<div id="root"></div>

* {
  border: 0;
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
:root {
  --hue: 223;
  --red: hsl(3,90%,50%);
  --white: hsl(0,0%,100%);
  --primary: hsl(var(--hue),90%,50%);
  --primary-t: hsla(var(--hue),90%,50%,0);
  --gray1: hsl(var(--hue),10%,90%);
  --gray2: hsl(var(--hue),10%,80%);
  --gray3: hsl(var(--hue),10%,70%);
  --gray4: hsl(var(--hue),10%,60%);
  --gray5: hsl(var(--hue),10%,50%);
  --gray6: hsl(var(--hue),10%,40%);
  --gray7: hsl(var(--hue),10%,30%);
  --gray8: hsl(var(--hue),10%,20%);
  --gray9: hsl(var(--hue),10%,10%);
  --trans-dur: 0.3s;
  --trans-timing: cubic-bezier(0.65,0,0.35,1);
  font-size: calc(28px + (60 - 28) * (100vw - 320px) / (3840 - 320));
}
body,
button {
  color: var(--gray9);
  font: 1em/1.5 "DM Sans", sans-serif;
  transition:
    background-color var(--trans-dur),
    color var(--trans-dur);
}
body {
  background-color: var(--gray1);
}
.recorder {
  background-color: transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  margin: auto;
  outline: transparent;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
  -webkit-appearance: none;
  appearance: none;
  -webkit-tap-highlight-color: transparent;

  &__label {
    &-start,
    &-end {
      display: block;
      position: relative;
    }
    &-start,
    &-end-text {
      transition: opacity var(--trans-dur);
    }
    &-start {
      margin-inline: 0 0.5em;
    }
    &-end {
      margin-inline: 0.5em 0;

      &-text {
        opacity: 0.4;

        & + & {
          opacity: 0;
          position: absolute;
          top: 0;
          left: 0;
    
          [dir="rtl"] & {
            right: 0;
            left: auto;
          }
        }
      }
    }
  }
  &__switch {
    background-color: var(--white);
    border-radius: 0.75em;
    box-shadow:
      0 0 0 0.125em var(--primary-t),
      0 0.25em 0.25em hsla(0,0%,0%,0.1);
    display: flex;
    padding: 0.25em;
    width: 2.5em;
    height: 1.5em;

    &,
    &-handle {
      transition:
        background-color var(--trans-dur),
        box-shadow var(--trans-dur),
        transform var(--trans-dur) var(--trans-timing),
        transform-origin var(--trans-dur) var(--trans-timing);
    }
    &-handle {
      background-color: var(--gray3);
      border-radius: 50%;
      display: block;
      transform-origin: 0 0.5em;
      width: 1em;
      height: 1em;

      [dir="rtl"] & {
        transform-origin: 100% 0.5em;
      }
    }
  }
  &__timer {
    display: block;
    overflow: visible;
    width: 100%;
    height: auto;

    &-ring {
      transition:
        r var(--trans-dur) var(--trans-timing),
        stroke-dasharray var(--trans-dur) var(--trans-timing),
        stroke-dashoffset var(--trans-dur) var(--trans-timing),
        stroke-width var(--trans-dur) var(--trans-timing);
    }
  }
  &:focus-visible &__switch {
    box-shadow:
      0 0 0 0.125em var(--primary),
      0 0.25em 0.25em hsla(0,0%,0%,0.1);
  }
  &:active &__switch-handle {
    transform: scaleX(1.5);
  }
  // recording state
  &[aria-pressed="true"] &__label-start {
    opacity: 0.4;
  }
  &[aria-pressed="true"] &__label-end-text {
    opacity: 0;
  }
  &[aria-pressed="true"] &__label-end-text + &__label-end-text {
    opacity: 1;
  }
  &[aria-pressed="true"] &__switch-handle {
    background-color: var(--red);
    transform: translateX(100%);
    transform-origin: 100% 0.5em;

