Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using it's URL and the proper URL extention.

+ add another resource

JavaScript

Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

Behavior

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML

              
                <div class="t">
	<div class="t__inner">
		<div class="t__value">
			<span class="t__digit" data-temp>-</span><span class="t__digit" data-temp>-</span><span class="t__degree">°</span>
		</div>
		<button class="t__drag" type="button" data-drag>
			<span class="t__sr" data-temp-sr>--</span>
		</button>
		<svg class="t__arrows" width="256px" height="256px" viewBox="0 0 256 256">
			<g fill="none" stroke="currentColor" stroke-width="4" stroke-linecap="round" stroke-linejoin="round" opacity="0.2">
				<polyline points="227.893 117.393 238.499 128 249.107 117.392"/>
				<polyline points="5.393 117.393 16 128 26.608 117.392"/>
				<path d="M16,128a111.25,111.25,0,0,1,222.5,0"/>
			</g>
		</svg>
		<span class="t__units">
			<button class="t__unit" type="button" value="f" aria-label="Fahrenheit" data-scale>F</button>
			<button class="t__unit" type="button" value="c" aria-label="Celsius" data-scale>C</button>
		</span>
	</div>
</div>
              
            
!

CSS

              
                * {
	border: 0;
	box-sizing: border-box;
	margin: 0;
	padding: 0;
}
:root {
	--hue: 223;
	--bg: hsl(var(--hue),10%,70%);
	--fg: hsl(var(--hue),10%,10%);
	--primary: hsl(var(--hue),90%,55%);
	--trans-dur: 0.3s;
	font-size: calc(16px + (20 - 16) * (100vw - 320px) / (1280 - 320));
}
body,
button {
	font: 1em/1.5 Montserrat, sans-serif;
}
body {
	background-color: var(--bg);
	color: var(--fg);
	height: 100vh;
	display: grid;
	place-items: center;
	transition:
		background-color var(--trans-dur),
		color var(--trans-dur);
}

.t,
.t__inner,
.t__inner:before,
.t__inner:after,
.t__drag {
	border-radius: 50%;
}
.t {
	--temp-hue: 50;
	box-shadow:
		0 0 0.1em hsl(var(--hue),10%,90%),
		0 0 0.3em hsl(var(--hue),10%,80%),
		0 0 0.1em hsl(var(--hue),10%,40%) inset;
	display: grid;
	place-items: center;
	position: relative;
	width: 16em;
	height: 16em;
	transition: box-shadow 0.3s;
	z-index: 0;
}
.t__inner {
	background-color: hsl(var(--hue),10%,80%);
	position: relative;
	width: 11.5em;
	height: 11.5em;
	transition: background-color 0.3s;
}
.t__inner:before,
.t__inner:after {
	content: "";
	display: block;
	position: absolute;
}
.t__inner:before {
	background-image: linear-gradient(hsl(var(--hue),10%,95%),hsl(var(--hue),10%,65%));
	top: -0.25em;
	left: -0.25em;
	width: 12em;
	height: 12em;
	z-index: -1;
}
.t__inner:after {
	background-image: linear-gradient(hsl(var(--temp-hue),90%,100%),hsl(var(--temp-hue),90%,50%));
	box-shadow:
		0 -0.25em 2em hsla(var(--temp-hue),90%,55%,0.3),
		0 2em 1em hsl(var(--temp-hue),20%,55%);
	top: -0.25em;
	left: -0.375em;
	width: 12.25em;
	height: 12.25em;
	z-index: -2;
}
.t__drag,
.t__value,
.t__units {
	position: absolute;
}
.t__drag,
.t__unit {
	background: transparent;
	-webkit-appearance: none;
	appearance: none;
}
.t__drag {
	cursor: grab;
	display: block;
	width: 100%;
	height: 100%;
	z-index: 2;
	-webkit-tap-highlight-color: transparent;
}
.t__drag:focus {
	outline: transparent;
}
.t__arrows {
	display: block;
	position: absolute;
	top: -2.25em;
	left: -2.25em;
	opacity: 0;
	width: 16em;
	height: auto;
	transition: opacity 0.15s linear;
	z-index: 1;
}
.t__drag:not(.t__drag--dragging):hover ~ .t__arrows {
	opacity: 1;
	transition-delay: 0.3s;
}
.t__drag--dragging ~ .t__arrows {
	opacity: 0;
	transition-delay: 0s;
}
.t__drag--dragging ~ .t__units {
	z-index: 0;
}
.t__value,
.t__unit {
	text-shadow: 0 0.15em 0.1em hsla(var(--hue),10%,10%,0.1);
}
.t__value {
	display: flex;
	justify-content: flex-end;
	align-items: center;
	padding-right: 3em;
	inset: 0;
	z-index: 0;
}
.t__digit,
.t__degree {
	display: inline-block;
	line-height: 1;
	-webkit-user-select: none;
	user-select: none;
}
.t__digit {
	font-size: 3em;
	font-weight: 300;
	text-align: center;
	width: 1ch;
}
.t__degree {
	color: hsl(var(--hue),10%,50%);
	font-size: 2em;
	transform: translateY(-0.5ch);
}
.t__units {
	top: calc(50% - 1.5em);
	right: 1.5em;
	z-index: 3;
}
.t__unit {
	color: hsl(var(--hue),10%,65%);
	display: block;
	font-size: 1em;
	font-weight: 500;
	line-height: 1;
	width: 1.5em;
	height: 1.5em;
}
.t__unit[aria-pressed="true"] {
	color: currentColor;
}
.t__sr {
	clip: rect(1px,1px,1px,1px);
	overflow: hidden;
	position: absolute;
	width: 1px;
	height: 1px;
}

