body {
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    height: 100vh;
    font-family: Arial, sans-serif;
}

#upper-section {
    flex: 3;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #f0f0f0;
    gap: 20px;
}

#lower-section {
    flex: 7;
    display: flex;
    justify-content: center;
    align-items: center;
}

.control-btn {
    padding: 10px 20px;
    font-size: 18px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.control-btn:hover {
    background-color: #ddd;
}

#count {
    font-size: 48px;
    min-width: 100px;
    text-align: center;
}

#main-btn {
    width: 100%;
    height: 100%;
    font-size: 36px;
    border: none;
    background-color: #4CAF50;
    color: white;
    cursor: pointer;
    transition: background-color 0.3s;
}

#main-btn:hover {
    background-color: #45a049;
}

#reset-btn {
    background-color: #ff4444;
    color: white;
}

#reset-btn:hover {
    background-color: #cc0000;
}

/* 添加到主屏幕提示 */
#installPrompt {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background-color: #333;
    color: white;
    padding: 10px 20px;
    border-radius: 5px;
    display: none;
    z-index: 1000;
}

#installPrompt button {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 5px 10px;
    margin-left: 10px;
    border-radius: 3px;
    cursor: pointer;
}