.header{
  background: linear-gradient(to top, #3b709f97, #3b709f97), url("https://static.igem.wiki/teams/5311/assets/collaborations/playing-videogame.jpeg") no-repeat center/cover;
}
.image-center{
    height:300px;
    padding-right:10px;
    text-align: center;
  }

.image-center-big-footer {
    text-align: center;
    font-size: 0.9em; /* Smaller font for footer */
    color: #555; /* Grey color for footer */
    margin-top: 8px;
    font-style:italic;
  }
.image-center img{
    object-fit: contain;
    width: 100%;
    height: 100%;
  }
.arrow ul {
    list-style-type: "\2192";
    padding: 20px;
    justify-content: center;
    margin: 0;
  }
  
.arrow li {
    margin-bottom: 15px;
    padding-left: 10px;
  }

  .tabs{
    display: flex;
    gap: 15px;
    padding-left: 0px;
    width: 100%
}

.tabs button{
    background-color: #efebdf;
    border-top-left-radius: 15px;
    border-top-right-radius: 15px;
    border: none;
    font-weight: bold;
    padding: 15px;
    position: relative;
    z-index: 0;
}



.tabs button.active,
.tabs button:hover{
    background-color: #3b719f;
    color: #efebdf;
    z-index: 1;
}

.tabs button:after,.tabs button:before {
    bottom: 0;
    content: "";
    display: block;
    height: 10px;
    position: absolute;
    width: 10px
}

.tabs button:before {
    background: radial-gradient(circle at 0 0,transparent 10px, #efebdf 10px);
    left: -10px
}

.tabs button:after {
    background: radial-gradient(circle at 10px 0,transparent 10px, #efebdf 10px);
    right: -10px
}

.tabs button.active:before, 
.tabs button:hover:before{
    background: radial-gradient(circle at 0 0,transparent 10px, #3b719f 10px);
    left: -10px
}

.tabs button.active:after, 
.tabs button:hover:after{
    background: radial-gradient(circle at 10px 0,transparent 10px, #3b719f 10px);
    right: -10px
}

.tabs button:first-child:before,
.tabs button:first-child.active:before,
.tabs button:first-child:hover:before{
    background: none;
}

.tabs button:last-child:after,
.tabs button:last-child.active:after,
.tabs button:last-child:hover:after{
    background: none;
}

.notebook{
    margin-top: 20px;
}

.notebook-body{
    display: none;
    height: 600px;
    background-color: #3b719f;
    border-radius: 0 15px 15px 15px;
    padding: 20px 30px;
    width: 100%;
    color: #efebdf;
}

iframe{
    width: 100%;
    height: 100%;
    border: none;
    display: block;
    overflow-clip-margin: content-box
}