Issues (bug?) with tailwind due to css minifier with future V4 true?

[yanshay]

Maybe it should be an issue and not a discussion since it seems like a bug, but not sure:

I started using docusaurus, added tailwind and when using npm run start everything works great.
When I use npm run build I get a long warning (see below) that seems related to minifying css, and the output styling looks pretty bad, not as it should.

When I removed the tailwind plugin the warning disappeared (that's why I believe its related to tailwind) but obviously site looks bad.

1. I used --no-minify and the issue was solved, no warning and site looks good.
2. I also disabled the v4 flag (so switched it to false) and things work fine as well. So seems it has to do with something in v4.

• Is it a bug? or am I doing something wrong?
• What is better at this state - to disable v4 or to disable minify?

Here is the warning:

[WARNING] {"message":"assets/css/styles.0c97f274.css from Css Minimizer plugin\nInvalid character(s) '0 2px 4px 0 #0000001a;--ifm-z-index-dropdown:100;--ifm-z-index-fixed:200;--ifm-z-index-overlay:400;--ifm-container-width:1140px;--ifm-container-width-xl:1320px;--ifm-code-background:#f6f7f8;--ifm-code-border-radius:var(--ifm-global-radius);--ifm-code-font-size:90%;--ifm-code-padding-horizontal:0.1rem;--ifm-code-padding-vertical:0.1rem;--ifm-pre-background:var(--ifm-code-background);--ifm-pre-border-radius:var(--ifm-code-border-radius);--ifm-pre-color:inherit;--ifm-pre-line-height:1.45;--ifm-pre-padding:1rem;--ifm-heading-color:inherit;--ifm-heading-margin-top:0;--ifm-heading-margin-bottom:var(--ifm-spacing-vertical);--ifm-heading-font-family:var(--ifm-font-family-base);--ifm-heading-font-weight:var(--ifm-font-weight-bold);--ifm-heading-line-height:1.25;--ifm-h1-font-size:2rem;--ifm-h2-font-size:1.5rem;--ifm-h3-font-size:1.25rem;--ifm-h4-font-size:1rem;--ifm-h5-font-size:0.875rem;--ifm-h6-font-size:0.85rem;--ifm-image-alignment-padding:1.25rem;--ifm-leading-desktop:1.25;--ifm-leading:calc(var(--ifm-leading-desktop)*1rem);--ifm-list-left-padding:2rem;--ifm-list-margin:1rem;--ifm-list-item-margin:0.25rem;--ifm-list-paragraph-margin:1rem;--ifm-table-cell-padding:0.75rem;--ifm-table-background:#0000;--ifm-table-stripe-background:#00000008;--ifm-table-border-width:1px;--ifm-table-border-color:var(--ifm-color-emphasis-300);--ifm-table-head-background:inherit;--ifm-table-head-color:inherit;--ifm-table-head-font-weight:var(--ifm-font-weight-bold);--ifm-table-cell-color:inherit;--ifm-link-color:var(--ifm-color-primary);--ifm-link-decoration:none;--ifm-link-hover-color:var(--ifm-link-color);--ifm-link-hover-decoration:underline;--ifm-paragraph-margin-bottom:var(--ifm-leading);--ifm-blockquote-font-size:var(--ifm-font-size-base);--ifm-blockquote-border-left-width:2px;--ifm-blockquote-padding-horizontal:var(--ifm-spacing-horizontal);--ifm-blockquote-padding-vertical:0;--ifm-blockquote-shadow:none;--ifm-blockquote-color:var(--ifm-color-emphasis-800);--ifm-blockquote-border-color:var(--ifm-color-emphasis-300);--ifm-hr-background-color:var(--ifm-color-emphasis-500);--ifm-hr-height:1px;--ifm-hr-margin-vertical:1.5rem;--ifm-scrollbar-size:7px;--ifm-scrollbar-track-background-color:#f1f1f1;--ifm-scrollbar-thumb-background-color:silver;--ifm-scrollbar-thumb-hover-background-color:#a7a7a7;--ifm-alert-background-color:inherit;--ifm-alert-border-color:inherit;--ifm-alert-border-radius:var(--ifm-global-radius);--ifm-alert-border-width:0px;--ifm-alert-border-left-width:5px;--ifm-alert-color:var(--ifm-font-color-base);--ifm-alert-padding-horizontal:var(--ifm-spacing-horizontal);--ifm-alert-padding-vertical:var(--ifm-spacing-vertical);--ifm-alert-shadow:var(--ifm-global-shadow-lw);--ifm-avatar-intro-margin:1rem;--ifm-avatar-intro-alignment:inherit;--ifm-avatar-photo-size:3rem;--ifm-badge-background-color:inherit;--ifm-badge-border-color:inherit;--ifm-badge-border-radius:var(--ifm-global-radius);--ifm-badge-border-width:var(--ifm-global-border-width);--ifm-badge-color:var(--ifm-color-white);--ifm-badge-padding-horizontal:calc(var(--ifm-spacing-horizontal)*0.5);--ifm-badge-padding-vertical:calc(var(--ifm-spacing-vertical)*0.25);--ifm-breadcrumb-border-radius:1.5rem;--ifm-breadcrumb-spacing:0.5rem;--ifm-breadcrumb-color-active:var(--ifm-color-primary);--ifm-breadcrumb-item-background-active:var(--ifm-hover-overlay);--ifm-breadcrumb-padding-horizontal:0.8rem;--ifm-breadcrumb-padding-vertical:0.4rem;--ifm-breadcrumb-size-multiplier:1;--ifm-breadcrumb-separator:url('data:image/svg+xml;utf8,<svg xmlns=\"http://www.w3.org/2000/svg\" x=\"0px\" y=\"0px\" viewBox=\"0 0 256 256\"><g><g><polygon points=\"79.093,0 48.907,30.187 146.72,128 48.907,225.813 79.093,256 