Here are some improvements I’ve found:
/* fix the code blocks background highlighting */
.theme-light .token.operator,
.theme-light .token.entity,
.theme-light .token.url,
.theme-light .language-css .token.string,
.theme-light .style .token.string {
background: transparent;
}
/* fix the checkbox indent */
.markdown-preview-view ul > li.task-list-item {
list-style: none;
margin-left: 0;
text-indent: -25px;
}
/* fix the margin after every indented ul/ol and p block */
.markdown-preview-view p,
.markdown-preview-view ul,
.markdown-preview-view ol {
margin-bottom: 0;
}