@import url('https://fonts.googleapis.com/css2?family=DM+Serif+Display:ital@0;1&family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;1,9..40,300;1,9..40,400&display=swap');

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

:root {
  --navy: #1a2b4a;
  --navy-light: #243761;
  --blue: #4a90d9;
  --blue-light: #6aaae8;
  --blue-pale: #e8f2fc;
  --white: #ffffff;
  --off-white: #f7f9fc;
  --gray-100: #f0f4f8;
  --gray-200: #e2e8f0;
  --gray-400: #94a3b8;
  --gray-600: #64748b;
  --gray-800: #334155;
  --text: #1e293b;
  --radius: 10px;
  --radius-sm: 6px;
  --shadow-sm: 0 1px 3px rgba(26,43,74,0.08), 0 1px 2px rgba(26,43,74,0.06);
  --shadow: 0 4px 16px rgba(26,43,74,0.10), 0 1px 4px rgba(26,43,74,0.06);
  --shadow-md: 0 8px 32px rgba(26,43,74,0.13), 0 2px 8px rgba(26,43,74,0.08);
  --transition: 0.2s ease;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'DM Sans', system-ui, sans-serif;
  font-size: 15px;
  line-height: 1.65;
  color: var(--text);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}

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

a:hover {
  color: var(--navy);
}

.page-wrapper {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 24px;
}

/* HEADER */

.header {
  padding: 56px 0 48px;
  border-bottom: 1px solid var(--gray-200);
}

.header-inner {
  display: flex;
  gap: 40px;
  align-items: flex-start;
}

.header-photo img {
  width: 128px;
  height: 128px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--gray-200);
  display: block;
  flex-shrink: 0;
}

.header-content {
  flex: 1;
  min-width: 0;
}

.header-name {
  font-family: 'DM Serif Display', Georgia, serif;
  font-size: 36px;
  font-weight: 400;
  color: var(--navy);
  line-height: 1.15;
  margin-bottom: 4px;
  letter-spacing: -0.3px;
}

.header-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--blue);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 14px;
}

.header-bio {
  font-size: 15px;
  color: var(--gray-800);
  line-height: 1.7;
  max-width: 520px;
  margin-bottom: 20px;
}

.open-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: var(--blue-pale);
  color: var(--blue);
  font-size: 12px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 20px;
  margin-top: 10px;
}

.open-badge::before {
  content: '';
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--blue);
  display: inline-block;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.header-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
}

.header-links a {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 13px;
  font-weight: 500;
  color: var(--gray-600);
  background: var(--gray-100);
  border: 1px solid var(--gray-200);
  padding: 5px 13px;
  border-radius: 20px;
  transition: all var(--transition);
}

.header-links a:hover {
  background: var(--navy);
  color: var(--white);
  border-color: var(--navy);
}

/* PINNED */

.pinned-section {
  padding: 40px 0 36px;
  border-bottom: 1px solid var(--gray-200);
}

.section-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--gray-400);
  margin-bottom: 18px;
}

.pinned-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

.pinned-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}

.pinned-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: var(--blue-light);
}

.pinned-card-img {
  width: 100%;
  height: 76px;
  object-fit: fill;
  display: block;
  background: var(--white);
}

.pinned-card-placeholder {
  width: 100%;
  height: 76px;
  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-light) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  opacity: 0.9;
}

.pinned-card-body {
  padding: 11px 13px 13px;
}

.pinned-card-title {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 3px;
  line-height: 1.35;
}

.pinned-card-desc {
  font-size: 11.5px;
  color: var(--gray-600);
  line-height: 1.5;
  margin-bottom: 9px;
}

.pinned-card-links {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.tag-link {
  font-size: 11px;
  font-weight: 500;
  color: var(--blue);
  background: var(--blue-pale);
  padding: 2px 8px;
  border-radius: 20px;
  transition: all var(--transition);
  display: inline-block;
}

.tag-link:hover {
  background: var(--blue);
  color: var(--white);
}

.tag-link.paper {
  color: #6d28d9;
  background: #ede9fe;
}

.tag-link.paper:hover {
  background: #6d28d9;
  color: var(--white);
}

.tag-link.appstore {
  color: #0369a1;
  background: #e0f2fe;
}

.tag-link.appstore:hover {
  background: #0369a1;
  color: var(--white);
}

/* TABS */

.tabs-section {
  padding: 40px 0 0;
}

.tabs-nav {
  display: flex;
  gap: 8px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.tab-btn {
  font-family: 'DM Sans', sans-serif;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--gray-600);
  background: var(--gray-100);
  border: 1px solid var(--gray-200);
  padding: 8px 22px;
  border-radius: 30px;
  cursor: pointer;
  transition: all var(--transition);
  outline: none;
}

.tab-btn:hover {
  background: var(--blue-pale);
  color: var(--blue);
  border-color: var(--blue-light);
}

