:root {
  --blue:           #2563eb;
  --blue-light:     #eff6ff;
  --bg:             #f0f4f8;
  --surface:        #ffffff;
  --border:         #e2e8f0;
  --text-primary:   #1e293b;
  --text-secondary: #64748b;
  --text-muted:     #94a3b8;
  --green:          #16a34a;
  --red:            #dc2626;
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-primary);
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 1rem;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ── Nav ── */
.blog-nav {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 1.25rem;
  height: 52px;
  display: flex;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 10;
}

.blog-nav a {
  color: var(--blue);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

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

/* ── Layout ── */
.blog-container {
  max-width: 680px;
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
}

/* ── Typography ── */
h1 {
  font-size: clamp(1.6rem, 4vw, 2.1rem);
  font-weight: 700;
  line-height: 1.25;
  margin: 0 0 1rem;
  color: var(--text-primary);
}

h2 {
  font-size: 1.25rem;
  font-weight: 600;
  margin: 2.25rem 0 0.75rem;
  color: var(--text-primary);
}

h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 1.75rem 0 0.5rem;
  color: var(--text-primary);
}

p { margin: 0 0 1.1rem; }

a { color: var(--blue); }

ul, ol {
  margin: 0 0 1.1rem;
  padding-left: 1.4rem;
}

li { margin-bottom: 0.35rem; }

/* ── Lead paragraph (answer paragraph) ── */
.lead {
  font-size: 1.08rem;
  color: var(--text-primary);
  background: var(--blue-light);
  border-left: 3px solid var(--blue);
  padding: 1rem 1.1rem;
  border-radius: 0 0.5rem 0.5rem 0;
  margin: 0 0 1.75rem;
}

/* ── Norm table ── */
.norm-table-wrap {
  overflow-x: auto;
  margin: 0 0 1.75rem;
  border-radius: 0.75rem;
  border: 1px solid var(--border);
}

table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.92rem;
}

thead {
  background: var(--bg);
}

thead th {
  text-align: left;
  font-weight: 600;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-secondary);
  padding: 0.65rem 1rem;
  border-bottom: 1px solid var(--border);
}

tbody td {
  padding: 0.6rem 1rem;
  border-bottom: 1px solid var(--border);
}

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

tbody tr:nth-child(even) { background: #fafbfc; }

/* ── Warning / when-to-call box ── */
.callout {
  background: #fff7ed;
  border: 1px solid #fed7aa;
  border-radius: 0.75rem;
  padding: 1rem 1.1rem;
  margin: 0 0 1.75rem;
  font-size: 0.95rem;
}

.callout strong { color: #9a3412; }

/* ── App CTA ── */
.cta-box {
  background: var(--blue-light);
  border: 1px solid #bfdbfe;
  border-radius: 0.75rem;
  padding: 1.25rem 1.25rem;
  margin: 2.5rem 0 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.cta-box p {
  margin: 0;
  font-size: 0.97rem;
  color: var(--text-primary);
}

.cta-btn {
  display: inline-block;
  background: var(--blue);
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.92rem;
  padding: 0.65rem 1.25rem;
  border-radius: 0.5rem;
  align-self: flex-start;
  transition: background 0.15s;
}

.cta-btn:hover { background: #1d4ed8; color: #fff; }

/* ── Disclaimer ── */
.disclaimer {
  font-size: 0.82rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  padding-top: 1.25rem;
  margin-top: 2.5rem;
  line-height: 1.6;
}

/* ── Footer ── */
.blog-footer {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-muted);
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  align-items: center;
}

.blog-footer a { color: var(--text-secondary); }

/* ── Meta row (read time, last updated) ── */
.article-meta {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.75rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1rem;
}