Articles

Why Does CSS align-items Move Sideways Sometimes?

Illustration showing how changing a Flexbox layout from a row to a column changes the direction controlled by align-items.

If align-items seems to move items sideways, your Flexbox direction probably changed. Learn how the main and cross axes make the behavior predictable.

Why Does My CSS Margin Move the Whole Section?

A heading box with a top margin extending outside a parent section beside the same spacing contained inside the section as padding.

A heading’s margin can seem to move an entire section. Learn what is happening and how to choose between margin and padding.

Why Does My CSS Hover Transition Snap Back?

Normal and raised hover-state buttons connected by a smooth forward arrow and a broken snap-back arrow, with the transition attached only to the hover state.

If a hover effect changes smoothly but returns instantly, the transition is probably in the hover rule. See where it belongs and how to check your CSS. Primary keyword: Why does my CSS hover transition snap back?

Why Isn’t CSS Height 100% Working?

A short child box marked 100% inside a taller parent box whose height is unknown.

CSS height: 100% often fails because percentage heights depend on the parent having an explicit height. Learn how to diagnose the issue and make full-height elements work reliably with CSS.

Why isn’t JavaScript classList.add() Working?

An active class token moves into an HTML card, which changes from a pale card to a blue styled card.

JavaScript can add the right class while the page still looks unchanged. Follow five beginner-friendly checks to find the mismatch between your JavaScript, HTML, and CSS.

Why Isn’t Margin Auto Centering My Element?

A full-width card changes into a narrower centered card with equal space on its left and right.

If margin: auto does not visibly center an element, check whether the box has leftover horizontal space and whether it behaves as a block.

Why Isn’t My CSS Background Image Showing?

CSS file and landscape image disconnected from an empty background area in a browser window.

A CSS background can disappear because the browser cannot find the file, the rule misses the element, or the element has no visible space. Work through five beginner-friendly checks to find the cause.

Why Is My CSS Box Wider Than the Width I Set?

Two CSS boxes with the same set width, one extending beyond the width marker and one fitting within it.

A box can be wider than its CSS width even when the number is correct. This beginner-friendly explanation shows where the extra space comes from and how to fix it.

Why Isn’t My CSS Selector Working?

CSS selector tile connected to a highlighted card in a browser window, with another selector arrow missing the card.

If a CSS selector is not working, the rule may not match your HTML, another rule may be winning, or the property may not create the visible change you expected.

Why Isn’t Overflow Hidden Working in CSS?

Container box clipping an oversized child element at its edge.

If overflow hidden is not doing what you expected, the problem is usually the box it is applied to, the size of that box, or a related layout rule.

Why isn’t my CSS applying to my HTML?

CSS file connected to a browser window showing a styled page element.

If your CSS is not changing your HTML page, use this beginner-friendly checklist to find whether the file is loading, the selector matches, or another rule is winning.

Why Isn’t Z-Index Working in CSS?

Two overlapping parent boxes with a small child badge contained in the rear box behind the front box.

If z-index is not changing which element appears in front, this guide shows the beginner checks to make first: overlap, position, parent groups, and simple layer order.

OLDER POSTS