:root {
  --font-heading: "Libre Baskerville", "Times New Roman", serif;
  --font-body: "Source Sans 3", "Helvetica Neue", Arial, sans-serif;
  --color-background: #f8f7f5;
  --color-surface: #ffffff;
  --color-muted: #eef0f4;
  --color-primary: #1c3d5a;
  --color-accent: #3d8cbf;
  --color-text: #1f1f1f;
  --color-text-muted: #4a4a4a;
  --shadow-soft: 0 12px 24px rgba(17, 26, 37, 0.08);
  --max-width: 1100px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  font-family: var(--font-body);
  color: var(--color-text);
  background-color: var(--color-background);
  line-height: 1.6;
}

img {
  max-width: 100%;
  display: block;
}

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

a:hover,
a:focus {
  text-decoration: underline;
}

.container {
  width: min(calc(100% - 3rem), var(--max-width));
  margin: 0 auto;
}

.container.narrow {
  width: min(calc(100% - 3rem), 820px);
}

.section {
  padding: 4.5rem 0;
  background-color: var(--color-surface);
}

/* Automatic alternating backgrounds for sections (skip hero) */
main .section:not(.hero):nth-child(even) {
  background-color: var(--color-surface);
}

main .section:not(.hero):nth-child(odd) {
  background-color: var(--color-muted);
}

.section h2 {
  font-family: var(--font-heading);
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  margin-bottom: 1.5rem;
}

.section-intro {
  max-width: 650px;
  margin-bottom: 2.5rem;
  color: var(--color-text-muted);
}

/* Keep .muted class for backward compatibility (other pages) */
.muted {
  background-color: var(--color-muted);
}

.page-header {
  text-align: center;
  background: linear-gradient(135deg, rgba(28, 61, 90, 0.05), rgba(61, 140, 191, 0));
}

.page-header h1 {
  margin: 0;
  font-family: var(--font-heading);
  font-size: clamp(2.3rem, 5vw, 3.1rem);
}

.page-subtitle {
  margin: 1rem auto 2rem;
  max-width: 600px;
  color: var(--color-text-muted);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(16px);
  background: rgba(248, 247, 245, 0.9);
  border-bottom: 1px solid rgba(28, 61, 90, 0.08);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
}

.brand {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--color-primary);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.site-nav a {
  font-weight: 600;
  color: var(--color-text);
}

.site-nav a.active {
  color: var(--color-primary);
}

.site-nav a:hover,
.site-nav a:focus {
  color: var(--color-primary);
}

.nav-toggle,
.nav-toggle-label {
  display: none;
}

.hero {
  padding-top: 7rem;
  background: linear-gradient(135deg, rgba(28, 61, 90, 0.07), rgba(61, 140, 191, 0));
  overflow-x: hidden;
}

.hero-content {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 2.5rem;
  align-items: center;
  max-width: clamp(320px, 90vw, 1080px);
  width: 100%;
  padding-inline: 0;
}

.hero-text {
  grid-column: span 7;
  max-width: min(520px, 100%);
}

.hero-text h1 {
  font-family: var(--font-heading);
  font-size: clamp(2.4rem, 5vw, 3.3rem);
  margin: 0 0 1rem;
}

.eyebrow {
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-primary);
  font-weight: 600;
  font-size: 0.8rem;
  margin-bottom: 1rem;
}

.hero-text p {
  max-width: 600px;
  margin-inline: auto;
  color: var(--color-text-muted);
}

.hero-links {
  display: flex;
  gap: 1rem;
  margin: 2rem 0 1.5rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.6rem;
  border-radius: 999px;
  border: 1px solid transparent;
  background-color: var(--color-primary);
  color: #ffffff;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.button:hover,
.button:focus {
  transform: translateY(-2px);
  box-shadow: var(--shadow-soft);
}

.button.secondary {
  background-color: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.social-links {
  display: flex;
  gap: 1.5rem;
  padding: 0;
  margin: 0;
  list-style: none;
  font-weight: 600;
}

.hero-image {
  grid-column: span 5;
  margin: 0;
  border-radius: 18px;
  overflow: hidden;
  box-shadow: var(--shadow-soft);
  justify-self: end;
  width: clamp(260px, 40vw, 420px);
}

.hero-image img {
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: 16px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.75rem;
}

.research-list,
.pub-list,
.education-list,
.blog-list {
  list-style: none;
  padding: 0;
  margin: 2rem 0 0;
  display: grid;
  gap: 1.75rem;
}

@media (min-width: 720px) {
  .research-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.research-list li {
  padding: 1.6rem;
  border-radius: 18px;
  background-color: var(--color-surface);
  box-shadow: var(--shadow-soft);
  border: 1px solid rgba(28, 61, 90, 0.08);
}

.education-list {
  gap: 1.5rem;
}

.education-list li {
  display: grid;
  gap: 0.5rem;
  padding: 1.5rem;
  border-radius: 16px;
  background-color: var(--color-surface);
  box-shadow: var(--shadow-soft);
  border: 1px solid rgba(28, 61, 90, 0.08);
}

.edu-period {
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary);
}

.edu-details h3 {
  margin: 0;
  font-family: var(--font-heading);
  font-size: 1.2rem;
}

.edu-details p {
  margin: 0.35rem 0 0;
  color: var(--color-text-muted);
}

.research-term {
  display: block;
  font-weight: 700;
  font-family: var(--font-heading);
  margin-bottom: 0.35rem;
  color: var(--color-primary);
}

