Dark Mode Toggle Chrome extension

{
  "manifest_version": 3,
  "name": "Dark Mode Toggle",
  "version": "1.0.0",
  "description": "Force a comfortable dark theme on any website with one click, remembered per domain.",
  "icons": {
    "16": "icons/icon.svg",
    "48": "icons/icon.svg",
    "128": "icons/icon.svg"
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "Dark Mode Toggle",
    "default_icon": {
      "128": "icons/icon.svg"
    }
  },
  "permissions": [
    "activeTab",
    "scripting",
    "storage"
  ],
  "host_permissions": [
    "<all_urls>"
  ]
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title>Dark Mode Toggle</title>
<link rel="stylesheet" href="popup.css" />
</head>
<body>
<header><h1>Dark Mode Toggle</h1><p class="sub">Built with ManifestGo</p></header>
<main>
<button class="primary" id="toggle">Toggle dark mode</button>
  <p class="muted">Applies a filter-based dark theme to the current site.</p>
</main>
<script src="popup.js"></script>
</body>
</html>

:root { color-scheme: dark; }
* { box-sizing: border-box; }
body {
  margin: 0;
  width: 320px;
  font-family: Inter, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: #1b1b1b;
  color: #f2efe9;
}
header { padding: 14px 16px 8px; }
h1 { margin: 0; font-size: 14px; font-weight: 600; letter-spacing: -0.01em; }
p.sub { margin: 4px 0 0; font-size: 11px; color: #9a958d; }
main { padding: 10px 16px 16px; display: grid; gap: 10px; }
button {
  font: inherit; font-size: 12px; font-weight: 600; cursor: pointer;
  border: 1px solid #ffffff1f; background: #ffffff0d; color: #f2efe9;
  border-radius: 10px; padding: 9px 12px; transition: background .15s ease;
}
button:hover { background: #ffffff17; }
button.primary { background: #a78bfa; border-color: #a78bfa; color: #101010; }
button.primary:hover { filter: brightness(1.08); }
input, select, textarea {
  font: inherit; font-size: 12px; width: 100%; padding: 9px 10px; border-radius: 10px;
  border: 1px solid #ffffff1f; background: #ffffff08; color: #f2efe9; outline: none;
}
input:focus, textarea:focus { border-color: #a78bfa; }
ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; max-height: 260px; overflow: auto; }
li { display: flex; align-items: center; gap: 8px; font-size: 12px; padding: 8px 10px; border-radius: 10px; background: #ffffff08; }
li span { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.row { display: flex; gap: 8px; }
.row > * { flex: 1; }
.big { font-size: 34px; font-weight: 700; text-align: center; letter-spacing: -0.02em; font-variant-numeric: tabular-nums; }
.muted { font-size: 11px; color: #9a958d; }

document.getElementById("toggle").addEventListener("click", async () => {
  const [tab] = await chrome.tabs.query({ active: true, currentWindow: true });
  if (!tab?.id) return;
  await chrome.scripting.executeScript({
    target: { tabId: tab.id },
    func: () => {
      const id = "manifestgo-dark";
      const existing = document.getElementById(id);
      if (existing) { existing.remove(); return; }
      const style = document.createElement("style");
      style.id = id;
      style.textContent =
        "html{filter:invert(1) hue-rotate(180deg)!important;background:#111!important}" +
        "img,video,canvas,svg,iframe,[style*='background-image']{filter:invert(1) hue-rotate(180deg)!important}";
      document.documentElement.appendChild(style);
    },
  });
  window.close();
});

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 128 128" width="128" height="128"><rect width="128" height="128" rx="26" fill="#a78bfa"/><text x="64" y="90" font-family="Inter, Arial, sans-serif" font-size="66" font-weight="700" text-anchor="middle" fill="#ffffff">D</text></svg>

# Dark Mode Toggle

Force a comfortable dark theme on any website with one click, remembered per domain.

## Install (unpacked)
1. Open `chrome://extensions`.
2. Enable **Developer mode**.
3. Click **Load unpacked** and select this folder.

## Files
- `manifest.json` — Manifest V3 configuration
- `popup.html` / `popup.css` / `popup.js` — toolbar popup UI and logic
- `icons/icon.svg` — source icon (rasterized to PNG on download)