HTML/CSS -文本不能在按钮内居中

<button class="centered-button">
  <span>按钮文本</span>
</button>

.centered-button {
  display: flex;
  justify-content: center;
  align-items: center;
}

<button class="centered-button">
  <span>按钮文本</span>
</button>

.centered-button {
  position: relative;
}

.centered-button span {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}