To create responsive images using CSS, it can be mainly achieved through the following methods: 1. Use max-width:100% and height:auto to allow the image to adapt to the container width while maintaining the proportion; 2. Use HTML's srcset and sizes attributes to intelligently load the image sources adapted to different screens; 3. Use object-fit and object-position to control image cropping and focus display. Together, these methods ensure that the images are presented clearly and beautifully on different devices.

class, id, style, data-, and title are the most commonly used global attributes in HTML. class is used to specify one or more class names to facilitate style setting and JavaScript operations; id provides unique identifiers for elements, suitable for anchor jumps and JavaScript control; style allows for inline styles to be added, suitable for temporary debugging but not recommended for large-scale use; data-properties are used to store custom data, which is convenient for front-end and back-end interaction; title is used to add mouseover prompts, but its style and behavior are limited by the browser. Reasonable selection of these attributes can improve development efficiency and user experience.

Native lazy loading is a built-in browser function that enables lazy loading of pictures by adding loading="lazy" attribute to the tag. 1. It does not require JavaScript or third-party libraries, and is used directly in HTML; 2. It is suitable for pictures that are not displayed on the first screen below the page, picture gallery scrolling add-ons and large picture resources; 3. It is not suitable for pictures with first screen or display:none; 4. When using it, a suitable placeholder should be set to avoid layout jitter; 5. It should optimize responsive image loading in combination with srcset and sizes attributes; 6. Compatibility issues need to be considered. Some old browsers do not support it. They can be used through feature detection and combined with JavaScript solutions.

Using HTML tags, you can use the href attribute to realize page jump, open new windows, positioning within pages and email and phone link functions. 1. Basic usage: Specify the target address through href, such as accessing a web page; 2. Open a new window: add target="_blank" and rel="noopener" attributes; 3. Jump within the page: combine id and # symbol to achieve anchor point positioning; 4. Email phone link: use mailto: or tel: protocol to trigger system applications.

The main difference is that textarea supports multiple lines of text input, while inputtext is only available in a single line. 1. Use inputtype="text" to be suitable for short and single-line user input, such as username, email address, etc., and can set maxlength to limit the number of characters. The browser provides automatic filling function, making it easier to uniformly style across browsers; 2. Use textarea for scenarios that require multiple lines of input, such as comment boxes, feedback forms, support line breaks and paragraphs, and can control the size through CSS or disable the adjustment function. Both support form features such as placeholders and required fills, but textarea defines the size through rows and cols, and input uses the size attribute.

srcset and sizes are key properties for HTML implementation of responsive images. srcset provides multiple image sources and their width or pixel density, such as 400w and 800w, and the browser selects the appropriate image accordingly; sizes defines the display width of the image under different screen widths, such as (max-width: 600px)100vw, 50vw, so that the browser can more accurately match the image size. In actual use, you need to prepare multi-size pictures, clearly named, design layout in accordance with media query, and test the performance of the equipment to avoid ignoring sizes or unit errors, thereby saving bandwidth and improving performance.

Elements are a native way to implement responsive images in HTML5. It allows the most appropriate image resources to be loaded according to factors such as the screen size, resolution, and direction of the device. Define multiple image sources and their corresponding media query conditions through tags. The browser will match and load pictures that meet the conditions in order, and finally use the tag as the default fallback. For example: when the device width is greater than or equal to 1024px, medium.jpg is loaded between 768 and 1023px, small.jpg is loaded if the device width is greater than or equal to 1024px. Compared with srcset, it provides more refined control capabilities, such as adapting to Retina screens, horizontal and vertical screen switching, completely different picture content, etc. Media checks should be set reasonably when using

The key to implementing responsive images in srcset is to understand the syntax and browser selection mechanism. 1. Basic structure: Provide multiple image versions through srcset, and use w descriptors to indicate the width, such as 320w and 480w; 2. Use sizes attribute to define the display size of the image under different screen widths, such as 100vw and 50vw; 3. Use x descriptors to provide high-definition images for high-resolution screens, such as 1x and 2x; 4. The actual suggestions include manually or tools to generate multi-size images, avoiding too many options affecting performance, and setting the alt attribute to ensure accessibility.