Ubuntu – How to .appendChild() to all elements with the same class

//Variables
const mercury = document.getElementById("mercury");
const venus = document.getElementById("venus");
const earth = document.getElementById("earth");
const mars = document.getElementById("mars");
const jupiter = document.getElementById("jupiter");
const saturn = document.getElementById("saturn");
const uranus = document.getElementById("uranus");
const neptune = document.getElementById("neptune");
const weight = document.getElementById("weight");

weight.addEventListener("input", Calc);

function Calc() {
  if (weight.value > 99999) {
    alert("Max Amount Of Numbers is 99999");
    weight.value = "";
  } else {
    var val = weight.value;
    console.log(val);
    var calculate = val * 0.38;
    calculate = Math.round(calculate);
    mercury.innerHTML = calculate;
    console.log(calculate);

    var val = weight.value;
    console.log(val);
    var calculate = val * 0.9;
    calculate = Math.round(calculate);
    venus.innerHTML = calculate;
    console.log(calculate);

    var val = weight.value;
    console.log(val);
    var calculate = val * 1;
    calculate = Math.round(calculate);
    earth.innerHTML = calculate;
    console.log(calculate);

    var val = weight.value;
    console.log(val);
    var calculate = val * 0.38;
    calculate = Math.round(calculate);
    mars.innerHTML = calculate;
    console.log(calculate);

    var val = weight.value;
    console.log(val);
    var calculate = val * 2.36;
    calculate = Math.round(calculate);
    jupiter.innerHTML = calculate;
    console.log(calculate);

    var val = weight.value;
    console.log(val);
    var calculate = val * 0.92;
    calculate = Math.round(calculate);
    saturn.innerHTML = calculate;
    console.log(calculate);

    var val = weight.value;
    console.log(val);
    var calculate = val * 0.89;
    calculate = Math.round(calculate);
    uranus.innerHTML = calculate;
    console.log(calculate);

    var val = weight.value;
    console.log(val);
    var calculate = val * 1.12;
    calculate = Math.round(calculate);
    neptune.innerHTML = calculate;
    console.log(calculate);
  }
}

function lbs() {
  let unit = document.getElementById("unit");
  if (unit == null) {
    let newElement = document.createElement("h3");
    newElement.setAttribute("class", "value");
    newElement.setAttribute("id", "unit");
    newElement.textContent = "Lbs";
    document.querySelector(".dynamic").appendChild(newElement);
  } else {
    if (unit.innerHTML == "Kg") {
      unit.innerHTML = "Lbs";
    }
  }
}

function kg() {
  let unit = document.getElementById("unit");
  if (unit == null) {
    let newElement = document.createElement("h3");
    newElement.setAttribute("class", "value");
    newElement.setAttribute("id", "unit");
    newElement.textContent = "Kg";
    document.querySelector(".dynamic").appendChild(newElement);
  } else {
    if (unit.innerHTML == "Lbs") {
      unit.innerHTML = "Kg";
    }
  }
}

@import url("https://fonts.googleapis.com/css2?family=Montserrat:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&display=swap");
@font-face {
  font-family: SpaceQuest;
  src: url(https://raw.githubusercontent.com/Lemirq/WODP/master/Fonts/SpaceQuest-yOY3.woff);
}

h1,
h2,
h3,
h4,
h5,
h6 {
  margin: 0;
}

 ::-webkit-scrollbar {
  width: 10px;
}


/* Track */

 ::-webkit-scrollbar-track {
  background: url(./dario-bronnimann-hNQwIirOseE-unsplash.jpg);
}


/* Handle */

 ::-webkit-scrollbar-thumb {
  background: rgba(59, 59, 59, 0.741);
  border-radius: 200px;
}


/* Handle on hover */

 ::-webkit-scrollbar-thumb:hover {
  background: rgb(255, 255, 255);
}

* {
  --c-light: #f4f4f4;
  --c-dark: #141414;
  --c-blue: rgb(10, 132, 255);
  --f-body: "Montserrat", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  --trans-ease-in-out: all 0.2s ease-in-out;
  color: var(--c-light);
}

body {
  background-image: url(https://raw.githubusercontent.com/Lemirq/WODP/master/images/dario-bronnimann-hNQwIirOseE-unsplash.jpg);
  margin: 0;
  inset: 50px;
  font-family: var(--f-body);
}

a {
  color: var(--c-light);
  text-decoration: none;
}


/***** NAVBAR *****/

.nav-item {
  transition: var(--trans-ease-in-out);
}

.ext-link {
  cursor: alias;
}

.nav-item:hover {
  color: var(--c-dark);
  background-color: var(--c-light);
}

.nav-item:hover li {
  color: var(--c-dark);
}

.nav-item.icon-link:hover i {
  color: var(--c-dark);
}

.nav-item:not(:last-child) {
  margin-right: 20px;
}

navbar {
  display: flex;
  flex-direction: row;
  justify-content: end;
  align-items: center;
  padding: 20px;
}

.nav-item-container {
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  margin: 0;
  padding: 0;
}

.nav-item {
  display: inline-block;
  list-style: none;
  padding: 10px;
  font-size: 20px;
  border-radius: 10px;
}

.gh-icon {
  font-size: 30px;
}


/***** End NAVBAR *****/


/***** Main *****/

#wrapper {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

h1 {
  font-family: SpaceQuest, sans-serif;
  font-size: 3.5rem;
}

.input-group {
  border: 2px var(--c-light) solid;
  border-radius: 10px;
  /* max-width: 400px; */
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  margin-top: 50px;
}

[type="number"]:focus {
  outline: none;
}

[type="number"] {
  font-size: 20px;
  padding: 5px;
  background-color: rgba(217, 217, 217, 0.2);
  border: none;
  font-family: var(--f-body);
  min-width: 280px;
}

