Modifying existing code

HTML Basics: HTML boilerplate, commenting, css styling, lists, and customization

Links: a, href, #, id (replaces name), link title text, top, mailto, subject, target, _blank, visited, external vs internal

Images and Media: jpg, png, gif, resizing, captions, alt text, sound file, video file, player controls

CSS Styling: text formatting, importing fonts, .class selectors, using ID and divs, transitions, transformations, and animations

CSS Layout: floating, positioning of text and images, padding, margin, border, flexbox, and grid

Tables and Forms: table rows, columns, headings, borders, padding,span rows and columns, positioning text and images within table cells, input form, text box, checkbox, pull down menus, prefilled entries, color selector, meter, and submit button