body {
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: #111;
    color: #fff;
    height: 100vh;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
  }
  
  #login-screen {
    background-color: #222;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
    text-align: center;
    font-size: 1.5rem;
  }
  
  #login-screen input, #login-screen button {
    padding: 0.8rem;
    font-size: 1.2rem;
    margin: 0.5rem 0;
    width: 100%;
    border: none;
    border-radius: 6px;
    outline: none;
  }
  
  #login-screen button {
    background-color: #4caf50;
    color: white;
    cursor: pointer;
  }
  #login-screen button:hover {
    background-color: #45a049;
  }
  
  #app {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background-size: cover;
    background-position: center;
  }
  
  #clock {
    position: absolute;
    top: 1rem;
    left: 50%;
    transform: translateX(-50%);
    font-size: 4rem;
    font-weight: bold;
    text-shadow: 0 0 10px rgba(0, 0, 0, 0.7);
    z-index: 10;
  }
  
  #card-container {
    position: absolute;
    top: 6rem;
    left: 0;
    width: 100%;
    height: calc(100% - 6rem);
    display: flex;
    transition: transform 0.5s ease;
    will-change: transform;
  }
  
  .card {
    min-width: 100%;
    height: 100%;
    padding: 2rem;
    box-sizing: border-box;
    overflow-y: auto;
    background-color: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(5px);
    font-size: 1.8rem;
    line-height: 2.5rem;
  }
  
  iframe {
    width: 100%;
    height: 100%;
    border: none;
  }
  
  .hidden {
    display: none;
  }
  .bestpreis {
    background-color: rgba(0, 255, 0, 0.2);
    padding: 0.5rem;
    border-radius: 6px;
    font-weight: bold;
  }
  #nav-left, #nav-right {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(0,0,0,0.5);
    border: none;
    color: white;
    font-size: 3rem;
    padding: 0.5rem 1rem;
    cursor: pointer;
    z-index: 20;
    border-radius: 10px;
    transition: background 0.3s;
  }
  
  #nav-left:hover, #nav-right:hover {
    background: rgba(255,255,255,0.2);
  }
  
  #nav-left {
    left: 1rem;
  }
  
  #nav-right {
    right: 1rem;
  }