Letter S

I solved it on November 1, 2022. You can try to beat my record on CSSBattle!

356 chars

<body bgcolor=4F77FF><p><p a><style>*{border-radius:10px}body{padding:62 72}p{background:#FFF;padding:25 120;box-shadow:#1038BF 20px -20px 0}p::before,p::after{content:"";position:absolute;background:#FFF;margin:0 -30vw;padding:32.4 10;border-radius:10px}p::after{border-radius:0 10px 0 0;padding:10 60;margin:45 0}[a]{margin:60 0;transform:rotate(180deg)}

Finally I can extensively practice rotations in this one.