207.093,128\"/></g></g><g></g><g></g><g></g><g></g><g></g><g></g><g></g><g></g><g></g><g></g><g></g><g></g><g></g><g></g><g></g></svg>');--ifm-breadcrumb-separator-filter:none;--ifm-breadcrumb-separator-size:0.5rem;--ifm-breadcrumb-separator-size-multiplier:1.25;--ifm-button-background-color:inherit;--ifm-button-border-color:var(--ifm-button-background-color);--ifm-button-border-width:var(--ifm-global-border-width);--ifm-button-color:var(--ifm-font-color-base-inverse);--ifm-button-font-weight:var(--ifm-font-weight-bold);--ifm-button-padding-horizontal:1.5rem;--ifm-button-padding-vertical:0.375rem;--ifm-button-size-multiplier:1;--ifm-button-transition-duration:var(--ifm-transition-fast);--ifm-button-border-radius:calc(var(--ifm-global-radius)*var(--ifm-button-size-multiplier));--ifm-button-group-spacing:2px;--ifm-card-background-color:var(--ifm-background-surface-color);--ifm-card-border-radius:calc(var(--ifm-global-radius)*2);--ifm-card-horizontal-spacing:var(--ifm-global-spacing);--ifm-card-vertical-spacing:var(--ifm-global-spacing);--ifm-toc-border-color:var(--ifm-color-emphasis-300);--ifm-toc-link-color:var(--ifm-color-content-secondary);--ifm-toc-padding-vertical:0.5rem;--ifm-toc-padding-horizontal:0.5rem;--ifm-dropdown-background-color:var(--ifm-background-surface-color);--ifm-dropdown-font-weight:var(--ifm-font-weight-semibold);--ifm-dropdown-link-color:var(--ifm-font-color-base);--ifm-dropdown-hover-background-color:var(--ifm-hover-overlay);--ifm-footer-background-color:var(--ifm-color-emphasis-100);--ifm-footer-color:inherit;--ifm-footer-link-color:var(--ifm-color-emphasis-700);--ifm-footer-link-hover-color:var(--ifm-color-primary);--ifm-footer-link-horizontal-spacing:0.5rem;--ifm-footer-padding-horizontal:calc(var(--ifm-spacing-horizontal)*2);--ifm-footer-padding-vertical:calc(var(--ifm-spacing-vertical)*2);--ifm-footer-title-color:inherit;--ifm-footer-logo-max-width:min(30rem,90vw);--ifm-hero-background-color:var(--ifm-background-surface-color);--ifm-hero-text-color:var(--ifm-color-emphasis-800);--ifm-menu-color:var(--ifm-color-emphasis-700);--ifm-menu-color-active:var(--ifm-color-primary);--ifm-menu-color-background-active:var(--ifm-hover-overlay);--ifm-menu-color-background-hover:var(--ifm-hover-overlay);--ifm-menu-link-padding-horizontal:0.75rem;--ifm-menu-link-padding-vertical:0.375rem;--ifm-menu-link-sublist-icon:url('data:image/svg+xml;utf8,<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"16px\" height=\"16px\" viewBox=\"0 0 24 24\"><path fill=\"rgba(0,0,0,0.5)\" d=\"M7.41 15.41L12 10.83l4.59 4.58L18 14l-6-6-6 6z\"></path></svg>');--ifm-menu-link-sublist-icon-filter:none;--ifm-navbar-background-color:var(--ifm-background-surface-color);--ifm-navbar-height:3.75rem;--ifm-navbar-item-padding-horizontal:0.75rem;--ifm-navbar-item-padding-vertical:0.25rem;--ifm-navbar-link-color:var(--ifm-font-color-base);--ifm-navbar-link-hover-color:var(--ifm-color-primary);--ifm-navbar-link-active-color:var(--ifm-link-color);--ifm-navbar-padding-horizontal:var(--ifm-spacing-horizontal);--ifm-navbar-padding-vertical:calc(var(--ifm-spacing-vertical)*0.5);--ifm-navbar-shadow:var(--ifm-global-shadow-lw);--ifm-navbar-search-input-background-color:var(--ifm-color-emphasis-200);--ifm-navbar-search-input-color:var(--ifm-color-emphasis-800);--ifm-navbar-search-input-placeholder-color:var(--ifm-color-emphasis-500);--ifm-navbar-search-input-icon:url('data:image/svg+xml;utf8,<svg fill=\"currentColor\" xmlns=\"http://www.w3.org/2000/svg\" viewBox=\"0 0 16 16\" height=\"16px\" width=\"16px\"><path d=\"M6.02945,10.20327a4.17382,4.17382,0,1,1,4.17382-4.17382A4.15609,4.15609,0,0,1,6.02945,10.20327Zm9.69195,4.2199L10.8989,9.59979A5.88021,5.88021,0,0,0,12.058,6.02856,6.00467,6.00467,0,1,0,9.59979,10.8989l4.82338,4.82338a.89729.89729,0,0,0,1.29912,0,.89749.89749,0,0,0-.00087-1.29909Z\" /></svg>');--ifm-navbar-sidebar-width:83vw;--ifm-pagination-border-radius:var(--ifm-global-radius);--ifm-pagination-color-active:var(--ifm-color-primary);--ifm-pagination-font-size:1rem;--ifm-pagination-item-active-background:var(--ifm-hover-overlay);--ifm-pagination-page-spacing:0.2em;--ifm-pagination-padding-horizontal:calc(var(--ifm-spacing-horizontal)*1);--ifm-pagination-padding-vertical:calc(var(--ifm-spacing-vertical)*0.25);--ifm-pagination-nav-border-radius:var(--ifm-global-radius);--ifm-pagination-nav-color-hover:var(--ifm-color-primary);--ifm-pills-color-active:var(--ifm-color-primary);--ifm-pills-color-background-active:var(--ifm-hover-overlay);--ifm-pills-spacing:0.125rem;--ifm-tabs-color:var(--ifm-font-color-secondary);--ifm-tabs-color-active:var(--ifm-color-primary);--ifm-tabs-color-active-border:var(--ifm-tabs-color-active);--ifm-tabs-padding-horizontal:1rem;--ifm-tabs-padding-vertical:1rem' at assets/css/styles.0c97f274.css:1:4933. Ignoring.","compilerPath":"client"}

