/* ===== CSS Variables ===== */
:root {
  --bg-primary: #f9fafb;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #fafafa;
  --accent: #8C1515;
  --accent-dim: #7a1212;
  --accent-glow: rgba(140, 21, 21, 0.09);
  --accent-secondary: #1e40af;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --border: #e2e8f0;
  --border-hover: #cbd5e1;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.07), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.05);
  --shadow-hover: 0 8px 28px rgba(140,21,21,0.12), 0 2px 8px rgba(0,0,0,0.06);
  --stanford-red: #8C1515;
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --max-width: 1100px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 72px;
}

body {
  font-family: var(--font-main);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  font-size: 17px;
  overflow-x: hidden;
}

/* Hide particles on light theme — clean background preferred */
#particles {
  display: none;
}

/* ===== Navigation ===== */
#navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 0.9rem 0;
  transition: var(--transition);
  background: rgba(249, 250, 251, 0.7);
  backdrop-filter: blur(12px);
}

#navbar.scrolled {
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 12px rgba(0,0,0,0.06);
  padding: 0.6rem 0;
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
  flex-shrink: 0;
}

.nav-stanford-logo {
  height: 28px;
  width: auto;
}

.nav-logo {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--stanford-red);
  letter-spacing: 1.5px;
}

.nav-divider {
  width: 1px;
  height: 20px;
  background: var(--border);
}

.nav-msl {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 1.75rem;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 500;
  letter-spacing: 0.3px;
  transition: var(--transition);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: var(--transition);
}

.nav-links a:hover {
  color: var(--accent);
}

.nav-links a:hover::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  transition: var(--transition);
}

/* ===== Hero Section ===== */
#hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  z-index: 1;
  padding-top: 5rem;
  background: linear-gradient(160deg, #fff 0%, #fdf4f4 45%, #f9fafb 100%);
}

.hero-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 4rem;
  max-width: var(--max-width);
  width: 100%;
  margin: 0 auto;
  padding: 2rem 2rem 2rem;
}

.hero-text { flex: 1; }

.hero-greeting {
  font-family: var(--font-mono);
  color: var(--accent);
  font-size: 1rem;
  margin-bottom: 0.55rem;
}

.hero-name {
  font-size: clamp(2.6rem, 5vw, 4.2rem);
  font-weight: 800;
  line-height: 1.08;
  margin-bottom: 0.55rem;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.hero-tagline {
  font-size: 1.45rem;
  color: var(--text-secondary);
  margin-bottom: 0.3rem;
  font-weight: 500;
}

.hero-sub {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
  font-style: italic;
}

/* Stanford badge in hero */
.stanford-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  background: #fff;
  border: 1.5px solid rgba(140, 21, 21, 0.25);
  border-radius: 10px;
  padding: 0.5rem 1rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.stanford-badge:hover {
  border-color: var(--stanford-red);
  box-shadow: var(--shadow-md);
}

.stanford-badge-logo {
  height: 36px;
  width: auto;
  flex-shrink: 0;
}

.stanford-info {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.stanford-university {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--stanford-red);
}

.stanford-dept {
  font-size: 0.75rem;
  color: #a0522d;
  font-family: var(--font-mono);
}

.hero-credentials {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1.75rem;
}

.hero-credential-badge {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 0.28rem 0.75rem;
  border-radius: 20px;
  background: #fff;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

/* Buttons */
.hero-cta {
  display: flex;
  gap: 0.85rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 0.72rem 1.6rem;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 2px 8px rgba(140,21,21,0.25);
}

.btn-primary:hover {
  background: var(--accent-dim);
  box-shadow: 0 4px 16px rgba(140,21,21,0.35);
  transform: translateY(-1px);
}

.btn-outline {
  background: #fff;
  color: var(--text-secondary);
  border: 1.5px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* Hero Image */
.hero-image { flex-shrink: 0; }

.image-frame {
  width: 270px;
  height: 310px;
  border-radius: 16px;
  overflow: hidden;
  border: 3px solid #fff;
  box-shadow: var(--shadow-md);
  transition: var(--transition);
}

.image-frame:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-4px);
}

.image-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
}

/* ===== Hero Spotlight tiles (visible in first viewport) ===== */
.hero-spotlight {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--border);
  background: #fff;
}

