A pottery studio’s dropdown submenu appears in the wrong position on the page — floating near the top-left corner of the browser window instead of just below its parent nav item. What’s the most likely missing piece?

A developer wants a video to show a custom thumbnail image before it’s played, and wants it to play inline on mobile rather than automatically going full-screen.

A developer wants to float an image so it sits centered within its container, expecting a float: center; value to be available. What actually happens when they try that?

Rooted Plant Nursery’s nav bar has Home, About, and Login links in a row, and needs the Login link pushed all the way to the far right while Home and About stay together on the left. What single declaration on the Login link achieves that?

A browser doesn’t support either AVIF or WebP, and a “ element lists both as “ elements above a plain “.

A community theater’s dropdown correctly uses both :hover and :focus-within, but a visitor testing with a keyboard says the submenu still closes the instant they tab from the parent link onto the first sub-link. What does this suggest?

A developer wants to horizontally center a 400px-wide content box inside a full-width page. Which combination of declarations accomplishes that using the auto-margin centering technique?

Copper Kettle Coffee’s default paragraph style shows font-weight: 400 in the CSS. Roughly where does this value sit on the weight scale relative to bold text?

A large retailer wants a mega-menu with multiple columns and rows of links appearing under one nav item — a genuinely two-dimensional layout. Which layout tool does the deck point to for this specific case?

A children’s museum plans a “Visit” nav item with a submenu of “Hours,” “Directions,” and “Tickets,” and wants visitors to know a submenu exists before they hover. Which two techniques from the deck combine to achieve both the submenu structure and that visual signal?