arrow down css
.arrow-down { width: 0; height: 0; border-left: 75px solid transparent; border-right: 75px solid transparent; border-top: 75px solid #f00; }
arrow left css
.arrow-left { width: 0; height: 0; border-top: 60px solid transparent; border-bottom: 60px solid transparent; border-right: 60px solid blue; }
arrow up css
.arrow-up { width: 0; height: 0; border-left: 75px solid transparent; border-right: 75px solid transparent; border-bottom: 75px solid #761E9B; }
arrow right css
.arrow-right { width: 0; height: 0; border-top: 60px solid transparent; border-bottom: 60px solid transparent; border-left: 60px solid green; }