@property --mask-top{syntax:"<length>";inherits:false;initial-value:0}@property --mask-bottom{syntax:"<length>";inherits:false;initial-value:0}@property --mask-left{syntax:"<length>";inherits:false;initial-value:0}@property --mask-right{syntax:"<length>";inherits:false;initial-value:0}.scroll-area-mask{-webkit-mask-image:linear-gradient(to bottom,transparent 0,black var(--mask-top),black calc(100% - var(--mask-bottom)),transparent 100%),linear-gradient(to right,transparent 0,black var(--mask-left),black calc(100% - var(--mask-right)),transparent 100%);mask-image:linear-gradient(to bottom,transparent 0,black var(--mask-top),black calc(100% - var(--mask-bottom)),transparent 100%),linear-gradient(to right,transparent 0,black var(--mask-left),black calc(100% - var(--mask-right)),transparent 100%);-webkit-mask-size:100% 100%;mask-size:100% 100%;-webkit-mask-repeat:no-repeat;mask-repeat:no-repeat;-webkit-mask-composite:source-in;mask-composite:intersect;-webkit-mask-mode:match-source;mask-mode:match-source;transition:--mask-top 50ms ease,--mask-bottom 50ms ease,--mask-left 50ms ease,--mask-right 50ms ease}