Like you see in inspector, you defined only border color but not border width. Because it is 0px, it is invisible ;)

You need to change it to

class="border border-gray-800"

"border" will by default mean border-width: 1px so if you need thicker use for example

class="border-2 border-gray-800"

or if you wanna it only on one side

class="border-right border-gray-800"

More in documentation.

Answer from chojnicki on Stack Overflow
🌐
Tailwind CSS
tailwindcss.com › docs › border-width
border-width - Borders - Tailwind CSS
Use border or border-<number> utilities like border-2 and border-4 to set the border width for all sides of an element:
Discussions

Tailwind Inputs have no Borders
You have to either have the @forms plugin added and installed or do class=“border border-gray-800” or class=“border-2 border-gray-800”. For ‘border-2’ you make have to do an npm build run to regenerate the css style sheet (depending on your setup). Edit: Also make sure you clear browser cache, sometimes it will hang and not update with the new style (not super common, but can happen). More on reddit.com
🌐 r/tailwindcss
9
1
October 28, 2022
Border - Top only
Firstly, thanks for Tailwind! I'm trying to add a border-top to a div and I'm not sure that's even possible currently... on version 0.2.2 More on github.com
🌐 github.com
11
October 7, 2017
Border-color issue In Tailwind 1.0
If you're sure that `.border-orange` ... before Tailwind CSS sees your CSS, as `@apply` can only be used for classes in the same CSS tree.` As if it does not default to the 300 orange like it does for text-{color} However @apply border-orange-300 OR @apply border-oranged; (when a custom color specified) does work... More on github.com
🌐 github.com
2
March 29, 2019
Tailwind does not work with some attributes in React project with NextUI
do the classes get generated in the css? open the browser and look. likely it is that the file you’re changing is not being read by tailwind. look into the configs, there’s a content array there. More on reddit.com
🌐 r/tailwindcss
10
2
November 27, 2023
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GitHub
github.com › tailwindlabs › tailwindcss › issues › 435
Browser ignoring .border · Issue #435 · tailwindlabs/tailwindcss
March 26, 2018 - I've come across an issue where the browser is ignoring the .border class: This happens in both Chrome & Firefox.
Published   Mar 26, 2018
🌐
GeeksforGeeks
geeksforgeeks.org › css › tailwind-css-border-color
Tailwind CSS Border Color - GeeksforGeeks
July 23, 2025 - This class accepts more than one value in tailwind CSS in which all the properties are covered in class form. It is the alternative to the CSS border-color property. This class is used to specify the border color of an element. ... Note: The color’s values can be changeable according to your need from 50-900, the span should be 100, after the 100.
🌐
Tailwind CSS
night-tailwindcss.vercel.app › docs › border-color
Border Color - Tailwind CSS
If you don't plan to use the border color utilities in your project, you can disable them entirely by setting the borderColor property to false in the corePlugins section of your config file: // tailwind.config.js module.exports = { corePlugins: ...
🌐
HubSpot
blog.hubspot.com › website › css-border
How to Create and Style Borders in CSS
February 23, 2023 - If you’ve set the shorthand border property in CSS and the border is not showing, the most likely issue is that you did not define the border style. While the border-width and border-color property values can be omitted, the border-style property ...
Find elsewhere
🌐
Tailwind CSS
tailwindcss.com › docs › border-style
border-style - Borders - Tailwind CSS
Use utilities like border-solid and border-dotted to control an element's border style:
🌐
GeeksforGeeks
geeksforgeeks.org › css › tailwind-css-border-width
Tailwind CSS Border Width - GeeksforGeeks
July 23, 2025 - <!DOCTYPE html> <html> <head> <link href= "https://unpkg.com/[email protected]/dist/tailwind.min.css" rel="stylesheet"> </head> <body class="text-center"> <h1 class="text-green-600 text-5xl font-bold"> GeeksforGeeks </h1> <b>Tailwind CSS Border Width Class</b> <div class="mx-4 grid grid-cols-4 gap-2 bg-green-200 p-2"> <!-- First sub div is not for roundig--> <div class="border-b-2 border-green-900 bg-green-400 w-full h-12"> border-b-2 </div> <div class="border-r-2 border-green-900 bg-green-400 w-full h-12"> border-r-2 </div> <div class="border-l-2 border-green-900 bg-green-400 w-full h-12"> border-l-2 </div> <div class="border-t-2 border-green-900 bg-green-400 w-full h-12"> border-t-2 </div> </div> </body> </html>
