body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    background: linear-gradient(to bottom, #4facfe, #00f2fe);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.game-container {
    background-color: #fff;
    width: 100%;
    max-width: 500px;
    border-radius: 15px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.25);
    padding: 20px;
    text-align: center;
}

header h1 {
    margin: 0;
    font-size: 2em;
    color: #333;
}

header p {
    color: #555;
}

.scoreboard {
    display: flex;
    justify-content: space-around;
    margin: 15px 0;
    font-weight: bold;
    font-size: 1.1em;
}

#game-area {
    position: relative;
    height: 300px;
    background-color: #f0f8ff;
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 15px;
}

.number {
    position: absolute;
    font-size: 1.5em;
    font-weight: bold;
    padding: 10px 15px;
    border-radius: 50%;
    cursor: pointer;
    transition: transform 0.2s ease, opacity 0.2s ease;
}

.number.even {
    background-color: #4caf50;
    color: #fff;
}

.number.odd {
    background-color: #f44336;
    color: #fff;
}

footer button {
    padding: 10px 20px;
    margin: 5px;
    font-size: 1em;
    cursor: pointer;
    border: none;
    border-radius: 8px;
    background: #2196f3;
    color: #fff;
    transition: background 0.2s ease;
}

footer button:hover {
    background: #1976d2;
}

#message {
    margin-top: 10px;
    font-weight: bold;
    color: #333;
}