body {
  padding: 0;
  margin: 10px;
}

.break-line {
  height: 10px;
  padding: 10px;
}

.square {
  width: 200px;
  height: 200px;
  background-color: orangered;
}

.rectangle {
  width: 400px;
  height: 200px;
  background-color: orange;
}

.rectangle-with-half-color {
  border: 5px solid #a00fc7;
  border-bottom-width: 50px;
  width: 100px;
  height: 50px;
}

.gradient-rectangle {
  width: 100px;
  height: 100px;
  background: linear-gradient(20deg, red, yellow);
}

.circle {
  width: 100px;
  height: 100px;
  border-radius: 50px;
  background-color: cornflowerblue;
}

.circle-beauty-1 {
  width: 100px;
  height: 100px;
  border: 10px solid red;
  border-radius: 30px;
}

.circle-beauty-2 {
  width: 50px;
  height: 50px;
  border: 10px solid red;
  border-radius: 50px 40px 0 40px;
}

.oval {
  width: 200px;
  height: 100px;
  background-color: aquamarine;
  border-radius: 100px  / 50px;
}

.half-oval {
  width: 200px;
  height: 100px;
  background-color: aquamarine;
  border-radius: 50%  / 100% 100% 0 0;
}

.quarter-oval {
  width: 200px;
  height: 100px;
  background-color: aquamarine;
  border-radius: 100% 0 0 0;
}

.topTriangle {
  width: 0;
  height: 0;
  border-left: 50px solid transparent;
  border-right: 50px solid transparent;
  border-bottom: 100px solid #a00fc7;
}

.rightTriangle {
  width: 0;
  height: 0;
  border-left: 100px solid #a00fc7;
  border-top: 50px solid transparent;
  border-bottom: 50px solid transparent;
}

.bottomTriangle {
  /*First way*/
  width: 0;
  height: 0;
  border-top: 100px solid #a00fc7;
  border-left: 50px solid transparent;
  border-right: 50px solid transparent;

  /*Second way*/
  /*
  此方法的局限性是不可以调整三角形的高度
  width: 0;
  height: 0;
  border: 100px solid transparent;
  border-top-color: #a00fc7;
  */
}

.leftTriangle {
  width: 0;
  height: 0;
  border-right: 100px solid #a00fc7;
  border-top: 50px solid transparent;
  border-bottom: 50px solid transparent;
}

/*-------------------------------------------------*/

.leftTopTriangle {
  width: 0;
  height: 0;
  border: 50px solid #a00fc7;
  border-right-color: transparent;
  border-bottom-color: transparent;

}

.rightTopTriangle {
  width: 0;
  height: 0;
  border: 50px solid transparent;
  border-top-color: #a00fc7;
  border-right-color: #a00fc7;
}

.rightBottomTriangle {
  width: 0;
  height: 0;
  border: 50px solid transparent;
  border-right-color: #a00fc7;
  border-bottom-color: #a00fc7;
}

.leftBottomTriangle {
  width: 0;
  height: 0;
  border: 50px solid transparent;
  border-left-color: #a00fc7;
  border-bottom-color: #a00fc7;
}

.parallelogram {
  width: 100px;
  height: 100px;
  margin-left: 20px;
  background-color: #ffcf22;
  transform: skew(30deg);
}

.trapezoid {
  width: 30px;
  height: 0;
  border-left: 50px solid transparent;
  border-right: 50px solid transparent;
  border-bottom: 100px solid #a00fc7;
}

.star-six {
  width: 0;
  height: 0;
  border-left: 50px solid transparent;
  border-right: 50px solid transparent;
  border-bottom: 100px solid #98bf21;
  position: relative;
}

.star-six:after {
  width: 0;
  height: 0;
  border-left: 50px solid transparent;
  border-right: 50px solid transparent;
  border-top: 100px solid #98bf21;
  content: "";
  position: absolute;
  left: -50px;
  top: 40px;
}

.star-five-step-1 {
  width: 0;
  height: 0;
  position: relative;
  display: block;
  color: red;
  border-right: 100px solid transparent;
  border-bottom: 60px solid red;
  border-left: 100px solid transparent;
}

.star-five-step-2 {
  width: 0;
  height: 0;
  position: relative;
  display: block;
  color: red;
  border-right: 100px solid transparent;
  border-bottom: 60px solid red;
  border-left: 100px solid transparent;
  -moz-transform: rotate(35deg);
  -webkit-transform: rotate(35deg);
  -ms-transform: rotate(35deg);
  -o-transform: rotate(35deg);
}

.star-five {
  margin: 50px 0;
  position: relative;
  display: block;
  color: red;
  width: 0;
  height: 0;
  border-right: 100px solid transparent;
  border-bottom: 70px solid red;
  border-left: 100px solid transparent;
  -moz-transform: rotate(35deg);
  -webkit-transform: rotate(35deg);
  -ms-transform: rotate(35deg);
  -o-transform: rotate(35deg);
}

.star-five:before {
  border-bottom: 80px solid red;
  border-left: 30px solid transparent;
  border-right: 30px solid transparent;
  position: absolute;
  height: 0;
  width: 0;
  top: -45px;
  left: -65px;
  display: block;
  content: '';
  -webkit-transform: rotate(-35deg);
  -moz-transform: rotate(-35deg);
  -ms-transform: rotate(-35deg);
  -o-transform: rotate(-35deg);

}

.star-five:after {
  position: absolute;
  display: block;
  color: red;
  top: 3px;
  left: -105px;
  width: 0;
  height: 0;
  border-right: 100px solid transparent;
  border-bottom: 70px solid red;
  border-left: 100px solid transparent;
  -webkit-transform: rotate(-70deg);
  -moz-transform: rotate(-70deg);
  -ms-transform: rotate(-70deg);
  -o-transform: rotate(-70deg);
  content: '';
}

