<div class="container">
  <div class="frame">
    <div class="reactor">
      <div class="support-trapezoid"></div>
      <div class="support-trapezoid"></div>
      <div class="support-trapezoid"></div>
      <div class="triangle">
        <div class="core">
          <div class="core-inside"></div>
        </div>
      </div>
    </div>
  </div>
</div>

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
:root {
  --bg: #000;
  --bg-frame: #4b615c;
  --bg-reactor: #96cfcb;
  --bg-triangle: #016c97;
  --bg-core: #fff7f1;
  --bg-core-inside: #2a7b88;
  --light: #49fae6;
}

body {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background-color: var(--bg);
}

.frame {
  width: 20rem;
  height: 20rem;
  border-radius: 50%;
  background-color: var(--bg-frame);
  box-shadow: 0 0 7px 2.5px #96cfcb;
}

.reactor {
  background-color: var(--bg-reactor);
  width: 16rem;
  height: 16rem;
  border-radius: 50%;
  position: relative;
  top: 2rem;
  margin: 0 auto;
  box-shadow: inset 0px 0px 7px 6px rgba(0, 0, 0, 0.75);
  border: 1px solid black;
}

.support-trapezoid {
  width: 10rem;
  height: 6rem;
  background-color: var(--bg-frame);
  clip-path: polygon(
    0 0,
    15% 100%,
    85% 100%,
    100% 0,
    80% 0,
    65% 75%,
    35% 75%,
    20% 0
  );
  margin: 0 auto;
}

.support-trapezoid:nth-of-type(2) {
  transform: rotate(240deg);
  position: absolute;
  top: 8rem;
  left: -1.5rem;
}
.support-trapezoid:nth-of-type(3) {
  transform: rotate(117deg);
  position: relative;
  left: 5rem;
  top: 1.6rem;
}

.triangle {
  clip-path: polygon(0 0, 50% 100%, 100% 0);
  width: 12rem;
  height: 10rem;
  background-color: var(--bg-triangle);
  margin: 0 auto;
  position: relative;
  top: -7.1rem;
}

.core {
  clip-path: polygon(0 0, 50% 100%, 100% 0);
  width: 6rem;
  height: 5rem;
  background-color: var(--bg-core);
  margin: 0 auto;
  position: relative;
  bottom: -1.5rem;
  /* animation: coreAnimate 1.5s ease-in-out infinite alternate; */
}

.core-inside {
  clip-path: polygon(0 0, 50% 100%, 100% 0);
  width: 3.5rem;
  height: 3rem;
  background-color: var(--bg-core-inside);
  margin: 0 auto;
  position: relative;
  bottom: -0.6rem;
}