styles.css

* {
  box-sizing: border-box;
}

body {
    font-family: Helvetica;
    font-size: 15pt;
    background-color: white;
    color:black;
    text-align:center;
}

#consent {
    display: flex;
    max-width: 80%;
    margin: 0 auto;
    align-items: center;
    flex-direction: column;
}
li {
    text-align: left;
    margin: 15px;
}
#consented {
    display: inherit;
}
button {
    display: none;
    padding: 0.5em;
}
#Instruction1,
#Instruction2,
#Instruction3,
#Instruction4,
#Instruction5  {
    display:none;
    max-width: 50%; 
    margin: 0 auto;
}
#canvas_L {
    display: none;
    background-color: gray;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%); 
}
#canvas_fixation {
    display: none;
    background-color: black;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%); 
}

#occluder {
    display: none;
    left: 50%;
    top: 50%;
}
.shape {
    display: none;
    width: 55px;
    height: 55px;
}