom: 9px;
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  word-break: break-word;
}

.member-interest {
  color: #9fd0dc;
  font-size: 12.5px;
  line-height: 1.45;
}

/* Alumni */
.alumni-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0,1fr));
  gap: 14px;
  margin-top: 24px;
}

.alumni-card {
  padding: 17px 18px;
  border: 1px solid var(--line);
  border-left: 4px solid var(--navy);
  border-radius: 6px;
}

.alumni-card h3 {
  margin: 0 0 5px;
  font-size: 17px;
}

.alumni-card p {
  margin: 2px 0;
  color: var(--muted);
  font-size: 12.5px;
}

/* Publications */
.pub-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 24px 0;
}

.pub-tab {
  padding: 10px 14px;
  font-weight: 800;
  background: #fff;
  border: 1px solid #d4dfe8;
  border-radius: 6px;
  cursor: pointer;
}

.pub-tab.active {
  color: #fff;
  background: var(--navy);
}

.pub-panel {
  display: none;
}

.pub-panel.active {
  display: block;
}

.pub-shell {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 10px;
}

.pub-bar {
  padding: 12px 15px;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  background: #f7f9fb;
  border-bottom: 1px solid var(--line);
}

.pub-frame {
  width: 100%;
  height: 1100px;
  border: 0;
}

/* Footer */
.footer {
  margin-top: 60px;
  color: #b5bfca;
  background: #06182e;
}

.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 36px 28px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 25px;
  font-size: 13px;
}

.footer strong {
  color: #fff;
}

@media (max-width: 950px) {
  .menu {
    display: none;
  }

  .quick-grid,
  .research-overview,
  .member-grid,
  .alumni-grid {
    grid-template-columns: 1fr;
  }

  .pi {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 600px) {
  .home-hero h1 {
    font-size: 42px;
  }

  .hero-intro {
    font-size: 16px;
  }

  .news-item {
    grid-template-columns: 1fr;
    gap: 5px;
  }

  .member-row {
    grid-template-columns: 96px 1fr;
    gap: 18px;
  }

  .member-photo {
    width: 90px;
    height: 90px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* =========================
   DS Han Lab. Header Logo
   ========================= */

.brand-logo {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  padding: 8px 0;
  line-height: 0;
}

.brand-logo img {
  display: block;
  width: auto;
  height: 82px;
  max-width: 390px;
  object-fit: contain;
}

@media (max-width: 700px) {
  .brand-logo img {
    height: 66px;
    max-width: 315px;
  }
}