.main-header{transition:all 0.3s ease;position:fixed;width:100%;z-index:9999}.main-header.scrolling-down{height:60px;background:rgba(255,255,255,0.8)}.main-header.scrolling-up{height:100px;background:rgba(255,255,255,1)}.main-header{transition:all 0.3s ease;position:fixed;width:100%;z-index:9999}.main-header.scrolling-down{height:60px;background:rgba(255,255,255,0.8)}.main-header.scrolling-up{height:100px;background:rgba(255,255,255,1)}