There is also this Userscript if you ever need Javascript (and Userscript injector isn’t broken). – [Userscript]: Hide Context Sentence Translation
Just decided to use a CSS solution. Mine is this:-
:root {
--hide-translation-color: lightgray;
}
.subject-collocations__collocations {
flex-grow: 1;
}
.context-sentences p:not([lang="ja"]):not(:hover),
.subject-section__text.subject-section__text--grouped p:not([lang="ja"]):not(:hover) {
text-shadow: none;
color: var(--hide-translation-color);
background-color: var(--hide-translation-color);
}