some CSS class names are valid

[shabishabishabishabi]

After updating from v3 to v4, some CSS class names are valid while others are invalid.For example, the grid layout is still valid, but the text-4xl is invalid

[wongjn]

Could you clarify what you mean by "invalid" please?

[wongjn]

Consider providing a git repo that reproduces the issue (can be a trimmed down version) and we can take a look for you.

[shabishabishabishabi]

Sorry, I have found the problem. The reason is in my reset. css. When I deleted as many files as possible, when I commented out reset. css, it returned to normal. However, I am still searching for the reason why most tailwindcss fail

[wongjn]

So you may have styles that are overriding Tailwind's class names. Tailwind v4 uses cascade layers, so any custom "base" styles not in a @layer would override Tailwind classes. So, ensure your resets are inside @layer base for example.

[shabishabishabishabi]

Consider providing a git repo that reproduces the issue (can be a trimmed down version) and we can take a look for you.
This is my reset file. I referenced it before using global to reference tailwind, and I have been using it with tailwinddv3 without affecting my usage. However, when upgrading to v4, the entire tailwind became very strange, especially the font part.
html,
body,
div,
span,
applet,
object,
iframe,
h1,
h2,
h3,
h4,
h5,
h6,
p,
blockquote,
pre,
a,
abbr,
acronym,
address,
big,
cite,
code,
del,
dfn,
em,
img,
ins,
kbd,
q,
s,
samp,
small,
strike,
strong,
sub,
sup,
tt,
var,
b,
u,
i,
center,
dl,
dt,
dd,
ol,
ul,
li,
fieldset,
form,
label,
legend,
table,
caption,
tbody,
tfoot,
thead,
tr,
th,
td,
article,
aside,
canvas,
details,
embed,
figure,
figcaption,
footer,
header,
hgroup,
menu,
nav,
output,
ruby,
section,
summary,
time,
mark,
audio,
video {
margin: 0;
padding: 0;
border: 0;
font-size: 100%;
font: inherit;
vertical-align: baseline;
text-decoration: none
}

article,
aside,
details,
figcaption,
figure,
footer,
header,
hgroup,
menu,
nav,
section {
display: block
}

body {
line-height: 1;
font-family: "Helvetica Neue", Helvetica, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", Arial, sans-serif
}

ol,
ul {
list-style: none
}

blockquote,
q {
quotes: none
}

blockquote:before,
blockquote:after,
q:before,
q:after {
content: "";
content: none
}

table {
border-collapse: collapse;
border-spacing: 0
}

.clearfix:before,
.clearfix:after {
content: "";
display: block;
visibility: hidden;
clear: both
}

[wongjn]

As per my previous comment:

ensure your resets are inside @layer base for example.

[rozsazoltan]

Related:

• From v4 the reset style cannot be overridden by TailwindCSS classes