/* --- Variables (Stanford Cardinal theme) --- */
:root {
  --stanford-red: #8C1515;
  --stanford-red-dark: #6B0F0F;
  --stanford-red-light: #B83A3A;
  --color-bg: #ffffff;
  --color-bg-warm: #fafaf9;
  --color-text: #2e2e2e;
  --color-text-muted: #5c5c5c;
  --color-accent: #8C1515;
  --color-accent-hover: #6B0F0F;
  --color-border: #e0dcd8;
  --font-display: "DM Serif Display", Georgia, serif;
  --font-body: "Source Sans 3", system-ui, sans-serif;
  --max-width: 800px;
  --spacing: 1.5rem;
  --radius: 12px;
  --shadow: 0 2px 12px rgba(140, 21, 21, 0.08);
  --shadow-hover: 0 8px 28px rgba(140, 21, 21, 0.12);
}

/* --- Reset & base --- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1.125rem;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

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

a:hover {
  color: var(--color-accent-hover);
  text-decoration: underline;
}

/* --- Header & nav --- */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 2px solid var(--color-border);
  transition: box-shadow 0.2s;
}

.header.scrolled {
  box-shadow: var(--shadow);
}

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

.nav-brand {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 400;
  text-decoration: none;
  color: var(--color-text);
}

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

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--color-text-muted);
  font-weight: 600;
  transition: color 0.2s;
  text-decoration: none;
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 6px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: transform 0.2s;
}

/* --- Hero --- */
.hero {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 4rem 1.5rem 5rem;
  text-align: center;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.25rem, 5vw, 3.25rem);
  font-weight: 400;
  line-height: 1.2;
  margin: 0 0 1rem;
}

.highlight {
  color: var(--stanford-red);
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--color-text-muted);
  margin: 0 0 2rem;
  margin-left: auto;
  margin-right: auto;
  white-space: nowrap;
}

@media (max-width: 640px) {
  .hero-subtitle {
    white-space: normal;
  }
}

.btn {
  display: inline-block;
  padding: 0.85rem 1.75rem;
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius);
  transition: background 0.2s, color 0.2s, transform 0.2s;
}

.btn-primary {
  background: var(--stanford-red);
  color: white;
  border: none;
  text-decoration: none;
}

.btn-primary:hover {
  background: var(--stanford-red-dark);
  color: white;
  text-decoration: none;
  transform: translateY(-1px);
}

/* --- Sections --- */
.section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem;
  border-top: 1px solid var(--color-border);
}

.section h2 {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 400;
  margin: 0 0 1rem;
  color: var(--color-text);
}

.section-content,
.section-intro {
  color: var(--color-text-muted);
  margin: 0 0 1rem;
}

.bio .section-content:last-child {
  margin-bottom: 0;
}

.bio-links {
  margin-top: 1.25rem;
}

.section-intro:last-of-type {
  margin-bottom: 1.5rem;
}

.section-intro a {
  font-weight: 600;
}

.about-layout {
  display: flex;
  align-items: flex-start;
  gap: 2rem;
  margin-top: 1rem;
}

.about-photo-wrap {
  flex-shrink: 0;
}

.about-photo {
  width: 180px;
  height: 180px;
  object-fit: cover;
  border-radius: 50%;
  display: block;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.about-layout .bio {
  flex: 1;
  min-width: 0;
}

@media (max-width: 560px) {
  .about-layout {
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
  }

  .about-photo {
    width: 160px;
    height: 160px;
  }
}

/* --- Work grid --- */
.work-grid {
  display: grid;
  gap: 1.5rem;
  margin-top: 1.5rem;
}

@media (min-width: 640px) {
  .work-grid.work-grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

.work-grid.work-grid-cards {
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .work-grid.work-grid-cards {
    grid-template-columns: repeat(2, 1fr);
  }
}

.work-card {
  padding: 0;
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow 0.25s, border-color 0.25s, transform 0.25s;
}

.work-card:hover {
  box-shadow: var(--shadow-hover);
  border-color: var(--stanford-red);
  transform: translateY(-2px);
}

.work-card-link {
  color: inherit;
  text-decoration: none;
  display: block;
}

.work-card-link:hover {
  color: inherit;
  text-decoration: none;
}

.work-card-img-wrap {
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: var(--color-border);
}

.work-card-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.work-card-link:hover .work-card-img {
  transform: scale(1.05);
}

.work-card-body {
  padding: 1.25rem 1.5rem;
}

.work-card h3 {
  font-size: 1.15rem;
  margin: 0 0 0.5rem;
  line-height: 1.35;
}

.work-card p {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* Research card (no image) */
.work-card.research-card {
  padding: 1.5rem;
}

.work-card.research-card .work-card-body {
  padding: 0;
}

.work-card.research-card h3 {
  font-size: 1.2rem;
}

/* --- Contact --- */
.contact-section {
  text-align: center;
}

.contact-links {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.contact-link {
  font-weight: 600;
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  transition: background 0.2s, color 0.2s;
}

.contact-link:hover {
  background: rgba(140, 21, 21, 0.08);
  color: var(--stanford-red);
}

/* --- Footer --- */
.footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.5rem;
  border-top: 2px solid var(--color-border);
  text-align: center;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.footer p {
  margin: 0;
}

.footer-logo-subtle {
  height: 28px;
  width: auto;
  opacity: 0.22;
  display: block;
  margin: 0 auto 0.5rem;
}

/* --- Portfolio --- */
.portfolio-section {
  /* inherit main page background (no tinted panel) */
}

.portfolio-wip {
  margin-top: 1rem;
  padding: 2rem;
  text-align: center;
  border: 2px dashed var(--color-border);
  border-radius: var(--radius);
  background: white;
}

.portfolio-wip-text {
  font-family: var(--font-display);
  font-size: 1.25rem;
  color: var(--color-text-muted);
  margin: 0 0 0.5rem;
}

.portfolio-wip .section-content {
  margin: 0;
}

/* --- Mobile --- */
@media (max-width: 600px) {
  .nav-links {
    display: none;
  }

  .nav-links.is-open {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    padding: 1rem;
    background: var(--color-bg);
    border-bottom: 2px solid var(--color-border);
  }

  .nav-links.is-open li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--color-border);
  }

  .nav-links.is-open li:last-child {
    border-bottom: none;
  }

  .nav-toggle {
    display: flex;
  }

  .work-grid.work-grid-cards {
    grid-template-columns: 1fr;
  }
}

/* --- Reduced motion --- */
@media (prefers-reduced-motion: reduce) {
  .work-card:hover,
  .btn-primary:hover {
    transform: none;
  }

  .work-card-img {
    transition: none;
  }
}