index.css

body, html {
    margin: 0;
    padding: 0;
    font-family: 'Open Sans', sans-serif;
    color: #fff;
}

body {
    background: url(./images/bg01.jpg) no-repeat center center fixed;
    background-size: cover;
}

#vanta {
    z-index: -1;
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
}

video {
    z-index: -1;
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

main {
    position: relative;
}

header {
    margin-top: 1em;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
}

header > img {
    width: 6em;
    height: 6em;
    border-radius: 100%;
    border: 1px solid #fff;
    box-shadow: rgb(28 32 93 / 24%) 0px 2px 12px 0px;
}

header > h1 {
    display: inline-block;
    font-size: 0.8em;
    font-weight: bold;
    border-radius: 1em;
    background-color: #000a;
    color: #fff;
    padding: 0.3em 1.6em;
    border: 1px solid #fffa;
    backdrop-filter: blur(10px) saturate(160%) contrast(180%);
    -webkit-backdrop-filter: blur(10px) saturate(160%) contrast(180%);
}

ul {
    box-sizing: border-box;
    list-style: none;
    margin: 0 auto;
    padding: 2em;
    max-width: 480px;
}

ul > li {
    background-color: #fffa;
    backdrop-filter: blur(10px) saturate(160%) contrast(180%);
    -webkit-backdrop-filter: blur(10px) saturate(160%) contrast(180%);
    border-radius: 10em;
    padding: 1em;
    margin: 1.4em 0;
    box-shadow: rgb(28 32 93 / 24%) 0px 2px 12px 0px;
}

ul > li > a {
    display: flex;
    flex-direction: row;
    justify-content: center;
    align-items: center;
    gap: 0.5em;
}

a {
    color: black;
    text-decoration: none;
}