.brief-section + .brief-section { margin-top: 28px; }
.brief-section h2 { margin: 0 0 12px; font-size: 1.22rem; color: var(--text); }
.brief-section h3 { margin: 18px 0 10px; font-size: 1rem; color: var(--signal-3); }
.brief-section p { margin: 0 0 14px; line-height: 1.82; color: var(--muted); }
.brief-bullets { margin: 0; padding-left: 20px; display: grid; gap: 8px; color: var(--muted); }
.brief-bullets li { line-height: 1.76; }
.link-stack { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.link-stack li a { display: block; padding: 12px 14px; border-radius: 14px; border: 1px solid rgba(143,255,122,.1); background: rgba(255,255,255,.02); color: var(--text); }
.link-stack li small { display: block; margin-top: 4px; color: var(--muted); }
.brief-code { margin: 14px 0; padding: 16px; border-radius: 16px; background: rgba(2,6,2,.92); border:1px solid rgba(143,255,122,.12); overflow:auto; color:#e9ffd7; font-family: var(--font-mono); font-size:.88rem; line-height:1.6; white-space:pre-wrap; word-break:break-word; }
.topic-grid { display:grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 18px; }
.topic-card { padding: 22px; position:relative; overflow:hidden; background: linear-gradient(180deg, rgba(12,18,12,.94), rgba(8,12,8,.98)); border:1px solid rgba(143,255,122,.1); box-shadow:0 14px 32px rgba(0,0,0,.2); border-radius: 22px; }
.topic-card::before { content:''; position:absolute; inset:0; background: radial-gradient(circle at top right, rgba(168,255,96,.08), transparent 34%); pointer-events:none; }
.topic-card h3 { position:relative; margin:10px 0 12px; font-size:1.1rem; }
.topic-card p { position:relative; margin:0 0 12px; color: var(--muted); line-height:1.75; }
.topic-card a { color: var(--text); }
.callout-note { padding: 14px 16px; border-radius: 16px; border:1px solid rgba(143,255,122,.12); background: rgba(255,255,255,.03); color: var(--muted); }
@media (max-width: 900px){ .topic-grid { grid-template-columns: 1fr; } }