.content {
  position: relative;
  right: 0;
  padding: 0 0 0 250px;
  overflow: hidden;
}

.ccont {
  position: relative;
  margin-top: 100px;
  padding-top: 20px;
}

.title {
  font-weight: 600;
  padding-bottom: 50px;
  margin-left: 50px;
  color: #000;
}
.title .t-tw {
  font-size: 1.4em;
  display: inline-block;
  letter-spacing: 0.2em;
}
.title .t-en {
  font-size: 1em;
  display: inline-block;
  margin-left: 10px;
  letter-spacing: 0.2em;
}
.title .t-en:after {
  content: "";
  padding-top: 31px;
  padding-left: 50px;
  background: #e6e6e6;
  position: relative;
  top: 5px;
  left: -30px;
  z-index: -1;
}

.inner {
  background-color: #efefef;
  width: 100%;
  overflow: hidden;
  margin-bottom: 55px;
}
.inner li {
  float: left;
  width: 20%;
  padding: 3.5%;
  position: relative;
  box-sizing: border-box;
  border-right: 1px solid #fff;
  border-bottom: 1px solid #fff;
}
.inner li:hover .mask {
  -moz-transition: all 300ms ease-in-out;
  -o-transition: all 300ms ease-in-out;
  -webkit-transition: all 300ms ease-in-out;
  transition: all 300ms ease-in-out;
  opacity: 1;
  -moz-transform: scale(1, 1);
  -ms-transform: scale(1, 1);
  -webkit-transform: scale(1, 1);
  transform: scale(1, 1);
}

.mask {
  position: absolute;
  top: 30%;
  left: 0;
  background-color: rgba(0, 0, 0, 0.5);
  height: 40%;
  width: 100%;
  opacity: 0;
  -moz-transform: scale(1, 0.8);
  -ms-transform: scale(1, 0.8);
  -webkit-transform: scale(1, 0.8);
  transform: scale(1, 0.8);
}
.mask .casename {
  text-align: center;
  position: relative;
  top: 50%;
  -moz-transform: translateY(-50%);
  -ms-transform: translateY(-50%);
  -webkit-transform: translateY(-50%);
  transform: translateY(-50%);
  font-size: 15px;
  letter-spacing: 0.2em;
  color: #fff;
}

.picture {
  position: relative;
  width: 100%;
}
.picture img {
  width: 100%;
}

.bt {
  position: absolute;
  top: 25px;
  right: 50px;
}

.bt-t {
  display: inline-block;
  padding: 0 5px;
}
.bt-t:hover {
  background-color: #ccc;
  color: #000;
}

.onn {
  background-color: #ccc;
  color: #000;
}

@media screen and (max-width: 1650px) {
  .inner {
    overflow: hidden;
    margin-bottom: 55px;
  }
  .inner li {
    float: left;
    width: 25%;
    padding: 4%;
  }
}
@media screen and (max-width: 1100px) {
  .content {
    padding: 0;
  }

  .mask {
    opacity: 1;
    -moz-transform: scale(1, 1);
    -ms-transform: scale(1, 1);
    -webkit-transform: scale(1, 1);
    transform: scale(1, 1);
    top: 60%;
    height: 20%;
    opacity: 1;
  }

  .title {
    margin-left: 30px;
  }
}
@media screen and (max-width: 900px) {
  .inner li {
    width: 33.3333%;
    padding: 4%;
  }

  .mask {
    top: 65%;
  }

  .title {
    margin-left: 10px;
  }
}
@media screen and (max-width: 860px) {
  .inner li {
    width: 33.3333%;
    padding: 4%;
  }

  .title {
    text-align: center;
  }

  .bt {
    position: relative;
    top: -20px;
    right: unset;
    margin: 10px auto 30px;
    width: fit-content;
  }
}
@media screen and (max-width: 640px) {
  .inner li {
    width: 50%;
  }

  .mask {
    top: 70%;
  }

  .title {
    padding-bottom: 30px;
    margin: 0;
    padding-right: 22px;
  }
  .title .t-en {
    display: block;
    margin-left: 0;
    position: relative;
    left: 22px;
    padding-top: 3px;
  }

  .ccont {
    margin-top: 70px;
  }

  .bt {
    top: 0px;
    margin: 20px auto 40px;
  }
}
@media screen and (max-width: 480px) {
  .inner li {
    width: 100%;
  }

  .mask {
    top: 78%;
    height: 15%;
  }
}