<h3>Bosnia and Herzegovina</h3>
<div class="flag bosnia">
  <div class="bosnia__triangle"></div>
  <div class="bosnia__star__wrapper">
    <div class="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;
}

.bosnia {
  background-color: #001e96;
}

.bosnia__triangle {
  position: absolute;
  top: -72%;
  left: 35%;
  border: 142px solid transparent;
  border-left-color: #ffcc01;
  transform: rotate(-45deg);
}
.bosnia__star__wrapper {
  filter: drop-shadow(25px 25px #fff) drop-shadow(25px 25px #fff)
    drop-shadow(25px 25px #fff) drop-shadow(25px 25px #fff)
    drop-shadow(25px 25px #fff) drop-shadow(25px 25px #fff)
    drop-shadow(25px 25px #fff) drop-shadow(25px 25px #fff);
}
.bosnia__star__wrapper > .star {
  width: 35px;
  height: 35px;
  margin: -20px 0px;
  background-color: white;
  clip-path: polygon(
    50% 0%,
    61% 35%,
    98% 35%,
    68% 57%,
    79% 91%,
    50% 70%,
    21% 91%,
    32% 57%,
    2% 35%,
    39% 35%
  );
}