Stack Trace Panel
A copy-paste code & terminal component in pure HTML & CSS. Zero dependencies, framework-agnostic, MIT-licensed.
Code & TerminalHTMLCSSany framework
TypeError: Cannot read properties of undefined
renderUsersrc/components/User.tsx:24:9
renderListsrc/components/List.tsx:12:3
Appnode_modules/react-dom/index.js:1
Copy into your project
HTML
<!-- Stack Trace Panel — the app-code frame (.is-hl) is highlighted lime with a soft pulsing inset glow -->
<div class="nuda-ct2-stack-trace">
<div class="nuda-ct2-stack-trace__err">TypeError: Cannot read properties of undefined</div>
<div class="nuda-ct2-stack-trace__frame is-hl">
<span class="nuda-ct2-stack-trace__fn">renderUser</span>
<span class="nuda-ct2-stack-trace__loc">src/components/User.tsx:24:9</span>
</div>
<div class="nuda-ct2-stack-trace__frame">
<span class="nuda-ct2-stack-trace__fn">renderList</span>
<span class="nuda-ct2-stack-trace__loc">src/components/List.tsx:12:3</span>
</div>
<div class="nuda-ct2-stack-trace__frame">
<span class="nuda-ct2-stack-trace__fn">App</span>
<span class="nuda-ct2-stack-trace__loc">node_modules/react-dom/index.js:1</span>
</div>
</div>CSS
.nuda-ct2-stack-trace {
width: 300px;
background: #09090b;
border: 1px solid rgba(255,255,255,.08);
border-radius: 8px;
padding: 11px 13px;
font: 500 11px ui-monospace,SFMono-Regular,Menlo,monospace;
display: flex;
flex-direction: column;
gap: 6px;
}
.nuda-ct2-stack-trace__err {
color: #ff8383;
font-weight: 600;
padding-bottom: 6px;
border-bottom: 1px solid rgba(255,255,255,.08);
}
.nuda-ct2-stack-trace__frame {
display: flex;
justify-content: space-between;
gap: 8px;
padding: 4px 6px;
border-left: 2px solid transparent;
border-radius: 0 4px 4px 0;
color: #777;
}
.nuda-ct2-stack-trace__fn {
color: #9a9aa2;
}
.nuda-ct2-stack-trace__loc {
color: #4b4b52;
white-space: nowrap;
overflow: hidden;
text-overflow: ellipsis;
}
.nuda-ct2-stack-trace__frame.is-hl {
border-left-color: #e4ff54;
background: rgba(228,255,84,.07);
animation: _nuda-ct2stacktraceglow 2.2s ease-in-out infinite;
}
.nuda-ct2-stack-trace__frame.is-hl .nuda-ct2-stack-trace__fn {
color: #e4ff54;
font-weight: 700;
}
.nuda-ct2-stack-trace__frame.is-hl .nuda-ct2-stack-trace__loc {
color: #cfcfcf;
}
@keyframes _nuda-ct2stacktraceglow {
0%,100% {
box-shadow: inset 0 0 0 rgba(228,255,84,0);
}
50% {
box-shadow: inset 2px 0 8px -4px rgba(228,255,84,.7);
}
}
@media (prefers-reduced-motion:reduce) {
.nuda-ct2-stack-trace__frame.is-hl {
animation: none;
}
}
How to use Stack Trace Panel
Paste the HTML where you need it and the CSS into a global stylesheet (or a <style> tag). Every class is prefixed nuda- so it never collides with Tailwind or your own styles. Tweak the CSS custom properties to match your design system.
Works in React, Vue, Svelte, Astro, Next.js, Nuxt, Laravel Blade, Django, Rails — or a single .html file. No npm install, no build step.