/* Dark theme */
@media (prefers-color-scheme: dark) {
	:root {
		--bg: hsl(var(--hue),10%,20%);
		--fg: hsl(var(--hue),10%,90%);
	}
	.t {
		box-shadow:
			0 0 0.1em hsl(var(--hue),10%,40%),
			0 0 0.3em hsl(var(--hue),10%,30%),
			0 0 0.1em hsl(var(--hue),10%,0%) inset;
	}
	.t__inner {
		background-color: hsl(var(--hue),10%,30%);
	}
	.t__inner:before {
		background-image: linear-gradient(hsl(var(--hue),10%,45%),hsl(var(--hue),10%,15%));
	}
	.t__inner:after {
		background-image: linear-gradient(hsl(var(--temp-hue),90%,10%),hsl(var(--temp-hue),90%,50%));
		box-shadow:
			0 -0.25em 2em hsla(var(--temp-hue),90%,55%,0.3),
			0 2em 1em hsl(var(--temp-hue),20%,25%);
	}
	.t__value {
		text-shadow: 0 0.15em 0.1em hsla(var(--hue),10%,10%,0.2);
	}
	.t__degree {
		color: hsl(var(--hue),10%,70%);
	}
	.t__unit {
		color: hsl(var(--hue),10%,45%);
	}
}
              
            
!

JS

              
                window.addEventListener("DOMContentLoaded",() => {
	const thermostat = new Thermostat(".t");
});

class Thermostat {
	constructor(qs) {
		this.el = document.querySelector(qs);
		this.temp = 60;
		this.scale = "f";
		this.min = {
			f: 60,
			c: 16,
			hue: 10,
			angle: 0
		};
		this.max = {
			f: 90,
			c: 32,
			hue: 50,
			angle: 359
		};
		this.init();
	}
	init() {
		const dataAttr = "[data-drag]";
		const dragEl = this.el?.querySelector(dataAttr);
		const draggingClass = "t__drag--dragging";

		dragEl?.addEventListener("keydown",this.changeTemp.bind(this));
		this.el?.addEventListener("click",this.changeScale.bind(this));

		Draggable.create(dataAttr,{
			type: "rotation",
			bounds: {
				minRotation: this.min.angle, 
				maxRotation: this.max.angle
			},
			onDrag: () => {
				this.temp = this.tempFromDrag();
				this.updateDisplay();
				dragEl.classList.add(draggingClass);
			},
			onDragEnd: () => {
				dragEl.classList.remove(draggingClass);
			}
		});

		this.updateDisplay();
	}
	changeTemp(e) {
		const { key } = e;
		const step = 1;
		
		// value change
		if (key === "ArrowUp" || key === "ArrowRight")
			this.temp += step;
		else if (key === "ArrowDown" || key === "ArrowLeft")
			this.temp -= step;

		// keep within bounds
		if (this.temp < this.min[this.scale])
			this.temp = this.min[this.scale];
		else if (this.temp > this.max[this.scale])
			this.temp = this.max[this.scale];

		this.updateDisplay();
	}
	changeScale(e) {
		if (e.target.hasAttribute("data-scale") && this.scale !== e.target.value) {
			this.scale = e.target.value;
			const rawTemp = this.scale === "f" ? this.CToF(this.temp) : this.FToC(this.temp);

			this.temp = Math.round(rawTemp);

			this.updateDisplay();
		}
	}
	setAriaPressed() {
		const scale = this.el?.querySelectorAll("[data-scale]");

		if (scale) {
			Array.from(scale).forEach(s => {
				s.setAttribute("aria-pressed",s.value === this.scale);
			});
		}
	}
	setDigits() {
		// screen reader value
		const sr = this.el?.querySelector("[data-temp-sr]");

		if (sr)
			sr.textContent = `${this.temp}°${this.scale.toUpperCase()}`;

		// displayed value
		const tempDigits = this.el?.querySelectorAll("[data-temp]");

		if (tempDigits) {
			const digitString = String(this.temp).split("").reverse();

			Array.from(tempDigits).reverse().forEach((digit,i) => {
				digit.textContent = digitString[i];
			})
		}
	}
	setTone() {
		const minHue = this.min.hue;
		const maxHue = this.max.hue;
		const temp = this.temp;
		const minTemp = this.min[this.scale];
		const maxTemp = this.max[this.scale];
		const hueDiff = maxHue - minHue;
		const relativeHue = hueDiff * ((temp - minTemp) / (maxTemp - minTemp));
		const hue = Math.round(maxHue - relativeHue);

		this.el?.style.setProperty("--temp-hue",hue);
	}
	CToF(c) {
		return c * (9 / 5) + 32;
	}
	FToC(f) {
		return (f - 32) * (5 / 9);
	}
	angleFromMatrix(transVal) {
		const matrixVal = transVal.split("(")[1].split(")")[0].split(",");
		const [cos1,sin] = matrixVal.slice(0,2);
		let angle = Math.round(Math.atan2(sin,cos1) * (180 / Math.PI));

		if (angle < 0)
			angle += 360;

		return angle;
	}
	tempFromDrag() {
		const drag = this.el.querySelector(".t__drag")

		if (drag) {
			const dragCS = window.getComputedStyle(drag);
			const trans = dragCS.getPropertyValue("transform");
			const dragAngle = this.angleFromMatrix(trans);
			const relAngle = dragAngle - this.min.angle;
			const angleFrac = relAngle / (this.max.angle - this.min.angle);
			const tempRange = this.max[this.scale] - this.min[this.scale];
			const result = angleFrac * tempRange + this.min[this.scale];

			return Math.round(result);
		}
	}
	updateDisplay() {
		this.setDigits();
		this.setAriaPressed();
		this.setTone();
	}
}
              
            
!
999px

Console