.spotlight-card {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding: 1.35rem 1.5rem;
  text-decoration: none;
  color: inherit;
  border-right: 1px solid var(--border);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.spotlight-card:last-child { border-right: none; }

.spotlight-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent);
  transform: scaleX(0);
  transition: var(--transition);
}

.spotlight-card:hover {
  background: #fdf4f4;
}

.spotlight-card:hover::before {
  transform: scaleX(1);
}

.spotlight-icon {
  font-size: 1.75rem;
  flex-shrink: 0;
  line-height: 1;
}

.spotlight-text {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.spotlight-title {
  font-size: 0.97rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.3;
}

.spotlight-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.4;
  font-family: var(--font-mono);
}

/* Scroll indicator */
.scroll-indicator {
  display: none; /* tiles serve as the visual bottom anchor */
}

/* ===== Sections ===== */
.section {
  padding: 4.5rem 2rem;
  position: relative;
  z-index: 1;
}

.section-alt {
  background: var(--bg-primary);
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 2.25rem;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.title-number {
  font-family: var(--font-mono);
  color: var(--accent);
  font-size: 1.1rem;
  margin-right: 0.5rem;
  font-weight: 500;
}

/* Section background alternation */
#research  { background: var(--bg-primary); }
#projects  { background: var(--bg-secondary); }
#experience{ background: var(--bg-primary); }
#education { background: var(--bg-secondary); }
#skills    { background: var(--bg-primary); }
#publications { background: var(--bg-secondary); }
#achievements { background: var(--bg-primary); }
#contact   { background: var(--bg-secondary); }

/* ===== Research ===== */
.research-content {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: 2.5rem;
  align-items: start;
}

.research-intro {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  font-size: 1.05rem;
  line-height: 1.8;
}

.research-intro strong { color: var(--text-primary); }

.research-current {
  background: #fff;
  border: 1.5px solid rgba(140,21,21,0.3);
  border-radius: 12px;
  padding: 1.5rem 1.75rem;
  margin-bottom: 1.25rem;
  box-shadow: 0 4px 20px rgba(140,21,21,0.07);
}

.research-current-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.6rem;
}

.research-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 1.5px;
}

.research-status {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: #16a34a;
  letter-spacing: 0.5px;
}

.research-current h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
  color: var(--text-primary);
}

.research-current .timeline-company {
  display: block;
  margin-bottom: 0.65rem;
  font-size: 0.9rem;
}

.research-current p {
  font-size: 0.975rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.75;
}

.research-tags-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.research-tags-strip span {
  font-size: 0.75rem;
  padding: 0.22rem 0.7rem;
  border-radius: 20px;
  background: rgba(140,21,21,0.07);
  color: var(--accent);
  font-family: var(--font-mono);
  border: 1px solid rgba(140,21,21,0.15);
}

.research-areas { margin-top: 1.25rem; }

.research-areas-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  font-family: var(--font-mono);
  margin-bottom: 0.6rem;
}

.research-broad-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.research-broad-tags span {
  font-size: 0.875rem;
  padding: 0.3rem 0.8rem;
  border-radius: 6px;
  background: #fff;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.research-broad-tags span:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* Stats / highlight cards */
.about-highlights {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem;
}

.highlight-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.35rem;
  text-align: center;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.highlight-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.highlight-number {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent);
  font-family: var(--font-mono);
}

.highlight-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* ===== Projects ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(330px, 1fr));
  gap: 1.25rem;
}

.project-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
}

.project-card:hover {
  border-color: rgba(140,21,21,0.35);
  box-shadow: var(--shadow-hover);
  transform: translateY(-4px);
}

.project-card.featured {
  border-top: 3px solid var(--accent);
}

/* Project visual thumbnail — kept dark for contrast against white cards */
.project-visual {
  height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  flex-shrink: 0;
}

.project-visual::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom, transparent 50%, rgba(0,0,0,0.25) 100%);
}

.project-visual svg {
  width: 52px;
  height: 52px;
  color: rgba(255,255,255,0.82);
  position: relative;
  z-index: 1;
  filter: drop-shadow(0 2px 6px rgba(0,0,0,0.35));
}

