The rational use of semantic tags in HTML can improve page structure clarity, accessibility and SEO effects. 1. Used for independent content blocks, such as blog posts or comments, it must be self-contained; 2. Used for classification related content, usually including titles, and is suitable for different modules of the page; 3. Used for auxiliary information related to the main content but not core, such as sidebar recommendations or author profiles. In actual development, labels should be combined and other, avoid excessive nesting, keep the structure simple, and verify the rationality of the structure through developer tools.

loading="lazy" is an HTML attribute for and which enables the browser's native lazy loading function to improve page performance. 1. It delays loading non-first-screen resources, reduces initial loading time, saves bandwidth and server requests; 2. It is suitable for large amounts of pictures or embedded content in long pages; 3. It is not suitable for first-screen images, small icons, or lazy loading using JavaScript; 4. It is necessary to cooperate with optimization measures such as setting sizes and compressing files to avoid layout offsets and ensure compatibility. When using it, you should test the scrolling experience and weigh the user experience.

When writing legal and neat HTML, you need to pay attention to clear structure, correct semantics and standardized format. 1. Use the correct document type declaration to ensure that the browser parses according to the HTML5 standard; 2. Keep the tag closed and reasonably nested to avoid forgetting closed or wrong nesting elements; 3. Use semantic tags such as, etc. to improve accessibility and SEO; 4. The attribute value is always wrapped in quotes, and single or double quotes are used uniformly. Boolean attributes only need to exist, and the class name should be meaningful and avoid redundant attributes.

The web page structure needs to be supported by core HTML elements. 1. The overall structure of the page is composed of , , which is the root element, which stores meta information and displays the content; 2. The content organization relies on title (-), paragraph () and block tags (such as ,) to improve organizational structure and SEO; 3. Navigation is implemented through and implemented, commonly used organizations are linked and supplemented with aria-current attribute to enhance accessibility; 4. Form interaction involves , , and , to ensure the complete user input and submission functions. Proper use of these elements can improve page clarity, maintenance and search engine optimization.

It is actually very simple to write inline styles using HTML's style attribute. Just add style="..." to the tag and then write CSS rules in it. 1. The basic writing method is CSS style with the attribute value in the form of a string. Each style is separated by a semicolon. The format is the attribute name: attribute value. For example: this paragraph of text is red. Note that the entire style string should be wrapped in double quotes. Each CSS attribute should be added with a semicolon after it. The attribute name is standard writing method of CSS; 2. Applicable scenarios for inline styles include dynamic style control, email template development and rapid debugging, such as allowing the picture to be displayed in the center to be written; 3. Several pitfalls that need to be avoided include high priority but difficult to maintain, many code repetitions, and special characters.

JavaScript dynamically creates, modifys, moves and deletes HTML elements through DOM operations. 1. Use document.createElement() to create a new element and add it to the page through appendChild() or insertBefore(); 2. Select existing elements through querySelector() or getElementById(), and modify them using textContent, innerHTML, setAttribute() and other methods; 3. When processing multiple elements through loops, you need to note that querySelectorAll() returns NodeList; 4. Move

ThefourmostimpactfulHTMLattributesforSEOarethetitletag,altattribute,hrefattribute,andmetadescription.1.Thetitletaginthesectioniscrucialasitinformsusersandsearchenginesaboutthepage’scontent,mustbeconcise,keyword-relevant,under60characters,anduniqueper

Client-sideformvalidationcanbedonewithoutJavaScriptbyusingHTMLattributes.1)Userequiredtoenforcemandatoryfields.2)ValidateemailsandURLswithtypeattributeslikeemailorurl,orusepatternwithregexforcustomformats.3)Limitvaluesusingmin,max,minlength,andmaxlen