话不多说，上代码

html

<div class="text-group">
  <span>$</span>
  <input type="text" value="25.00" />
</div>

scss

.text-group {
  width: 120px;
  height: 30px;
  display: flex;
  align-items: center;
  border: 1px solid #999999;
  border-radius: 2px 2px 2px 2px;
  span {
    width: 17px;
  }
  input {
    width: 100%;
    text-align: right;
    padding: 0px 10px;
    border: none;
    background: none;
  }
}

最终结果