.pv-ai     { background: linear-gradient(135deg, #0a0630 0%, #1a0d55 100%); }
.pv-rl     { background: linear-gradient(135deg, #051a08 0%, #0d3016 100%); }
.pv-robot  { background: linear-gradient(135deg, #1a1208 0%, #332200 100%); }
.pv-vision { background: linear-gradient(135deg, #050e20 0%, #0d2045 100%); }
.pv-space  { background: linear-gradient(135deg, #04040e 0%, #080830 100%); }
.pv-flight { background: linear-gradient(135deg, #200d00 0%, #3d1c00 100%); }
.pv-aircraft { background: linear-gradient(135deg, #160e04 0%, #2c1c08 100%); }
.pv-safety { background: linear-gradient(135deg, #081420 0%, #0d2538 100%); }

.pv-space::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(1px 1px at 18% 28%, rgba(255,255,255,0.6) 0%, transparent 100%),
    radial-gradient(1px 1px at 58% 18%, rgba(255,255,255,0.4) 0%, transparent 100%),
    radial-gradient(1px 1px at 78% 68%, rgba(255,255,255,0.5) 0%, transparent 100%),
    radial-gradient(1px 1px at 10% 78%, rgba(255,255,255,0.35) 0%, transparent 100%),
    radial-gradient(1.5px 1.5px at 45% 52%, rgba(255,255,255,0.65) 0%, transparent 100%),
    radial-gradient(1px 1px at 72% 38%, rgba(255,255,255,0.4) 0%, transparent 100%),
    radial-gradient(1px 1px at 32% 68%, rgba(255,255,255,0.35) 0%, transparent 100%),
    radial-gradient(1px 1px at 88% 22%, rgba(255,255,255,0.5) 0%, transparent 100%);
}

.project-body {
  padding: 1.35rem 1.6rem;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.project-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.55rem;
}

.project-type-badge {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.project-date {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.project-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.45rem;
  color: var(--text-primary);
  line-height: 1.35;
}

.project-plain-desc {
  font-size: 0.965rem;
  color: var(--text-secondary);
  margin-bottom: 0.7rem;
  line-height: 1.6;
  font-style: italic;
}

.project-desc {
  font-size: 0.93rem;
  color: var(--text-secondary);
  margin-bottom: 0.85rem;
  flex: 1;
}

ul.project-desc {
  list-style: none;
  padding: 0;
}

ul.project-desc li {
  padding-left: 1.2rem;
  position: relative;
  margin-bottom: 0.35rem;
  line-height: 1.6;
}

ul.project-desc li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-size: 0.8em;
  top: 0.15em;
}

.project-outcome {
  font-size: 0.9rem;
  color: var(--text-secondary);
  background: rgba(140,21,21,0.04);
  border-left: 2.5px solid var(--accent);
  padding: 0.65rem 0.9rem;
  margin-bottom: 0.85rem;
  border-radius: 0 6px 6px 0;
}

.project-outcome strong { color: var(--accent); }

.project-metric {
  color: var(--accent);
  font-weight: 700;
  font-family: var(--font-mono);
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 0.75rem;
}

.project-tags span {
  font-size: 0.75rem;
  padding: 0.2rem 0.65rem;
  border-radius: 20px;
  background: rgba(140,21,21,0.06);
  color: var(--accent);
  font-family: var(--font-mono);
  border: 1px solid rgba(140,21,21,0.15);
}

.project-companies {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem;
  padding-top: 0.65rem;
  border-top: 1px solid var(--border);
  margin-top: auto;
}

.companies-label {
  font-size: 0.7rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  white-space: nowrap;
}

.project-companies span:not(.companies-label) {
  font-size: 0.72rem;
  padding: 0.18rem 0.55rem;
  border-radius: 4px;
  background: rgba(30,64,175,0.06);
  color: var(--accent-secondary);
  border: 1px solid rgba(30,64,175,0.15);
  font-family: var(--font-mono);
}

.project-link { margin-top: 0.6rem; }

.project-link a {
  font-size: 0.82rem;
  font-family: var(--font-mono);
  color: var(--accent);
  text-decoration: none;
  transition: var(--transition);
}

.project-link a:hover { text-decoration: underline; }

/* ===== Experience Timeline ===== */
.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border);
}

.timeline-item {
  position: relative;
  margin-bottom: 1.75rem;
}

.timeline-marker {
  position: absolute;
  left: -2rem;
  top: 8px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #fff;
  border: 2.5px solid var(--accent);
  z-index: 1;
}

.timeline-item:first-child .timeline-marker {
  background: var(--accent);
}

.timeline-content {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.35rem 1.75rem;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.timeline-content:hover {
  border-color: rgba(140,21,21,0.3);
  box-shadow: var(--shadow-md);
}

.timeline-header { margin-bottom: 0.85rem; }

.timeline-header h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.2rem;
}

.timeline-company {
  display: block;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.95rem;
}

.timeline-date,
.timeline-location {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.timeline-date::after { content: ' | '; }

.timeline-content ul { list-style: none; }

.timeline-content li {
  font-size: 0.93rem;
  color: var(--text-secondary);
  margin-bottom: 0.45rem;
  padding-left: 1.2rem;
  position: relative;
  line-height: 1.6;
}

.timeline-content li::before {
  content: '›';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
  font-size: 1.1em;
}

/* ===== Education ===== */
.education-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.edu-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.75rem;
  transition: var(--transition);
  display: flex;
  gap: 1.4rem;
  align-items: flex-start;
  box-shadow: var(--shadow-sm);
}

.edu-card:hover {
  border-color: rgba(140,21,21,0.3);
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.edu-logo {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.75rem;
  color: var(--accent);
  background: rgba(140,21,21,0.07);
  border: 1px solid rgba(140,21,21,0.18);
  padding: 0.6rem 0.7rem;
  border-radius: 8px;
  white-space: nowrap;
  flex-shrink: 0;
}

.edu-info h3 {
  font-size: 1.08rem;
  font-weight: 700;
  margin-bottom: 0.2rem;
}

.edu-degree {
  color: var(--text-secondary);
  font-size: 0.93rem;
}

.edu-gpa {
  font-family: var(--font-mono);
  color: var(--accent);
  font-size: 0.88rem;
  font-weight: 600;
}

.edu-date {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  margin-bottom: 0.3rem;
}

.edu-courses {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 0.45rem;
  line-height: 1.6;
}

.edu-honors {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.4rem;
}

.edu-honors span {
  font-size: 0.68rem;
  padding: 0.2rem 0.55rem;
  border-radius: 20px;
  background: rgba(30,64,175,0.07);
  color: var(--accent-secondary);
  font-family: var(--font-mono);
  border: 1px solid rgba(30,64,175,0.15);
}

/* ===== Skills ===== */
.skills-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.skill-category {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.35rem 1.6rem;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.skill-category:hover {
  border-color: rgba(140,21,21,0.3);
  box-shadow: var(--shadow-md);
}

.skill-category h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 0.9rem;
  color: var(--accent);
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.skill-tags span {
  font-size: 0.85rem;
  padding: 0.3rem 0.78rem;
  border-radius: 6px;
  background: var(--bg-primary);
  color: var(--text-secondary);
  border: 1px solid var(--border);
  transition: var(--transition);
}

.skill-tags span:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ===== Publications ===== */
.publications-list {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  margin-bottom: 0.5rem;
}

.pub-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.35rem 1.6rem;
  transition: var(--transition);
  display: flex;
  gap: 1.35rem;
  align-items: flex-start;
  box-shadow: var(--shadow-sm);
}

.pub-card:hover {
  border-color: rgba(140,21,21,0.3);
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.pub-badge {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 700;
  padding: 0.38rem 0.65rem;
  border-radius: 8px;
  white-space: nowrap;
  flex-shrink: 0;
  align-self: flex-start;
  margin-top: 2px;
  text-align: center;
}

.pub-badge.journal {
  background: rgba(140,21,21,0.08);
  color: var(--accent);
  border: 1px solid rgba(140,21,21,0.2);
}

.pub-badge.patent {
  background: rgba(30,64,175,0.08);
  color: var(--accent-secondary);
  border: 1px solid rgba(30,64,175,0.2);
}

.pub-info h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
  color: var(--text-primary);
}

.pub-venue {
  font-size: 0.88rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.pub-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 0.35rem;
  line-height: 1.65;
}

.pub-date {
  font-size: 0.77rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* ===== Achievements ===== */
.achievements-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(235px, 1fr));
  gap: 1.1rem;
}

.achievement-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.achievement-card:hover {
  border-color: rgba(140,21,21,0.3);
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
}

