<h3>São Tomé</h3>

<div class="flag são_tomé">
  <div class="são_tomé__center">
    <div class="são_tomé__star"></div>
    <div class="são_tomé__star"></div>
  </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;
}

.são_tomé {
  background: linear-gradient(#009739 30%, #ffd100 30%, #ffd100 70%, #009739 0);
}

.são_tomé::before {
  position: absolute;
  content: "";
  left: 0;
  border: 100px solid transparent;
  border-left: 75px solid #ef3340;
}

.são_tomé__center {
  position: absolute;
  inset: 0;
  left: 75px;

  height: 60px;
  width: 225px;
  margin: auto;

  display: flex;
  justify-content: space-evenly;
}

.são_tomé__star {
  width: 65px;
  aspect-ratio: 1;
  background-color: black;
  clip-path: polygon(
    50% 0%,
    61% 35%,
    98% 35%,
    68% 57%,
    79% 91%,
    50% 70%,
    21% 91%,
    32% 57%,
    2% 35%,
    39% 35%
  );
}