For diagrams... draw.io seems pretty great.

Steps to embed a diagram from there...

1. File / Export as / SVG... 2. Selection Only (w/ Cropping) 2. Do not include a copy of my diagram
2. Download
3. Open the file 2. Copy the <svg line (not the DOCTYPE) 2. Add the viewbox attribute, documenting the internal canvas size (format is 0 0 {width attribute} {height attribute}) 2. Changing width to be 100%, and remove the height attribute.
4. Reference the SVG from your document using snippet form (e.g. --8<-- "snippets/diagrams/my-diagram-export.svg")

Example of the file change...

# before
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="806px" height="304px" version="1.1"

# after
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewbox="0 0 806 304" width="100%" version="1.1"