style.css

body {
    display: flex;
    background-color: rgb(65, 65, 65);
    color: white;
    font-family: JetBrains Mono;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    padding: 10px;
}
header {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    border: 1px solid white;
    border-radius: 10px;
    margin-bottom: 30px;
    padding: 10px;
    text-align: center;
}
header > * { margin: 5px; }
header > h1 { font-weight: lighter; }
button {
    padding: 10px;
    border-radius: 10px;
    border: none;
}
button:hover { background-color: rgb(201, 201, 201); }
button:active { background-color: rgb(139, 139, 139); }
.files {
    width: 100%;
    border: 1px solid white;
    border-radius: 10px;
    padding: 10px 5px;
    display: grid;
    grid-template-columns: repeat( auto-fill, minmax(200px, 1fr) );
    column-gap: 5px;
    row-gap: 10px;
    align-items: center;
    list-style-type: none;
}
@media (max-width: 300px) {
    .files {
        grid-template-columns: auto;
    }
    .files > li:hover { opacity: 1; }
}
.files > li {
    height: 100%;
    border: 1px solid white;
    border-radius: 10px;
    padding: 2px;
    text-align: center;
    background-color: rgba(18, 18, 18, 0.2);
}
.files > li:hover { opacity: 0.5; }
.files > li > a {
    margin: 0px;
    display: flex;
    width: 100%;
    height: 100%;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    color: white;
}