.word-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
    margin: 20px 0;
  }
  
  .word-button {
    padding: 12px 20px;
    font-size: 1.2rem;
    background-color: #d6f3ff;
    border: 2px solid #0066cc;
    border-radius: 8px;
    cursor: pointer;
    transition: 0.3s;
  }
  
  .word-button:hover {
    background-color: #c0e6f7;
  }
  
  .correct, .wrong {
    font-size: 1.4rem;
    margin: 10px 0;
    text-align: center;
  }
  
  .correct {
    color: green;
  }
  
  .wrong {
    color: red;
  }
  
  .next-button {
    padding: 10px 18px;
    font-size: 1rem;
    background-color: #ffde59;
    border: none;
    border-radius: 6px;
    margin-top: 15px;
    cursor: pointer;
  }
  
  .explanation {
    margin-top: 30px;
    padding: 10px;
    background-color: #f1f9ff;
    border-left: 5px solid #007acc;
  }
  
  .explanation h3 {
    margin-top: 0;
  }
  
  .music-toggle-absolute {
    position: fixed;
    bottom: 20px;
    right: 20px;
    font-size: 1.5rem;
    background: #f1f1f1;
    border: 2px solid #ccc;
    padding: 8px;
    border-radius: 50%;
    z-index: 1000;
  }
  .back-button {
    position: absolute;
    top: 25px;
    left: 25px;
    background-color: var(--primary-blue); 
    color: var(--text-light);
    padding: 10px 20px; 
    border: none;
    border-radius: 10px; 
    font-size: 1em; 
    font-weight: 600; 
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease, box-shadow 0.3s ease;
    z-index: 10;
    box-shadow: 0 3px 6px var(--shadow-light);
}

.back-button:hover {
    background-color: #5c8ae6; 
    transform: translateY(-3px);
    box-shadow: 0 5px 10px var(--shadow-medium);
}

.back-button:active {
    transform: translateY(0);
    box-shadow: 0 1px 3px var(--shadow-light);
}

/* Mobile-specific adjustments for very small screens */
@media (max-width: 480px) {
    .math-controls button {
        font-size: 1em;
        padding: 12px 25px;
    }
    .back-button {
        padding: 6px 12px;
        font-size: 0.8em;
        top: 15px; 
        left: 15px; 
        border-radius: 8px;
    }
    #math-problem-text {
        font-size: clamp(2em, 6vw, 4em); 
    }
    #answer-input {
        font-size: 1.2em;
        padding: 12px 15px;
    }
    #feedback-message {
        font-size: 1.4em;
    }
    .container {
        padding: 40px 20px 20px 20px; 
    }
}
#target-word {
  margin-top: 20px;
  font-size: 1.5rem;
  text-align: center;
}

#target-word .target {
  font-size: 2.5rem;
  font-weight: bold;
  color: #1a73e8;
  background: #fff59d;
  padding: 8px 14px;
  border-radius: 8px;
}