🌐
Aleksandr Hovhannisyan
aleksandrhovhannisyan.com › blog › why-i-dont-like-tailwind-css
Why I Don’t Like Tailwind CSS | Aleksandr Hovhannisyan
December 18, 2021 - .thing { width: 16px; height: 16px; color: white; background-color: black; padding: 0.25rem 0.5rem; margin: 0.25rem; border-radius: 0.25rem; font-size: 0.875rem; line-height: 1.25rem; } @media screen and (min-width: 768px) { .thing { width: 32px; height: 32px; border-radius: 0.375rem; font-size: 1rem; line-height: 1.5rem; } } @media screen and (min-width: 1024px) { .thing { width: 48px; height: 48px; border-radius: 0.5rem; font-size: 1.125rem; line-height: 1.75rem; } } If you’re tracking down a UI bug and you know it’s not in your tablet/desktop version, then you can simply ignore the blocks of media queries and focus on the base styles. Over in Tailwind-land, you have to mentally exclude the responsive class names as you scan your classes horizontally, and then you have to figure out how all of these separate pieces fit together to create the final look of your UI.
🌐
Tailwind CSS
tailwind.build › classes › border-color › border-current
.border-current - Tailwind CSS class
← Tailwind CSS classes list · <div class="border-current border-4 p-8"></div> Click one of the examples listed below to open the Shuffle Visual Editor with the UI library that uses the selected component. Open in Visual Editor → · .border-current { border-color: currentColor; } .border-transparent ·
🌐
GitHub
github.com › tailwindlabs › tailwindcss › issues › 289
Border - Top only · Issue #289 · tailwindlabs/tailwindcss
October 7, 2017 - .border-solid { border-style: solid; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; } Which works...except it also adds a border on all the other sides of the div of 4px!
Published   Dec 04, 2017
🌐
GitHub
github.com › tailwindlabs › tailwindcss › issues › 808
Border-color issue In Tailwind 1.0 · Issue #808 · tailwindlabs/tailwindcss
March 29, 2019 - If you're sure that `.border-orange` exists, make sure that any `@import` statements are being properly processed before Tailwind CSS sees your CSS, as `@apply` can only be used for classes in the same CSS tree.` As if it does not default to the 300 orange like it does for text-{color} However @apply border-orange-300 OR @apply border-oranged; (when a custom color specified) does work.
Published   Mar 29, 2019
🌐
LogRocket
blog.logrocket.com › home › comparing tailwind css to bootstrap: is it time to ditch ui kits?
Comparing Tailwind CSS to Bootstrap: Is it time to ditch UI kits?
June 4, 2024 - Which even if it does change, you get the benefit of not breaking other components by changing your design requirements 🙂 · People often forget that other programming languages apply the styling directly to the elements rather than global style sheets, so if it works for them! Can work for you ... Nice introduction! Really helpful for beginners. ... It looks like ‘button’ needs to added to the class of the Tailwind button.
🌐
CodePen
codepen.io › adamwathan › pen › eejzGO
Tailwind CSS :focus-within demo
Note: your code becomes un-folded during formatting. ... Visit your global Editor Settings. ... <div class="flex items-center justify-center min-h-screen"> <form class="w-full max-w-sm"> <div class="flex items-center border-b-2 border-grey-light focus-within:border-teal py-2"> <input class="outline-none appearance-none bg-transparent border-none w-full text-grey-darker mr-3 py-1 px-2" type="text" placeholder="Jane Doe" aria-label="Full name"> <button class="flex-no-shrink bg-teal hover:bg-teal-dark border-teal hover:border-teal-dark text-sm border-4 text-white py-1 px-2 rounded" type="button"> Sign Up </button> <button class="flex-no-shrink border-transparent border-4 text-teal hover:text-teal-darker text-sm py-1 px-2 rounded" type="button"> Cancel </button> </div> </form> </div>
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Pretagteam
ww25.pretagteam.com › question › border-color-doesnt-work-in-tailwind-css
Pretagteam
August 1, 2021 - We cannot provide a description for this page right now
🌐
Newbedev
newbedev.com › javascript-tailwind-css-hover-border-not-working-code-example
tailwind css hover border not working code example
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