CSS

Question

如何在封面图片上添加渐变层？

例如：

header {
  position: relative;
  height: 300px;
  background-repeat: no-repeat;
  background-position: center bottom;
  background-image: url('http://www.planwallpaper.com/static/images/Free-Wallpaper-Nature-Scenes.jpg');
  background-size: cover;
  border-bottom-left-radius: 50%;
  border-bottom-right-radius: 50%;
}

h1 {
  margin: 0;
  padding: 100px 0;
  font: 44px "Arial";
  text-align: center;
}

header h1 {
  color: white;
}

<header>
  <h1>Header Content</h1>
</header>

<section>
  <h1>Section Content</h1>
</section>

我想要在该图像上使用此渐变：

background-image: linear-gradient(to bottom right, #002f4b, #dc4225);

可能吗？

Answer 1

您可以在 :before 或 :after 元素上放置一个叠加层

header {
  position: relative;
  height: 300px;
  background-repeat: no-repeat;
  background-position: center bottom;
  background-image: url('http://www.planwallpaper.com/static/images/Free-Wallpaper-Nature-Scenes.jpg');
  background-size: cover;
  border-bottom-left-radius: 50%;
  border-bottom-right-radius: 50%;
}

header:before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: linear-gradient(to bottom right,#002f4b, #dc4225);
    opacity: .6; 
    border-bottom-left-radius: 50%;
    border-bottom-right-radius: 50%;
}

h1 {
  margin: 0;
  padding: 100px 0;
  font: 44px "Arial";
  text-align: center;
}

header h1 {
  color: white;
}

<header>
  <h1>Header Content</h1>
</header>

<section>
  <h1>Section Content</h1>
</section>

Answer 2

您可以定义多个背景，然后将background-blend-mode设置为multiply。像这样

header {
  position: relative;
  height: 300px;
  background-repeat: no-repeat;
  background-position: center bottom;
  background-size: cover;
  border-bottom-left-radius: 50%;
  border-bottom-right-radius: 50%;
  background-blend-mode: multiply;
  background: linear-gradient(to bottom right, #002f4b, #dc4225), url('http://www.planwallpaper.com/static/images/Free-Wallpaper-Nature-Scenes.jpg');
  background-size: cover;
}

h1 {
  margin: 0;
  padding: 100px 0;
  font: 44px "Arial";
  text-align: center;
}

header h1 {
  color: white;
}

<header>
  <h1>Header Content</h1>
</header>

<section>
  <h1>Section Content</h1>
</section>

Answer 3

使用 rgba 透明和双重 background-image。

header {
  position: relative;
  height: 300px;
  background-repeat: no-repeat;
  background-position: center bottom;
  background-image: linear-gradient(to bottom right, rgba(0, 47, 75, .5), rgba(220, 66, 37, .5)), url('http://www.planwallpaper.com/static/images/Free-Wallpaper-Nature-Scenes.jpg');
  background-size: cover;
  border-bottom-left-radius: 50%;
  border-bottom-right-radius: 50%;
}
h1 {
  margin: 0;
  padding: 100px 0;
  font: 44px "Arial";
  text-align: center;
}

header h1 {
  color: white;
}

<header>
  <h1>Header Content</h1>
</header>

<section>
  <h1>Section Content</h1>
</section>

Answer 4

注意：您可以使用 opacity 进行调整以更改渐变的强度。

header {
  position: relative;
  height: 300px;
  background-repeat: no-repeat;
  background-position: center bottom;
  background-image: url('http://www.planwallpaper.com/static/images/Free-Wallpaper-Nature-Scenes.jpg');
  background-size: cover;
  border-bottom-left-radius: 50%;
  border-bottom-right-radius: 50%;
  z-index: -1;
}

h1 {
  margin: 0;
  padding: 100px 0;
  font: 44px "Arial";
  text-align: center;
}

header h1 {
  color: white;
}

div#gradient {
 position: absolute;
 top: 0;
 left: 0;
 width: 100%;
 height: 300px;
 background-image: linear-gradient(to bottom right, #002f4b, #dc422b);
 border-bottom-left-radius: 50%;
 border-bottom-right-radius: 50%;
 z-index: -1;
 opacity: 0.75;
}

<header>
  <div id="gradient"></div>
  <h1>Header Content</h1>
</header>

<section>
  <h1>Section Content</h1>
</section>

CSS - 封面图片上的渐变？

CSS - gradient over a cover image?

html

cover

background-image