I keep getting this message on compile

warn - No utility classes were detected in your source files. If this is unexpected, double-check the `content` option in your Tailwind CSS configuration.
warn - https://tailwindcss.com/docs/content-configuration
/*
! tailwindcss v3.4.3 | MIT License | https://tailwindcss.com
*/

/*
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: #e5e7eb;
  /* 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 */
  -o-tab-size: 4;
     tab-size: 4;
  /* 3 */
  font-family: ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
  /* 4 */
  font-feature-settings: normal;
  /* 5 */
  font-variation-settings: 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]) {
  -webkit-text-decoration: underline dotted;
          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: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  /* 1 */
  font-feature-settings: normal;
  /* 2 */
  font-variation-settings: 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::-moz-placeholder, textarea::-moz-placeholder {
  opacity: 1;
  /* 1 */
  color: #9ca3af;
  /* 2 */
}

input::placeholder,
textarea::placeholder {
  opacity: 1;
  /* 1 */
  color: #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] {
  display: none;
}

*, ::before, ::after {
  --tw-border-spacing-x: 0;
  --tw-border-spacing-y: 0;
  --tw-translate-x: 0;
  --tw-translate-y: 0;
  --tw-rotate: 0;
  --tw-skew-x: 0;
  --tw-skew-y: 0;
  --tw-scale-x: 1;
  --tw-scale-y: 1;
  --tw-pan-x:  ;
  --tw-pan-y:  ;
  --tw-pinch-zoom:  ;
  --tw-scroll-snap-strictness: proximity;
  --tw-gradient-from-position:  ;
  --tw-gradient-via-position:  ;
  --tw-gradient-to-position:  ;
  --tw-ordinal:  ;
  --tw-slashed-zero:  ;
  --tw-numeric-figure:  ;
  --tw-numeric-spacing:  ;
  --tw-numeric-fraction:  ;
  --tw-ring-inset:  ;
  --tw-ring-offset-width: 0px;
  --tw-ring-offset-color: #fff;
  --tw-ring-color: rgb(59 130 246 / 0.5);
  --tw-ring-offset-shadow: 0 0 #0000;
  --tw-ring-shadow: 0 0 #0000;
  --tw-shadow: 0 0 #0000;
  --tw-shadow-colored: 0 0 #0000;
  --tw-blur:  ;
  --tw-brightness:  ;
  --tw-contrast:  ;
  --tw-grayscale:  ;
  --tw-hue-rotate:  ;
  --tw-invert:  ;
  --tw-saturate:  ;
  --tw-sepia:  ;
  --tw-drop-shadow:  ;
  --tw-backdrop-blur:  ;
  --tw-backdrop-brightness:  ;
  --tw-backdrop-contrast:  ;
  --tw-backdrop-grayscale:  ;
  --tw-backdrop-hue-rotate:  ;
  --tw-backdrop-invert:  ;
  --tw-backdrop-opacity:  ;
  --tw-backdrop-saturate:  ;
  --tw-backdrop-sepia:  ;
  --tw-contain-size:  ;
  --tw-contain-layout:  ;
  --tw-contain-paint:  ;
  --tw-contain-style:  ;
}

