.snowEffect {
    position: fixed;
    width: 100%;
    height: 100%;
    left: 0;
    top: 0;
    z-index: 10;
    overflow: hidden;
    pointer-events:none; /*Không có dòng này là ko click đc các phần tử khác*/
}
#snowcanvas{
    position: fixed;
    z-index: 0;
}
		@media only screen and (max-width: 600px) {
			.img_none {
				display: none;
			}


		}

		.dropdown {
			position: relative;
			display: inline-block;
		}

		.dropdown-content {
			display: none;
			position: fixed;
			min-width: 85px;
			background: rgba(0, 0, 0, .5);
			box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
			z-index: 1;
		}

		.dropdown:hover .dropdown-content {
			display: block;
		}

		.card-deck .card {
			margin-bottom: auto;
		}

		.btn_collapsed {
			width: 100%;
			text-align: left;
			border: 0px solid;
			text-decoration: none;
			color: black;
		}

		.btn_collapsed:hover {
			text-decoration: none;
			border: 0px solid;
		}

		.img_request {
			display: block;
			margin-left: auto;
			margin-right: auto;
			width: 50%;
		}

		.bd-placeholder-img {
			font-size: 1.125rem;
			text-anchor: middle;
			-webkit-user-select: none;
			-moz-user-select: none;
			-ms-user-select: none;
			user-select: none;
		}

		@media (min-width: 768px) {
			.bd-placeholder-img-lg {
				font-size: 3.5rem;
			}


		}

		.text-a-none {
			text-decoration: none !important;
		}