With properties introduced in Obsidian 1.4, this is largely obsolete.
For styling properties I recommend this:
This is what I use now to achieve a similar effect as before:
/* no heading, no folding */
.metadata-properties-heading {
display: none;
}
/* no add button */
.metadata-container .metadata-add-button {
display: none;
}
/* no bottom margin / padding (where it meets the note) */
body {
--metadata-padding: var(--size-4-2) 0 0 0;
}
.metadata-container {
margin-block-end: 0;
}
/* pill-like */
.metadata-property[data-property-key='aliases'] .multi-select-pill {
font-weight: var(--font-semibold);
background-color: var(--color-base-30);
padding: var(--tag-padding-y) var(--tag-padding-x);
}