CSS @import and url() references resolve to existing files

An @import './variables.css' or url('/fonts/Inter.woff2') pointing at a file that does not exist produces no build error in most setups — the bundler emits a warning, the missing font falls back to the system default, and the broken background shows as a color block. The regression is invisible in code review and invisible in the build log, but the rendered page loses the typography and visuals the design system intended. AI-generated CSS especially drifts this way when the model hallucinates font filenames.

Open the flagged CSS file and for each unresolved reference either create the file at the path or correct the path to an existing one. A typical Next.js src/app/globals.css layout:

@import "tailwindcss";
@import './design-tokens.css';

@font-face {
  font-family: 'Inter';
  src: url('/fonts/Inter-Regular.woff2') format('woff2');
}

Confirm the font file sits at public/fonts/Inter-Regular.woff2.

• ID: ai-slop-hallucinations.asset-references.css-references-resolve

• Severity: medium

• What to look for: Walk all .css, .scss, .sass, .less files in the project (excluding node_modules/, dist/, build/, .next/, coverage/). For each file, extract references from two patterns: (1) @import '...', @import "...", @import url('...'), @import url("...") — file import statements. (2) url(...) in property values (background, background-image, font-face src, cursor, list-style-image, border-image, mask-image, content). For each reference, determine its type and resolve: Relative paths (starting with ./ or ../ or no prefix) — resolve relative to the CSS file's own directory, then verify the file exists. Absolute paths (starting with /) — check under public/ (Next.js, Remix, Astro) or static/ (Nuxt, SvelteKit). SKIP these patterns entirely — do not attempt to resolve them: data URIs (data:...), external URLs (http://, https://, //), CSS custom property references (var(--...)), fragment-only references (#id), Tailwind/PostCSS directives (@tailwind, @apply, @config, @plugin, @theme, @layer, @utility, @variant, @source, @import "tailwindcss"), empty url() calls. Count all CSS file references inspected, total resolved, total skipped (external/data/directive), total unresolved.

• Pass criteria: 100% of local CSS file references (after skipping external/data/directives) resolve to existing files. Report: "X CSS references inspected, Y resolved, Z skipped (external/directives), 0 unresolved."

• Fail criteria: At least 1 local CSS reference does not resolve to an existing file.

• Skip (N/A) when: Project has zero .css/.scss/.sass/.less files, OR all CSS files contain only Tailwind directives and framework imports with no local url() or file-referencing @import statements.

• Detail on fail: "2 unresolved CSS references: @import './variables.css' in src/app/globals.css (file src/app/variables.css does not exist), url('/fonts/Inter.woff2') in src/styles/typography.css (file public/fonts/Inter.woff2 does not exist)"

• Remediation: Broken CSS references cause missing fonts, broken backgrounds, and layout regressions — all silent failures with no build error. Fix each one:

  /* Bad: file doesn't exist */
  @import './variables.css';
  @font-face { src: url('/fonts/Inter.woff2'); }
  
  /* Good: create the file or fix the path */
  @import './design-tokens.css';  /* actual file name */
  @font-face { src: url('/fonts/Inter-Regular.woff2'); }  /* actual file */
  

  For Next.js projects using Tailwind, most CSS files should only contain @import "tailwindcss" and custom properties — if you see broken url() references, the AI likely generated CSS patterns from a different framework.