:root {
  --color-canvas-default: #ffffff;
  --color-canvas-subtle: #f6f8fa;
  --color-border-default: #d0d7de;
  --color-fg-default: #1f2328;
  --color-fg-muted: #656d76;
  --color-fg-subtle: #6e7781;
  --color-accent-fg: #0969da;
  --color-accent-emphasis: #0969da;
  --color-success-fg: #1a7f37;
  --color-attention-fg: #9a6700;
  --color-done-fg: #8250df;
  --color-neutral-emphasis: #6e7781;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-canvas-default: #0d1117;
    --color-canvas-subtle: #161b22;
    --color-border-default: #30363d;
    --color-fg-default: #e6edf3;
    --color-fg-muted: #7d8590;
    --color-fg-subtle: #8b949e;
    --color-accent-fg: #58a6ff;
    --color-accent-emphasis: #1f6feb;
    --color-success-fg: #3fb950;
    --color-attention-fg: #d29922;
    --color-done-fg: #a371f7;
    --color-neutral-emphasis: #8b949e;
  }
}

*, *::before, *::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-fg-default);
  background-color: var(--color-canvas-default);
}

/* Layout */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 24px;
}

@media (min-width: 768px) {
  .container {
    padding: 0 48px;
  }
}

/* Navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-default);
}

@media (prefers-color-scheme: dark) {
  .site-header {
    background-color: rgba(13, 17, 23, 0.85);
  }
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  gap: 16px;
}

.site-nav-logo {
  font-weight: 600;
  font-size: 15px;
  color: var(--color-fg-default);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
}

.site-nav-logo:hover {
  color: var(--color-accent-fg);
}

.site-nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
}

.site-nav-links a {
  font-size: 14px;
  color: var(--color-fg-muted);
  text-decoration: none;
  padding: 6px 10px;
  border-radius: 6px;
  transition: color 0.15s, background-color 0.15s;
}

.site-nav-links a:hover,
.site-nav-links a.active {
  color: var(--color-fg-default);
  background-color: var(--color-canvas-subtle);
}

/* Main content */
main {
  min-height: calc(100vh - 56px - 64px);
  padding-top: 48px;
  padding-bottom: 64px;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--color-border-default);
  padding: 24px 0;
  color: var(--color-fg-muted);
  font-size: 13px;
}

.site-footer .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.site-footer a {
  color: var(--color-fg-muted);
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--color-accent-fg);
  text-decoration: underline;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  margin-top: 0;
  margin-bottom: 0.5em;
  font-weight: 600;
  line-height: 1.25;
  color: var(--color-fg-default);
}

h1 { font-size: 2em; }
h2 { font-size: 1.5em; }
h3 { font-size: 1.25em; }
h4 { font-size: 1em; }

p {
  margin-top: 0;
  margin-bottom: 1em;
}

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

a:hover {
  text-decoration: underline;
}

code {
  font-family: ui-monospace, SFMono-Regular, SF Mono, Menlo, monospace;
  font-size: 0.875em;
  background-color: var(--color-canvas-subtle);
  border: 1px solid var(--color-border-default);
  border-radius: 3px;
  padding: 0.2em 0.4em;
}

pre {
  font-family: ui-monospace, SFMono-Regular, SF Mono, Menlo, monospace;
  font-size: 0.875em;
  background-color: var(--color-canvas-subtle);
  border: 1px solid var(--color-border-default);
  border-radius: 6px;
  padding: 16px;
  overflow-x: auto;
  line-height: 1.5;
}

pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: 1em;
}

blockquote {
  margin: 0 0 1em 0;
  padding: 0 1em;
  border-left: 4px solid var(--color-border-default);
  color: var(--color-fg-muted);
}

hr {
  border: none;
  border-top: 1px solid var(--color-border-default);
  margin: 32px 0;
}

ul, ol {
  margin-top: 0;
  margin-bottom: 1em;
  padding-left: 2em;
}

li {
  margin-bottom: 0.25em;
}

/* Status badges */
.badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 500;
  padding: 2px 10px;
  border-radius: 2em;
  border: 1px solid currentColor;
  background: transparent;
  white-space: nowrap;
  line-height: 1.5;
}

