CSS 三角形作法

語法

HTML

<div class="box"></div>

CSS

.box {
  width: 0px;
  height: 0px;
  border-right: 40px solid transparent;
  border-bottom: 40px solid blue;
  border-left: 40px solid transparent;
}

CSS 折角三角形做法

HTML

<div class="tab">
  三角形折角
  <div class="arrow"></div>
</div>

CSS

.tab {
  width: 100px;
  height: 30px;
  line-height: 30px;
  position: relative;
  background-color: #fa0;
}

.arrow {
  width: 0;
  height: 0;
  position: absolute;
  border-top: 5px solid #850;
  border-left: 10px solid transparent;
}

CSS 轉 45 度漸層色

HTML

<div class="box"></div>

CSS

.box {
  width: 300px;
  height: 300px;
  background-color: #f00;
  background-image: linear-gradient(45deg, #f00 0%, #ff0 50%, #0f0 100%);
}

background-image: linear-gradient(角度, 色標, 色標);

0 度是由下往上，角度是順時針轉