fix unexpected background color for content lines in dark mode #21

first and last line of any page with file content get this unexpected background color that obscures the text (on dark mode at least)

the empty bg: setting seemed to conflict w Tailwind background coloring in the template

<div class="whitespace-pre peer-target:bg-yellow-200 dark:peer-target:bg-yellow-900">

for example, run this in the console on any such page

document.querySelectorAll('code[style*="background-color:#fff"]').forEach(el => {
    el.style.backgroundColor = '';
});

not so familiar w this stack, preemptive sorry if I missed something!