Make text easier to read in light/dark mode, make outlines of images less distracting

[KaiMagnusMueller]

• [x] Possibly reduce outline transparency

position: relative; outline: 2px solid rgba(0, 0, 0, 0.05); outline-offset: -2px; border-radius: 4px; overflow: clip; box-shadow: 0 2px 12px #0000001c;

• [x] Dark mode: Make colors brighter

--color-text: #f2f2f2; --color-text-low-contrast: #aaa;

• [x] Light mode: Adjust background and low contrast

--background-color: hsl(0, 0%, 100%); --color-text: #000; --color-text-low-contrast: #666;