/* 中间主题 */
.main {
  width: 100%;
  height: 900px;
  background: #f8f8f8;
}
.main-center {
  width: 1500px;
  height: 100%;
  margin: 0 auto;
}
.main-center-img {
  width: 100%;
  height: 850px;
  overflow: hidden;
  position: relative;
}
.main-center-entry {
  width: 392px;
  height: 220px;
  background: #000000;
  opacity: 0.65;
  outline: none;
  border: none;
  border-radius: 20px;
  color: #fff;
  font-size: 40px;
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  margin: auto;
  z-index: 999;
  cursor: pointer;
}
.main-center-img img {
  width: 100%;
  height: 100%;
}

/* 页脚 */
.footer {
  width: 100%;
  height: 80px;
  background-color: #fff;
  display: flex;
  justify-content: center;
  align-items: center;
}
.footer-center {
  font-size: 20px;
  color: #333333;
}

@media screen and (max-width: 1510px) {
  .main {
    height: calc( 1200px * 0.67 );
  }
  .main-center {
    width: 1200px;
    height: calc( 1200px * 0.67 );
  }
  .main-center-img {
    height: calc( 1200px * 0.57 );
  }
}

@media screen and (max-width: 1210px) {
  .main {
    height: calc( 1000px * 0.67 );
  }
  .main-center {
    width: 1000px;
    height: calc( 1000px * 0.67 );
  }
  .main-center-img {
    height: calc( 1000px * 0.57 );
  }
}

@media screen and (max-width: 1010px) {
  .main {
    height: calc( 800px * 0.67 );
  }
  .main-center {
    width: 800px;
    height: calc( 800px * 0.67 );
  }
  .main-center-img {
    height: calc( 800px * 0.57 );
  }

}

@media screen and (max-width: 810px) {
  .main {
    height: calc( 600px * 0.67 );
  }
  .main-center {
    width: 600px;
    height: calc( 600px * 0.67 );
  }
  .main-center-img {
    height: calc( 600px * 0.57 );
  }
	
}

@media screen and (max-width: 610px) {
  .main {
    height: calc( 500px * 0.67 );
  }
  .main-center {
    width: 500px;
    height: calc( 500px * 0.67 );
  }
  .main-center-img {
    height: calc( 500px * 0.57 );
  }
  .main-center-entry {
    width: 320px;
    height: 180px;
  }
}

@media screen and (max-width: 510px) {
  .main {
    height: calc( 360px * 0.67 );
  }
  .main-center {
    width: 360px;
    height: calc( 360px * 0.67 );
  }
  .main-center-img {
    height: calc( 360px * 0.57 );
  }
  .main-center-entry {
    width: 178px;
    height: 100px;
    font-size: 26px;
  }
}