/* CSS Variables - Paul Tol Muted Colorscheme & Layout Config */
:root {
  /* Colors - Paul Tol Muted palette */
  --color-primary: #332288; /* purple */
  --color-secondary: #88ccee; /* blue */
  --color-accent1: #44aa99; /* teal */
  --color-accent2: #117733; /* green */
  --color-accent3: #ddcc77; /* yellow */
  --color-accent4: #cc6677; /* red */

  /* Colors - Neutrals */
  --color-bg: #fafaf8;
  --color-bg-alt: #ffffff;
  --color-text: #2d2d2d;
  --color-text-muted: #666666;
  --color-border: #e0e0dc;

  /* Typography - Fonts */
  --font-sans:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, sans-serif;
  --font-serif: "Georgia", "Times New Roman", serif;

  /* Typography - Sizes */
  --font-size-xs: 12px;
  --font-size-sm: 13px;
  --font-size-md: 14px;
  --font-size-base: 15px;
  --font-size-lg: 16px;
  --font-size-xl: 18px;
  --font-size-xxl: 22px;
  --font-size-h1: 28px;

  /* Typography - Line Heights */
  --line-height-tight: 1.4;
  --line-height-base: 1.5;
  --line-height-relaxed: 1.6;
  --line-height-loose: 1.7;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;

  /* Layout Dimensions */
  --layout-max-width: 800px;
  --layout-sidebar-width: 100px; /* Width for publication venues & course semesters */

  /* Components */
  --size-headshot: 160px;
  --size-icon: 24px;

  /* Borders */
  --radius-sm: 3px;
  --radius-md: 4px;
  --radius-lg: 6px;
  --radius-xl: 8px;

  /* Transitions */
  --transition-fast: 0.2s;
  --transition-normal: 0.3s;

  /* Z-Index */
  --z-nav: 100;
  --z-menu: 999;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-lg);
  line-height: var(--line-height-relaxed);
  color: var(--color-text);
  background-color: var(--color-bg);
  transition:
    background-color var(--transition-fast),
    color var(--transition-fast);
}

/* Navigation bar */
.menu-toggle {
  display: none;
  position: fixed;
  top: var(--spacing-sm);
  right: var(--spacing-sm);
  z-index: var(--z-menu);
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
  flex-direction: column;
  gap: 5px;
}

.menu-toggle span {
  width: var(--size-icon);
  height: 2px;
  background-color: var(--color-primary);
  transition: all var(--transition-normal);
}

.menu-toggle:hover span {
  background-color: var(--color-secondary);
}

.top-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background-color: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
  z-index: var(--z-nav);
  padding: 0;
}

.top-nav ul {
  list-style: none;
  display: flex;
  gap: var(--spacing-lg);
  justify-content: flex-end;
  max-width: var(--layout-max-width);
  margin: 0 auto;
  padding: var(--spacing-md) var(--spacing-lg);
}

.top-nav a {
  color: var(--color-primary);
  text-decoration: none;
  font-size: var(--font-size-base);
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast) ease;
}

.top-nav a:hover {
  text-decoration: underline;
}

.top-nav a.active {
  background-color: var(--color-primary);
  color: white;
  text-decoration: none;
}

.top-nav a.active:hover {
  text-decoration: none;
}

@media (max-width: 768px) {
  .menu-toggle {
    display: flex;
  }

  .top-nav {
    position: fixed;
    top: 0;
    right: 0;
    left: 0;
    height: 100vh;
    background-color: var(--color-bg-alt);
    padding: 4rem var(--spacing-lg) var(--spacing-lg);
    border-bottom: none;
    transform: translateX(100%);
    transition: transform var(--transition-normal);
  }

  .top-nav.open {
    transform: translateX(0);
  }

  .top-nav ul {
    flex-direction: column;
    gap: var(--spacing-md);
    padding: 0;
    justify-content: flex-start;
  }

  .top-nav a {
    font-size: var(--font-size-lg);
    display: inline-block;
  }
}

.container {
  max-width: var(--layout-max-width);
  margin: 0 auto;
  padding: var(--spacing-lg);
  padding-top: calc(var(--spacing-lg) + 90px);
}

@media (max-width: 640px) {
  .container {
    padding: var(--spacing-md);
    padding-top: calc(var(--spacing-md) + 70px);
  }
}

.header {
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-xl);
  border-bottom: 1px solid var(--color-border);
}

.header-content {
  display: flex;
  gap: var(--spacing-lg);
  align-items: flex-start;
}

@media (max-width: 640px) {
  .header-content {
    flex-direction: column;
    align-items: center;
  }
}

.headshot {
  width: var(--size-headshot);
  height: var(--size-headshot);
  border-radius: var(--radius-xl);
  object-fit: cover;
  flex-shrink: 0;
  border: 1px solid var(--color-border);
}

.header-text {
  flex: 1;
}

.header-text h1 {
  font-size: var(--font-size-h1);
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  color: var(--color-text);
}

.header-text .title {
  font-size: var(--font-size-xl);
  color: var(--color-primary);
  font-weight: 500;
  margin-bottom: var(--spacing-xs);
}

.header-text .affiliation {
  font-size: var(--font-size-md);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-md);
}

.social-links {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.social-links a {
  width: var(--size-icon);
  height: var(--size-icon);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  text-decoration: none;
  transition:
    color var(--transition-fast),
    transform var(--transition-fast);
}

.social-links a:hover {
  color: var(--color-secondary);
  transform: translateY(-2px);
}

.social-links svg {
  width: 100%;
  height: 100%;
}

.bio {
  font-size: var(--font-size-base);
  line-height: var(--line-height-loose);
  color: var(--color-text-muted);
  text-align: left;
}

