.flexContainer{
    display:flex;
    flex-direction: column;
    flex-wrap: wrap;
    margin: 5%;
    max-width: 90%;
}
.letter{
padding: 30px;
border: 1px solid #0dcaf0;
flex: 0 0 200px;
margin: 10px;
background: #ccc;
max-width: 400px;
}
.hidden {
   display: none;
}
header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 20px 40px;
      background-color: #0dcaf0;
      color: #212529;
      position: relative;
      z-index: 1000;
    }

    .logo {
      display: flex;
      align-items: center;
    }

    .logo img {
      height: 70px;
      margin-right: 10px;
    }

    .logo span {
      font-size: 1.5rem;
      font-weight: bold;
    }

    nav {
      display: flex;
      gap: 30px;
    }

    nav a {
      text-decoration: none;
      color: #212529;
      font-size: 1rem;
      transition: color 0.3s;
    }

    nav a:hover {
      color: #ffffff;
    }
    .menu-toggle {
      display: none;
      flex-direction: column;
      cursor: pointer;
    }

    .menu-toggle span {
      width: 25px;
      height: 3px;
      background-color: #212529;
      margin: 4px 0;
      transition: 0.4s;
    }

    @media (max-width: 768px) {
      nav {
        display: none;
        flex-direction: column;
        background-color: #0dcaf0;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        padding: 20px;
        gap: 20px;
        z-index: 999;
      }

      nav.active {
        display: flex;
      }
      .menu-toggle {
        display: flex;
      }
    }