/* ─── Global Colors ─────────────────────────────────────────── */

:root {
  --columbia-blue: #3f6098;   /* Accent color */
  --columbia-blue-png: #2b4e8c;
}

/* ─── Reset & Base ──────────────────────────────────────────── */

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: #1a1a1a;
  background: #ffffff;
  -webkit-font-smoothing: antialiased;
}

a {
  font-weight: 600;
  color: var(--columbia-blue);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* ─── Layout ────────────────────────────────────────────────── */

.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 2rem;
}

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

#navbar {
  background: #ffffff;
  border-bottom: 1px solid #e5e7eb;
}

.nav-inner {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo-link {
  display: flex;
  align-items: center;
  flex-shrink: 0;
  text-decoration: none;
}

.nav-logo {
  height: 32px;
  width: auto;
  display: block;
  opacity: 0.9;
}

.nav-brand {
  font-weight: 700;
  font-size: 1rem;
  color: #1a1a1a;
  text-decoration: none;
  flex-shrink: 0;
}

.nav-brand:hover {
  text-decoration: none;
  color: var(--columbia-blue);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 1.75rem;
  align-items: center;
  margin-right: 2px;
}

.nav-links a {
  color: #333;
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: color 0.15s;
}

.nav-links a:hover {
  color: var(--columbia-blue);
  text-decoration: none;
}

/* Hamburger button — hidden on desktop */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 22px;
  height: 16px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}

.nav-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: #1a1a1a;
  border-radius: 2px;
  transition: transform 0.2s, opacity 0.2s;
}

/* ─── Hero ──────────────────────────────────────────────────── */

#home {
  padding: 3.5rem 0 3rem;
  border-bottom: 1px solid #e5e7eb;
}

.highlight {
  font-weight: 600;
  color: var(--columbia-blue);
}

.hero {
  display: flex;
  gap: 6rem;
  align-items: flex-start;
}

.hero-text {
  flex: 1;
  min-width: 0;
}

h1 {
  font-family: 'Google Sans', 'Inter', sans-serif;
  font-size: 2rem;
  font-weight: 500;
  letter-spacing: -0.02em;
  margin-bottom: 0.2rem;
  /* color: var(--columbia-blue); */
  color: #111;
}

.hero-role {
  font-size: 1rem;
  color: #555;
  margin-bottom: 0.15rem;
}

.hero-affil {
  font-size: 0.9rem;
  color: #666;
  margin-bottom: 0.15rem;
}

.hero-advisor {
  font-size: 0.9rem;
  color: #666;
  margin-bottom: 1.4rem;
}

.hero-tagline {
  font-size: 1rem;
  font-style: italic;
  color: #333;
  border-left: 2px solid var(--columbia-blue);
  padding-left: 1rem;
  margin-bottom: 1.5rem;
  line-height: 1.6;
}

#joke-text {
  white-space: pre-line;
}

#joke-refresh {
  display: inline;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1rem;
  color: #9ca3af;
  padding: 0 0 0 0.3rem;
  font-style: normal;
  vertical-align: middle;
  transition: color 0.15s, transform 0.3s;
}

#joke-refresh:hover {
  color: var(--columbia-blue);
  transform: rotate(180deg);
}

/* Social links */
.social-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  align-items: center;
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: #333;
  font-size: 0.85rem;
  font-weight: 500;
  text-decoration: none;
  transition: color 0.15s;
}

.social-link:hover {
  color: var(--columbia-blue);
  text-decoration: none;
}

.social-link svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
  flex-shrink: 0;
}

/* Profile photo */
.hero-photo {
  flex-shrink: 0;
  width: 210px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.hero-photo > img:first-child {
  width: 210px;
  height: 210px;
  border-radius: 12px;
  object-fit: cover;
  object-position: top;
  display: block;
}

.photo-email {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: #333;
  font-size: 0.8rem;
  font-weight: 500;
  text-decoration: none;
  transition: color 0.15s;
  overflow-wrap: break-word;
}