.badge-active {
  color: var(--color-success-fg);
}

.badge-hypothesis {
  color: var(--color-attention-fg);
}

.badge-published {
  color: var(--color-done-fg);
}

.badge-archived {
  color: var(--color-neutral-emphasis);
}

/* Area / taxonomy tags */
.tag {
  display: inline-block;
  font-size: 12px;
  color: var(--color-fg-muted);
  background-color: var(--color-canvas-subtle);
  border: 1px solid var(--color-border-default);
  border-radius: 2em;
  padding: 2px 10px;
  white-space: nowrap;
  text-decoration: none;
  line-height: 1.5;
}

.tag:hover {
  color: var(--color-accent-fg);
  text-decoration: none;
  border-color: var(--color-accent-fg);
}

/* Research card */
.research-card {
  display: block;
  padding: 20px 0;
  border-bottom: 1px solid var(--color-border-default);
  color: inherit;
  text-decoration: none;
  transition: background-color 0.1s;
}

.research-card:first-child {
  border-top: none;
}

.research-card:hover {
  text-decoration: none;
}

.research-card:hover .research-card-title {
  color: var(--color-accent-fg);
}

.research-card-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 6px;
}

.research-card-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-fg-default);
  transition: color 0.15s;
  flex: 1;
}

.research-card-date {
  font-size: 13px;
  color: var(--color-fg-muted);
  white-space: nowrap;
  flex-shrink: 0;
}

.research-card-meta {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
  margin-bottom: 8px;
}

.research-card-description {
  font-size: 14px;
  color: var(--color-fg-muted);
  margin: 0;
  line-height: 1.5;
}

/* Homepage hero */
.hero {
  padding: 64px 0 32px;
  border-bottom: 1px solid var(--color-border-default);
  margin-bottom: 32px;
}

.hero-name {
  font-size: 2.5em;
  font-weight: 700;
  margin-bottom: 4px;
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: 1.1em;
  color: var(--color-fg-muted);
  margin-bottom: 24px;
  font-weight: 400;
}

.hero-thesis {
  font-size: 1.15em;
  color: var(--color-fg-muted);
  max-width: 640px;
  line-height: 1.5;
  font-style: italic;
  margin: 0;
}

/* Section headings on homepage */
.section-heading {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-fg-muted);
  margin-bottom: 0;
  margin-top: 48px;
}

.section-heading:first-of-type {
  margin-top: 0;
}

/* Page header */
.page-header {
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--color-border-default);
}

.page-header h1 {
  font-size: 2em;
  margin-bottom: 8px;
}

.page-header-description {
  color: var(--color-fg-muted);
  font-size: 15px;
  margin: 0;
}

/* Single page article */
.article-header {
  margin-bottom: 32px;
}

.article-title {
  font-size: 2em;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.article-date {
  font-size: 13px;
  color: var(--color-fg-muted);
}

.article-description {
  color: var(--color-fg-muted);
  font-size: 1.05em;
  margin-bottom: 0;
}

.article-content {
  max-width: 720px;
}

.article-content h2 {
  margin-top: 2em;
  font-size: 1.4em;
  padding-bottom: 0.3em;
  border-bottom: 1px solid var(--color-border-default);
}

.article-content h3 {
  margin-top: 1.5em;
  font-size: 1.15em;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--color-fg-muted);
  text-decoration: none;
  margin-bottom: 32px;
}

.back-link:hover {
  color: var(--color-accent-fg);
  text-decoration: none;
}

.back-link::before {
  content: "←";
}

/* Empty state */
.empty-state {
  color: var(--color-fg-muted);
  font-size: 14px;
  padding: 24px 0;
}

/* Tables */
.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5em 0;
  font-size: 0.95em;
  overflow-x: auto;
  display: block;
}

.article-content thead {
  background-color: var(--color-canvas-subtle);
}

.article-content th {
  text-align: left;
  padding: 10px 14px;
  font-weight: 600;
  border-bottom: 2px solid var(--color-border-default);
  white-space: nowrap;
}

.article-content td {
  padding: 9px 14px;
  border-bottom: 1px solid var(--color-border-default);
  vertical-align: top;
}

.article-content tr:last-child td {
  border-bottom: none;
}

.article-content tbody tr:hover {
  background-color: var(--color-canvas-subtle);
}

/* Profile photo (About page) */
.profile-photo {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  border: 2px solid var(--color-border-default);
  float: right;
  margin: 0 0 24px 32px;
}

.hero .profile-photo {
  float: none;
  display: block;
  margin: 16px 0 24px;
}

@media (max-width: 600px) {
  .hero {
    padding: 32px 0 24px;
    margin-bottom: 24px;
  }

  .profile-photo {
    float: none;
    display: block;
    margin: 0 auto 24px;
  }
}