body {
        font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        background: linear-gradient(135deg, #f9f7f6, #d7e1ec);
        margin: 0;
        padding: 20px;
    }
    .container {
        max-width: 900px;
        margin: 0 auto;
        background: #fff;
        border-radius: 15px;
        box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        padding: 30px;
    }
   
    h1 {
        text-align: center;
        color: #ff4d6d;
        margin-bottom: 20px;
    }
    .question-box {
        margin-bottom: 25px;
        padding: 20px;
        border-left: 5px solid #ff4d6d;
        background: #f0f8ff;
        border-radius: 10px;
        animation: fadeIn 0.5s ease-in-out;
    }
    .question-box p {
        font-size: 1.1rem;
        margin-bottom: 15px;
        color: #333;
    }
    .options button {
        display: block;
        width: 100%;
        margin-bottom: 10px;
        padding: 10px 15px;
        font-size: 1rem;
        border: 2px solid #ff4d6d;
        border-radius: 10px;
        background: #fff;
        cursor: pointer;
        transition: all 0.3s ease;
    }
    .options button:hover {
        background: #ff4d6d;
        color: #fff;
    }
    .options button.correct {
        background: #4caf50;
        color: #fff;
        border-color: #4caf50;
    }
    .options button.wrong {
        background: #f44336;
        color: #fff;
        border-color: #f44336;
    }
    .explanation {
        margin-top: 10px;
        font-style: italic;
        color: #555;
    }
    @keyframes fadeIn {
        from {opacity: 0; transform: translateY(10px);}
        to {opacity: 1; transform: translateY(0);}
    }


    /* next lesson button  */
/* Button container */
.button-container {
  display: flex;
  justify-content: space-between;
  max-width: 800px;
  margin: 50px auto;
}

/* Common button style */
.lesson-button {
  padding: 12px 25px;
  font-size: 16px;
  font-weight: bold;
  text-decoration: none;
  border-radius: 8px;
  transition: 0.3s;
  color: white;
}

/* Previous button */
.prev-btn {
  background-color: #ff4d4d; /* Red */
}

.prev-btn:hover {
  background-color: #e60000; /* Darker red on hover */
}

/* Next button */
.next-btn {
  background-color: #4CAF50; /* Green */
}

.next-btn:hover {
  background-color: #2e7d32; /* Darker green on hover */
}