*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
/*
  rem 自适应（带上下限）：
  - 设计稿 1920：理想 1rem = 100px → 100vw / 19.2
  - 最小 75px：约对应 1440 宽，笔记本不再把字压得过小
  - 最大 100px：超大屏不再无限放大
  若仍偏小，可把 75px 调到 80~85px
*/
html {
  font-size: clamp(80px, calc(100vw / 19.2), 100px);
  -webkit-text-size-adjust: 100%;
}
body {
  font-family: Microsoft YaHei, Microsoft YaHei;
  font-size: 0.16rem;
  line-height: 1.6;
  color: #1a1a1a;
  background: #fff;
  overflow-x: hidden;
}
ul,
ol {
  list-style: none;
}
a {
  text-decoration: none;
  color: inherit;
}
img,
video {
  display: block;
  max-width: 100%;
  height: auto;
}
button {
  border: none;
  background: none;
  cursor: pointer;
  font: inherit;
}
input,
textarea {
  font: inherit;
  border: none;
  outline: none;
}
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: normal;
}
.clearfix::after {
  content: "";
  display: block;
  clear: both;
}
.flex,
.d-flex {
  display: flex;
}
.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}
.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.align-center {
  align-items: center;
}
.justify-center {
  justify-content: center;
}
.justify-between {
  justify-content: space-between;
}
.justify-around {
  justify-content: space-around;
}
.ellipsis3 {
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
}
/* 移动端：按 750 设计习惯，并限制过小屏字号 */
@media screen and (max-width: 768px) {
  html {
    font-size: clamp(46px, calc(100vw / 7.5), 54px);
  }
}