~/sandbox/
HTML
CSS
JS
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LIVE PREVIEW
LIVE
quick-start.md
- Write HTML, CSS and JS in the three panes, then click RUN to render the result below.
- Use the gear icon for Pen Settings: preprocessors, <html> classes, <head> extras, and external stylesheets/scripts. Settings are saved with the X-Script.
- Log in to SAVE an X-Script, or FORK someone else’s X-Script to create your own editable copy.
- X-Scripts need a title, and it must be different from your other saved X-Script titles.
- The preview runs in a sandboxed frame and cannot access this site or your cookies.
- DOWNLOAD .HTML saves a single self-contained HTML file with your CSS and JS inlined.
pen.settings.json
Slim has no in-browser compiler — the source runs unprocessed.
Compiled with the Jade engine (Pug's predecessor) — most Pug syntax works; newer Pug-only features may not.
Raw HTML injected into the preview's <head> — e.g. the viewport meta tag, or a webfont <link>.
Runs without a plugin pipeline in-browser — output matches the input CSS.
CSS Base
Autoprefixing here covers common properties (flex, transforms, transitions, animations) — not a full browserslist-driven Autoprefixer.
Add External Stylesheets
Added as <link>s in order, before the CSS in the editor.
Add External Scripts
Loaded in order, before the JS in the editor runs.
register.sh
min. 8 characters