如何使用：：在用图像在div顶部形成阴影之前

Question

我有这个小图像，我想重复一遍，这样它看起来就像我的div上的一个阴影，就像一个cookie通知。我怎样才能把它放在我的div cookieConsent的顶部，就像一个阴影在上面？

图片：

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​

#cookieConsent {
  width: 100%;
  background-color: #474540F2;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: none;
  z-index: 9999;
}

.cookieContainer {
  padding: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  font-size: 12px;
}

.cookieConsent-txt {
  color: #FFFFFF;
  width: calc (100% - 101px);
  margin: 0;
}

#cookieConsent a.cookieConsentOK {
  width: 85px;
  height: 56px;
  background: #FFFFFF;
  display: inline-block;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}

<div id="cookieConsent">
  <div class="cookieContainer">
    <p class="cookieConsent-txt">
      This site uses cookies
    </p>
    <a class="cookieConsentOK">Aceitar Cookies</a>
  </div>
</div>

​

Answer 1

您不需要为此使用图像，您可以使用box-shadow属性和负值-特别是y和spread属性。

​

#cookieConsent {
  width: 100%;
  background-color: #474540F2;
  position: fixed;
  bottom: 50px;
  left: 0;
  right: 0;
  z-index: 9999;
  box-shadow: 0px -4px 10px -2px rgb(0, 0, 0,0.4);
}

.cookieContainer {
  padding: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  font-size: 12px;
}

.cookieConsent-txt {
  color: #FFFFFF;
  width: calc (100% - 101px);
  margin: 0;
}

#cookieConsent a.cookieConsentOK {
  width: 85px;
  height: 56px;
  background: #FFFFFF;
  display: inline-block;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}

<div id="cookieConsent">
  <div class="cookieContainer">
    <p class="cookieConsent-txt">
      This site uses cookies
    </p>
    <a class="cookieConsentOK">Aceitar Cookies</a>
  </div>
</div>

​

如果需要使用图像，请将图像设置为伪元素的背景：

#cookieConsent::before {
  content: '';
  display: block;
  background-image: url(https://via.placeholder.com/10);
  background-repeat: repeat-x;
  width: 100%;
  height: 10px;
  position: absolute;
  left: 0;
  top: -10px;
}

​

#cookieConsent {
  width: 100%;
  background-color: #474540F2;
  position: fixed;
  bottom: 50px;
  left: 0;
  right: 0;
  z-index: 9999;
}

#cookieConsent::before {
  content: '';
  display: block;
  background-image: url(https://via.placeholder.com/10);
  background-repeat: repeat-x;
  width: 100%;
  height: 10px;
  position: absolute;
  left: 0;
  top: -10px;
}

.cookieContainer {
  padding: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  font-size: 12px;
}

.cookieConsent-txt {
  color: #FFFFFF;
  width: calc (100% - 101px);
  margin: 0;
}

#cookieConsent a.cookieConsentOK {
  width: 85px;
  height: 56px;
  background: #FFFFFF;
  display: inline-block;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}

<div id="cookieConsent">
  <div class="cookieContainer">
    <p class="cookieConsent-txt">
      This site uses cookies
    </p>
    <a class="cookieConsentOK">Aceitar Cookies</a>
  </div>
</div>

​