Result
Output code:
            .button-with-gradient-border {
                
                    background-image:
                    radial-gradient(circle at 100% 100%, transparent 9px, #d50000 9px, #d50000 10px, transparent 10px),
                    linear-gradient(to right, #d50000, #304ffe),
                    radial-gradient(circle at 0% 100%, transparent 9px, #304ffe 9px, #304ffe 10px, transparent 10px),
                    linear-gradient(to bottom, #304ffe, #05ffde),
                    radial-gradient(circle at 0% 0%, transparent 9px, #05ffde 9px, #05ffde 10px, transparent 10px),
                    linear-gradient(to left, #05ffde, #ffd600),
                    radial-gradient(circle at 100% 0%, transparent 9px, #ffd600 9px, #ffd600 10px, transparent 10px),
                    linear-gradient(to top, #ffd600, #d50000)
                
                
                    background-size:
                    10px 10px,
                    calc(100% - 20px) 1px,
                    10px 10px,
                    1px calc(100% - 20px)
                
                
                    background-position:
                    top left,top center,top right,center right, bottom right,bottom center,bottom left,center left
                
                
                    background-repeat:
                    no-repeat
                
            }