我在我的第一年编程和刚刚学习Java这就是为什么我完全失去了与CSS和需要帮助。我想编辑此代码（不是我的）

===== CUSTOMIZABLE COLORS =====
:root { 
main-color: #057F95;
hover-color: #045B6B;
}

===== CUSTOMIZABLE IMAGES =====
IMPORTANT: EVERY URL MUST BE HTTPS:// IN ORDER TO WORK IN DISCORD
RECOMMENDATIONS: EVERY URL AT THE BOTTOM SHOULD BE THE SAME TO MAKE THE
tHEM MATCH. (YOUR CHOICE)
/*Change the url in .app to change the background behind chat */
.app { background-image: url("https://imgur.com/RG03PyX.png") !important;
background-size: cover !important; }

/*Change the url in .callout-backdrop to change the background when modal pop outs happen */

.callout-backdrop { background-color: black !important; background-image:     url("https://imgur.com/RG03PyX.png") !important; -webkit-transition: 0.3s all     ease; -o-transition: 0.3s all ease; -moz-transition: 0.3s all ease; transition:     0.3s all ease; background-size: cover !important; -webkit-filter:     brightness(75%); }

/*Change the urls below to change the background of a profile modal pop up     */

.user-popout:before {
    background-image: url("https://imgur.com/RG03PyX.png") !important;
    content: "";position: absolute;left: 0;top: 0;height: 100%;width:     100%;z-index: -1;background-position: 50% 50%;-webkit-filter: blur(3px);-webkit-    transform: scale(1.05);transform: scale(1.05);}

#user-profile-modal .header:before {
    background: -webkit-linear-gradient(top, rgba(0, 0, 0, .3), rgba(0, 0,     0, 0.5)), url("https://imgur.com/RG03PyX.png") !important;
    background: linear-gradient(to bottom, rgba(0, 0, 0, .3), rgba(0, 0, 0,     0.5)), url("https://imgur.com/RG03PyX.png") !important;
    content: "";position: absolute;left: 0;top: 0;width: 100%;height:     100%;z-index: -1;background-position: 50% 50%;background-size: cover     !important;-webkit-filter: blur(3px);-webkit-transform: scale(1.1);transform:     scale(1.1);}

我尝试不同的东西（颜色：透明，透明度：真，RGBA（0，0，0，0.1），可见性：隐藏，不透明度：0.5，做一个透明背景和其他一些，但没有一个工作。2我希望你能找到一个解决我的问题。