* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
    text-align: center;
    max-width: 600px;
    width: 90%;
}

h1 {
    color: #333;
    margin-bottom: 30px;
    font-size: 2.5rem;
}

.level-selection {
    margin-bottom: 30px;
}

.level-btn {
    background: #667eea;
    color: white;
    border: none;
    padding: 15px 30px;
    margin: 10px;
    border-radius: 10px;
    font-size: 1.2rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.level-btn:hover {
    background: #5a67d8;
    transform: translateY(-2px);
}

.word-display {
    display: none;
}

.current-word {
    font-size: 4rem;
    font-weight: bold;
    color: #333;
    margin: 40px 0;
    min-height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 3px solid #667eea;
    border-radius: 15px;
    background: #f8f9ff;
}

.progress {
    margin-bottom: 20px;
    font-size: 1.2rem;
    color: #666;
}

.controls {
    margin-top: 30px;
}

.next-btn {
    background: #48bb78;
    color: white;
    border: none;
    padding: 15px 40px;
    border-radius: 10px;
    font-size: 1.3rem;
    cursor: pointer;
    margin: 10px;
    transition: all 0.3s ease;
}

.next-btn:hover {
    background: #38a169;
    transform: translateY(-2px);
}

.back-btn {
    background: #ed8936;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    margin: 10px;
    transition: all 0.3s ease;
}

.back-btn:hover {
    background: #dd7624;
}