You can use large, low-c ontrast type, or small (well, smallish) high-contrast type. But never use small, low-contrast type. (And try to stay away from the other two, too.) Unless you’re designing your own design portfolio site, and you really, truly don’t care whether anybody can read the text or not.
Yes, it can be very tempting, especially on cramped mobile screens. But don’t do it unless all of these are true: The form is exceptionally simple, the labels disappear when you start typing and reappear if you empty the field, the labels can never be confused with answers, and there’s no possibility that you’ll end up submitting the labels along with what you type (“Job TiAssistant Managertle”). And you’ve made sure they’re completely accessible. If you don’t agree, before you send me email please search for “Don’t Put Labels Inside Text Boxes (Unless You’re Luke W)” and read it.
By default, Web browsers display links to pages that you’ve already opened in a different color so you can see which options you’ve already tried. This turns out to be very useful information, especially since it’s tracked by URL, not by the wording of the link. So if you clicked on Book a trip, when you see Book a flight later you know that it would take you to the same page. You can choose any colors you want, as long as they’re noticeably different.
Headings should be closer to the text that follows them than the text that precedes them.