[v4] v3 preflight styles option

[zoltanszogyenyi]

Currently switching from v3 to v4 clearly changes the layout and styles of the website because of the new preflight stuff.

Why not allow users to opt-in for two basic preflight styles (v3 or v4) and just recommend v4?

What version of Tailwind CSS are you using?

v4.0.0+

Describe your issue

Button styles, form styles, whatever that was previously set in v3 preflight no longer applies for v4 and you need to manually update the whole preflight styles and configuration to resolve let's say 90% of issues. I wouldn't just simply override v4 preflight with v3 preflight but I would add the possibility to keep v3 preflight and just recommend v4 preflight.

[zoltanszogyenyi]

Currently this is my workaround:

@layer theme, base, components, utilities;
@import "tailwindcss/theme" layer(theme);
@import "tailwindcss/utilities" layer(utilities);

// v3 preflight styles
@layer base {
    /*
1. Prevent padding and border from affecting element width. (https://github.com/mozdevs/cssremedy/issues/4)
2. Allow adding a border to an element by just adding a border-width. (https://github.com/tailwindcss/tailwindcss/pull/116)
*/

*,
::before,
::after {
  box-sizing: border-box; /* 1 */
  border-width: 0; /* 2 */
  border-style: solid; /* 2 */
  border-color: theme('borderColor.DEFAULT', currentColor); /* 2 */
}

::before,
::after {
  --tw-content: '';
}

/*
1. Use a consistent sensible line-height in all browsers.
2. Prevent adjustments of font size after orientation changes in iOS.
3. Use a more readable tab size.
4. Use the user's configured `sans` font-family by default.
5. Use the user's configured `sans` font-feature-settings by default.
6. Use the user's configured `sans` font-variation-settings by default.
7. Disable tap highlights on iOS
*/

html,
:host {
  line-height: 1.5; /* 1 */
  -webkit-text-size-adjust: 100%; /* 2 */
  -moz-tab-size: 4; /* 3 */
  tab-size: 4; /* 3 */
  font-family: theme('fontFamily.sans', ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji"); /* 4 */
  font-feature-settings: theme('fontFamily.sans[1].fontFeatureSettings', normal); /* 5 */
  font-variation-settings: theme('fontFamily.sans[1].fontVariationSettings', normal); /* 6 */
  -webkit-tap-highlight-color: transparent; /* 7 */
}

/*
1. Remove the margin in all browsers.
2. Inherit line-height from `html` so users can set them as a class directly on the `html` element.
*/

body {
  margin: 0; /* 1 */
  line-height: inherit; /* 2 */
}

/*
1. Add the correct height in Firefox.
2. Correct the inheritance of border color in Firefox. (https://bugzilla.mozilla.org/show_bug.cgi?id=190655)
3. Ensure horizontal rules are visible by default.
*/

hr {
  height: 0; /* 1 */
  color: inherit; /* 2 */
  border-top-width: 1px; /* 3 */
}

/*
Add the correct text decoration in Chrome, Edge, and Safari.
*/

abbr:where([title]) {
  text-decoration: underline dotted;
}

/*
Remove the default font size and weight for headings.
*/

h1,
h2,
h3,
h4,
h5,
h6 {
  font-size: inherit;
  font-weight: inherit;
}

/*
Reset links to optimize for opt-in styling instead of opt-out.
*/

a {
  color: inherit;
  text-decoration: inherit;
}

/*
Add the correct font weight in Edge and Safari.
*/

b,
strong {
  font-weight: bolder;
}

/*
1. Use the user's configured `mono` font-family by default.
2. Use the user's configured `mono` font-feature-settings by default.
3. Use the user's configured `mono` font-variation-settings by default.
4. Correct the odd `em` font sizing in all browsers.
*/

code,
kbd,
samp,
pre {
  font-family: theme('fontFamily.mono', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace); /* 1 */
  font-feature-settings: theme('fontFamily.mono[1].fontFeatureSettings', normal); /* 2 */
  font-variation-settings: theme('fontFamily.mono[1].fontVariationSettings', normal); /* 3 */
  font-size: 1em; /* 4 */
}

/*
Add the correct font size in all browsers.
*/

small {
  font-size: 80%;
}

/*
Prevent `sub` and `sup` elements from affecting the line height in all browsers.
*/

sub,
sup {
  font-size: 75%;
  line-height: 0;
  position: relative;
  vertical-align: baseline;
}

sub {
  bottom: -0.25em;
}

sup {
  top: -0.5em;
}

/*
1. Remove text indentation from table contents in Chrome and Safari. (https://bugs.chromium.org/p/chromium/issues/detail?id=999088, https://bugs.webkit.org/show_bug.cgi?id=201297)
2. Correct table border color inheritance in all Chrome and Safari. (https://bugs.chromium.org/p/chromium/issues/detail?id=935729, https://bugs.webkit.org/show_bug.cgi?id=195016)
3. Remove gaps between table borders by default.
*/

table {
  text-indent: 0; /* 1 */
  border-color: inherit; /* 2 */
  border-collapse: collapse; /* 3 */
}

