html {
    font-size: 10px;
    background: url(full-bloom.png) bottom center;
}

body, html {
    margin: 0;
    padding: 0;
    font-family: sans-serif;
    text-align: center;
}

a {
    text-decoration: none;
}

ul {
    list-style-type: none;
}

div.lessons ul li {
    padding: 0;
}

div.lessons ul li a {
    margin: 0;
    display: block;
    width: 100%;
    height: 100%;
}

.lessons {
    display: flex;
    flex: 1;
    min-height: 100vh;
    align-items: center;
    justify-content: center;
}

.lesson {
    border: 4px solid darkblue;
    border-radius: 10px;
    margin: 1rem;
    font-size: 1.5rem;
    padding: 1rem 0.5rem;
    text-align: center;
    width: 300px;
    height: 100px;
    color: white;
    background: rgba(0,0,50,0.5);
    text-shadow: 0 0 5px black;
}

.lesson a {
    line-height: 100px;
    text-decoration: none;
    color: yellow;
}

.lesson-title {
    font-size: 1.8rem;
    display: inline-block;
    vertical-align: middle;
}