.bio a {
  color: var(--color-primary);
  font-weight: 600;
  text-decoration: none;
}

.bio a:hover {
  text-decoration: underline;
}

main {
  margin-bottom: var(--spacing-xl);
}

.section {
  margin-bottom: var(--spacing-xl);
}

.section h2 {
  font-size: var(--font-size-xxl);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
  padding-bottom: var(--spacing-sm);
  border-bottom: 2px solid var(--color-primary);
}

/* Section-specific accent colors for borders */
#publications h2 {
  border-bottom-color: var(--color-primary);
}

#projects h2 {
  border-bottom-color: var(--color-primary);
}

#teaching h2 {
  border-bottom-color: var(--color-primary);
}

/* Projects */
.projects-list {
  display: grid;
  gap: var(--spacing-lg);
}

.project-item {
  display: grid;
  gap: var(--spacing-sm);
}

.project-item h3 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin: 0;
  color: var(--color-text);
  line-height: var(--line-height-base);
}

.project-item h3 a {
  color: var(--color-primary);
  text-decoration: none;
}

.project-item h3 a:hover {
  text-decoration: underline;
}

.project-item p {
  color: var(--color-text-muted);
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  margin: 0;
}

.project-links {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.project-links a {
  font-size: var(--font-size-md);
  color: var(--color-primary);
  text-decoration: none;
  padding: 4px 10px;
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-lg);
  transition: all var(--transition-fast);
}

.project-links a:hover {
  background-color: var(--color-primary);
  color: white;
  text-decoration: none;
}

/* Publications */
.publications-list {
  display: grid;
  gap: var(--spacing-lg);
}

.publication-item {
  display: flex;
  gap: var(--spacing-md);
  align-items: flex-start;
}

.publication-venue {
  flex-shrink: 0;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  width: var(--layout-sidebar-width);
  text-align: right;
  padding-top: 2px;
}

.publication-venue a {
  color: var(--color-text-muted);
  text-decoration: none;
}

.publication-venue a:hover {
  color: var(--color-primary);
}

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

.publication-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  color: var(--color-text);
  line-height: var(--line-height-base);
}

.publication-title a {
  color: var(--color-primary);
  text-decoration: none;
}

.publication-title a:hover {
  text-decoration: underline;
}

.publication-meta {
  display: block;
  font-size: var(--font-size-md);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-sm);
  line-height: var(--line-height-relaxed);
}

.publication-actions {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
  margin-top: var(--spacing-sm);
  align-items: center;
}

.publication-actions a,
.toggle-btn {
  color: var(--color-primary);
  text-decoration: none;
  padding: 4px 10px;
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-lg);
  transition: all var(--transition-fast);
  font-size: var(--font-size-md);
  white-space: nowrap;
  display: inline-block;
  line-height: var(--line-height-relaxed);
  background: none;
  font-family: inherit;
  font-weight: normal;
  user-select: none;
  cursor: pointer;
  margin: 0;
}

.publication-actions a:hover,
.toggle-btn:hover {
  background-color: var(--color-primary);
  color: white;
  text-decoration: none;
}

/* Content hidden by default */
.publication-abstract-content {
  display: none;
  margin-top: var(--spacing-sm);
  padding: var(--spacing-sm) 0;
  color: var(--color-text-muted);
  font-size: var(--font-size-md);
  line-height: var(--line-height-relaxed);
  animation: fadeIn var(--transition-fast) ease-out;
}

.publication-bibtex-content {
  display: none;
  margin-top: var(--spacing-sm);
  animation: fadeIn var(--transition-fast) ease-out;
}

/* Visibility toggles */
.publication-abstract-content.show {
  display: block;
}

.publication-bibtex-content.show {
  display: flex;
  gap: var(--spacing-sm);
  align-items: flex-start;
}

.publication-bibtex-content code {
  display: block;
  background-color: var(--color-border);
  padding: var(--spacing-sm);
  border-radius: var(--radius-md);
  overflow-x: auto;
  font-size: var(--font-size-xs);
  line-height: var(--line-height-tight);
  white-space: pre-wrap;
  word-wrap: break-word;
  flex: 1;
}

.publication-bibtex-content .copy-btn {
  flex-shrink: 0;
  background: none;
  border: 1px solid var(--color-primary);
  color: var(--color-primary);
  padding: 6px 8px;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.publication-bibtex-content .copy-btn:hover {
  background-color: var(--color-primary);
  color: white;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@media (max-width: 640px) {
  .publication-item {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .publication-venue {
    width: auto;
    text-align: left;
  }
}

/* Teaching section */
.teaching-list {
  display: grid;
  gap: var(--spacing-sm);
}

.teaching-item {
  display: flex;
  gap: var(--spacing-md);
  align-items: baseline;
}

.course-semesters {
  flex-shrink: 0;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  width: 80px;
  text-align: left;
}

.course-header {
  flex: 1;
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
}

.course-header a {
  color: var(--color-primary);
  text-decoration: none;
}

.course-header a:hover {
  text-decoration: underline;
}

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

@media (max-width: 640px) {
  .teaching-item {
    flex-direction: column;
    gap: 0;
  }

  .course-semesters {
    width: auto;
    margin-bottom: 2px;
  }
}

/* Footer */
footer {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
  font-size: var(--font-size-md);
  color: var(--color-text-muted);
}

/* Utilities */
a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

strong {
  font-weight: 600;
}

em {
  font-style: italic;
}

code {
  font-family: "Monaco", "Courier New", monospace;
  font-size: var(--font-size-md);
  background-color: var(--color-border);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
}