within bounds - Phrases/Idioms
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Reasonable and allowable, up to a certain point, as in It's all right to play your stereo, but please keep the volume within bounds. Like its antonym, out of bounds, this term originally referred to the boundaries of a playing area of field.