Three stripes should be such an easy thing to draw. Here’s a bunch of different ways to do it on the web. That said, SVG is definitely the nicest way to handle it. A hamburger menu is so simple that we can draw it by hand in SVG.
Three rectangles, evenly distributed:
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Feel free to fiddle with those numbers to get the sizing and style you like.
Something awesome you might not know? SVG has rounded corners, just like CSS has border-radius! It comes in the form of the rx attribute. Check it out:
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That might work better for your design if your design is softer and makes use of rounded stuff.