Work with legacy and simple sites using jQuery selectors, events, AJAX, effects, and plugins.
Lessons
Move sideways through related elements.
siblings(), next() and prev() is easiest to learn by reading the example, changing it, and observing the result.
const $card = $('.start-btn').closest('.card'); // nearest ancestor
$card.find('h3').addClass('highlight'); // descendant search
$card.children('.body').css('color', 'green'); // direct children
$card.siblings().fadeTo(200, 0.5); // sibling elementsPractice the siblings(), next() and prev() example in a small scratch file, then explain what changed and why.