Style your ReactiveHTML template#

In this guide we will show you how to style your ReactiveHTML _template using the _stylesheets attribute and CSS.

If you are not familiar with CSS then the W3 CSS School is a good resource to learn from. You can also ask ChatGPT for help. It can often provide you with an HTML and CSS starting point that you can fine tune.

A Layout with CSS Styling#

import param
import panel as pn
from panel.reactive import ReactiveHTML


class SensorLayout(ReactiveHTML):
    object = param.Parameter(allow_refs=False)

    _template = """
    <div class="pn-container styled-container">
        <h1 id="name">Temperature</h1>
        <h2 id="subtitle">A measurement from the sensor</h1>
        <div id="object" class="styled-object">${object}</div>

    _stylesheets = ["""
        .pn-container {height: 100%;width: calc(100% - 20px); margin:10px;}
        .styled-container {border-radius: 10px;border: 2px solid gray;text-align: center; padding:10px;}
        .styled-object {display: inline-block;}

dial = pn.widgets.Dial(
    name="°C", value=37, format="{value}", colors=[(0.40, "green"), (1, "red")], bounds=(0, 100),
    object=dial, name="Temperature",
    styles={"border": "2px solid lightgray"},

Note the difference between styles and _stylesheets.

  • styles styles the outer HTML element wrapping the component

  • _stylesheets styles the HTML elements inside the component