html body{
  height: 100vh;
}

body{
  margin: 0px;
}

#all{
  background-image: url('../images/othello.jpeg');
  background-size: cover;
  background-attachment: fixed;
  height: 100vh;
  min-height: 500vh;
}

h1{
  background-color: #F6F61A;
  text-align:center;
  border-left: 15px;
  border-right: 15px;
  border-top: 0px;
  border-bottom: 0px;
  border-color: black;
  border-style: ridge;
}

#title{
  margin-top: 0px;
}

p{
  text-align: center;
}

#history p{
  text-align: left;
  margin-left: 20%;
}

a{
  text-align: center;

  color: black;
  position: relative;
  display: inline-block;
  transition: .3s;
  text-decoration: none;
  border-bottom: solid 1.5px #F6F61A;
}

a::after {
  position: absolute;
  bottom: 0;
  left: 50%;
  content: '';
  width: 0;
  height: 2px;
  background-color: #F6F61A;
  transition: .3s;
  transform: translateX(-50%);
}

a:hover::after{
  width: 100%;
}

a:visited{
  color : black;
}

button{
  margin: 1.5px 2.5px;
  background: linear-gradient(white, lightgray);
  border-radius: 10px;
  box-shadow: 3px 3px 3px rgba(0,0,0,0.2);
}

.link{
  text-align: center;
}

.mask{
  height: 100%;
  background: rgba(255,255,255,0.5);
}

.support{
  margin-top: 10px;
}

.series{
  padding-left: 5%;
  font-weight: normal;
  background-color: #F6F61A;
  border-left: 10px;
  border-right: 0px;
  border-top: 0px;
  border-bottom: 0px;
  border-color: black;
  border-style: ridge;
}

.others{
  text-align: center;
}

#fixedVolume{
  position: fixed;
  bottom: 10px;
  right: 10px;
  background-color: #F6F61A;
  padding: 10px;
  border-color: black;
  border-style: double;
}

*:focus {
outline: none;
}