（参考サイト） https://design-remarks.com/stripe-css/

style.css

.top_introduction_inner {
  background: -webkit-repeating-linear-gradient(
    -45deg,
    #00a0ea 0,
    #00a0ea 11px,
    #1aaaec 12px,
    #1aaaec 13px
  );
  background: -o-repeating-linear-gradient(
    -45deg,
    #00a0ea 0,
    #00a0ea 11px,
    #1aaaec 12px,
    #1aaaec 13px
  );
  background: repeating-linear-gradient(
    -45deg,
    #00a0ea 0,
    #00a0ea 11px,
    #1aaaec 12px,
    #1aaaec 13px
  );
}