解析background-repeat: no-repeat; background-position: 87px 16px, 99px 192px; border-radius: 30px 30px 0 0;

这段CSS代码包含了三个属性：

1. background-repeat: no-repeat;

这个属性指定了背景图像不应该重复。也就是说，如果背景图像需要占据整个元素，它只会被绘制一次。

2. background-position: 87px 16px, 99px 192px;

这个属性指定了背景图像的位置。它使用了两个值对来指定两张不同的背景图像的位置。第一个值对指定了第一张背景图像的位置，第二个值对指定了第二张背景图像的位置。

3. border-radius: 30px 30px 0 0;

这个属性指定了元素的圆角半径。它使用了四个值，每个值指定一个角的半径。第一个值指定左上角的半径，第二个值指定右上角的半径，第三个值指定右下角的半径，第四个值指定左下角的半径。在这个例子中，左上角和右上角的半径是30像素，而右下角和左下角的半径是0，也就是说它们没有圆角。

相关问题

优化下面代码.bg { width: 100%; height: 100vh; background-image: url('../../assets/img/info-bg.png'); background-size: 100% 100%; background-repeat: no-repeat; position: relative; font-family: AlibabaPuHuiTiR; .goBack { position: absolute; top: 34px; right: 65px; cursor: pointer; color: #ffffff; width: 181px; padding: 15px 10px; background: rgba(24, 31, 30, 0.52); border: 1px solid #4a524e; border-radius: 5px; font-size: 18px; font-family: AlibabaPuHuiTiR; z-index: 111; display: flex; flex-direction: row; justify-content: space-between; align-items: center; } .home-left { position: absolute; top: 18%; left: 40px; width: 41%; height: 76%; font-size: 24px; color: #ffffff; } .unit { font-size: 24px; color: #636363; } .home-left-title { font-size: 24px; color: #ffffff; line-height: 36px; } .home-right { position: absolute; top: 18%; right: 88px; width: 46%; height: 78%; } .model { display: flex; justify-content: center; align-items: center; height: 90%; } #threeContained { width: 100%; height: 100%; } .model-qk-img { width: 82%; height: 90%; background-image: url('../../assets/img/howo.png'); background-size: 100% 100%; background-repeat: no-repeat; } .model-zk-img { width: 56%; height: 90%; background-image: url('../../assets/img/heavyT.png'); background-size: 100% 100%; background-repeat: no-repeat; } .model-gj-img { width: 82%; height: 90%; background-image: url('../../assets/img/transit.png'); background-size: 100% 100%; background-repeat: no-repeat; } .car-online { margin-bottom: 50px; } } .day-data { display: flex; flex-direction: row; justify-content: space-between; align-items: center; height: 29%; margin-left: 30px; } .day-val { width: 40%; } .prefix { display: inline-block; width: 6px; height: 14px; background: #ffffff; margin-right: 20px; } .zh-title { margin-left: 30px; padding-top: 30px; font-size: 30px; font-weight: 700; text-align: left; color: #ffffff; line-height: 32px; letter-spacing: 0.3px; font-family: AlibabaPuHuiTiB; } .en-title { margin-left: 30px; font-size: 14px; font-weight: 400; text-align: left; color: #ffffff; line-height: 32px; letter-spacing: -0.91px; font-family: AlibabaPuHuiTiR; }

Here are some suggestions to optimize the code:

1. Use shorthand properties whenever possible. For example, instead of writing `background-size: 100% 100%;`, you can write `background-size: cover;`.

2. Consolidate similar styles into classes, instead of repeating them for every element. For example, you can create a class for the font family and apply it to all elements that use that font.

3. Remove unnecessary styles that are not being used or overwritten by other styles.

4. Use more specific selectors to target elements, instead of relying on the order of elements in the HTML. This will make the code more robust and easier to maintain.

