Yeah! The text is extremely tiny on a Desktop (I'm also on a 5K 27”). Here is my only custom style that uplifts HackerNews to my preference;
:root {
--font-size: 20px;
--font-weight: 500;
--border-radius: 5px;
--line-height: 1.6;
--spacing-min: 05px;
--spacing-mid: 10px;
--spacing-max: 20px;
--zoom-min: 110%;
--zoom-mid: 125%;
--zoom-max: 150%;
/* grays */
--color-50 : #f9fafb;
--color-100: #f3f4f6;
--color-200: #e5e7eb;
--color-300: #d1d5db;
--color-400: #9ca3af;
--color-500: #6b7280;
--color-600: #4b5563;
--color-700: #374151;
--color-800: #1f2937;
--color-900: #111827;
/* background */
--color-bg-cool-1: #eceff4;
--color-bg-cool-2: #e5e9f0;
--color-bg-cool-3: #d8dee9;
--color-bg-warm-1: #fdf6e3;
--color-bg-warm-2: #eee8d5;
--color-bg-warm-3: #fffcf0;
}
/* HackerNews - news.ycombinator.com */
table#hnmain {
zoom: var(--zoom-min);
margin: var(--spacing-mid) auto !important;
padding: var(--spacing-mid) !important;
max-width: 960px !important;
background: var(--color-100) !important;
/* border: 1px solid var(--color-200) !important;*/
border-radius: var(--border-radius) !important;
line-height: var(--line-height) !important;
}
table.fatitem .toptext {
color: var(--color-700) !important;
}