demo.css

html,
body {
    padding: 0;
    margin: 0;
    height: 100%;
}
body {
    position: relative;
    background-color: #5888aa;
    -webkit-text-size-adjust: none;
    font-family: Arial, Helvetica, Verdana;
    font-size: 20px;
    line-height: 30px;
    color: #fff;
}

h1 {
    margin: 0 0 100px;
    text-shadow: 8px 10px 1px rgba(0, 0, 0, 0.1);
    text-transform: lowercase;
    font-family: "Pacifico", Arial, sans-serif;
    font-weight: normal;
    font-size: 150px;
    line-height: 1;
    letter-spacing: -6px;
}

pre {
    font-size: 16px;
    line-height: 24px;
    width: 100%;
    overflow: auto;
    margin: 75px 0;
}

@media (max-width: 500px) {
    h1 {
        font-size: 105px;
        letter-spacing: -2px;
    }
}

select {
    display: block;
    width: 100%;
    padding: 15px;
    border: unset;
    border-radius: 5px;
    background: #ffffff99;
}

a,
a:hover {
    color: #fff;
    text-decoration: underline;
}

#page {
    max-width: 600px;
    min-width: 300px;
    width: 90%;
    padding: 100px 10px;
    margin: auto;
}

.xmpls {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    margin: 75px -10px;
}

.xmpl {
    position: relative;
    box-sizing: border-box;
    width: calc(50% - 20px);
    padding-top: calc(50% - 20px);
    margin: 10px;
    background: rgba(255, 255, 255, 0.05);
    box-shadow: 6px 8px 1px rgba(0, 0, 0, 0.1);
    transition: none 0.2s ease;
    transition-property: background-color, box-shadow, transform;
    text-align: center;
    cursor: pointer;
}
.xmpl:hover {
    background: rgba(255, 255, 255, 0.15);
    box-shadow: 4px 6px 0 rgba(0, 0, 0, 0.15);
    transform: translateY(2px);
}

@media (min-width: 1280px) {
    .xmpls {
        margin-left: -320px;
        margin-right: -320px;
    }
    .xmpl {
        width: calc(25% - 20px);
        padding-top: calc(25% - 20px);
    }
}
.xmpl > mm-burger {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}
.xmpl > span {
    position: absolute;
    bottom: 10%;
    left: 0;
    right: 0;
}

mm-burger {
    padding: 5px;
}

mm-burger.custom-burger-1 {
    --mb-bar-height: 5px;
    --mb-bar-spacing: 5px;

    padding: 10px 15px;
    border-radius: 10px;
    border: 2px solid #fff;
}

mm-burger.custom-burger-2 {
    --mb-bar-width: 50px;
    --mb-bar-height: 2px;
    --mb-bar-spacing: 12px;

    width: 80px;
    height: 80px;
    padding: 25px 15px;
    border-radius: 40px;
    background-color: rgba(255, 255, 255, 0.7);
    color: #3ea7e1;
}