Backdrop-filter is used to apply visual effects to the content behind the elements. 1. Use backdrop-filter:blur(10px) and other syntax to achieve the frosted glass effect; 2. Supports multiple filter functions such as blur, brightness, contrast, etc. and can be superimposed; 3. It is often used in glass card design, and it is necessary to ensure that the elements overlap with the background; 4. Modern browsers have good support, and @supports can be used to provide downgrade solutions; 5. Avoid excessive blur values and frequent redrawing to optimize performance. This attribute only takes effect when there is content behind the elements.

User agent stylesheets are the default CSS styles that browsers automatically apply to ensure that HTML elements that have not added custom styles are still basic readable. They affect the initial appearance of the page, but there are differences between browsers, which may lead to inconsistent display. Developers often solve this problem by resetting or standardizing styles. Use the Developer Tools' Compute or Style panel to view the default styles. Common coverage operations include clearing inner and outer margins, modifying link underscores, adjusting title sizes and unifying button styles. Understanding user agent styles can help improve cross-browser consistency and enable precise layout control.

Define@keyframesbouncewith0%,100%attranslateY(0)and50%attranslateY(-20px)tocreateabasicbounce.2.Applytheanimationtoanelementusinganimation:bounce0.6sease-in-outinfiniteforsmooth,continuousmotion.3.Forrealism,use@keyframesrealistic-bouncewithscale(1.1

Usetheelementwithinatagtocreateasemanticsearchfield.2.Includeaforaccessibility,settheform'sactionandmethod="get"attributestosenddatatoasearchendpointwithashareableURL.3.Addname="q"todefinethequeryparameter,useplaceholdertoguideuse

rel="stylesheet"linksCSSfilesforstylingthepage;2.rel="preload"hintstopreloadcriticalresourcesforperformance;3.rel="icon"setsthewebsite’sfavicon;4.rel="alternate"providesalternateversionslikeRSSorprint;5.rel=&qu

To achieve CSS element overlap, you need to use positioning and z-index attributes. 1. Use position and z-index: Set elements to non-static positioning (such as absolute, relative, etc.), and control the stacking order through z-index, the larger the value, the higher the value. 2. Common positioning methods: absolute is used for precise layout, relative is used for relatively offset and overlap adjacent elements, fixed or sticky is used for fixed positioning of suspended layers. 3. Actual example: By setting the parent container position:relative, child element position:absolute and different z-index, the card overlap effect can be achieved.

Using tags is the easiest and recommended method. The syntax is suitable for modern browsers to embed PDF directly; 2. Using tags can provide better control and backup content support, syntax is, and provides download links in tags as backup solutions when they are not supported; 3. It can be embedded through Google DocsViewer, but it is not recommended to use widely due to privacy and performance issues; 4. In order to improve the user experience, appropriate heights should be set, responsive sizes (such as height: 80vh) and PDF download links should be provided so that users can download and view them themselves.

ThetargetattributeinanHTMLanchortagspecifieswheretoopenthelinkeddocument.1._selfopensthelinkinthesametab(default).2._blankopensthelinkinanewtaborwindow.3._parentopensthelinkintheparentframe.4._topopensthelinkinthefullwindowbody,removingframes.Forexte