My card container is moving down when I click a button

I've got a problem with my code and I don't know if it's a css issue or a js issue. When I click the button of my page, my card-container2 is moving down. Here's all my code:

HTML:

<div class="card-container">
    <h1>splitter bill</h1>
    <p>enter the name of the person and his amount (21% of iva included):</p>
    <label id="name-text">Nombre</label>
    <br>
    <input type="text" id="name">
    <br>
    <label id="monto-texto">amount</label>
    <br>
    <input type="number" id="amount">
    <br>
    <button id="calculate">Ingresar</button>
    <p>Total: <span id="total"></span> </p>
    <div id="each-person">
    </div>
    <p> Cada uno le toca aportar: <span id="split"></span> </p>
</div>
<div class="card-container2">
    <div id="clima">   
    </div>
</div>

JavaScript:

//there is more js code if you need 
function defineTotal() {

  personsListHTMLelemento = "";

  let list = "";
  let total = 0;

  for (let i = 0; i < persons.length; i++) {
    total += persons[i].amount
    list += `${persons[i].name}: ${persons[i].amount} <br>`;
  }

  let iva = 1.21

  totalHTMLelemento.innerHTML = total * iva;
  personsListHTMLelemento.innerHTML = list;
  splitHTMLelemento.innerHTML = (total * iva) / persons.length;

CSS:

.card-container {
    margin-left: 500px;
    margin-right: 500px;
    padding-left: 50px;
    background-color: #302b63;
    border-radius: 20px;
    margin-top: 150px;
}

.card-container2 {
    margin-left: 1270px;
    padding-left: 35px;
    background-color: #302b63;
    border-radius: 5px;
    margin-top: -490px;
}

If you need more of my CSS/JavaScript code, let me know and i will post it