/* ===== Content Pages (theory, lab_guide, homework, answer) ===== */
body { line-height: 1.7; }
header { position: sticky; top: 0; z-index: 100; padding: 16px 24px; }
nav { display: flex; gap: 4px; flex-wrap: wrap; }
nav a { color: var(--text-muted); text-decoration: none; font-size: 0.82rem; padding: 4px 12px; border-radius: 6px; border: 1px solid transparent; transition: all 0.15s; }
nav a:hover { color: var(--text-primary); background: var(--bg-hover); }
nav a.active { color: var(--accent-text); border-color: var(--accent); background: var(--accent-bg); }
main { max-width: 860px; margin: 0 auto; padding: 48px 24px 80px; }
h1 { font-size: 2rem; font-weight: 700; color: var(--text-primary); margin-bottom: 8px; }
.subtitle { color: var(--text-muted); font-size: 1rem; margin-bottom: 40px; }
h2 { font-size: 1.35rem; font-weight: 600; color: var(--text-primary); margin: 40px 0 12px; padding-bottom: 8px; border-bottom: 1px solid var(--border-light); }
h3 { font-size: 1.05rem; font-weight: 600; color: var(--text-secondary); margin: 24px 0 8px; }
p { margin-bottom: 16px; color: var(--text-secondary); }
ul, ol { margin: 0 0 16px 24px; color: var(--text-secondary); }
li { margin-bottom: 6px; }
pre { margin: 20px 0; border-radius: 8px; overflow: auto; border: 1px solid var(--border); max-height: 60vh; }
pre code { font-size: 0.85rem; padding: 0; background: none; border: none; color: inherit; }
blockquote { border-left: 3px solid var(--accent); padding: 12px 20px; margin: 20px 0; background: var(--quote-bg); border-radius: 0 8px 8px 0; color: var(--text-muted); font-style: italic; }
.callout { background: var(--callout-bg); border: 1px solid var(--border); border-radius: 8px; padding: 16px 20px; margin: 20px 0; }
.callout.info { border-left: 4px solid var(--accent); }
.callout.tip { border-left: 4px solid #2ea043; }
.callout.warning { border-left: 4px solid #d29922; }
table { margin: 20px 0; font-size: 0.9rem; }
.task { background: var(--bg-surface); border: 1px solid var(--border); border-radius: 8px; padding: 20px; margin: 16px 0; }
.task h3 { margin-top: 0; }
.check { color: #2ea043; font-weight: 600; }

/* ===== Download Resources ===== */
.resources { background: var(--bg-surface); border: 1px solid var(--border); border-radius: 10px; padding: 20px 24px; margin: 28px 0; }
.resources h3 { margin-top: 0; margin-bottom: 10px; font-size: 1rem; color: var(--text-primary); }
.resources > p { font-size: 0.88rem; margin-bottom: 16px; color: var(--text-muted); }
.download-list { list-style: none; margin: 0 !important; padding: 0; display: flex; flex-direction: column; gap: 8px; }
.download-list li { margin: 0; }
.download-btn {
  display: inline-flex; align-items: center; gap: 10px;
  background: var(--bg-hover); border: 1px solid var(--border);
  color: var(--accent-text); text-decoration: none;
  font-family: 'SF Mono','Fira Code',monospace; font-size: 0.82rem;
  padding: 8px 14px; border-radius: 6px;
  transition: background 0.15s, border-color 0.15s, transform 0.1s; cursor: pointer;
  max-width: 100%;
}
.download-btn:hover { background: var(--accent-bg); border-color: var(--accent); text-decoration: none; transform: translateX(2px); }
.download-btn .dl-icon { font-size: 1rem; flex-shrink: 0; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; }
.download-btn .dl-size { color: var(--text-muted); font-size: 0.72rem; flex-shrink: 0; font-variant-numeric: tabular-nums; margin-left: 4px; }