As many people using reveal.js, I wanted to reduce the vertical blank space at top of each slides.
The problem, a css style is injected from reveal.js script so using directly css to solve this issue will be a fail as the script will provide these default values.
Indeed for each section
tag the script compute and inject the css attribute top
. This is done at line 1761 version 3.4.1 .
slide.style.top = Math.max( ( size.height - slide.scrollHeight ) / 2, 0 ) + 'px';
So you have to change the calculus for your expected results.
To be at the top most:
slide.style.top = 0;
To reduce the size increase the divisor value (default 2), here i use 3:
slide.style.top = Math.max( ( size.height - slide.scrollHeight ) / 3, 0 ) + 'px';
Good luck