.pub-list {
  counter-reset: pub-counter;
}

.pub-list > li {
  position: relative;
  padding-left: 2.75rem;
}

.pub-list > li::before {
  counter-increment: pub-counter;
  content: counter(pub-counter) ".";
  position: absolute;
  left: 0;
  top: 0.3rem;
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--color-primary);
}

.pub-title {
  margin: 0 0 0.5rem;
  font-size: 1.35rem;
  font-family: var(--font-heading);
}

.pub-authors,
.pub-venue {
  margin: 0.1rem 0;
  color: var(--color-text-muted);
}

.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
  margin-top: 0.75rem;
}

.pub-links a {
  font-weight: 600;
}

.cv-list {
  list-style: disc;
  padding-left: 1.5rem;
  display: grid;
  gap: 0.5rem;
  color: var(--color-text-muted);
}

.cv-list li {
  line-height: 1.55;
}

.blog-list li {
  padding: 1.5rem;
  border-radius: 16px;
  background-color: var(--color-surface);
  box-shadow: var(--shadow-soft);
  border: 1px solid rgba(28, 61, 90, 0.08);
  display: grid;
  gap: 0.75rem;
}

.blog-header {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: baseline;
  justify-content: space-between;
}

.blog-date {
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.85rem;
  color: var(--color-primary);
}

.blog-title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: 1.3rem;
}

.blog-summary {
  margin: 0;
  color: var(--color-text-muted);
}

.card {
  background-color: var(--color-surface);
  border-radius: 16px;
  padding: 1.75rem;
  box-shadow: var(--shadow-soft);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  border: 1px solid rgba(28, 61, 90, 0.08);
}

.card h3 {
  margin: 0;
  font-family: var(--font-heading);
  font-size: 1.3rem;
}

.meta {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.25rem;
}

.link-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.link-row a {
  font-weight: 600;
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
}

.gallery-grid figure {
  margin: 0;
  border-radius: 16px;
  overflow: hidden;
  background-color: var(--color-surface);
  box-shadow: var(--shadow-soft);
  border: 1px solid rgba(28, 61, 90, 0.08);
}

.gallery-grid img {
  width: 100%;
  height: 240px;
  object-fit: cover;
}

.gallery-grid figcaption {
  padding: 0.9rem 1.1rem;
  font-size: 0.95rem;
  color: var(--color-text-muted);
}

.placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, rgba(60, 136, 188, 0.15), rgba(28, 61, 90, 0.15));
}

.placeholder-box {
  text-transform: uppercase;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--color-primary);
}

.read-more {
  align-self: flex-start;
  font-weight: 600;
}

.site-footer {
  background-color: var(--color-primary);
  color: #f1f5f9;
  padding: 3rem 0 2rem;
}

.footer-content {
  display: grid;
  gap: 2rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}

.footer-links a {
  color: #f1f5f9;
}

.footer-note {
  text-align: center;
  margin-top: 2rem;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.7);
}

/* Slightly smaller gaps on very small phones */
@media (max-width: 600px) {
  .hero-content { gap: 1.5rem; }
}

@media (max-width: 900px) {
  .hero-content {
    grid-template-columns: repeat(12, 1fr);
    justify-items: center;
  }

  .hero-text {
    grid-column: span 12;
    text-align: center;
  }

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

  .hero-image {
    grid-column: span 12;
    width: clamp(240px, 70vw, 380px);
    justify-self: center;
  }
}

@media (max-width: 720px) {
  .nav-toggle {
    position: absolute;
    opacity: 0;
    pointer-events: none;
  }

  .nav-toggle-label {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    border-radius: 8px;
    border: 1px solid rgba(28, 61, 90, 0.15);
    cursor: pointer;
    margin-left: auto;
  }

  /* Hamburger bars */
  .nav-toggle-label span,
  .nav-toggle-label span::before,
  .nav-toggle-label span::after {
    content: "";
    display: block;
    width: 22px;
    height: 2px;
    background: var(--color-text);
    position: relative;
    transition: transform 0.2s ease, opacity 0.2s ease;
  }

  .nav-toggle-label span::before {
    transform: translateY(-6px);
  }

  .nav-toggle-label span::after {
    transform: translateY(6px);
  }

  /* Closed state: hide links */
  .site-nav {
    display: none;
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    padding: 0.75rem 1rem 1rem;
    background: rgba(248, 247, 245, 0.96);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(28, 61, 90, 0.08);
    flex-direction: column;
    gap: 0.8rem;
  }

  /* When checked: show links */
  .nav-toggle:checked + .nav-toggle-label + .site-nav {
    display: flex;
  }

  /* Animate hamburger into an "X" when open */
  .nav-toggle:checked + .nav-toggle-label span {
    transform: rotate(45deg);
  }

  .nav-toggle:checked + .nav-toggle-label span::before {
    transform: rotate(90deg);
  }

  .nav-toggle:checked + .nav-toggle-label span::after {
    opacity: 0;
  }

  .hero-links {
    flex-direction: column;
  }

  .hero-text h1 {
    font-size: clamp(2rem, 8vw, 2.6rem);
  }

  .hero-text p {
    font-size: clamp(1rem, 3.8vw, 1.2rem);
  }

  .hero-image {
    width: clamp(220px, 75vw, 320px);
  }

  .gallery-grid img {
    height: 200px;
  }
}

@media (max-width: 540px) {
  .container {
    width: min(calc(100% - 2rem), var(--max-width));
  }

  .container.narrow {
    width: min(calc(100% - 2rem), 860px);
  }

  .hero {
    padding-top: 6rem;
  }

  .section {
    padding: 3.5rem 0;
  }

  .hero-links,
  .social-links {
    gap: 0.75rem;
  }

  .card {
    padding: 1.5rem;
  }
}