Reasoning Panel

A panel that shows each thinking step while the AI works, then folds itself away with a summary you can open again.

Download the file Open full screen

One HTML file with the CSS and JavaScript inside. No library needed. MIT license.

Live preview

How to use it

Click Copy the code, or download the file.
Paste the CSS into your stylesheet, the HTML where you want the component, and the script before the closing body tag.
Change --accent at the top of the CSS to your brand color, then connect the events to your AI service.

What you get

Works in light and dark mode automatically
Keyboard friendly, with labels for screen readers
Fits phones, tablets and desktops
Respects the reduced motion setting
No framework, so it works with any stack

The code

<!DOCTYPE html>
<!--
  Reasoning Panel: a free AI UI component
  From 100 Free AI UI Components by MM Rahman Bappi, MIT license
  https://mmrahmanbappi.github.io/100-free-ai-ui-components/

  How to use: copy the CSS, HTML and JavaScript below into your page.
  Colors are CSS variables at the top. Change --accent to match your brand.
  Light and dark themes follow the visitor's system setting, or set
  data-theme="dark" or data-theme="light" on the html element.
-->
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Reasoning Panel | Free AI UI Component</title>
<meta name="description" content="A panel that shows each thinking step while the AI works, then folds itself away with a summary you can open again.">
<meta name="robots" content="noindex, follow">
<style>
:root{
  --accent:#5b5bd6; --accent-ink:#fff; --accent-soft:#ececfc;
  --bg:#f7f7f8; --surface:#fff; --surface-2:#f1f1f4; --ink:#17171c; --text:#3a3a44; --muted:#6c6c78;
  --line:#e3e3e8; --good:#15803d; --warn:#b45309; --bad:#c62828;
  --radius:14px; --shadow:0 1px 2px rgba(20,20,30,.06),0 8px 24px -12px rgba(20,20,30,.18);
  --font:system-ui,-apple-system,"Segoe UI",Roboto,Ubuntu,sans-serif; --mono:ui-monospace,"Cascadia Code",Menlo,Consolas,monospace;
}
@media (prefers-color-scheme:dark){:root:not([data-theme=light]){
  --accent:#8b8bff; --accent-ink:#0f0f16; --accent-soft:#25254a;
  --bg:#0f0f13; --surface:#18181f; --surface-2:#212129; --ink:#f3f3f6; --text:#d4d4dc; --muted:#9a9aa8;
  --line:#2c2c36; --good:#4ade80; --warn:#fbbf24; --bad:#f87171; --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 30px -12px rgba(0,0,0,.6);
}}
:root[data-theme=dark]{
  --accent:#8b8bff; --accent-ink:#0f0f16; --accent-soft:#25254a;
  --bg:#0f0f13; --surface:#18181f; --surface-2:#212129; --ink:#f3f3f6; --text:#d4d4dc; --muted:#9a9aa8;
  --line:#2c2c36; --good:#4ade80; --warn:#fbbf24; --bad:#f87171; --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 30px -12px rgba(0,0,0,.6);
}
*{box-sizing:border-box}
html,body{margin:0}
body{min-height:100vh;display:grid;grid-template-columns:minmax(0,1fr);place-items:center;padding:24px;background:var(--bg);color:var(--text);font:15px/1.5 var(--font);-webkit-font-smoothing:antialiased}
button,input,textarea,select{font:inherit;color:inherit}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
[hidden]{display:none!important}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition:none!important}}
/* ---- component ---- */
.wrap{width:min(100%,640px);display:flex;flex-direction:column;gap:14px}
.ai{display:flex;gap:12px;align-items:flex-start}
.av{width:32px;height:32px;border-radius:50%;background:var(--accent);color:var(--accent-ink);display:grid;place-items:center;flex:none}
.bubble{background:var(--surface);border:1px solid var(--line);border-radius:4px 16px 16px 16px;padding:12px 15px;box-shadow:var(--shadow);color:var(--text);min-width:0;max-width:100%}
.meta{font-size:12px;color:var(--muted)}
.replay{align-self:center;border:1px solid var(--line);background:var(--surface);color:var(--text);border-radius:999px;padding:6px 14px;font-size:13px;cursor:pointer}
.replay:hover{border-color:var(--accent);color:var(--ink)}
