html{-webkit-filter:grayscale(100%);filter:grayscale(100%)}body::before{content:"";position:fixed;top:0;left:0;width:110px;height:110px;background:linear-gradient(135deg,
transparent 0 32%,
#000 32% 46%,
transparent 46% 100%);z-index:2147483647;pointer-events:none}@media (max-width: 1024px){body::before{width:30px;height:30px}}