<h3>South Sudan</h3>

<div class="flag south_sudan">
  <div class="south_sudan__star"></div>
</div>
* {
  box-sizing: border-box;
  margin: 0;
}

body {
  width: 100%;
  height: 100vh;
  background-color: rgb(221, 239, 255);
  display: grid;
  place-items: center;
  font-family: cursive;
  font-weight: bold;
}

h3 {
  position: absolute;
  text-align: center;
  top: 20px;
}

/* Main Style Stars from here  */
.flag {
  position: relative;
  width: 300px;
  height: 200px;
  box-shadow: 0 0 1px rgba(0, 0, 0, 0.5);
  overflow: hidden;
}

.south_sudan {
  background: linear-gradient(#000 50%, #078930 0);
  display: grid;
  place-items: center;
}

.south_sudan::before {
  position: absolute;
  content: "";
  height: 33%;
  width: 100%;
  background: #da121a;
  border: 7px solid white;
  transform: scalex(10px);
}
.south_sudan::after {
  position: absolute;
  content: "";
  left: 0;
  border: 100px solid transparent;
  border-left: 130px solid #0f47af;
}

.south_sudan__star {
  position: absolute;
  left: 7%;

  height: 50px;
  aspect-ratio: 1;
  background: #fcdd09;
  rotate: -15deg;
  z-index: 1;

  clip-path: polygon(
    50% 0%,
    61% 35%,
    98% 35%,
    68% 57%,
    79% 91%,
    50% 70%,
    21% 91%,
    32% 57%,
    2% 35%,
    39% 35%
  );
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.