.photo-email:hover {
  color: var(--columbia-blue);
  text-decoration: none;
}

.photo-email svg {
  width: 14px;
  height: 14px;
  fill: currentColor;
  flex-shrink: 0;
}

/* ─── Sections — shared ─────────────────────────────────────── */

section {
  padding: 2.75rem 0;
  border-bottom: 1px solid #e5e7eb;
}

section:last-of-type {
  border-bottom: none;
}

.section-title {
  font-family: 'Google Sans', 'Inter', sans-serif;
  font-size: 1.3rem;
  font-weight: 500;
  /* color: var(--columbia-blue); */
  color: #111;
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid #e5e7eb;
}

.section-note {
  font-size: 0.85rem;
  color: #666;
  margin-bottom: 1.25rem;
}

/* ─── Research ──────────────────────────────────────────────── */

.prose {
  font-size: 0.9375rem;
  color: #333;
  margin-bottom: 1rem;
  line-height: 1.75;
}

.prose:last-of-type {
  margin-bottom: 0;
}

.research-areas {
  margin-top: 1.5rem;
  padding: 1.25rem 1.5rem;
  background: #f9fafb;
  border-radius: 6px;
  border: 1px solid #e5e7eb;
}

.research-areas h3 {
  font-size: 0.9rem;
  font-weight: 600;
  color: #111;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.research-areas ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0;
}

.research-areas li {
  font-size: 0.85rem;
  color: #374151;
  background: #ffffff;
  border: 1px solid #d1d5db;
  border-radius: 999px;
  padding: 0.25rem 0.85rem;
}

/* ─── Research Vectors ──────────────────────────────────────── */

.research-vectors {
  margin-top: 1.75rem;
}

.vectors-heading {
  font-size: 0.9rem;
  font-weight: 600;
  color: #111;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.9rem;
}

.vectors-bars {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.vector-row {
  display: grid;
  grid-template-columns: 160px 1fr 3rem 5.5rem;
  align-items: center;
  gap: 0.75rem;
}

.vector-label {
  font-size: 0.85rem;
  color: #374151;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.vector-track {
  background: #f3f4f6;
  border-radius: 999px;
  height: 8px;
  overflow: hidden;
}

.vector-fill {
  height: 100%;
  background: var(--columbia-blue);
  border-radius: 999px;
  transition: width 0.7s cubic-bezier(0.4, 0, 0.2, 1);
  opacity: 0.85;
}

.vector-pct {
  font-size: 0.8rem;
  color: #555;
  font-weight: 600;
  text-align: right;
}

.vector-count {
  font-size: 0.78rem;
  color: #9ca3af;
  white-space: nowrap;
}

.vectors-loading {
  font-size: 0.85rem;
  color: #9ca3af;
}

.vectors-meta {
  margin-top: 0.65rem;
  font-size: 0.78rem;
  color: #9ca3af;
}

/* ─── Publications ──────────────────────────────────────────── */

.pub-list {
  list-style: none;
  position: relative;
  padding-left: 2rem;      /* 32px — space for the timeline + dot */
}

/* Vertical timeline line — straight with gradient-curved ends */
.pub-list::before {
  content: '';
  position: absolute;
  left: 5px;               /* center of the 10px dot (5px + 5px half-dot - 1px half-line) */
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(
    to bottom,
    transparent 0%,
    #d1d5db 7%,
    #d1d5db 93%,
    transparent 100%
  );
}

/* Year labels */
.pub-year-label {
  position: relative;
  padding: 0.5rem 0;
  line-height: 1;
  font-size: 0.72rem;
  font-weight: 700;
  color: #9ca3af;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* Small filled circle on the line for year labels */
.pub-year-label::before {
  content: '';
  position: absolute;
  left: calc(-2rem + 2px);   /* center 8px circle on 2px line at left: 5px */
  top: 50%;
  transform: translateY(-50%);
  width: 8px;
  height: 8px;
  background: #d1d5db;
  border-radius: 50%;
}

/* Publication entries */
.pub-item {
  position: relative;
  padding: 0.6rem 0 1.1rem;
  border-bottom: none;
}

