body {
            background-image: url('https://cdn.kldhsh.top/klbk/202501/bc761737287860.png');
            background-size: cover;
            background-repeat: no-repeat;
            background-attachment: fixed;
            margin: 0;
            padding: 0;
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            font-family: Arial, sans-serif;
        }
        .container {
            text-align: center;
            background-color: rgba(255, 255, 255, 0.8);
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
            backdrop-filter: blur(10px);
            width: 90%;
            max-width: 400px;
            margin-top: 20px;
            margin-bottom: 20px;
        }
        .options, .time-container, .test-text, .buttons {
            background-color: rgba(255, 255, 255, 1);
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
            margin-bottom: 20px;
        }
        .options {
            display: flex;
            flex-direction: column;
            align-items: center;
        }
        h1 {
            font-size: 24px;
            margin-bottom: 10px;
            color: #333333;
            font-weight: bold; 
        }
        #time-difference {
            font-size: 18px;
            color: #666666;
            margin-bottom: 20px;
        }
        .loader {
            border: 4px solid #f3f3f3;
            border-top: 4px solid #3498db;
            border-radius: 50%;
            width: 30px;
            height: 30px;
            animation: spin 1s linear infinite;
            display: inline-block;
            vertical-align: middle;
            margin-bottom: 5px;
        }
        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }
        .test-text {
            margin-bottom: 20px;
        }
        .buttons {
            display: flex;
            flex-wrap: wrap;
            justify-content: center; 
        }
        .button {
            background-color: rgba(255, 255, 255, 0.9);
            padding: 10px 20px;
            border-radius: 5px;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
            margin: 10px;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.3s ease;
            border: none;
        }
        .button:hover {
            background-color: rgba(255, 255, 255, 1);
            transform: scale(1.05);
        }
        .footer {
            font-size: 14px;
            color: #999999;
            margin-top: 10px;
        }
        .checkbox-label {
            margin: 10px 0;
        }
        .hidden-content {
            display: none;
            visibility: hidden;
        }