.graph-board {
  border: none;
  height: 520px;
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 78% 22%, rgba(74, 146, 255, .14), transparent 30%),
    radial-gradient(circle at 15% 80%, rgba(134, 67, 255, .12), transparent 28%),
    linear-gradient(135deg, #0a1f45 0%, #091835 46%, #0c234f 100%);
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.03);
}

.function-graph {
  position: absolute;
  inset: 18px;
}

.function-graph canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.function-graph span {
  position: absolute;
  top: 34px;
  left: 42px;
  z-index: 2;
  padding: 11px 24px;
  border: 1.8px solid rgba(243, 190, 43, .92);
  border-radius: 999px;
  background: rgba(6, 15, 37, .78);
  color: #fff9ea;
  font: italic 24px Georgia, "Times New Roman", serif;
  letter-spacing: .01em;
  box-shadow: 0 10px 24px rgba(0, 0, 0, .16);
  backdrop-filter: blur(4px);
}

@media (max-width: 850px) {
  .graph-board {
  border: none;
    height: 450px;
  }

  .function-graph {
    inset: 10px;
  }

  .function-graph span {
    top: 20px;
    left: 22px;
    padding: 9px 18px;
    font-size: 19px;
  }
}