.tab-btn.active {
  background: var(--navy);
  color: var(--white);
  border-color: var(--navy);
}

.tab-panel {
  display: none;
  padding-bottom: 8px;
}

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

/* PROJECTS */

.project-row {
  display: flex;
  gap: 22px;
  align-items: flex-start;
  padding: 22px 0;
  border-bottom: 1px solid var(--gray-200);
  transition: all var(--transition);
  border-radius: var(--radius-sm);
}

.project-row:last-child {
  border-bottom: none;
}

.project-row:hover {
  background: var(--off-white);
  padding-left: 12px;
  padding-right: 12px;
  margin-left: -12px;
  margin-right: -12px;
}

.project-thumb {
  flex-shrink: 0;
  width: 118px;
  height: 78px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--gray-200);
  background: var(--gray-100);
}

.project-thumb img {
  width: 100%;
  height: 100%;
  object-fit: fill;
  display: block;
  background: var(--white);
}

.project-thumb-placeholder {
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-light) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  opacity: 0.85;
}

.project-info {
  flex: 1;
  min-width: 0;
}

.project-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 3px;
  line-height: 1.35;
}

.project-meta {
  font-size: 11.5px;
  font-weight: 600;
  color: var(--gray-400);
  margin-bottom: 5px;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.project-desc {
  font-size: 13.5px;
  color: var(--gray-600);
  line-height: 1.6;
  margin-bottom: 10px;
}

.project-links {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

/* RESEARCH */

.research-row {
  display: flex;
  gap: 22px;
  align-items: flex-start;
  padding: 28px 0;
  border-bottom: 1px solid var(--gray-200);
}

.research-row:last-child {
  border-bottom: none;
}

.research-thumb {
  flex-shrink: 0;
  width: 118px;
  height: 78px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--gray-200);
  background: var(--white);
}

.research-thumb-placeholder {
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #2d1b6b 0%, #4a2fa0 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  opacity: 0.85;
}

.research-info {
  flex: 1;
  min-width: 0;
}

.research-title {
  font-family: 'DM Serif Display', Georgia, serif;
  font-size: 16px;
  color: var(--navy);
  line-height: 1.35;
  margin-bottom: 5px;
}

.research-venue {
  font-size: 11.5px;
  font-weight: 600;
  color: var(--blue);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 10px;
}

.research-abstract {
  font-size: 13.5px;
  color: var(--gray-600);
  line-height: 1.65;
  margin-bottom: 12px;
}

.research-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

/* CERTIFICATIONS */

.certs-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.cert-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 22px 24px;
  transition: box-shadow var(--transition), border-color var(--transition);
}

.cert-card:hover {
  box-shadow: var(--shadow);
  border-color: var(--blue-light);
}

.cert-issuer {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 6px;
}

.cert-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--navy);
  line-height: 1.35;
  margin-bottom: 6px;
}

.cert-status {
  font-size: 12.5px;
  color: var(--gray-400);
  font-style: italic;
}

/* RESUME */

.resume-section {
  padding: 52px 0 64px;
  border-top: 1px solid var(--gray-200);
  margin-top: 52px;
  text-align: center;
}

.resume-title {
  font-family: 'DM Serif Display', Georgia, serif;
  font-size: 28px;
  color: var(--navy);
  margin-bottom: 8px;
}

.resume-sub {
  font-size: 14px;
  color: var(--gray-600);
  margin-bottom: 28px;
}

.resume-buttons {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: 'DM Sans', sans-serif;
  font-size: 14px;
  font-weight: 600;
  padding: 11px 26px;
  border-radius: 8px;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--navy);
  color: var(--white);
  border-color: var(--navy);
}

.btn-primary:hover {
  background: var(--navy-light);
  color: var(--white);
  border-color: var(--navy-light);
  box-shadow: var(--shadow);
}

.btn-secondary {
  background: var(--white);
  color: var(--navy);
  border-color: var(--gray-200);
}

.btn-secondary:hover {
  border-color: var(--navy);
  color: var(--navy);
  box-shadow: var(--shadow-sm);
}

/* FOOTER */

.footer {
  border-top: 1px solid var(--gray-200);
  padding: 20px 0;
  text-align: center;
}

.footer p {
  font-size: 12.5px;
  color: var(--gray-400);
}

.footer a {
  color: var(--gray-400);
}

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

/* RESPONSIVE */

@media (max-width: 680px) {
  .header-inner {
    flex-direction: column;
    gap: 20px;
    align-items: center;
    text-align: center;
  }

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

  .header-bio {
    max-width: 100%;
  }

  .pinned-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .project-thumb,
  .research-thumb {
    display: none;
  }
}

@media (max-width: 400px) {
  .pinned-grid {
    grid-template-columns: 1fr;
  }

  .header-name {
    font-size: 28px;
  }
}