I am using sphinx for generating html documentation for a project. I make extensive use of field lists.
When generating html, each label/value pair is rendered as a sing
I think your approach doesn't work because sphinx uses its own html writer.
However I think it should work, if you adapt the style for field_name. I (once) used a custom css file with
field_name
.field-name { white-space: nowrap; }
or set it to a fixed width.