body{
  list-style: none;
}
ul{
  margin:0;
  padding: 0;
}

.ytp-chrome-top, .ytp-chrome-top, .ytp-chrome-top, .ytp-show-cards-title{
  display: none;
}

.board {
  width: 90%;
  margin-left: 5%;
}
.read_body{
  margin-bottom: 5%;
}
.container{
  width: 100%;
  position: relative;
  padding-bottom: 56.25%; /*アスペクト比 16:9の場合の縦幅*/
  height: 0;
  overflow: hidden;
}
 
.container iframe {
     position: absolute;
     top: 0;
     left: 0;
     width: 100%;
     height: 100%;
}
 .board li {
  list-style: none;
  width: 46%;
  margin:0 1.5%; 
  overflow: hidden;
  display: inline-flex;
  position: relative;
}


.mov{
  width: 100%;
  height: 0;
   padding-bottom: 56.25%; /*アスペクト比 16:9の場合の縦幅*/
  overflow: hidden;
}
.mov iframe {
     position: absolute;
     top: 0;
     left: 0;
     width: 100%;
     height: 53.25%;
}
span{
  background-color: black!important;
  color: white!important;
  padding: 2px;
  font-size: 12px!important;
}
p{
  font-size: 10px!important;
}
.text1{
  margin-bottom: 10%;
}
a {
  text-decoration: none;
  color:black;
}

a:hover {
  text-decoration: underline;
}


@media screen and (min-width:640px){
  .board li {
  list-style: none;
  width: 28%;
  margin:0 2%; 
  overflow: hidden;
  display: inline-block;
  position: relative;
}

.mov iframe{
  width:100%;
  height:56.25%; 
}