:root {
  --text-color: #2c2c2c;
  --muted-color: #666666;
  --link-color: #1a0dab;
  --border-color: #e3e3e3;
  --content-width: 1020px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Roboto", "Helvetica Neue", Arial, sans-serif;
  color: var(--text-color);
  background: #ffffff;
  line-height: 1.7;
}

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

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

.container {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 20px;
}

.site-header {
  border-bottom: 1px solid var(--border-color);
  background: #ffffff;
}

.header-inner {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 20px 0 18px;
}

.site-title {
  font-family: "Roboto Slab", "Times New Roman", serif;
  font-size: 30px;
  font-weight: 600;
  color: var(--text-color);
  letter-spacing: 0.2px;
}

.site-nav {
  margin-left: auto;
  flex: 1 1 auto;
}

.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  padding: 6px;
  cursor: pointer;
}

.nav-toggle svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

.nav-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 12px 18px;
  margin: 0;
  padding: 0;
  align-items: center;
  justify-content: flex-end;
}

.nav-item {
  position: relative;
}

.nav-item-row {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link {
  color: var(--text-color);
  font-size: 14px;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.nav-link img {
  width: 16px;
  height: 16px;
}

.submenu-toggle {
  display: none;
  background: transparent;
  border: 0;
  padding: 4px;
  cursor: pointer;
}

.submenu-toggle svg {
  width: 16px;
  height: 16px;
}

.nav-item.has-children:hover .nav-submenu,
.nav-item.has-children:focus-within .nav-submenu {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.nav-submenu {
  list-style: none;
  position: absolute;
  top: 28px;
  left: 0;
  background: #ffffff;
  border: 1px solid var(--border-color);
  padding: 8px 0;
  margin: 0;
  min-width: 180px;
  opacity: 0;
  transform: translateY(8px);
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
  z-index: 10;
}

.nav-subitem {
  padding: 4px 16px;
}

.nav-sublink {
  color: var(--text-color);
  font-size: 14px;
}

.site-main {
  padding: 32px 0 60px;
}

.content {
  font-size: 17px;
}

.content::after {
  content: "";
  display: block;
  clear: both;
}

.content p {
  margin: 0 0 18px;
}

.content h1,
.content h2,
.content h3 {
  font-family: "Roboto Slab", "Times New Roman", serif;
  color: var(--text-color);
}

.page-title {
  font-size: 28px;
  font-weight: 600;
  margin: 0 0 20px;
}

.content blockquote {
  margin: 24px 0;
  padding: 10px 20px;
  border-left: 3px solid var(--border-color);
  color: var(--muted-color);
}

.home .content img {
  float: right;
  width: 280px;
  max-width: 50%;
  margin: 6px 0 16px 24px;
}

.home .about-photo img {
  width: 100%;
  max-width: none;
  float: none;
  margin: 0;
} 

.content ul {
  padding-left: 20px;
  margin: 0 0 18px;
}

.about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 24px;
  align-items: start;
}

.about-photo img {
  width: 100%;
  height: auto;
}

.research-aside {
  width: 100%;
}

.research-aside .video-embed {
  margin-top: 0;
}

.research-aside .twitter-tweet {
  margin: 16px 0 0;
}

.research-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 320px);
  gap: 24px;
  align-items: start;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  margin: 20px 0 16px;
}

.video-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.video-caption {
  margin: 0;
}

.video-embed {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
  margin: 0;
}

.video-embed iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.cv-embed {
  margin: 16px 0 0;
  border: 1px solid var(--border-color);
}

.cv-embed iframe {
  width: 100%;
  height: 900px;
  border: 0;
}

.site-footer {
  border-top: 1px solid var(--border-color);
  padding: 20px 0 30px;
  font-size: 13px;
  color: var(--muted-color);
}

.footer-text {
  margin: 0;
}

@media (max-width: 640px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .site-title {
    font-size: 26px;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    width: 100%;
  }

  .site-nav {
    width: 100%;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

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

  .nav-submenu {
    position: static;
    opacity: 1;
    transform: none;
    border: none;
    padding: 4px 0 0 10px;
    pointer-events: auto;
    display: none;
  }

  .nav-item.submenu-open .nav-submenu {
    display: block;
  }

  .submenu-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .about-layout {
    grid-template-columns: 1fr;
  }

  .research-aside {
    width: 100%;
    margin: 16px 0 0;
  }

  .research-layout {
    grid-template-columns: 1fr;
  }

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