.rp{border:1px solid var(--line);border-radius:12px;background:var(--surface-2);margin-bottom:10px;overflow:hidden}
.rp summary{list-style:none;display:flex;align-items:center;gap:8px;padding:9px 12px;cursor:pointer;font-size:14px;color:var(--muted);font-weight:600}
.rp summary::-webkit-details-marker{display:none}
.rp summary .ch{margin-left:auto;transition:transform .2s}.rp[open] summary .ch{transform:rotate(180deg)}
.rp ol{margin:0;padding:0 14px 12px 32px;font-size:14px;color:var(--text)}
.rp li{margin:4px 0;animation:in .25s ease}@keyframes in{from{opacity:0;transform:translateY(4px)}}
.live{background:linear-gradient(90deg,var(--muted),var(--ink),var(--muted));background-size:200% 100%;-webkit-background-clip:text;background-clip:text;color:transparent;animation:s 1.5s linear infinite}
@keyframes s{from{background-position:100% 0}to{background-position:-100% 0}}
.ans{animation:in .3s ease}
</style>
</head>
<body>
<div class="wrap">
  <div class="ai"><div class="av" aria-hidden="true"><svg viewBox="0 0 24 24" width="16" height="16" fill="currentColor" aria-hidden="true"><path d="M12 2l1.8 6.2L20 10l-6.2 1.8L12 18l-1.8-6.2L4 10l6.2-1.8z"/></svg></div><div class="bubble" style="flex:1">
    <details class="rp" id="rp" open><summary><span id="lab" class="live">Thinking</span><span class="ch"><svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" stroke-width="2.2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M6 9l6 6 6-6"/></svg></span></summary><ol id="steps" aria-live="polite"></ol></details>
    <div id="ans"></div>
  </div></div>
  <button class="replay" id="r" type="button">Run again</button>
</div>
<script>
// Demo helper: add ?theme=dark or ?theme=light to the address to preview a theme.
(function(){var t=new URLSearchParams(location.search).get('theme');if(t)document.documentElement.dataset.theme=t;})();
var STEPS=['Reading the question about moving the meeting','Checking which days both people are free','Thursday afternoon works for everyone','Writing a short, polite message'];
var rp=document.getElementById('rp'),lab=document.getElementById('lab'),steps=document.getElementById('steps'),ans=document.getElementById('ans'),timers=[];
function run(){timers.forEach(clearTimeout);timers=[];steps.innerHTML='';ans.innerHTML='';rp.open=true;lab.className='live';lab.textContent='Thinking';var start=Date.now();
  STEPS.forEach(function(s,i){timers.push(setTimeout(function(){var li=document.createElement('li');li.textContent=s;steps.appendChild(li);},700*(i+1)));});
  timers.push(setTimeout(function(){rp.open=false;lab.className='';lab.textContent='Thought for '+Math.round((Date.now()-start)/1000)+' seconds';
    ans.innerHTML='<div class="ans">Here is a message you can send: "Hi Sam, could we move our meeting to Thursday at 3pm? Thanks!"</div>';},700*(STEPS.length+1)+300));}
document.getElementById('r').addEventListener('click',run);run();
</script>
</body>
</html>

More thinking and loading components

Typing Dots
Three bouncing dots inside an answer bubble, the classic sign that the AI is writing a reply.
Thinking Shimmer
A soft light moves across the word Thinking while the AI works, then it changes to how long the thinking took.
Streaming Text
The answer appears word by word with a blinking cursor, the way most AI chat apps show a reply as it is written.
Agent Progress Steps
A checklist of what an AI agent is doing right now. Each step shows a spinner while it runs and a tick when it is done.
Skeleton Message
Grey placeholder lines with a moving shine that hold the space of the answer while it loads, so the page does not jump.
AI Orb
A glowing orb that shows what the assistant is doing: resting, listening or thinking. Great for voice and assistant screens.

Reasoning Panel

How to use it

What you get

The code

More thinking and loading components

Typing Dots

Thinking Shimmer

Streaming Text

Agent Progress Steps

Skeleton Message

AI Orb