    [dir="rtl"] & {
      transform: translateX(-100%);
      transform-origin: 0 0.5em;
    }
  }
  &[aria-pressed="true"] &__timer-ring {
    r: 6.5px;
    stroke-width: 3px;
  }
  &[aria-pressed="true"]:active &__switch-handle {
    transform: translateX(100%) scaleX(1.5);

    [dir="rtl"] & {
      transform: translateX(-100%) scaleX(1.5);
    }
  }
}


/* Dark theme */
@media (prefers-color-scheme: dark) {
  body,
  button {
    color: var(--gray1);
  }
  body {
    background-color: var(--gray9);
  }
  .recorder {
    &__switch {
      background-color: var(--gray8);
      box-shadow:
        0 0 0 0.125em var(--primary-t),
        0 0.25em 0.25em hsla(0,0%,0%,0.2);

      &-handle {
        background-color: var(--gray6);
      }
    }
    &:focus-visible &__switch {
      box-shadow:
        0 0 0 0.125em var(--primary),
        0 0.25em 0.25em hsla(0,0%,0%,0.2);
    }
  }
}

import React, { StrictMode, useEffect, useState } from "https://esm.sh/react";
import { createRoot } from "https://esm.sh/react-dom/client";

createRoot(document.getElementById("root")!).render(
  <StrictMode>
    <RecordingToggle />
  </StrictMode>
);

function RecordingToggle() {
  const [recording, setRecording] = useState(false);
  const [time, setTime] = useState(0);
  const timeMax = 60;
  const [timeStopped, setTimeStopped] = useState(0);
  const circumference = recording ? 40.84 : 50.27;
  const circumferencePart = recording ? 1 - (time / timeMax) : 1;
  const strokeDashArray = `${circumference} ${circumference}`;
  const strokeDashOffset = +(circumference * circumferencePart).toFixed(2);

  function timeFormatted() {
    const timeToDisplay = recording ? time : timeStopped;
    const minutes = `0${Math.floor(timeToDisplay / 60)}`.slice(-2);
    const seconds = `0${timeToDisplay % 60}`.slice(-2);
    return `${minutes}:${seconds}`;
  }
  // timer loop
  useEffect(() => {
    let frameId = 0;

    if (recording) {
      setTimeStopped(0);
      const render = () => {
        setTime((time) => time + 1);
        // allow the time to be shown in the transition when stopping
        setTimeStopped((time) => time + 1);
        frameId = setTimeout(render,1e3);
      };
      frameId = setTimeout(render,1e3);
    } else {
      setTime(0);
      clearTimeout(frameId);
    }
    return () => {
      clearTimeout(frameId);
    };
  }, [recording]);
  // stop automatically if time hits limit
  useEffect(() => {
    if (time >= timeMax) {
      setRecording(false);
    }
  }, [time])

  return (
    <button
      className="recorder"
      type="button"
      aria-pressed={recording}
      onClick={() => setRecording(!recording)}
    >
      <span className="recorder__label-start" aria-hidden={recording}>Stop</span>
      <span className="recorder__switch">
        <span className="recorder__switch-handle">
          <svg className="recorder__timer" viewBox="0 0 16 16" width="16px" height="16px" aria-hidden="true">
            <g fill="none" strokeLinecap="round" strokeWidth="0" transform="rotate(-90,8,8)">
              <circle className="recorder__timer-ring" stroke="hsla(0,0%,100%,0.3)" cx="8" cy="8" r="8" />
              <circle className="recorder__timer-ring" stroke="hsla(0,0%,100%,0.5)" cx="8" cy="8" r="8" strokeDasharray={strokeDashArray} strokeDashoffset={strokeDashOffset} />
            </g>
          </svg>
        </span>
      </span>
      <span className="recorder__label-end" aria-hidden={!recording}>
        <span className="recorder__label-end-text">Record</span>
        <span className="recorder__label-end-text">{timeFormatted()}</span>
      </span>
    </button>
  )
}