Can require introduce CSS?

To create a hover effect for table rows, you need to use the CSS :hover pseudo-class. It is recommended to set background color, text color and other styles for cells in the row through tr:hovertd to ensure compatibility. You can combine transitions to achieve smooth transitions and cursor:pointer prompts interactivity. You can also distinguish between processing table headers and data rows through class names to avoid style conflicts, and ultimately achieve a simple and efficient hover effect.

Usingbox-sizing:border-boxensuresanelement’sdeclaredwidthincludesitscontent,padding,andborder,preventingunexpectedlayoutoverflow;applyingitgloballyvia,::before,*::after{box-sizing:border-box;}standardizessizingacrossallelementsandpseudo-elements,maki

To completely customize the horizontal line style, you must first remove the default style, and then use the background, border and other properties of CSS to redefine the appearance. The specific method is to first set border:none to clear the browser's default style. Then you can create custom lines through background-color or border-top. It is recommended to use background-color to obtain higher control. If you need a dotted line or dotted line effect, use border-top and match dashed, dotted and other values. By setting width and margin:auto, you can control the line width and achieve horizontal centering. Use linear-gradient to create gradient effects on the background.

To customize the style of the file upload button, you need to hide the native input box and replace it with a label. By setting the input box to be transparent and absolutely positioned, it is overlaid on the styleable label, thus achieving a fully customizable appearance while retaining functionality and accessibility. This method is compatible with all browsers and supports displaying file names, hover status and keyboard navigation, and ultimately creating a file upload button that is both beautiful and practical.

To achieve smooth scrolling on web pages, you need to use the scroll-behavior attribute of CSS; 1. Apply scroll-behavior:smooth to the html element to enable global smooth scrolling; 2. When clicking an anchor link (such as #section), animated scrolling is triggered instead of instant jumps; 3. It is recommended to set it on html instead of body to ensure compatibility; 4. This property can be applied separately in a custom scroll container to achieve local smooth scrolling; 5. Note that JavaScript scrolling operations can override this effect through behavior:'auto'; this method is compatible with modern mainstream browsers and significantly improves the user experience, which can be easily implemented with one sentence of CSS.

Use hidden check boxes as status switches to control the display and hiding of modal boxes through the checked selector of CSS; 2. Use label's for attribute to associate check boxes to achieve opening and closing operations; 3. Use adjacent brother selectors ( ) to display modal boxes when the check box is selected; 4. Add appropriate styles to achieve visual effects such as centering, masking, rounding corners, shadows, etc.; 5. Ensure accessibility, add aria-hidden and role attributes, and ensure that the keyboard is operable. This method can create a modal window with complete functionality, clear structure and easy to maintain without JavaScript, suitable for simple prompts or information display scenarios.

@supports rules are used to implement progressive enhancement based on whether the browser supports specific CSS attributes or values. 1. The basic syntax is @supports(property:value){...}. If display:grid is supported, the grid layout is applied. 2. The conditions can be combined using and, or, and not logical operators, such as supporting multiple features at the same time or providing a fallback scheme. 3. Support grouping complex conditions in brackets and can be nested with other at rules such as @media. 4. In actual applications, it is recommended to set basic styles and gradually enhance them to avoid excessive use, ensure that browsers that do not support new features can still display content normally, and ultimately achieve the effect of safely adopting modern CSS.

To effectively and consistently beautify form input across browsers, the following steps must be followed: 1. Use standard CSS properties to customize the appearance of text input, password, mailbox, etc., set width, margins, borders, rounded corners and fonts, and add interactive feedback through the:focus pseudo-class; 2. Use the ::placeholder pseudo-element to adjust the color and style of the placeholder text to ensure it is clear and readable; 3. Make the input box responsive and maintain the layout stable by setting box-sizing:border-box and using relative units; 4. Use native controls to hide native controls and combine pseudo-elements and labels to achieve custom visual effects; 5. Always pay attention to accessibility and provide visible focus indicators