html - 无论是大写字母还是小写字母，都可以在视觉上将单个字母居中

Question

所以我需要制作圆圈，每个圆圈中都有一个字母，我希望将字母居中。然而，当我使用不同大小的字母时，它们居中的方式有​​所不同，在这种情况下，小写 q 和 大写 A(只是一个例子，它可能是任何字母):

span {
  align-items: center;
  display: flex;
  font-family: sans-serif;
  justify-content: center;
  border-radius: 50%;
  height: 30px;
  width: 30px;
  border: 1px solid black;
  float: left;
}

<span>q</span>
<span>A</span>

可以看到小写的q比大写的A小，这是因为字母大小不一样，q没有填满上半部分。这会导致字母 q 看起来不正确居中。

这是一张展示我的意思的图片，左边是我得到的，右边是我想要的:

q 应该高一点，以使其看起来正确居中。是否可以在不为每个不同大小的字母更改 CSS 的情况下做到这一点？

Answer 1

JavaScript 解决方案。我将小写字母分为三种不同的类型:标准小写字母、线下字母和高字母。我的目标是使用 ASCII 代码并添加 CSS 类并相应地更改 margin-top。您可以相应地添加更多异常(exception)(字母 j 可能需要下降一个像素。)

Here is a pen.

$('span').each(function(){
    var letter = $(this).text();
    var letterCode = letter.charCodeAt(0);
  //check if lowercase
  if (letter == letter.toLowerCase()){
   $(this).addClass('lowercase');
  }
    if (letterCode == 106 || letterCode == 112 || letterCode == 113 || letterCode == 121 || letterCode == 103 ){ //jpqyg
      $(this).addClass('below-line');
}
  //All these other letters : bdfiklt
  if(letterCode == 98 || letterCode == 100 || letterCode == 102 || letterCode == 105 || letterCode == 107 || letterCode == 108 || letterCode == 116){
    $(this).addClass('tall-letters');
  }
});

div {
  align-items: center;
  display: flex;
  font-family: sans-serif;
  justify-content: center;
  border-radius: 50%;
  height: 30px;
  width: 30px;
  border: 1px solid black;
  float: left;
}
span{
  margin-top: 0;
}
.lowercase{
  margin-top: -3px;
}
.below-line{
    margin-top: -6px;
}
.tall-letters{
  margin-top: -1px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div><span>A</span></div>
<div><span>a</span></div>
<div><span>B</span></div>
<div><span>b</span></div>
<div><span>C</span></div>
<div><span>c</span></div>
<div><span>D</span></div>
<div><span>d</span></div>
<div><span>E</span></div>
<div><span>e</span></div>
<div><span>F</span></div>
<div><span>f</span></div>
<div><span>G</span></div>
<div><span>g</span></div>
<div><span>H</span></div>
<div><span>h</span></div>
<div><span>I</span></div>
<div><span>i</span></div>
<div><span>J</span></div>
<div><span>j</span></div>
<div><span>K</span></div>
<div><span>k</span></div>
<div><span>L</span></div>
<div><span>l</span></div>
<div><span>M</span></div>
<div><span>m</span></div>
<div><span>N</span></div>
<div><span>n</span></div>
<div><span>O</span></div>
<div><span>o</span></div>
<div><span>P</span></div>
<div><span>p</span></div>
<div><span>Q</span></div>
<div><span>q</span></div>
<div><span>R</span></div>
<div><span>r</span></div>
<div><span>S</span></div>
<div><span>s</span></div>
<div><span>T</span></div>
<div><span>t</span></div>
<div><span>U</span></div>
<div><span>u</span></div>
<div><span>T</span></div>
<div><span>t</span></div>
<div><span>U</span></div>
<div><span>u</span></div>
<div><span>V</span></div>
<div><span>v</span></div>
<div><span>W</span></div>
<div><span>w</span></div>
<div><span>X</span></div>
<div><span>x</span></div>
<div><span>Y</span></div>
<div><span>y</span></div>
<div><span>Z</span></div>
<div><span>z</span></div>