Which CSS3 feature enables content to adapt to different screen sizes and resolutions across devices?

• A. Media Query
• B. Responsive Grid
• C. Fluid Layout
• D. Adaptive Layout

Answer: (A)

Media queries are the mechanism that lets CSS apply different styles based on the device's characteristics, so content can fit various screen sizes and resolutions. By using conditions like in CSS, you can target the viewport width, height, orientation, or pixel density and adjust the layout accordingly. For example, you might switch from a multi-column grid to a single-column layout at smaller widths, resize images, or adjust font sizes with specific rules under @media blocks. This approach is fundamental to responsive design, allowing a page to adapt gracefully from phones to tablets to desktops. Other phrases describe design approaches rather than a CSS3 feature, whereas media queries provide the actual tool to tailor styles to the device.