.btn-form {
  font-size: 20px;
  padding: 5px;
  background-color: rgba(217, 217, 217, 0.2);
  border: none;
  transition: var(--trans-ease-in-out);
  cursor: pointer;
  font-family: var(--f-body);
}

.btn-form:hover {
  background-color: rgba(217, 217, 217, 0.4);
}

.btn-form:first {
  border-right: var(--c-light) 1px solid;
}

.input-group-text {
  background-color: rgba(217, 217, 217, 0.2);
  font-size: 17px;
  padding: 7px;
}


/***** End Main *****/


/***** CARDS *****/

.card-container {
  margin: 50px;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  grid-template-rows: 1fr 1fr;
  align-items: center;
  grid-gap: 10px;
  width: calc(100vw - 200px);
}

.card {
  background-color: #141414;
  width: auto;
  height: auto;
  border-radius: 10px;
  padding: 30px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  box-shadow: 0 1rem 3rem rgba(0, 0, 0, 0.175);
}

.planet-info {
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
}

.planet {
  font-size: 50px;
  margin: 0;
  text-transform: capitalize;
}

.planet-img {
  width: 80px;
  height: auto;
  margin-right: 30px;
}

[src="./images/planets/Saturn.png"] {
  height: 79.25px;
  width: auto;
}

.weight {
  margin-top: 10px;
  text-transform: capitalize;
  font-size: 20px;
}

.weight::after {
  content: ":";
}

.divider {
  height: 1px;
  width: 100%;
  margin: 20px 0;
  background-color: var(--c-light);
}

.value {
  font-size: 60px;
  color: var(--c-blue);
}

.dynamic>.value:nth-child(2) {
  margin-left: 10px;
}

.dynamic {
  display: flex;
  flex-direction: row;
  justify-content: space-between;
}


/***** End CARDS *****/

.input-error {
  outline: 1px solid red;
}

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/font/bootstrap-icons.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>




<navbar>
  <ul class="nav-item-container">
    <a target="_blank" class="nav-item ext-link" href="https://lemirq.github.io">
      <li>Website</li>
    </a>
    <a target="_blank" class="nav-item icon-link ext-link" href="https://github.com/Lemirq">
      <li><i class="bi bi-github gh-icon"></i></li>
    </a>

  </ul>

</navbar>
<div id="wrapper">
  <h1 id="vs-h1">Your Weight On Different Planets</h1>
  <div class="input-group">
    <input id="weight" placeholder="Enter your Weight" type="number">
    <button id="kg" onclick="kg()" class="btn-form" type="button">Kg</button>
    <button id="lbs" onclick="lbs()" class="btn-form" type="button">Lbs</button>


  </div>

  <div class="card-container">
    <div class="card">
      <div class="planet-info">
        <img class="planet-img" src="./images/planets/Mercury.png" alt="EARTH">
        <h3 class="planet">mercury</h3>
      </div>
      <div class="divider"></div>
      <h4 class="weight">weight</h4>
      <div class="dynamic">
        <h3 id="mercury" class="value">F</h3>
      </div>
    </div>
    <div class="card">
      <div class="planet-info">
        <img class="planet-img" src="./images/planets/Venus.png" alt="EARTH">
        <h3 class="planet">venus</h3>
      </div>
      <div class="divider"></div>
      <h4 class="weight">weight</h4>
      <div class="dynamic">
        <h3 id="venus" class="value">F</h3>
      </div>
    </div>
    <div class="card">
      <div class="planet-info">
        <img class="planet-img" src="./images/planets/Earth.png" alt="EARTH">
        <h3 class="planet">earth</h3>
      </div>
      <div class="divider"></div>
      <h4 class="weight">weight</h4>
      <div class="dynamic">
        <h3 id="earth" class="value">F</h3>
      </div>
    </div>
    <div class="card">
      <div class="planet-info">
        <img class="planet-img" src="./images/planets/Mars.png" alt="EARTH">
        <h3 class="planet">mars</h3>
      </div>
      <div class="divider"></div>
      <h4 class="weight">weight</h4>
      <div class="dynamic">
        <h3 id="mars" class="value">F</h3>
      </div>
    </div>
    <div class="card">
      <div class="planet-info">
        <img class="planet-img" src="./images/planets/Jupiter.png" alt="EARTH">
        <h3 class="planet">jupiter</h3>
      </div>
      <div class="divider"></div>
      <h4 class="weight">weight</h4>
      <div class="dynamic">
        <h3 id="jupiter" class="value">F</h3>
      </div>
    </div>
    <div class="card">
      <div class="planet-info">
        <img class="planet-img" src="./images/planets/Saturn.png" alt="EARTH">
        <h3 class="planet">saturn</h3>
      </div>
      <div class="divider"></div>
      <h4 class="weight">weight</h4>
      <div class="dynamic">
        <h3 id="saturn" class="value">F</h3>
      </div>
    </div>
    <div class="card">
      <div class="planet-info">
        <img class="planet-img" src="./images/planets/Uranus.png" alt="EARTH">
        <h3 class="planet">uranus</h3>
      </div>
      <div class="divider"></div>
      <h4 class="weight">weight</h4>
      <div class="dynamic">
        <h3 id="uranus" class="value">F</h3>
      </div>
    </div>
    <div class="card">
      <div class="planet-info">
        <img class="planet-img" src="./images/planets/Neptune.png" alt="EARTH">
        <h3 class="planet">neptune</h3>
      </div>
      <div class="divider"></div>
      <h4 class="weight">weight</h4>
      <div class="dynamic">
        <h3 id="neptune" class="value">F</h3>
      </div>
    </div>
  </div>

</div>