/* Body */
        body {
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            min-height: 100vh;
            margin: 0;
            font-family: 'Arial', sans-serif;
        }

        /* Overlay mờ nền */
        .overlay {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.6);
            z-index: 999;
            backdrop-filter: blur(2px); /* Hiệu ứng mờ nhẹ */
        }

        /* Container popup */
        .popup {
            display: none;
            position: fixed;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            background: linear-gradient(145deg, #ffffff, #f0f4f8); /* Gradient nền popup */
            padding: 5px;
            border-radius: 20px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2), /* Đổ bóng lớn hơn */
                        0 0 15px rgba(52, 152, 219, 0.3); /* Ánh sáng màu xanh */
            width: 100%;
            max-width: 900px;
            z-index: 1000;
            animation: popupAppear 0.4s ease-out;
            border: 1px solid rgba(255, 255, 255, 0.5);
        }

        /* Animation khi xuất hiện */
        @keyframes popupAppear {
            0% { 
                opacity: 0; 
                transform: translate(-50%, -55%) scale(0.95); 
            }
            100% { 
                opacity: 1; 
                transform: translate(-50%, -50%) scale(1); 
            }
        }

        /* Tiêu đề */
        .popup-header {
            text-align: center;
            color: #2c3e50;
            font-size: 18px;
            font-weight: bold;
            margin-bottom: 25px;
            padding-bottom: 12px;
            border-bottom: 3px solid #3498db;
            background: linear-gradient(to right, #3498db, #9b59b6); /* Gradient chữ */
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
        }

        /* Nội dung */
        .popup-content {
            text-align: left;
			color: #34495e;
            line-height: 1.8;
            margin-bottom: 25px;
            font-size: 14px;
            background: rgba(255, 255, 255, 0.7);
            padding: 15px;
            border-radius: 10px;
            box-shadow: inset 0 2px 5px rgba(0, 0, 0, 0.05);
        }

        /* Nút đóng */
        .close-btn {
            display: inline-block;
            padding: 12px 25px;
            background: linear-gradient(45deg, #3498db, #2980b9);
            color: white;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-size: 16px;
            transition: all 0.3s ease;
            box-shadow: 0 4px 10px rgba(52, 152, 219, 0.4);
        }

        .close-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 15px rgba(52, 152, 219, 0.6);
            background: linear-gradient(45deg, #2980b9, #3498db);
        }

        /* Nút mở lại */
        .reopen-btn {
            position: fixed;
            top: 35%;
            right: 10px;
            padding: 12px 25px;
            background: linear-gradient(45deg, #2ecc71, #27ae60);
            color: white;
            border: none;
            border-radius: 50px; /* Bo tròn mạnh hơn */
            cursor: pointer;
            font-size: 16px;
            transition: all 0.3s ease;
            box-shadow: 0 4px 10px rgba(46, 204, 113, 0.4);
        }

        .reopen-btn:hover {
            transform: scale(1.05);
            box-shadow: 0 6px 15px rgba(46, 204, 113, 0.6);
            background: linear-gradient(45deg, #27ae60, #2ecc71);
        }

        /* Container nút trong popup */
        .button-container {
            text-align: center;
        }
          a {
            color: #007bff; /* Màu mặc định */
            text-decoration: none; /* Bỏ gạch chân (nếu muốn) */
        }

        a:visited {
            color: #2196F3; /* Giữ màu giống như link chưa nhấp */
        }

        a:hover {
            color: #ff5733; /* Màu khi di chuột qua */
        }

        a:active {
            color: #007bff; /* Màu khi click */
        }