@charset "UTF-8";
* {
  margin: 0;
  padding: 0;
  list-style: none;
  text-decoration: none;
  box-sizing: border-box;
}

.box {
  color: #f00;
  background-color: #f00;
}

.part4 {
  cursor: pointer;
  width: 100px;
  height: 100px;
  background: plum;
}

.box {
  width: 800px;
  height: 800px;
  border: 1px solid #000;
  background-color: #ff0;
  border-radius: 20px;
  border: 3px double #00f;
  box-shadow: 30px 35px 15px #f0f;
  font-size: 25px;
  font-weight: 600;
}

.box h1 {
  font-size: 20px;
  color: red;
}

.box .main {
  border: 1px solid #f00;
  color: purple;
  width: 200px;
  height: 100px;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #00f;
}

.box .main:hover {
  color: #f00;
}

.box h2, .box h3, .box h4, .box h5, .box h6 {
  width: 200px;
  height: 300px;
  background-color: yellow;
  background-color: white;
  margin-top: 20px;
}

/*
    哈哈哈哈
*/