.pub-item:last-child {
  padding-bottom: 0.25rem;
}

/* Hollow circle dot on the timeline for each paper */
.pub-item::before {
  content: '';
  position: absolute;
  left: calc(-2rem + 1px);   /* center 10px circle on 2px line at left: 5px */
  top: 1rem;
  width: 10px;
  height: 10px;
  background: #ffffff;
  border: 2px solid var(--columbia-blue);
  border-radius: 50%;
}

.pub-placeholder {
  opacity: 0.45;
}

.pub-title {
  font-size: 1rem;
  font-weight: 500;
  color: #111;
  margin-bottom: 0.2rem;
  line-height: 1.5;
}

.pub-authors {
  font-style: italic;
  font-size: 0.875rem;
  color: #555;
  margin-bottom: 0.15rem;
}

.pub-venue {
  font-size: 0.875rem;
  color: #777;
  margin-bottom: 0.5rem;
}

.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 0.75rem;
  align-items: center;
}

.pub-link {
  font-size: 0.8rem;
  color: var(--columbia-blue);
  font-weight: 500;
  text-decoration: none;
}

.pub-link:hover {
  text-decoration: underline;
}

.pub-award {
  font-size: 0.8rem;
  color: #92400e;
  font-weight: 500;
}

/* ─── Achievements ───────────────────────────────────────────── */

.achievements-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.achievement-card {
  background: #ffffff;
  border-radius: 8px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.achievement-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.13);
}

.achievement-img-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 8;
  overflow: hidden;
  background: #f3f4f6;
}

.achievement-img-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  display: block;
  transition: transform 0.3s ease;
}

.achievement-card:hover .achievement-img-wrap img {
  transform: scale(1.02);
}

.achievement-body {
  padding: 0.9rem 1rem 1.1rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  flex: 1;
}

.achievement-date {
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  font-size: 0.7rem;
  font-weight: 700;
  color: #ffffff;
  background: rgba(0, 0, 0, 0.52);
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  letter-spacing: 0.05em;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  line-height: 1.4;
}

.achievement-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--columbia-blue);
  line-height: 1.45;
  margin: 0;
}

.achievement-desc {
  font-size: 0.8rem;
  color: #555;
  line-height: 1.55;
  margin: 0;
}

.achievement-footer {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 0.5rem;
}

.achievement-tag {
  flex-shrink: 0;
  font-size: 0.7rem;
  font-weight: 700;
  color: #ffffff;
  background: rgba(0, 0, 0, 0.52);
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  letter-spacing: 0.05em;
  line-height: 1.4;
  text-decoration: none;
  transition: background 0.15s;
}

.achievement-tag:hover {
  background: rgba(0, 0, 0, 0.7);
  text-decoration: none;
}

@media (max-width: 560px) {
  .achievements-grid {
    grid-template-columns: 1fr;
  }
}

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

footer {
  padding: 1rem 0;
  background: #f9fafb;
  border-top: 1px solid #e5e7eb;
  text-align: center;
  color: #888;
  font-size: 0.825rem;
}

/* ─── Responsive ────────────────────────────────────────────── */

@media (max-width: 640px) {
  h1 {
    font-size: 1.6rem;
  }

  .hero {
    flex-direction: column-reverse;
    align-items: center;
    gap: 1.5rem;
  }

  .hero-photo {
    width: 160px;
  }

  .hero-photo > img:first-child {
    width: 160px;
    height: 160px;
    border-radius: 10px;
  }


  .hero-text {
    text-align: center;
  }

  .hero-tagline {
    text-align: left;
  }

  .social-links {
    justify-content: center;
  }

  .nav-links {
    display: none;
    flex-direction: column;
    gap: 0;
    position: absolute;
    top: 58px;
    left: 0;
    right: 0;
    background: #fff;
    border-bottom: 1px solid #e5e7eb;
    padding: 0.5rem 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  }

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

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

  .nav-links a {
    display: block;
    padding: 0.65rem 2rem;
    font-size: 0.9rem;
  }

  .nav-toggle {
    display: flex;
  }

  .photo-email {
    font-size: 0.72rem;
  }

}