[slorber]

It's difficult to help without a minimal repro showing versions and config.

In particular, have you tried Docusaurus Faster and the lightningCssMinimizer option?

We don't use Tailwind and we haven't created any plugin for it. We can't guarantee third-party plugins we didn't develop work great.

Most likely, the v4 future flag issue is related to the introduction of CSS Cascade Layers in v3.8: https://docusaurus.io/blog/releases/3.8#css-cascade-layers

We also have a Tailwind-related issue here, maybe you'll find an answer if you post a minimal repro the community can take a look at: #2961

[yanshay]

Setting as follows seem to solve the issue, (will test it some more):

  future: {
    v4: {
      useCssCascadeLayers: false,
    }
  },

Does this keep the v4 compatibility?

To reproduce, what I did is as follows:

1. Create a docusaurus site (using npx create-docusaurus@latest my-website classic)
2. Follow a few simple steps from this article: https://dev.to/michalwrzosek/adding-tailwind-v4-to-docusaurus-v3-3poa

npm run build generate the warning which reproduce the issue.

I also disabled the preflight of tailwind because it hurts Docusaurus look and feel (maybe also a v4 issue since in the article it isn't mentioned), but the above reproduce the warning immediately.

[slorber]

Thanks for the repro steps, that should help us investigate

--

  future: {
    v4: {
      useCssCascadeLayers: false,
    }
  },

Does this keep the v4 compatibility?

No, by default all flags are false so you would have to add each flag with a true value unfortunately.

[yanshay]

So this is practically equivalent to setting v4 to false?

[slorber]

Yes, exactly the same as v4: false, since false is the default value for all subflags