5. Consider using a CSS preprocessor like Sass or Less, which can help you write cleaner and more organized code.

Here's an example of how the code could be optimized:

.bg {
  width: 100%;
  height: 100vh;
  background: url('../../assets/img/info-bg.png') no-repeat center center / cover;
  position: relative;
  font-family: AlibabaPuHuiTiR;
}

.goBack {
  position: absolute;
  top: 34px;
  right: 65px;
  cursor: pointer;
  color: #fff;
  width: 181px;
  padding: 15px 10px;
  background: rgba(24, 31, 30, 0.52);
  border: 1px solid #4a524e;
  border-radius: 5px;
  font-size: 18px;
  font-family: AlibabaPuHuiTiR;
  z-index: 111;
  display: flex;
  flex-direction: row;
  justify-content: space-between;
  align-items: center;
}

.home-left {
  position: absolute;
  top: 18%;
  left: 40px;
  width: 41%;
  height: 76%;
  font-size: 24px;
  color: #fff;
}

.unit {
  font-size: 24px;
  color: #636363;
}

.home-left-title {
  font-size: 24px;
  color: #fff;
  line-height: 36px;
}

.home-right {
  position: absolute;
  top: 18%;
  right: 88px;
  width: 46%;
  height: 78%;
}

.model {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 90%;
}

#threeContained {
  width: 100%;
  height: 100%;
}

.model-qk-img {
  width: 82%;
  height: 90%;
  background: url('../../assets/img/howo.png') no-repeat center center / cover;
}

.model-zk-img {
  width: 56%;
  height: 90%;
  background: url('../../assets/img/heavyT.png') no-repeat center center / cover;
}

.model-gj-img {
  width: 82%;
  height: 90%;
  background: url('../../assets/img/transit.png') no-repeat center center / cover;
}

.car-online {
  margin-bottom: 50px;
}

.day-data {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 29%;
  margin-left: 30px;
}

.day-val {
  width: 40%;
}

.prefix {
  display: inline-block;
  width: 6px;
  height: 14px;
  background: #fff;
  margin-right: 20px;
}

.zh-title {
  margin-left: 30px;
  padding-top: 30px;
  font-size: 30px;
  font-weight: 700;
  text-align: left;
  color: #fff;
  line-height: 32px;
  letter-spacing: 0.3px;
  font-family: AlibabaPuHuiTiB;
}

.en-title {
  margin-left: 30px;
  font-size: 14px;
  font-weight: 400;
  text-align: left;
  color: #fff;
  line-height: 32px;
  letter-spacing: -0.91px;
  font-family: AlibabaPuHuiTiR;
}

.font-alibaba {
  font-family: AlibabaPuHuiTiR;
}

.font-alibaba-bold {
  font-family: AlibabaPuHuiTiB;
}

#fixed-button { width: 50px; height: 50px; border-radius: 50%; background-image: url("images/service.png"); background-repeat: no-repeat; background-size: cover; position: fixed; top: 50%; left: 50%; transform: translate(-50%, -50%); z-index: 9999; }什么意思

这是一个CSS样式代码，用于设置一个固定位置的圆形按钮。具体解释如下：

- `width: 50px;` 设置按钮宽度为50像素；
- `height: 50px;` 设置按钮高度为50像素；
- `border-radius: 50%;` 设置按钮的圆角半径为50%，使其变为圆形；
- `background-image: url("images/service.png");` 设置按钮的背景图片为名为"service.png"的图片；
- `background-repeat: no-repeat;` 设置背景图片不重复；
- `background-size: cover;` 让背景图片占满整个按钮，不留空白；
- `position: fixed;` 让按钮的定位方式为固定，即不随页面滚动；
- `top: 50%;` 将按钮向上偏移50%的页面高度；
- `left: 50%;` 将按钮向左偏移50%的页面宽度；
- `transform: translate(-50%, -50%);` 让按钮水平和垂直方向都向左上方偏移50%的宽度和高度，使得按钮的中心点位于页面的正中心；
- `z-index: 9999;` 设置按钮的层级为9999，确保它在页面上最前面。