Html – Issue with animation not starting from the correct point

const root = document.documentElement;

function toggleDropdown() {
  var dropdownContent = document.getElementById("dropdown-content");
  dropdownContent.classList.toggle("show");
}

var timer;

function selectExercise(exerciseId) {
  // Hide all exercises
  var exercises = document.getElementsByClassName("exercise");
  for (var i = 0; i < exercises.length; i++) {
    exercises[i].style.display = "none";
  }

  // Reset animation for all circles
  var circles = document.getElementsByClassName("circle");
  for (var i = 0; i < circles.length; i++) {
    root.style.setProperty('--transition-duration', "0");
    circles[i].innerHTML = "Ready";
    //void circles[i].offsetWidth; // Trigger reflow to apply the class immediately
    circles[i].classList.remove("inhale");
  }


  // Show selected exercise
  var selectedExercise = document.getElementById(exerciseId);
  selectedExercise.style.display = "block";

  var dropdownContent = document.getElementById("dropdown-content");
  dropdownContent.classList.remove("show");

  clearInterval(timer);

  var timerElement = document.getElementById("timer" + exerciseId.slice(-1));
  timerElement.innerHTML = "";
}

function startAnimation(circleId, duration, totalCycles, timerId) {
  var circle = document.getElementById(circleId);
  var cycles = 0;
  var remainingTime = duration * totalCycles;
  var inhaleTime = duration / 2;
  var exhaleTime = duration / 2;
  root.style.setProperty('--transition-duration', `${inhaleTime}ms`);

  clearInterval(timer);

  animate();

  function animate() {
    circle.innerHTML = "Inhale";
    circle.classList.add('inhale')
    setTimeout(function() {
      circle.innerHTML = "Exhale";
      circle.classList.remove('inhale')
      setTimeout(function() {
        circle.innerHTML = "Inhale";
        circle.classList.add('inhale')

        cycles++;
        if (cycles < totalCycles) {
          animate(); // Start the next cycle
        } else {
          //circle.style.animationDuration = "0ms"; // Stop the animation
        }
      }, inhaleTime);
    }, exhaleTime);
  }

  // circle.style.animationDuration = duration + "ms";

  var timerElement = document.getElementById(timerId);
  timerElement.innerHTML = "Time left: " + (remainingTime / 1000) + " seconds";

  timer = setInterval(function() {
    remainingTime -= 1000;
    if (remainingTime <= 0) {
      clearInterval(timer);
      timerElement.innerHTML = "Time left: 0 seconds";
    } else {
      timerElement.innerHTML = "Time left: " + (remainingTime / 1000) + " seconds";
    }
  }, 1000);
}

selectExercise('exercise1', 4000);

:root {
  --transition-duration: 0;
}

body {
  background: #005eb8;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  font-family: "Helvetica Neue", Arial, sans-serif;
}

.container {
  max-width: 350px;
  margin: 0 auto;
  border-radius: 5px;
  overflow: hidden;
  background: #ffffff;
  padding: 20px;
}

h1 {
  margin-bottom: 20px;
  text-align: center;
  color: #003087;
}

.dropdown {
  position: relative;
}

.button {
  width: 100%;
  padding: 10px;
  margin-bottom: 1px;
  color: #ffffff;
  background: #0072ce;
  border: none;
  cursor: pointer;
  border-radius: 5px;
}

.dropdown-content {
  display: none;
  position: absolute;
  background-color: #ffffff;
  width: 100%;
  border-radius: 5px;
  box-shadow: 0 0 15px rgba(0, 0, 0, 0.15);
  z-index: 1;
}

.dropdown-content a {
  display: block;
  padding: 10px;
  color: #003087;
  text-decoration: none;
}

.dropdown:hover .dropdown-content {
  display: block;
}

.exercise {
  display: none;
  padding: 2px;
  background-color: #ffffff;
  border-radius: 5px;
  margin-top: 0px;
  text-align: center;
  color: #003087;
}

.exercise h2 {
  margin-top: 10px;
  margin-bottom: 10px;
}

.exercise p {
  margin-top: 10px;
  margin-bottom: 20px;
}

.circle-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  margin-bottom: 20px;
}

.circle {
  width: 200px;
  height: 200px;
  background-color: #4BC0C0;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
  font-size: 24px;
  font-weight: bold;
  /* animation-name: breathe;
  animation-timing-function: ease-in-out;
  animation-iteration-count: infinite;
  animation-fill-mode: forwards; */
  margin-bottom: 5px;
  transform: scale(1.0);
  transition: all var(--transition-duration);
}

.circle.inhale {
  transform: scale(1.2);
}

.circle.exhale {}

.start-button {
  padding: 10px;
  color: #ffffff;
  background: #0072ce;
  width: 100%;
  border: none;
  cursor: pointer;
  border-radius: 5px;
  font-weight: bold;
  margin-top: 5px;
}

.start-button:hover {
  background: #003087;
}

<div class="container">
  <h1>Breathing Exercises</h1>

  <div class="dropdown">
    <button class="button" onclick="toggleDropdown()">Select Exercise</button>
    <div id="dropdown-content" class="dropdown-content">
      <a href="#" onclick="selectExercise('exercise1')">Exercise 1</a>
      <a href="#" onclick="selectExercise('exercise2')">Exercise 2</a>
      <a href="#" onclick="selectExercise('exercise3')">Exercise 3</a>
      <a href="#" onclick="selectExercise('exercise4')">Exercise 4</a>
    </div>
  </div>

  <div id="exercise1" class="exercise">
    <h2>Exercise 1</h2>
    <p>This is the description for Exercise 1.</p>
    <div class="circle-wrapper">
      <div id="circle1" class="circle"></div>
    </div>
    <div id="timer1" class="timer"></div>
    <button class="start-button" onclick="startAnimation('circle1', 10000, 5, 'timer1')">Start</button>
  </div>

  <div id="exercise2" class="exercise" style="display: none;">
    <h2>Exercise 2</h2>
    <p>This is the description for Exercise 2.</p>
    <div class="circle-wrapper">
      <div id="circle2" class="circle"></div>
    </div>
    <div id="timer2" class="timer"></div>
    <button class="start-button" onclick="startAnimation('circle2', 6000, 3, 'timer2')">Start</button>
  </div>

  <div id="exercise3" class="exercise" style="display: none;">
    <h2>Exercise 3</h2>
    <p>This is the description for Exercise 3.</p>
    <div class="circle-wrapper">
      <div id="circle3" class="circle"></div>
    </div>
    <div id="timer3" class="timer"></div>
    <button class="start-button" onclick="startAnimation('circle3', 8000, 2, 'timer3')">Start</button>
  </div>

  <div id="exercise4" class="exercise" style="display: none;">
    <h2>Exercise 4</h2>
    <p>This is the description for Exercise 4.</p>
    <div class="circle-wrapper">
      <div id="circle4" class="circle"></div>
    </div>
    <div id="timer4" class="timer"></div>
    <button class="start-button" onclick="startAnimation('circle4', 4000, 10, 'timer4')">Start</button>
  </div>
</div>