css - 保持 Popover 相对于按钮居中

Question

我正在试验发现的这个 CSS 弹出框 http://codepen.io/derekpcollins/pen/JCLhG/ .这是弹出窗口的代码。

.popover {
    background-color: rgba(0,0,0,0.85);
    border-radius: 5px;
    bottom: 42px;
    box-shadow: 0 0 5px rgba(0,0,0,0.4);
    color: #fff;
    display: none;
    font-size: 12px;
    font-family: 'Helvetica',sans-serif;
    left: -95px;
    padding: 7px 10px;
    position: absolute;
    width: 200px;
    z-index: 4;
}

悬停时，弹出框看起来像这样

我想让弹出窗口更宽，但是当我将宽度更改为 600 像素时，它会变得错位。

无论按钮有多宽，我都希望弹出框的箭头指向按钮怎么办？

谢谢

Answer 1

如果您希望弹出框为任意动态宽度并居中，请移除width，设置white-space:nowrap并更改定位到

left: 50%;
transform:translateX(-50%);
white-space: nowrap;

* {
  box-sizing: border-box;
}

body {
  background-color: #e3fbff;
}

/* Just to center things */
.center {
  margin: 75px auto;
  width: 30px;
}

/* The element to hover over */
.qs {
  background-color: #02bdda;
  border-radius: 16px;
  color: #e3fbff;
  cursor: default;
  display: inline-block;
  font-family: 'Helvetica',sans-serif;
  font-size: 18px;
  font-weight: bold;
  height: 30px;
  line-height: 30px;
  position: relative;
  text-align: center;
  width: 30px;
}
.qs .popover {
  background-color: rgba(0, 0, 0, 0.85);
  border-radius: 5px;
  bottom: 42px;
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.4);
  color: #fff;
  display: none;
  font-size: 12px;
  font-family: 'Helvetica',sans-serif;
  padding: 7px 10px;
  position: absolute;
  white-space: nowrap;
  z-index: 4;
  left: 50%;
  transform: translateX(-50%);
}
.qs .popover:before {
  border-top: 7px solid rgba(0, 0, 0, 0.85);
  border-right: 7px solid transparent;
  border-left: 7px solid transparent;
  bottom: -7px;
  content: '';
  display: block;
  left: 50%;
  margin-left: -7px;
  position: absolute;
}
.qs:hover .popover {
  display: block;
  -webkit-animation: fade-in .3s linear 1, move-up .3s linear 1;
  -moz-animation: fade-in .3s linear 1, move-up .3s linear 1;
  -ms-animation: fade-in .3s linear 1, move-up .3s linear 1;
}

@-webkit-keyframes fade-in {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}
@-moz-keyframes fade-in {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}
@-ms-keyframes fade-in {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}
@-webkit-keyframes move-up {
  from {
    bottom: 30px;
  }
  to {
    bottom: 42px;
  }
}
@-moz-keyframes move-up {
  from {
    bottom: 30px;
  }
  to {
    bottom: 42px;
  }
}
@-ms-keyframes move-up {
  from {
    bottom: 30px;
  }
  to {
    bottom: 42px;
  }
}

<div class="center">
  <span class="qs">? <span class="popover above">Hey bro, cool popover!</span></span>
</div>

<div class="center">
  <span class="qs">? <span class="popover above">Short popover!</span></span>
</div>