.filter-btn{background:0 0;border:1px solid var(--brand-border);color:var(--brand-gray);font-size:.82rem;font-weight:600;padding:6px 16px;border-radius:20px;cursor:pointer;transition:all var(--transition);letter-spacing:.04em;white-space:nowrap}.filter-btn.active,.filter-btn:hover{background:var(--brand-primary);border-color:var(--brand-primary);color:#fff}.spec-card[data-category]{transition:opacity var(--transition),transform var(--transition)}.spec-card.hidden{opacity:0;pointer-events:none;height:0;overflow:hidden;padding:0;margin:0;border:none}