:root {
  --color-primary: #0f172a;
  --color-secondary: #0d9488;
  --color-text: #334155;
  --color-bg: #ffffff;
  --color-light: #f1f5f9;
  --font-serif: "Merriweather", "Times New Roman", Serif;
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --container-width: 920px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--color-text);
  background: #f8fafc;
  line-height: 1.7;
}

a { color: inherit; }
a:hover { color: var(--color-secondary); }

.top-bar {
  background: var(--color-primary);
  color: white;
  font-size: 0.8rem;
  padding: 0.6rem 0;
}

.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

.top-bar .container {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
}

.brand {
  display: inline-block;
  text-decoration: none;
  color: white;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.header {
  background: white;
  border-bottom: 1px solid #e2e8f0;
  padding: 1.25rem 0;
  box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05);
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.journal-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 900;
  color: var(--color-primary);
  text-decoration: none;
  line-height: 1.1;
}
.journal-subtitle {
  display: block;
  font-size: 0.78rem;
  font-family: var(--font-sans);
  font-weight: 500;
  color: var(--color-secondary);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-top: 0.25rem;
}

.nav {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav a {
  text-decoration: none;
  color: var(--color-primary);
  font-weight: 700;
  font-size: 0.9rem;
}

.hero {
  background: white;
  border-bottom: 1px solid #e2e8f0;
  padding: 2.25rem 0;
}

.badge {
  display: inline-block;
  background: #ecfeff;
  color: #155e75;
  border: 1px solid #a5f3fc;
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

h1 {
  font-family: var(--font-serif);
  font-size: 2.1rem;
  color: var(--color-primary);
  margin: 0.75rem 0 0.75rem 0;
  line-height: 1.2;
}

.meta {
  color: #64748b;
  font-size: 0.95rem;
}

.meta strong { color: var(--color-secondary); }

.card {
  background: white;
  border: 1px solid #e2e8f0;
  border-radius: 8px;
  padding: 1.25rem;
  margin: 1.25rem 0;
}

.card h2 {
  font-family: var(--font-serif);
  margin: 0 0 0.5rem 0;
  color: var(--color-primary);
  font-size: 1.25rem;
}

.doi {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  background: var(--color-light);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.85rem;
  display: inline-block;
}

.actions {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 0.85rem;
}

.btn {
  display: inline-block;
  text-decoration: none;
  border-radius: 6px;
  padding: 0.6rem 0.85rem;
  font-weight: 800;
  font-size: 0.95rem;
}

.btn-primary {
  background: var(--color-secondary);
  color: white;
}
.btn-primary:hover { background: #0f766e; color: white; }

.btn-outline {
  border: 2px solid var(--color-secondary);
  color: var(--color-secondary);
  background: transparent;
}
.btn-outline:hover { background: #f0fdfa; }

.footer {
  background: var(--color-primary);
  color: #94a3b8;
  padding: 2.5rem 0;
  margin-top: 2rem;
  font-size: 0.9rem;
}

.footer a { color: #cbd5e1; text-decoration: none; }
.footer a:hover { color: white; }

.small {
  font-size: 0.9rem;
  color: #64748b;
}

@media (max-width: 740px) {
  h1 { font-size: 1.7rem; }
  .header .container { flex-direction: column; align-items: flex-start; }
  .nav { justify-content: flex-start; }
}