.achievement-icon {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 0.85rem;
}

.subsection-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-secondary);
  margin-bottom: 1.1rem;
  margin-top: 1.75rem;
  padding-left: 0.6rem;
  border-left: 3px solid var(--accent);
}

.subsection-title:first-of-type { margin-top: 0; }

.achievement-icon.fellowship {
  background: rgba(22,163,74,0.1);
  color: #16a34a;
  border: 2px solid rgba(22,163,74,0.25);
  font-size: 0.72rem;
}

.achievement-icon.trophy {
  background: rgba(140,21,21,0.1);
  color: var(--accent);
  border: 2px solid rgba(140,21,21,0.25);
}

.achievement-icon.medal {
  background: rgba(30,64,175,0.08);
  color: var(--accent-secondary);
  border: 2px solid rgba(30,64,175,0.2);
}

.achievement-card h3 {
  font-size: 0.97rem;
  font-weight: 700;
  margin-bottom: 0.45rem;
  line-height: 1.35;
  color: var(--text-primary);
}

.achievement-card p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 0.65rem;
  line-height: 1.55;
}

.achievement-date {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* ===== Contact ===== */
.contact-content {
  text-align: center;
  max-width: 620px;
  margin: 0 auto;
}

.contact-lead {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
  line-height: 1.7;
}

.contact-lead strong { color: var(--accent); }

.contact-content p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  font-size: 1rem;
}

.contact-links {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 2rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 0.7rem 1.2rem;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  transition: var(--transition);
  font-size: 0.93rem;
  background: #fff;
  box-shadow: var(--shadow-sm);
}

.contact-item:hover {
  color: var(--accent);
  border-color: var(--accent);
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.contact-item svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

/* AI Profile copy button */
.ai-profile-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 2rem;
  padding: 0.6rem 1.2rem;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-muted);
  font-size: 0.8rem;
  font-family: var(--font-mono);
  cursor: pointer;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.ai-profile-btn:hover {
  border-color: var(--accent-secondary);
  color: var(--accent-secondary);
}

.ai-profile-btn.copied {
  border-color: #16a34a;
  color: #16a34a;
}

/* ===== Footer ===== */
footer {
  text-align: center;
  padding: 1.75rem;
  color: var(--text-muted);
  font-size: 0.82rem;
  border-top: 1px solid var(--border);
  background: #fff;
}

footer a {
  color: var(--text-muted);
  text-decoration: none;
  transition: var(--transition);
}

footer a:hover { color: var(--accent); }

/* ===== Animations ===== */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
  .hero-spotlight {
    grid-template-columns: repeat(2, 1fr);
  }

  .spotlight-card:nth-child(2) { border-right: none; }
  .spotlight-card:nth-child(1),
  .spotlight-card:nth-child(2) { border-bottom: 1px solid var(--border); }

  .nav-msl { display: none; }
  .nav-divider { display: none; }
}

@media (max-width: 768px) {
  body { font-size: 16px; }

  .hero-main {
    flex-direction: column-reverse;
    text-align: center;
    gap: 1.75rem;
    padding: 1.5rem 1.25rem;
  }

  .hero-cta { justify-content: center; }
  .stanford-badge { display: inline-flex; }
  .hero-credentials { justify-content: center; }

  .image-frame {
    width: 200px;
    height: 240px;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(255,255,255,0.98);
    flex-direction: column;
    padding: 1.25rem 2rem;
    gap: 0.85rem;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-md);
  }

  .nav-links.active { display: flex; }
  .nav-toggle { display: flex; }

  .research-content { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: 1fr; }
  .education-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: 1fr; }

  .edu-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .edu-honors { justify-content: center; }
  .achievements-grid { grid-template-columns: 1fr 1fr; }
  .contact-links { flex-direction: column; align-items: center; }

  .section { padding: 3rem 1.25rem; }
}

@media (max-width: 520px) {
  .hero-spotlight { grid-template-columns: 1fr; }

  .spotlight-card {
    border-right: none !important;
    border-bottom: 1px solid var(--border);
  }

  .spotlight-card:last-child { border-bottom: none; }
  .achievements-grid { grid-template-columns: 1fr; }
  .about-highlights { grid-template-columns: 1fr 1fr; }
}