<style>
    .back-to-top {
      position: fixed;
      bottom: 20px;
      right: 20px;
      width: 50px;
      height: 50px;
      background-color:var(--primary-color);;
      color: white;
      border-radius: 50%;
      display: flex;
      justify-content: center;
      align-items: center;
      cursor: pointer;
      box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
      transition: opacity 0.3s;
      opacity: 0;
      visibility: hidden;
    }

    .back-to-top.show {
      opacity: 1;
      visibility: