body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #fceabb, #f8b500);
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.math-container {
    background: white;
    padding: 30px 40px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
    width: 320px;
}

h1 {
    margin-bottom: 20px;
}

.stats {
    display: flex;
    justify-content: space-between;
    font-weight: bold;
    margin-bottom: 15px;
}

.question-container {
    margin: 20px 0;
    font-size: 1.2rem;
    min-height: 40px;
}

input[type="number"] {
    padding: 10px;
    width: 100%;
    font-size: 1rem;
    margin-bottom: 15px;
    border-radius: 5px;
    border: 1px solid #ccc;
    text-align: center;
}

.controls button {
    padding: 8px 12px;
    margin: 5px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.2s ease;
}

#start-btn { background: #4caf50; color: white; }
#submit-btn { background: #2196f3; color: white; }
#restart-btn { background: #f44336; color: white; }

.controls button:hover {
    transform: scale(1.05);
}

#feedback {
    margin-top: 15px;
    font-weight: bold;
    min-height: 20px;
}