! YouTube Fix & Customization by Arch v1.8.4 ! (1/11) YouTube 4 Videos Per Row Fix (Home and Channel Pages) / YouTube Fix & Customization
youtube.com##ytd-rich-grid-row, #contents.ytd-rich-grid-row:style(display:contents !important;)
youtube.com##ytd-rich-grid-renderer, html:style(--ytd-rich-grid-items-per-row: 5 !important;)
youtube.com##ytd-rich-grid-renderer, html:style(--ytd-rich-grid-posts-per-row: 5 !important;)
(source: https://www.reddit.com/r/youtube/comments/1g5l9mc/comment/ls...)You can put the relevant CSS into a custom YouTube stylesheet if you like.
(I re-skin many sites, including HN, see my profile page for links to recent-ish CSS.)