/* Grundlayout */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }
  
  body, html {
    width: 100%;
    height: 100%;
    font-family: Arial, sans-serif;
    background-color: #ffffff;
  }
  
  #gameContainer {
    position: relative;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
  }
  
  /* Overlay für Start- und Endbildschirm */
  .overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #ffffff;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10;
  }
  
  /* Start Button */
  #startButton {
    font-size: 4rem;
    padding: 20px 40px;
    cursor: pointer;
    border-radius: 50%;
    color: #ffffff;
    border: 3px solid #ffffff;
    width: 300px;
    height: 300px;
    background-color: #93A9A4;
  }
  
  /* Punkteanzeige */
  #score {
    position: fixed;
    top: 20px;
    right: 30px;
    font-size: 2rem;
    font-weight: bold;
    z-index: 5;
  }
  
  /* Rechenaufgabe in der Mitte */
  #problemContainer {
    position: absolute;
    width: 300px;
    height: 150px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 6;
    display: flex;
    justify-content: center;
    align-items: center;
  }
  
  #problem {
    font-size: 3rem;
    font-weight: bold;
    text-align: center;
  }
  
  /* Antwortkreise */
  .circle {
    position: absolute;
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background-color: #D7DFDA;
    border: 3px solid #FFFFFF;
    color:#ffffff;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 2rem;
    cursor: pointer;
    user-select: none;
    transition: background-color 0.3s;
  }
  
  /* Bei falscher Antwort wird der Kreis rot markiert */
  .circle.incorrect {
    background-color: #ffb3b3;
    border-color: #ff0000;
  }
  
  /* Endbildschirm: Anzeige der finalen Punktzahl */
  #finalScreen {
    font-size: 4rem;
    font-weight: bold;
    color: #333;
    text-align: center;
  }