If I'm interpreting the css right, the class .basic-paragraph IS your default paragraph styling, right?
I wonder if it might help to add "important" to your zero-indent. Thus:
text-indent: 0 !important;
I have read here and elsewhere that some devices need that to ensure the app / device software doesn't override your zero-indent. It is worth a try anyway. You could also add that attribute to your styling for <a> "_idgencolorinherit" as a fail-safe.