/* perf 20261031p (engine worker): skip rendering of below-the-fold blocks on legacy calculator pages until they
   approach the viewport. Screen only; print renders everything. Cuts the first full-page layout under 4x CPU. */
@media screen{.opr,.site-footer,#calc-root .tool-content,#calc-root .calc{content-visibility:auto;contain-intrinsic-size:auto 900px}}