Metadata in HTMLhead is crucial for SEO, social sharing, and browser behavior. 1. Set the page title and description, use and keep it concise and unique; 2. Add OpenGraph and Twitter card information to optimize social sharing effects, pay attention to the image size and use debugging tools to test; 3. Define the character set and viewport settings to ensure multi-language support is adapted to the mobile terminal; 4. Optional tags such as author copyright, robots control and canonical prevent duplicate content should also be configured reasonably.

TolearnHTMLin2025,chooseatutorialthatbalanceshands-onpracticewithmodernstandardsandintegratesCSSandJavaScriptbasics.1.Prioritizehands-onlearningwithstep-by-stepprojectslikebuildingapersonalprofileorbloglayout.2.EnsureitcoversmodernHTMLelementssuchas,

How to make HTML mail templates with good compatibility? First, you need to build a structure with tables to avoid using div flex or grid layout; secondly, all styles must be inlined and cannot rely on external CSS; then the picture should be added with alt description and use a public URL, and the buttons should be simulated with a table or td with background color; finally, you must test and adjust the details on multiple clients.

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.

When there is no backend server, HTML form submission can still be processed through front-end technology or third-party services. Specific methods include: 1. Use JavaScript to intercept form submissions to achieve input verification and user feedback, but the data will not be persisted; 2. Use third-party serverless form services such as Formspree to collect data and provide email notification and redirection functions; 3. Use localStorage to store temporary client data, which is suitable for saving user preferences or managing single-page application status, but is not suitable for long-term storage of sensitive information.

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.

To add a video background to a web page, the key is to use HTML tags correctly and optimize relevant attributes. 1. Use tags as background and use CSS positioning to fill the page or local area; 2. The video format is preferred.mp4, and WebM is added to consider compatibility; 3. Add muted and playsinline attributes to ensure automatic playback on the mobile side; 4. Control the video size to optimize the loading speed, and it is recommended to keep it at tens of MB; 5. Add loops to achieve seamless loop playback; 6. It can be flexibly applied to full screen or local blocks, and different effects are achieved by adjusting the container size and positioning method. The above steps can achieve a stable and beautiful video background.

To make iframes responsive, the core is to use CSS to control the aspect ratio and combine it with the wrapping container to achieve adaptation. 1. Use padding techniques to create container boxes with fixed proportions. Common ratios such as 16:9 correspond to padding-top56.25%, 4:3 correspond to 75%, and 1:1 correspond to 100%; 2. Set the iframe width to 100% and use absolute positioning to fill the container, or use the aspect-ratio attribute to maintain the proportion; 3. When processing third-party embedded content, control the ratio through container wrapping, and ensure that the allowfullscreen attribute is added to support full-screen playback on mobile terminals. Master the container and proportion settings to realize the responsiveness of the iframe