The recent discussion of ems vs pixels got me thinking about the site tweak I was exploring recently, when I inquired about the validity of display: table-cell. I still haven't implemented the changes I was looking at; I'm still in exploratory mode, and - as usual - have too much hands on my time. (The person who figures out how to apply Microsoft's "DriveSpace" to real life will make a fortune!)
I'd like to confirm my understanding of how sizes in ems are applied to various elements: If I set a width on an element - or a max-width or min-width - in ems, is it correct to assume that the "actual" size will be based on the font size OF THE PARENT ELEMENT? In other words, if the font size in the BODY is 12-point, and I set the width of a DIV to 10em, it will be 120 points - or, at 16px=1em (same as 12 point, at 96ppi), 160px - correct? And then, the text inside that div will default to the same 12pt=16px=1em unless I reset it - and if I reset it to e.g., 0.75em, and then there is a SPAN inside a P in that DIV, the 'default' em size for the SPAN will be 9pt=12px="1em", unless I reset THAT: (In the below, I'm using curly brackets instead of angle brackets to keep HTML-based mail programs from "accidentally" trying to render it.) {!DOCTYPE HTML} {HTML style="font-size: 12pt;"} {BODY} {!-- 1 em is (still) 12 points --} {DIV style="width: 10em;"} {!-- width will be 120 points --} {P}This text's em size is 12 points.{/P} {P style="font-size: 0.75em;"}This P's em size is effectively 9 points, and {SPAN style="font-size: 0.67em"}this SPAN's em size is effectively 6 points,{/SPAN} and this is back to 9 points.{/P} {P}And this is back to 12 points.{/P} {/DIV} {/BODY} {/HTML} HOWEVER, if I use *rem* instead of *em* in the sample above, the BODY will still have an em size of 12 points, the DIV will still be 120 points wide, the first and third P will still be 12 points, the second P will still be 9 points, but the SPAN inside the second P will be EIGHT (8) points instead of SIX (6), correct? Now, assuming that my understanding is correct... Are the character entities emsp (em space) and mdash (em dash) truly and reliably one em in width? Or does the lousiness of many (free) fonts out there extend even to this? -- Jeff Zeitlin, Editor Freelance Traveller The Electronic Fan-Supported Traveller® Fanzine and Resource edi...@freelancetraveller.com http://www.freelancetraveller.com http://freelancetraveller.downport.com/ ®Traveller is a registered trademark of Far Future Enterprises, 1977-2014. Use of the trademark in this notice and in the referenced materials is not intended to infringe or devalue the trademark. Freelance Traveller extends its thanks to the following enterprises for hosting services: CyberNET Web Hosting (http://www.cyberwebhosting.net) The Traveller Downport (http://www.downport.com) ______________________________________________________________________ css-discuss [css-d@lists.css-discuss.org] http://www.css-discuss.org/mailman/listinfo/css-d List wiki/FAQ -- http://css-discuss.incutio.com/ List policies -- http://css-discuss.org/policies.html Supported by evolt.org -- http://www.evolt.org/help_support_evolt/