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HTML 

              
                <emerald-counter current-count=7>
</emerald-counter>

<div>
  <p style="max-width: 65ch">An experiment in creating a re-usable web component for a notification indicator with a counter.  The biggest disappointment in this experiment was discovering that the SVG component does not respond to the <kbd>::part()</kbd> selector, so it's not possible
    to change the color of the SVG component without providing some hacky extra property
    on the element itself.
  </p>
  <p style="max-width: 65ch">Of note here is the <kbd>::root</kbd> declaration in the CSS.  That specifies 
  a size between 12px and 48px, depending on how wide your viewport is.  If you resize the browser window (or just <kbd>inspect</kbd> to get a slideable resizable viewport), you can play with the viewport size and watch the component scale smoothly from "10 foot display" all the way down to "looks good on your phone" size.</p>
</div>
!

CSS 

              
                    body {
      background: #fafafa;
    }
   :root {
       --step-0: clamp(0.75rem, 0.491rem + 1.295vw, 3rem);
   }
   emerald-counter {
       width: calc(var(--step-0) * 4);
       font-size: calc(var(--step-0) * 4);
   }
   emerald-counter::part(counter) {
       background-color: green;
   }
   emerald-counter::part(number) {
       color: yellow;
   }
   emerand-counter::part(bell) {
       fill: navy;
       stroke: navy;
   }
!

JS 

              
                import {
  html,
  css,
  LitElement
} from "https://cdn.skypack.dev/lit@2.0.0-rc.2?dts";

import {
  customElement,
  property,
  state
} from "https://cdn.skypack.dev/lit@2.0.0-rc.2/decorators.js";

@customElement("emerald-counter")
class EmeraldCounter extends LitElement {
    static styles = css`
        :host {
            display: inline-block;
            aspect-ratio: 1 / 1;
        }

        div#main {
            position: relative;
            display: block;
            width: 100%;
            height: 100%;
        }

        svg {
            position: relative;
            display: block;
            width: 100%;
            height: 100%;
            z-index: 0;
        }

        div#counter {
            display: grid;
            justify-content: center;
            align-content: center;
            position: absolute;
            z-index: 1;
            font-family: "Helvetica Neue", "Arial Nova", Helvetica, Arial, sans-serif;
            font-size: 0.25em;
            top: 8%;
            left: 60%;
            width: 30%;
            height: 30%;
            aspect-ratio: 1 / 1;
            border-radius: 50%;
            border: 0.2em solid white;
            font-weight: bold;
            background: red;
            color: white;
        }

        div#counter span {
            padding-top: 0.1em;
            vertical-align: text-bottom;
        }
    `;

    @property({ type: Number, attribute: "current-count" })
    counter = 0;

    render() {
        return html`
            <div id="main">
                <svg
                    id="Layer_1"
                    version="1.1"
                    viewBox="0 0 512 512"
                    xml:space="preserve"
                    xmlns="http://www.w3.org/2000/svg"
                    xmlns:xlink="http://www.w3.org/1999/xlink"
                    part="bell"
                >
                    <g>
                        <path
                            part="bell"
                            d="M381.7,225.9c0-97.6-52.5-130.8-101.6-138.2c0-0.5,0.1-1,0.1-1.6c0-12.3-10.9-22.1-24.2-22.1c-13.3,0-23.8,9.8-23.8,22.1   c0,0.6,0,1.1,0.1,1.6c-49.2,7.5-102,40.8-102,138.4c0,113.8-28.3,126-66.3,158h384C410.2,352,381.7,339.7,381.7,225.9z"
                        />
                        <path
                            part="bell"
                            d="M256.2,448c26.8,0,48.8-19.9,51.7-43H204.5C207.3,428.1,229.4,448,256.2,448z"
                        />
                    </g>
                </svg>
                ${!this.counter || this.counter < 1
                    ? nothing
                    : html`<div id="counter" part="counter"><span part="number">${this.counter}</span></div>`}
            </div>
        `;
    }
}
!
999px

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