[html] Make <body> fill entire screen?

Try using viewport (vh, vm) units of measure at the body level

html, body { margin: 0; padding: 0; } body { min-height: 100vh; }

Use vh units for horizontal margins, paddings, and borders on the body and subtract them from the min-height value.

I've had bizarre results using vh,vm units on elements within the body, especially when re-sizing.