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

:root {
  --bg:        #fff;
  --bg-nav:    #fff;
  --text:      #222;
  --text-mid:  #333;
  --text-muted:#555;
  --text-faint:#666;
  --text-dim:  #888;
  --text-pale: #aaa;
  --border:    #ddd;
  --border-lt: #eee;
  --tag-bg:    #f5f5f5;
  --btn-bg:    #222;
  --btn-text:  #fff;
}

[data-theme="dark"] {
  --bg:        #111;
  --bg-nav:    #111;
  --text:      #e8e8e8;
  --text-mid:  #d0d0d0;
  --text-muted:#aaa;
  --text-faint:#999;
  --text-dim:  #777;
  --text-pale: #555;
  --border:    #333;
  --border-lt: #2a2a2a;
  --tag-bg:    #1e1e1e;
  --btn-bg:    #e8e8e8;
  --btn-text:  #111;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:        #111;
    --bg-nav:    #111;
    --text:      #e8e8e8;
    --text-mid:  #d0d0d0;
    --text-muted:#aaa;
    --text-faint:#999;
    --text-dim:  #777;
    --text-pale: #555;
    --border:    #333;
    --border-lt: #2a2a2a;
    --tag-bg:    #1e1e1e;
    --btn-bg:    #e8e8e8;
    --btn-text:  #111;
  }
}

body {
  font-family: 'Georgia', serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  transition: background 0.2s, color 0.2s;
}

/* DARK MODE TOGGLE */
.dark-toggle {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-family: 'Arial', sans-serif;
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0.4rem 0.8rem;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
  margin: auto 1.5rem 1.5rem;
  display: block;
  width: calc(100% - 3rem);
}
.dark-toggle:hover {
  color: var(--text);
  border-color: var(--text-muted);
}

/* NAV */
nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 200px;
  height: 100vh;
  background: var(--bg-nav);
  border-right: 1px solid var(--border);
  z-index: 100;
  display: flex;
  flex-direction: column;
}

nav .nav-inner {
  display: flex;
  flex-direction: column;
  padding: 2rem 0;
  height: 100%;
}

nav .site-name {
  font-size: 2rem;
  font-weight: normal;
  color: var(--text);
  text-decoration: none;
  letter-spacing: 0.01em;
  padding: 0 1.5rem 2rem;
  line-height: 1.4;
  cursor: pointer;
  transition: color 0.15s;
}
nav .site-name:hover {
  color: var(--text-muted);
}

nav ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0;
}

nav ul li a {
  display: block;
  text-decoration: none;
  color: var(--text-muted);
  font-family: 'Arial', sans-serif;
  font-size: 0.95rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.9rem 1.5rem;
  transition: background 0.15s, color 0.15s, padding-left 0.15s;
  border-left: 3px solid transparent;
}

nav ul li a:hover {
  color: var(--text);
  background: var(--tag-bg);
  padding-left: 2rem;
  border-left-color: var(--text-muted);
}

nav ul li a.active {
  color: var(--text);
  background: var(--tag-bg);
  border-left-color: var(--text);
  padding-left: 2rem;
}

/* HEADSHOT */
.intro-header {
  display: flex;
  align-items: flex-start;
  gap: 2.5rem;
  margin-bottom: 2rem;
}

.headshot {
  width: 280px;
  height: 340px;
  object-fit: cover;
  object-position: center top;
  flex-shrink: 0;
  filter: grayscale(15%);
}

.intro-text {
  padding-top: 0.3rem;
}

@media (max-width: 650px) {
  nav {
    position: relative;
    width: 100%;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  nav .nav-inner {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    padding: 1rem;
    gap: 0.5rem;
  }
  nav .site-name {
    padding: 0;
    flex: 1;
  }
  nav ul {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 0;
    width: 100%;
  }
  nav ul li a {
    padding: 0.5rem 0.8rem;
    font-size: 0.8rem;
    border-left: none;
    border-bottom: 2px solid transparent;
  }
  nav ul li a:hover,
  nav ul li a.active {
    padding-left: 0.8rem;
    border-left-color: transparent;
    border-bottom-color: var(--text);
  }
  .dark-toggle {
    margin: 0;
    width: auto;
  }
  body {
    padding-left: 0;
  }
}

@media (max-width: 550px) {
  .intro-header {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  .headshot {
    width: 150px;
    height: 180px;
  }

  /* Stack image grids to single column */
  .chart-section div[style*="grid-template-columns"] {
    grid-template-columns: 1fr !important;
  }

  /* Full width callout boxes */
  #national-callout,
  #chart-callout {
    width: 100% !important;
    box-sizing: border-box;
    font-size: 0.75rem;
  }

  /* Chart controls stack vertically */
  .chart-controls {
    flex-direction: column;
    align-items: flex-start;
  }

  .chart-controls select {
    width: 100%;
  }

  /* Chart height shorter on mobile */
  .chart-wrapper {
    height: 260px !important;
  }

