css样式，高斯模糊

.blur-container.blur-3 {
 --bg: url("background.jpg");
 background-image: var(--bg);
}
.blur-container.blur-3 .blur-box {
 color: #31405e;
 width: 100%;
 height: 100%;
 max-height: 300px;
 overflow: hidden;
}
.blur-container.blur-3 .blur-box h2 {
 font-size: 37px;
}
.blur-container.blur-3 .blur-box::before {
 z-index: 10;
 opacity: 0.5;
 background-color: #fff;
}
.blur-container.blur-3 .blur-box::after {
 background-size: cover;
 background-position: center;
 background-attachment: fixed;
 -webkit-filter: blur(15px) brightness(110%);
 filter: blur(15px) brightness(110%);
 background-image: var(--bg);
}