代码可以是:

<div class="text-class"><span>hello</span><span>How are you</span></div>

CSS将是:

.text-class {
  display: flex;
  justify-content: flex-start;
  flex-direction: column;
  align-items: center;
}

代码可以是:

<div class="text-class"><span>hello</span><span>How are you</span></div>

CSS将是:

.text-class {
  display: flex;
  justify-content: flex-start;
  flex-direction: column;
  align-items: center;
}

不可能使用相同的HTML结构，你必须有一些东西来区分Hello和How are you。

我建议使用span，然后显示为块(实际上就像<div>)。

P跨度{ 显示:块; ｝ <p><span>hello</span><span>How are you</span></p>

有几个选项可以定义空格和换行符的处理。 如果你可以把内容放在<p>标签中，你就很容易得到你想要的东西。

要保留换行符而不保留空格，请使用pre-line(而不是pre)，如in:

<style>
 p {
     white-space: pre-line; /* collapse WS, preserve LB */
   }
</style>

<p>hello
How are you</p>

如果需要另一种行为，请选择其中之一(WS=WhiteSpace, LB=LineBreak):

white-space: normal;   /* collapse WS, wrap as necessary, collapse LB */
white-space: nowrap;   /* collapse WS, no wrapping,       collapse LB */
white-space: pre;      /* preserve WS, no wrapping,       preserve LB */
white-space: pre-wrap; /* preserve WS, wrap as necessary, preserve LB */
white-space: inherit;  /* all as parent element */

资料来源:W3学校

要使元素在后面有换行符，为它赋值:

显示:块;

块级元素之后的非浮动元素将在下一行出现。许多元素，如<p>和<div>已经是块级元素，所以您可以只使用它们。

But while this is good to know, this really depends more on the context of your content. In your example, you would not want to use CSS to force a line break. The <br /> is appropriate because semantically the p tag is the the most appropriate for the text you are displaying. More markup just to hang CSS off it is unnecessary. Technically it's not exactly a paragraph, but there is no <greeting> tag, so use what you have. Describing your content well with HTMl is way more important - after you have that then figure out how to make it look pretty.

下面是一个糟糕问题的糟糕解决方案，但它确实符合概要:

p {
    width : 12ex;
}

p:before {
    content: ".";
    float: right;
    padding-left: 6ex;
    visibility: hidden;
}