Others
- AMP for Email (amp4email)
- BIMI (bimi, logo, brand)
CSS
- accent-color (accent,color)
- align-items (align,items,flexbox,grid)
- animation (keyframes)
- aspect-ratio (ratio)
- @font-face (font face, web fonts, google fonts)
- @import (css, style)
- @keyframes (animation)
- @media (media queries, media query, media feature)
- @media (-webkit-device-pixel-ratio) (media queries, media query, media feature)
- @media (hover), @media (any-hover) (media, media query, hover, any-hover)
- @media (orientation) (media queries, media query, media feature, portrait, landscape)
- @media (prefers-color-scheme) (media queries, media query, media feature, dark mode, light mode)
- @media (prefers-reduced-motion) (media queries, media query, media feature, prefers-reduced-motion, animation, accessibility)
- @supports (feature queries)
- backdrop-filter (filter)
- background
- background-blend-mode
- background-clip
- background-color
- background-image
- background-origin
- background-position
- background-repeat
- background-size
- block-size & inline-size (block-size, inline-size)
- border (border-width, border-style, border-color, border-top, border-bottom, border-left, border-right, border-top-width, border-top-style, border-top-color, border-bottom-width, border-bottom-style, border-bottom-color, border-left-width, border-left-style, border-left-color, border-right-width, border-right-style, border-right-color)
- border-collapse (table)
- border-image
- border-inline & border-block (border-inline, border-block)
- border-inline & border-block individual logical properties (border-inline-color, border-block-color, border-inline-style, border-block-style, border-inline-width, border-block-width, border-inline-start, border-inline-end, border-block-start, border-block-end)
- border-inline & border-block longhand properties (border-inline-start-color, border-block-start-color, border-inline-start-style, border-block-start-style, border-inline-start-width, border-block-start-width, border-inline-end-color, border-block-end-color, border-inline-end-style, border-block-end-style, border-inline-end-width, border-block-end-width)
- border-radius (rounded corners)
- border-radius logical properties (border-start-start-radius, border-start-end-radius, border-end-start-radius, border-end-end-radius)
- border-spacing (table)
- box-shadow
- box-sizing (box model)
- caption-side (caption,table)
- clip-path (clip,path,svg,mask)
- color-scheme CSS property (dark mode, light mode)
- column-count (columns)
- css column properties (columns, column-count, column-fill, column-gap, column-rule, column-rule-color, column-rule-style, column-rule-width, column-span, column-width)
- CSS comments
- conic-gradient() (gradients)
- direction
- display (inline, block, inline-block)
- display:flex (flexbox)
- display:grid
- display:none
- empty-cells (blank)
- filter
- flex-direction:column (flexbox)
- flex-wrap: wrap (flexbox)
- float
- font shorthand
- font-kerning (font,kerning)
- font-size (font,size)
- font-stretch (font)
- font-weight (font,weight)
- clamp()
- light-dark() (dark, light)
- max()
- min()
- gap, column-gap, row-gap (gap)
- grid-template-* properties (grid-template, grid-template-areas, grid-template-columns, grid-template-rows)
- height property
- hyphenate-character (hyphens, break)
- hyphenate-limit-chars
- hyphens (hyphens, break)
- !important keyword
- inline-size
- inset
- fit-content, min-content, max-content
- justify-content (justify,align,flexbox,grid)
- left, right, top, bottom (absolute, sticky, fixed, relative, position)
- letter-spacing
- line-height
- linear-gradient() (gradients)
- list-style
- list-style-image
- list-style-position
- list-style-type
- margin (margin-left, margin-right, margin-top, margin-bottom)
- margin-block-start & margin-block-end (margin-block-start, margin-block-end)
- margin-inline & margin-block (margin-inline, margin-block)
- margin-inline & margin-block (margin-inline, margin-block)
- margin-inline-start & margin-inline-end (margin-inline-start, margin-inline-end)
- max-block-size (max, block, size)
- max-height property
- max-inline-size (max, inline, size)
- max-width (size)
- min-block-size (min, block, size)
- min-height property
- min-inline-size (min, inline, size)
- min-width property
- mix-blend-mode (mix-blend-mode,blend,filter)
- lch(), oklch(), lab(), oklab() (color)
- CSS Nesting
- object-fit
- object-position
- opacity
- orphans (columns)
- outline
- outline-offset
- overflow
- overflow-wrap
- padding
- padding-block-start & padding-block-end (padding-block-start, padding-block-end)
- padding-inline & padding-block (padding-inline, padding-block)
- padding-inline-start & padding-inline-end (padding-inline-start, padding-inline-end)
- position (absolute, sticky, fixed, relative, static)
- :active (pseudo-class)
- :checked (check, interactive, pseudo-class)
- :first-child
- :first-of-type
- :focus (pseudo-class)
- :has()
- :hover (rollover, pseudo-class)
- lang()
- :last-child
- :last-of-type
- :link (pseudo-class)
- :not (pseudo-class)
