Change Details

**Steps to replicate the issue** (include links if applicable): * Load [[ https://en.wikipedia.org/wiki/Earth | enwiki:Earth ]] with device emulation set to a mobile device * From the Performance tab, apply 4x CPU slowdown and Slow 4G network throttling (for example) * Record and reload, screenshot the graph for comparison * Load [[ https://44bb00ec83.catalyst.wmcloud.org/wiki/Earth | the same page from patchdemo ]] in another tab with the same settings * Record and reload, screenshot the graph for comparison **What happens?**: HTML parsing is delayed, waiting for the stylesheets to be loaded (which blocks the inline script). {F66755858} {F66756368} **What should have happened instead?**: HTML parsing goes along while the HTML content is downloading, and sections are expandable as soon as First Contentful Paint. {F66756374} {F66756376} **Software version** (on `Special:Version` page; skip for WMF-hosted wikis like Wikipedia): **Other information** (browser name/version, screenshots, etc.):

**Steps to replicate the issue** (include links if applicable): * Load [[ https://en.wikipedia.org/wiki/Earth | enwiki:Earth ]] with device emulation set to a mobile device * From the Performance tab, apply 4x CPU slowdown and Slow 4G network throttling (for example) * Record and reload, screenshot the graph for comparison * Load [[ https://44bb00ec83.catalyst.wmcloud.org/wiki/Earth | the same page from patchdemo ]] in another tab with the same settings * Record and reload, screenshot the graph for comparison **What happens?**: HTML parsing is delayed, waiting for the stylesheets to be loaded (which blocks the inline script). {F66755858} {F66756368} **What should have happened instead?**: HTML parsing goes along while the HTML content is downloading, and sections are expandable as soon as First Contentful Paint. {F66756374} {F66756376} IMPORTANT: It should also be possible to load sections before the code has finished loading. To test this scroll down to the first section heading and make sure it can be expanded via click as soon as the page renders. **Software version** (on `Special:Version` page; skip for WMF-hosted wikis like Wikipedia): **Other information** (browser name/version, screenshots, etc.):

**Steps to replicate the issue** (include links if applicable): * Load [[ https://en.wikipedia.org/wiki/Earth | enwiki:Earth ]] with device emulation set to a mobile device * From the Performance tab, apply 4x CPU slowdown and Slow 4G network throttling (for example) * Record and reload, screenshot the graph for comparison * Load [[ https://44bb00ec83.catalyst.wmcloud.org/wiki/Earth | the same page from patchdemo ]] in another tab with the same settings * Record and reload, screenshot the graph for comparison **What happens?**: HTML parsing is delayed, waiting for the stylesheets to be loaded (which blocks the inline script). {F66755858} {F66756368} **What should have happened instead?**: HTML parsing goes along while the HTML content is downloading, and sections are expandable as soon as First Contentful Paint. {F66756374} {F66756376} IMPORTANT: It should also be possible to load sections before the code has finished loading. To test this scroll down to the first section heading and make sure it can be expanded via click as soon as the page renders. **Software version** (on `Special:Version` page; skip for WMF-hosted wikis like Wikipedia): **Other information** (browser name/version, screenshots, etc.):