:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --accent: #0969da;
  --meta: #57606a;
  --border: #d0d7de;
  --code-bg: #f6f8fa;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  max-width: 820px;
  margin: 0 auto;
  padding: 2.5rem 1.25rem;
}

header {
  border-bottom: 2px solid var(--border);
  padding-bottom: 1.5rem;
  margin-bottom: 2.5rem;
}

nav a {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
}

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

h1 {
  font-size: 2.1rem;
  line-height: 1.25;
  margin: 1.2rem 0 0.5rem 0;
  color: #111;
}

.byline {
  font-size: 1rem;
  color: var(--meta);
  margin-bottom: 1rem;
}

.badge-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.badge {
  display: inline-block;
  font-size: 0.8rem;
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  background: var(--code-bg);
  border: 1px solid var(--border);
  color: #24292f;
  text-decoration: none;
}

.badge.doi {
  border-color: #0969da;
  color: #0969da;
  font-weight: 600;
}

.abstract-card {
  background: var(--code-bg);
  border-left: 4px solid var(--accent);
  padding: 1.25rem 1.5rem;
  margin: 2rem 0;
  border-radius: 0 4px 4px 0;
}

.abstract-card h3 {
  margin-top: 0;
  margin-bottom: 0.5rem;
  font-size: 1.05rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--meta);
}

h2 {
  font-size: 1.5rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.4rem;
  margin-top: 2.5rem;
  color: #111;
}

h3 {
  font-size: 1.2rem;
  margin-top: 1.75rem;
  color: #24292f;
}

p { margin: 1.1rem 0; }

ol.bibliography {
  padding-left: 1.5rem;
  font-size: 0.95rem;
  color: #333;
}

ol.bibliography li {
  margin-bottom: 0.75rem;
}

footer {
  border-top: 1px solid var(--border);
  margin-top: 4rem;
  padding-top: 1.5rem;
  font-size: 0.9rem;
  color: var(--meta);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}