::backdrop {
  --tw-border-spacing-x: 0;
  --tw-border-spacing-y: 0;
  --tw-translate-x: 0;
  --tw-translate-y: 0;
  --tw-rotate: 0;
  --tw-skew-x: 0;
  --tw-skew-y: 0;
  --tw-scale-x: 1;
  --tw-scale-y: 1;
  --tw-pan-x:  ;
  --tw-pan-y:  ;
  --tw-pinch-zoom:  ;
  --tw-scroll-snap-strictness: proximity;
  --tw-gradient-from-position:  ;
  --tw-gradient-via-position:  ;
  --tw-gradient-to-position:  ;
  --tw-ordinal:  ;
  --tw-slashed-zero:  ;
  --tw-numeric-figure:  ;
  --tw-numeric-spacing:  ;
  --tw-numeric-fraction:  ;
  --tw-ring-inset:  ;
  --tw-ring-offset-width: 0px;
  --tw-ring-offset-color: #fff;
  --tw-ring-color: rgb(59 130 246 / 0.5);
  --tw-ring-offset-shadow: 0 0 #0000;
  --tw-ring-shadow: 0 0 #0000;
  --tw-shadow: 0 0 #0000;
  --tw-shadow-colored: 0 0 #0000;
  --tw-blur:  ;
  --tw-brightness:  ;
  --tw-contrast:  ;
  --tw-grayscale:  ;
  --tw-hue-rotate:  ;
  --tw-invert:  ;
  --tw-saturate:  ;
  --tw-sepia:  ;
  --tw-drop-shadow:  ;
  --tw-backdrop-blur:  ;
  --tw-backdrop-brightness:  ;
  --tw-backdrop-contrast:  ;
  --tw-backdrop-grayscale:  ;
  --tw-backdrop-hue-rotate:  ;
  --tw-backdrop-invert:  ;
  --tw-backdrop-opacity:  ;
  --tw-backdrop-saturate:  ;
  --tw-backdrop-sepia:  ;
  --tw-contain-size:  ;
  --tw-contain-layout:  ;
  --tw-contain-paint:  ;
  --tw-contain-style:  ;
}

heres the config

// See the Tailwind configuration guide for advanced usage
// https://tailwindcss.com/docs/configuration

const plugin = require("tailwindcss/plugin")
const fs = require("fs")
const path = require("path")

module.exports = {
  content: [
    "./js/**/*.js",
    "../lib/*_web.ex",
    "../lib/*_web/**/*.*ex",
    "../lib/**/*.heex",
    "../lib/**/*.leex",
    "../lib/**/*.eex",
    "../lib/**/*.html",
    "../lib/**/*.html.heex",
    "../lib/**/*.html.eex"
  ],
  theme: {
    extend: {
      colors: {
        brand: "#FD4F00",
      }
    },
  },
  plugins: [
    require("@tailwindcss/forms"),
    // Allows prefixing tailwind classes with LiveView classes to add rules
    // only when LiveView classes are applied, for example:
    //
    //     <div class="phx-click-loading:animate-ping">
    //
    plugin(({addVariant}) => addVariant("phx-no-feedback", [".phx-no-feedback&", ".phx-no-feedback &"])),
    plugin(({addVariant}) => addVariant("phx-click-loading", [".phx-click-loading&", ".phx-click-loading &"])),
    plugin(({addVariant}) => addVariant("phx-submit-loading", [".phx-submit-loading&", ".phx-submit-loading &"])),
    plugin(({addVariant}) => addVariant("phx-change-loading", [".phx-change-loading&", ".phx-change-loading &"])),

    // Embeds Heroicons (https://heroicons.com) into your app.css bundle
    // See your `CoreComponents.icon/1` for more information.
    //
    plugin(function({matchComponents, theme}) {
      let iconsDir = path.join(__dirname, "./vendor/heroicons/optimized")
      let values = {}
      let icons = [
        ["", "/24/outline"],
        ["-solid", "/24/solid"],
        ["-mini", "/20/solid"]
      ]
      icons.forEach(([suffix, dir]) => {
        fs.readdirSync(path.join(iconsDir, dir)).forEach(file => {
          let name = path.basename(file, ".svg") + suffix
          values[name] = {name, fullPath: path.join(iconsDir, dir, file)}
        })
      })
      matchComponents({
        "hero": ({name, fullPath}) => {
          let content = fs.readFileSync(fullPath).toString().replace(/\r?\n|\r/g, "")
          return {
            [`--hero-${name}`]: `url('data:image/svg+xml;utf8,${content}')`,
            "-webkit-mask": `var(--hero-${name})`,
            "mask": `var(--hero-${name})`,
            "mask-repeat": "no-repeat",
            "background-color": "currentColor",
            "vertical-align": "middle",
            "display": "inline-block",
            "width": theme("spacing.5"),
            "height": theme("spacing.5")
          }
        }
      }, {values})
    })
  ]
}