/*
1. Change the font styles in all browsers.
2. Remove the margin in Firefox and Safari.
3. Remove default padding in all browsers.
*/

button,
input,
optgroup,
select,
textarea {
  font-family: inherit; /* 1 */
  font-feature-settings: inherit; /* 1 */
  font-variation-settings: inherit; /* 1 */
  font-size: 100%; /* 1 */
  font-weight: inherit; /* 1 */
  line-height: inherit; /* 1 */
  letter-spacing: inherit; /* 1 */
  color: inherit; /* 1 */
  margin: 0; /* 2 */
  padding: 0; /* 3 */
}

/*
Remove the inheritance of text transform in Edge and Firefox.
*/

button,
select {
  text-transform: none;
}

/*
1. Correct the inability to style clickable types in iOS and Safari.
2. Remove default button styles.
*/

button,
input:where([type='button']),
input:where([type='reset']),
input:where([type='submit']) {
  -webkit-appearance: button; /* 1 */
  background-color: transparent; /* 2 */
  background-image: none; /* 2 */
}

/*
Use the modern Firefox focus style for all focusable elements.
*/

:-moz-focusring {
  outline: auto;
}

/*
Remove the additional `:invalid` styles in Firefox. (https://github.com/mozilla/gecko-dev/blob/2f9eacd9d3d995c937b4251a5557d95d494c9be1/layout/style/res/forms.css#L728-L737)
*/

:-moz-ui-invalid {
  box-shadow: none;
}

/*
Add the correct vertical alignment in Chrome and Firefox.
*/

progress {
  vertical-align: baseline;
}

/*
Correct the cursor style of increment and decrement buttons in Safari.
*/

::-webkit-inner-spin-button,
::-webkit-outer-spin-button {
  height: auto;
}

/*
1. Correct the odd appearance in Chrome and Safari.
2. Correct the outline style in Safari.
*/

[type='search'] {
  -webkit-appearance: textfield; /* 1 */
  outline-offset: -2px; /* 2 */
}

/*
Remove the inner padding in Chrome and Safari on macOS.
*/

::-webkit-search-decoration {
  -webkit-appearance: none;
}

/*
1. Correct the inability to style clickable types in iOS and Safari.
2. Change font properties to `inherit` in Safari.
*/

::-webkit-file-upload-button {
  -webkit-appearance: button; /* 1 */
  font: inherit; /* 2 */
}

/*
Add the correct display in Chrome and Safari.
*/

summary {
  display: list-item;
}

/*
Removes the default spacing and border for appropriate elements.
*/

blockquote,
dl,
dd,
h1,
h2,
h3,
h4,
h5,
h6,
hr,
figure,
p,
pre {
  margin: 0;
}

fieldset {
  margin: 0;
  padding: 0;
}

legend {
  padding: 0;
}

ol,
ul,
menu {
  list-style: none;
  margin: 0;
  padding: 0;
}

/*
Reset default styling for dialogs.
*/
dialog {
  padding: 0;
}

/*
Prevent resizing textareas horizontally by default.
*/

textarea {
  resize: vertical;
}

/*
1. Reset the default placeholder opacity in Firefox. (https://github.com/tailwindlabs/tailwindcss/issues/3300)
2. Set the default placeholder color to the user's configured gray 400 color.
*/

input::placeholder,
textarea::placeholder {
  opacity: 1; /* 1 */
  color: theme('colors.gray.400', #9ca3af); /* 2 */
}

/*
Set the default cursor for buttons.
*/

button,
[role="button"] {
  cursor: pointer;
}

/*
Make sure disabled buttons don't get the pointer cursor.
*/
:disabled {
  cursor: default;
}

/*
1. Make replaced elements `display: block` by default. (https://github.com/mozdevs/cssremedy/issues/14)
2. Add `vertical-align: middle` to align replaced elements more sensibly by default. (https://github.com/jensimmons/cssremedy/issues/14#issuecomment-634934210)
   This can trigger a poorly considered lint error in some tools but is included by design.
*/

img,
svg,
video,
canvas,
audio,
iframe,
embed,
object {
  display: block; /* 1 */
  vertical-align: middle; /* 2 */
}

/*
Constrain images and videos to the parent width and preserve their intrinsic aspect ratio. (https://github.com/mozdevs/cssremedy/issues/14)
*/

img,
video {
  max-width: 100%;
  height: auto;
}

/* Make elements with the HTML hidden attribute stay hidden by default */
[hidden]:where(:not([hidden="until-found"])) {
  display: none;
}
}

@import "./docs.css";
@config "./../tailwind.config.js";

[adamwathan]

Hey! This change is covered in the docs here:

https://tailwindcss.com/docs/v4-beta#normalized-form-element-styles

The only thing you need to add to your CSS to make things behave like v3 are these few lines, as mentioned in the docs:

@layer base {
  input,
  textarea,
  select,
  button {
    border: 0px solid;
    border-radius: 0;
    padding: 0;
    color: inherit;
    background-color: transparent;
  }
}