/* ============================================================
   Research Unit Tests — Academic stylesheet
   Inspired by NBER / IZA aesthetic:
   serif headings, white background, functional typography
   ============================================================ */

:root {
  --text:        #1a1a1a;
  --text-sec:    #555555;
  --accent:      #1a3a6b;   /* dark academic blue */
  --border:      #d8d8d4;
  --bg-light:    #f7f7f5;
  --blocker:     #9b2317;
  --warning:     #a85e0a;
  --info:        #2a6e2a;
  --font-serif:  Georgia, "Times New Roman", serif;
  --font-sans:   -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --font-mono:   "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --max-width:   780px;
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
img { max-width: 100%; display: block; }

/* ── Base ── */
body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: #fff;
}

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

code, pre {
  font-family: var(--font-mono);
  font-size: 0.875em;
}

pre {
  background: var(--bg-light);
  border: 1px solid var(--border);
  padding: 1rem;
  overflow-x: auto;
  border-radius: 3px;
  margin: 1.2rem 0;
}

/* ── Layout ── */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ── Header ── */
header {
  border-bottom: 2px solid var(--text);
  padding: 0.85rem 0;
  margin-bottom: 2.5rem;
}

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

.site-title {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: normal;
  color: var(--text);
  letter-spacing: 0.01em;
}
.site-title:hover { text-decoration: none; color: var(--accent); }

header nav {
  display: flex;
  gap: 1.5rem;
  font-size: 0.9rem;
}

header nav a { color: var(--text-sec); }
header nav a:hover { color: var(--accent); text-decoration: none; }

/* ── Hero ── */
.hero {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: normal;
  margin-bottom: 0.75rem;
  line-height: 1.25;
}

.hero .lead {
  font-size: 1.08rem;
  color: var(--text);
  margin-bottom: 0.75rem;
}

.hero p {
  color: var(--text-sec);
  font-size: 0.95rem;
  margin-bottom: 0.5rem;
  max-width: 640px;
}

.hero-meta {
  margin-top: 1.25rem;
  font-size: 0.9rem;
  color: var(--text-sec);
}

.hero-meta a { color: var(--accent); }

/* ── Methodology sections ── */
.method-section {
  margin-bottom: 2.75rem;
}

.method-section h2 {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: normal;
  margin-bottom: 0.6rem;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--border);
  color: var(--text);
}

.count {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  color: var(--text-sec);
  font-weight: normal;
}

/* ── Tables ── */
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

thead th {
  text-align: left;
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-sec);
  padding: 0.4rem 0.6rem 0.4rem 0;
  border-bottom: 1px solid var(--border);
}

tbody tr {
  border-bottom: 1px solid #eeeeeb;
}

tbody tr:last-child { border-bottom: none; }

tbody td {
  padding: 0.45rem 0.6rem 0.45rem 0;
  vertical-align: middle;
}

tbody td:first-child { width: 55%; }
tbody td:last-child  { color: var(--text-sec); font-size: 0.85rem; }

/* ── Badges ── */
.badge {
  display: inline-block;
  font-size: 0.72rem;
  font-family: var(--font-mono);
  padding: 0.1em 0.45em;
  border-radius: 2px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 600;
}

.badge-blocker { background: #fde8e7; color: var(--blocker); }
.badge-warning  { background: #fdf0e0; color: var(--warning); }
.badge-info     { background: #e7f4e7; color: var(--info); }

.clarity {
  font-size: 0.82rem;
  color: var(--text-sec);
  font-style: italic;
}

.scope-tag {
  font-size: 0.8rem;
  color: var(--text-sec);
}

/* ── Breadcrumb ── */
.breadcrumb {
  font-size: 0.85rem;
  color: var(--text-sec);
  margin-bottom: 1.5rem;
}
.breadcrumb a { color: var(--text-sec); }
.breadcrumb a:hover { color: var(--accent); }

/* ── Individual test page ── */
.test h1 {
  font-family: var(--font-serif);
  font-size: 1.65rem;
  font-weight: normal;
  line-height: 1.3;
  margin-bottom: 1rem;
}

.test-meta {
  background: var(--bg-light);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 0.9rem 1rem;
  margin-bottom: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.meta-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.meta-tag {
  font-size: 0.82rem;
  background: #e8edf5;
  color: var(--accent);
  padding: 0.15em 0.5em;
  border-radius: 2px;
}

.meta-secondary {
  font-size: 0.82rem;
  color: var(--text-sec);
  gap: 1rem;
}

.meta-secondary a { font-size: 0.82rem; }

/* ── Test body ── */
.test-body h2 {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: normal;
  margin: 2rem 0 0.6rem;
  padding-bottom: 0.2rem;
  border-bottom: 1px solid var(--border);
}

.test-body h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin: 1.2rem 0 0.4rem;
  color: var(--text);
}

.test-body p {
  margin-bottom: 0.9rem;
  max-width: 660px;
}

.test-body ol, .test-body ul {
  margin: 0.5rem 0 1rem 1.4rem;
}

.test-body li {
  margin-bottom: 0.35rem;
  max-width: 660px;
}

.test-body blockquote {
  border-left: 3px solid var(--border);
  padding-left: 1rem;
  color: var(--text-sec);
  margin: 1rem 0;
}

.test-body strong { font-weight: 600; }
.test-body em { font-style: italic; }

/* ── Static pages (contributing, etc.) ── */
.page h1 {
  font-family: var(--font-serif);
  font-size: 1.65rem;
  font-weight: normal;
  margin-bottom: 1.5rem;
}

.page-body h2 {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: normal;
  margin: 2rem 0 0.6rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.2rem;
}

.page-body h3 { font-size: 1rem; margin: 1.2rem 0 0.4rem; }
.page-body p  { margin-bottom: 0.9rem; max-width: 660px; }
.page-body ul, .page-body ol { margin: 0.5rem 0 1rem 1.4rem; }
.page-body li { margin-bottom: 0.35rem; }

.page-body table {
  margin: 1rem 0;
  font-size: 0.9rem;
}

/* ── Footer ── */
footer {
  margin-top: 4rem;
  padding: 1.5rem 0;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-sec);
}

footer a { color: var(--text-sec); }
footer a:hover { color: var(--accent); }

/* ── Responsive ── */
@media (max-width: 600px) {
  .hero h1 { font-size: 1.5rem; }

  thead th:nth-child(3),
  thead th:nth-child(4),
  tbody td:nth-child(3),
  tbody td:nth-child(4) { display: none; }
}