- :nth-child
- :nth-last-child
- :nth-last-of-type
- :nth-of-type
- :only-child
- :only-of-type
- :target (pseudo-class)
- :visited (pseudo-class)
- ::after (pseudo-element)
- ::before (pseudo-element)
- ::first-letter (pseudo-element)
- ::first-line (pseudo-element)
- ::marker (pseudo-element)
- ::placeholder (pseudo-element)
- radial-gradient() (gradients)
- resize (textarea)
- rgb() (rgb,color)
- rgba() (rgb,rgba,color,alpha)
- scroll-snap
- Adjacent sibling combinator
- Attribute selector
- Chaining selectors
- Child combinator
- Class selector
- Descendant combinator
- General sibling combinator
- Grouping selectors
- ID selector
- Type selector (element)
- Universal selector *
- shape-margin (shape, margin)
- shape-outside (shape)
- system-ui, ui-serif, ui-sans-serif, ui-rounded, ui-monospace
- tab-size (tab,size)
- table-layout (table,layout)
- text-align (align)
- text-align-last (align, align-last)
- text-decoration (underline)
- text-decoration-color (underline)
- text-decoration-line (underline, overline, line-through)
- text-decoration-skip-ink (underline)
- text-decoration-style (underline)
- text-decoration-thickness (underline)
- text-emphasis
- text-emphasis-position
- text-indent (indent)
- text-justify
- text-orientation (vertical orientation)
- text-overflow
- text-shadow
- text-transform
- text-underline-offset (underline)
- text-underline-position (underline)
- text-wrap
- transform
- transition (animation)
- CSS calc() function (unit, calc)
- ch unit (unit, ch)
- cm unit (unit, cm)
- em unit (unit, em)
- ex unit (unit, ex)
- in unit (unit, in)
- initial unit (unit, initial)
- mm unit (unit, mm)
- pc unit (unit, pc)
- % unit (unit, %)
- pt unit (unit, pt)
- px unit (unit, px)
- rem unit (unit, rem)
- vh unit (unit, vh)
- vmax unit (unit, vmax)
- vmin unit (unit, vmin)
- vw unit (unit, vw)
- user-select (select, copy)
- CSS Variables (Custom Properties)
- vertical-align
- visibility
- white-space
- widows (columns)
- width property
- word-break (a, b, c)
- word-spacing (word)
- writing-mode
- z-index (absolute, sticky, fixed, relative, position)
HTML
- <abbr> element
- <acronym> element
- address (address)
- align attribute (left, center, right)
- Local anchors (hash, fragment identifiers, URLs, URIs, document fragments, local, named, anchor, anchors, links)
- aria-describedby attribute (accessibility, a11y, wai-aria)
- aria-hidden attribute (accessibility, a11y, wai-aria)
- aria-label attribute (accessibility, a11y, wai-aria)
- aria-labelledby attribute (accessibility, a11y, wai-aria)
- aria-live attribute (accessibility, a11y, wai-aria)
- <audio> element (audio)
- background attribute
- <base>
- <bdi> element
- <blockquote> element
- <body> element
- <button type="reset"> element (form, reset, button)
- <button type="submit"> element (form, submit, button)
- cellpadding attribute
- cellspacing attribute
- <code> element
- HTML comments
- <del> element
- <dfn> element
- <dialog> element
- dir attribute (direction, ltr, rtl)
- <div> element
- HTML5 doctype
- <form> element (form)
- <h1> to <h6> elements (headings, h1, h2, h3, h4, h5, h6)
- height attribute
- hidden attribute
- <hr> element
- Image maps (image maps, map element, area element, usemap attribute)
- <img> element
- <input type="checkbox"> element (form, checkbox)
- <input type="hidden"> element (form, hidden)
- <input type="radio"> element (form, radio)
- <input type="reset"> element (form, reset)
- <input type="submit"> element (form, submit)
- <input type="text"> element (form, text)
- lang attribute
- <link> element (css, style)
- <ul>, <ol> and <dl> (ul, ol, li, dl, dt, dd)
- loading attribute (img,image,loading)
- mailto: links
- <marquee> element (marquee)
- color-scheme meta tag (dark-mode)
- <meter> element
- <object> element (object,embed,video,image,pdf)
- <p> element (paragraph)
- <picture> element (picture, responsive image)
- popover attribute
- <pre> element
- <progress> element
- required attribute (form, required)
- role attribute (accessibility, a11y, wai-aria)
- <rp> element
- <rt> element
- <ruby> element
- <select> element (form, select)
- HTML5 semantics (article, aside, details, figcaption, figure, footer, header, main, mark, nav, section, summary, time)
- <small> element
- <span> element
- srcset and sizes attributes
- <strike> element
- <strong> element
- <style> element
- Embedded <svg> image (image, SVG)
- <table> element
- target attribute
- <textarea> element (form, text)
- valign attribute
- <video> element (mp4)
- <wbr> element
- width attribute
Image formats
- Animated PNG image format (image, apng, png, animation)
- AVIF image format (image,img,AVIF)
- Base 64 image format (image, Base 64)
- BMP image format (image, BMP)
- GIF image format (image, GIF)
- HDR image format (image, HDR)
- HEIF image format (image, HEIF)
- ICO image format (image, ICO)
- JPG image format (image, JPG, jpeg)
- Video as Image Assets (mp4)
- PNG image format (image, PNG)
- SVG image format (image, SVG)
- TIFF image format (image, TIFF)
- webP image format (image, webP)