.pentagon {
  width: 0;
  height: 0;
  border-left: 68.5px solid transparent;
  border-right: 68.5px solid transparent;
  border-bottom: 50px solid red;
  position: relative;
  margin: 50px 0;

}

.pentagon:after {
  content: "";
  width: 84px;
  height: 0;
  border-top: 80.36px solid red;
  border-left: 26px solid transparent;
  border-right: 26px solid transparent;
  position: absolute;
  top: 50px;
  left: -68px;
}

.hexagon {
  width: 100px;
  height: 55px;
  background: red;
  position: relative;
  margin: 50px 0;
}

.hexagon:before {
  content: "";
  position: absolute;
  top: -25px;
  left: 0;
  width: 0;
  height: 0;
  border-left: 50px solid transparent;
  border-right: 50px solid transparent;
  border-bottom: 25px solid red;
}

.hexagon:after {
  content: "";
  position: absolute;
  bottom: -25px;
  left: 0;
  width: 0;
  height: 0;
  border-left: 50px solid transparent;
  border-right: 50px solid transparent;
  border-top: 25px solid red;
}

.octagon {
  width: 100px;
  height: 50px;
  background: red;
  position: relative;
  margin: 50px 0;
}

.octagon:before {
  content: "";
  position: absolute;
  top: -29px;
  left: 0;
  border-bottom: 29px solid red;
  border-left: 29px solid transparent;
  border-right: 29px solid transparent;
  width: 42px;
  height: 0;
}

.octagon:after {
  content: "";
  position: absolute;
  top: 50px;
  left: 0;
  border-top: 29px solid red;
  border-left: 29px solid transparent;
  border-right: 29px solid transparent;
  width: 42px;
  height: 0;
}

.heart {
  position: relative;
  width: 100px;
  height: 90px;
  margin: 50px 0;
}

.heart:before,
.heart:after {
  position: absolute;
  content: "";
  left: 50px;
  top: 0;
  width: 50px;
  height: 80px;
  background: red;
  -moz-border-radius: 50px 50px 0 0;
  border-radius: 50px 50px 0 0;
  -webkit-transform: rotate(-45deg);
  -moz-transform: rotate(-45deg);
  -ms-transform: rotate(-45deg);
  -o-transform: rotate(-45deg);
  transform: rotate(-45deg);
  -webkit-transform-origin: 0 100%;
  -moz-transform-origin: 0 100%;
  -ms-transform-origin: 0 100%;
  -o-transform-origin: 0 100%;
  transform-origin: 0 100%;
}

.heart:after {
  left: 0;
  -webkit-transform: rotate(45deg);
  -moz-transform: rotate(45deg);
  -ms-transform: rotate(45deg);
  -o-transform: rotate(45deg);
  transform: rotate(45deg);
  -webkit-transform-origin: 100% 100%;
  -moz-transform-origin: 100% 100%;
  -ms-transform-origin: 100% 100%;
  -o-transform-origin: 100% 100%;
  transform-origin: 100% 100%;
}

.infinity {
  width: 50px;
  height: 50px;
  border: 10px solid red;
  border-radius: 50px 50px 0 50px;
  transform: rotate(-45deg);
  position: relative;
  margin: 50px 0;
}

.infinity:after {
  position: absolute;
  left: 50px;
  top: 50px;
  content: "";
  width: 50px;
  height: 50px;
  border: 10px solid red;
  border-radius: 50px 50px 0 50px;
  transform: rotate(180deg);
}

.pacman {
  width: 0;
  height: 0;
  border-right: 60px solid transparent;
  border-top: 60px solid red;
  border-left: 60px solid red;
  border-bottom: 60px solid red;
  border-top-left-radius: 60px;
  border-top-right-radius: 60px;
  border-bottom-left-radius: 60px;
  border-bottom-right-radius: 60px;
  margin: 50px 0;
}

.check {
  position: relative;
  display: inline-block;
}

.check:after {
  display: inline-block;
  content: '\20';
  width: 6px;
  height: 12px;
  border: 2px solid #ffcf22;
  border-top: 0;
  border-left: 0;
  transform: rotate(45deg) scale(1);
}

.big-check {
  position: relative;
  left: 50px;
  display: inline-block;
}

.big-check:after {
  display: inline-block;
  content: '\20';
  width: 30px;
  height: 60px;
  border: 3px solid #22c9ff;
  border-top: 0;
  border-left: 0;
  transform: rotate(45deg) scale(1);
}

.hero-rectangle {
  width: 100%;
  height: 100px;
  background-color: red;
}

.hero-triangle {
  height: 0;
  border-left: 100vw solid #107be7;
  border-bottom: 50px solid transparent;
}

.hero-rectangle-ad {
  width: 100%;
  height: 100px;
  background-color: red;
  margin-top: 30px;
}

.hero-triangle-ad {
  background-color: #107be7;
  position: relative;
  height: 99px;
  bottom: 50px;
  width: 100%;
  z-index: -1;
  -webkit-transform: skewY(-6deg);
  -ms-transform: skewY(-6deg);
  transform: skewY(-6deg);
}

.parallelogram-word {
  margin-top: 50px;
  margin-left: 50px;
  color: white;
  display: inline-block;
  padding: 10px;
  position: relative;
}

.parallelogram-word:after {
  background: #22c9ff;
  content: '';
  position: absolute;
  z-index: -1;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  transform: skew(-45deg);
}