.header{background:linear-gradient(to bottom,rgb(255 255 255/0%),rgb(255 255 255/37%)),url(../image/bj12.webp);background-size:cover;background-position:center;width:100%;height:500px}@media(max-width:768px){.header{height:200px}}.center-image{display:flex;justify-content:center;align-items:center;width:100%;margin:20px 0}.center-image img{max-width:100%;height:auto;display:block;margin:0 auto}.color-picker{text-align:center;margin:20px}body{overflow-x:hidden;transition:background-color .3s,color .3s;background-color:#fff;color:#000}.mode-toggle{position:fixed;bottom:75px;right:18px;background-color:#fff;border:none;border-radius:79%;width:39px;height:39px;font-size:22px;cursor:pointer;z-index:1001}body.night-mode .mode-toggle{background-color:#444}