  /* Smaller heading */
  h1 { font-size: 1.6rem; }
  h2 { font-size: 1rem; }

  main {
    padding: 2rem 1rem;
  }

  /* Nav name smaller on mobile */
  nav .site-name {
    font-size: 1.2rem !important;
  }
}

/* MAIN CONTENT */
@media (min-width: 651px) {
  body {
    padding-left: 200px;
  }
}

main {
  max-width: 800px;
  margin: 0 auto;
  padding: 4rem 2rem;
}

h1 {
  font-size: 2.2rem;
  font-weight: normal;
  margin-bottom: 0.3rem;
  letter-spacing: -0.01em;
}

.bio-name {
  font-size: 2.2rem;
  cursor: default;
  transition: color 0.15s;
  display: inline-block;
}

.bio-name:hover {
  color: var(--text-muted);
}

h2 {
  font-size: 1.2rem;
  font-weight: normal;
  font-family: 'Arial', sans-serif;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-faint);
  margin: 2.5rem 0 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border-lt);
}

h3 {
  font-size: 1rem;
  font-weight: bold;
  margin-bottom: 0.2rem;
}

p {
  margin-bottom: 1rem;
  color: var(--text-mid);
}

/* HOME PAGE */
.intro {
  margin-bottom: 3rem;
}

.intro .title {
  font-family: 'Arial', sans-serif;
  color: var(--text-dim);
  font-size: 0.95rem;
  margin-bottom: 2rem;
}

/* RESEARCH PAGE */
.paper {
  margin-bottom: 1.8rem;
}

.paper .paper-title {
  font-style: italic;
  color: var(--text);
  margin-bottom: 0.2rem;
}

.paper .paper-author {
  font-family: 'Arial', sans-serif;
  font-size: 0.88rem;
  color: var(--text-faint);
}

.paper .paper-status {
  display: inline-block;
  font-family: 'Arial', sans-serif;
  font-size: 0.78rem;
  color: var(--text-dim);
  background: var(--tag-bg);
  padding: 0.15rem 0.5rem;
  border-radius: 2px;
  margin-top: 0.3rem;
}

/* EXPANDABLE PAPERS */
details.paper {
  border-bottom: 1px solid var(--border-lt);
  padding-bottom: 1.2rem;
  margin-bottom: 1.2rem;
}

details.paper summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

details.paper summary::-webkit-details-marker {
  display: none;
}

details.paper summary .paper-title {
  font-style: italic;
  color: var(--text);
}

details.paper summary:hover .paper-title {
  color: var(--text-muted);
}

.paper-abstract {
  margin-top: 0.8rem;
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.7;
}

.paper-links {
  margin-top: 0.8rem;
  display: flex;
  gap: 1.2rem;
}

.paper-links a {
  font-family: 'Arial', sans-serif;
  font-size: 0.85rem;
  color: var(--text-muted);
  text-decoration: underline;
}

.paper-links a:hover {
  color: var(--text);
}

.conf-year {
  font-weight: bold;
  margin-right: 0.5rem;
}

.conf-item {
  margin-bottom: 0.6rem;
  font-family: 'Arial', sans-serif;
  font-size: 0.92rem;
  color: var(--text-muted);
}

/* CV PAGE */
.cv-download {
  display: inline-block;
  margin-bottom: 2.5rem;
  padding: 0.6rem 1.4rem;
  border: 1px solid var(--text);
  text-decoration: none;
  color: var(--text);
  font-family: 'Arial', sans-serif;
  font-size: 0.88rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  transition: background 0.15s, color 0.15s;
}

.cv-download:hover {
  background: var(--btn-bg);
  color: var(--btn-text);
}

.cv-entry {
  margin-bottom: 1.2rem;
}

.cv-entry .degree {
  font-weight: bold;
}

.cv-entry .institution {
  color: var(--text-muted);
  font-family: 'Arial', sans-serif;
  font-size: 0.9rem;
}

.cv-entry .year {
  color: var(--text-dim);
  font-family: 'Arial', sans-serif;
  font-size: 0.88rem;
}

.teaching-item {
  margin-bottom: 1.4rem;
}

.teaching-item .course {
  font-weight: bold;
  font-family: 'Arial', sans-serif;
  font-size: 0.92rem;
}

.teaching-item .details {
  color: var(--text-faint);
  font-family: 'Arial', sans-serif;
  font-size: 0.88rem;
}

/* CONTACT PAGE */
.contact-info {
  font-family: 'Arial', sans-serif;
  font-size: 0.95rem;
  color: var(--text-mid);
}

.contact-info a {
  color: var(--text);
}

.contact-info p {
  margin-bottom: 0.5rem;
}

/* FOOTER */
footer {
  border-top: 1px solid var(--border-lt);
  padding: 2rem;
  text-align: center;
  font-family: 'Arial', sans-serif;
  font-size: 0.8rem;
  color: var(--text-pale);
  margin-top: 4rem;
}