CSS 过渡不适用于输入宽度

Question

我想看到输入框增加或减少 width，但我无法使 transition 起作用。有人知道为什么它不起作用吗？

.expand input[type = "text"], 
.expand input[type = "password"]{
    border: 2px solid rgb(0, 119, 255);
    border-radius: 30px;
    background: none;
    transition: 0.25s;
}

.expand input[type = "text"]:hover,
.expand input[type = "password"]:hover{
    width: 210px;
    border-color: rgb(47, 255, 57);
}

<form>
  <h3 style="color: white; font-family: Montserrat; text-align: center;">Login</h3>
  <div class="center">
    <div class="expand">
      <input type="text" placeholder="Username" style="font-family: Montserrat; height: 30px; text-align: center; color: white; font-size: 13px;">
    </div>
  </div>
</form>

Answer 1

您不能使用 width: auto 进行过渡（这是默认设置，因为您没有指定宽度），您的元素需要定义一个初始宽度。

.expand input[type = "text"], 
.expand input[type = "password"]{
    border: 2px solid rgb(0, 119, 255);
    border-radius: 30px;
    background: none;
    transition: 0.25s;
    width: 100px; /* New CSS */
}

.expand input[type = "text"]:hover,
.expand input[type = "password"]:hover{
    width: 210px;
    border-color: rgb(47, 255, 57);
}

<form>
  <h3 style="color: white; font-family: Montserrat; text-align: center;">Login</h3>
  <div class="center">
    <div class="expand">
      <input type="text" placeholder="Username" style="font-family: Montserrat; height: 30px; text-align: center; color: white; font-size: 13px;">
    </div>
  </div>
</form>

Answer 2

您需要设置输入的初始宽度

.expand input[type = "text"], 
.expand input[type = "password"]{
    border: 2px solid rgb(0, 119, 255);
    border-radius: 30px;
    background: none;
    transition: 0.25s;
    width: 100px;
}

.expand input[type = "text"]:hover,
.expand input[type = "password"]:hover{
    width: 210px;
    border-color: rgb(47, 255, 57);
}

<form>
  <h3 style="color: white; font-family: Montserrat; text-align: center;">Login</h3>
  <div class="center">
    <div class="expand">
      <input type="text" placeholder="Username" style="font-family: Montserrat; height: 30px; text-align: center; color: white; font-size: 13px;">
    </div>
  </div>
</form>

CSS 过渡不适用于输入宽度

CSS transition does not work on input width

html

css

width

css-transitions