html, body {
    margin: 0; 
    height: 100%; 
    font-family: Arial, sans-serif;
    scrollbar-width: none;
}

.masked-text {
    font-weight: bold;
    color: transparent;
    background-image: url('https://static.scientificamerican.com/sciam/assets/Image/2019/GIF1_Brain.gif'); 
    background-size: 50%;
    background-clip: text;
    background-position: center;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.fs-xl {
    font-size: 6rem;
}

.fs-lg {
    font-size: 1.7rem;
}

.fs-sm {
    font-size: 1.2rem;
}

.fullscreen-video {
    position: fixed;
    bottom: -800px;
    min-width: 100%;
    min-height: 100%;
    z-index: -1;
    mix-blend-mode: luminosity;
}

.over-flow-hidden {
    overflow: hidden;
}

.position-sticky {
    position: sticky;
    z-index: 1000;
}

.menu {
    top: 45vh;
    left: 70px;
    font-size: 2rem;
}

.menu > div {
    margin-bottom: 20px;
}

.menu > div:hover {
    cursor: pointer;
    font-weight: bold;
}

@keyframes resizing-text {
    from {font-size: 2rem;}
    to {font-size: 2.3rem;}
}

.menu > div > span {
    animation: resizing-text var(--animation-time) ease alternate infinite;
}

.vh-80 {
    height: 80vh;
}

.w-90 {
    width: 90vw;
}

.bg-translucent {
    background-color: rgba(0, 0, 0, 0.5);
}

.bg-translucent-light {
    background-color: rgba(196, 196, 196, 0.5);
}

.blur {
    backdrop-filter: blur(20px);
}

@keyframes wave {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-5px);
    }
}

.wave-text > span {
    display: inline-block;
    animation: wave 2s ease-in-out infinite;
    animation-delay: var(--delay);
}