CSS blocks page rendering because browsers view inline and external CSS as key resources by default, especially with imported stylesheets, header large amounts of inline CSS, and unoptimized media query styles. 1. Extract critical CSS and embed it into HTML; 2. Delay loading non-critical CSS through JavaScript; 3. Use media attributes to optimize loading such as print styles; 4. Compress and merge CSS to reduce requests. It is recommended to use tools to extract key CSS, combine rel="preload" asynchronous loading, and use media delayed loading reasonably to avoid excessive splitting and complex script control.

ToimplementdarkmodeinCSSeffectively,useCSSvariablesforthemecolors,detectsystempreferenceswithprefers-color-scheme,addamanualtogglebutton,andhandleimagesandbackgroundsthoughtfully.1.DefineCSSvariablesforlightanddarkthemestomanagecolorsefficiently.2.Us

The topic differencebetweenem, Rem, PX, andViewportunits (VH, VW) LiesintheirreFerencepoint: PXISFixedandbasedonpixelvalues, emissrelative EtothefontsizeFheelementoritsparent, Remisrelelatotherootfontsize, AndVH/VwarebaseDontheviewporttimensions.1.PXoffersprecis

ThebestapproachforCSSdependsontheproject'sspecificneeds.Forlargerprojects,externalCSSisbetterduetomaintainabilityandreusability;forsmallerprojectsorsingle-pageapplications,internalCSSmightbemoresuitable.It'scrucialtobalanceprojectsize,performanceneed

Choosing the correct display value in CSS is crucial because it controls the behavior of elements in the layout. 1.inline: Make elements flow like text, without occupying a single line, and cannot directly set width and height, suitable for elements in text, such as; 2.block: Make elements exclusively occupy one line and occupy all width, can set width and height and inner and outer margins, suitable for structured elements, such as; 3.inline-block: has both block characteristics and inline layout, can set size but still display in the same line, suitable for horizontal layouts that require consistent spacing; 4.flex: Modern layout mode, suitable for containers, easy to achieve alignment and distribution through justify-content, align-items and other attributes, yes

Autoprefixer is a tool that automatically adds vendor prefixes to CSS attributes based on the target browser scope. 1. It solves the problem of manually maintaining prefixes with errors; 2. Work through the PostCSS plug-in form, parse CSS, analyze attributes that need to be prefixed, and generate code according to configuration; 3. The usage steps include installing plug-ins, setting browserslist, and enabling them in the build process; 4. Notes include not manually adding prefixes, keeping configuration updates, prefixes not all attributes, and it is recommended to use them with the preprocessor.

AnimatingSVGwithCSSispossibleusingkeyframesforbasicanimationsandtransitionsforinteractiveeffects.1.Use@keyframestodefineanimationstagesforpropertieslikescale,opacity,andcolor.2.ApplytheanimationtoSVGelementssuchas,,orviaCSSclasses.3.Forhoverorstate-b

CSSselectorsandpropertynamesarecase-insensitive,whilevaluescanbecase-sensitivedependingoncontext.1)Selectorslike'div'and'DIV'areequivalent.2)Propertiessuchas'background-color'and'BACKGROUND-COLOR'aretreatedthesame.3)Valueslikecolornamesarecase-insens