style.css

body {
    display: flex;
    flex-flow: column;
    align-items: stretch;
    
    min-height: 100vh;
    margin: 0;
    padding: 0;
    
    font-family: 'Overpass', sans-serif;
    font-size: 14px;
    font-weight: 400;
    line-height: 1.5;
}

header {
    margin: 0;
    padding: 12px;
    background: #1a805d;
    
    color: #fff;
}

h1 {
    margin: 0;
    padding: 0;
    
    font-size: 24px;
    font-weight: 100;
}

main {
    flex-grow: 1;
    padding: 12px 0;    
}

p {
    margin: 0;
    padding: 0 12px;
}

blockquote {
    position: relative;
    margin: 12px 0 0;
    padding: 12px 24px;
    border-top-width: 1px;
    border-top-style: solid;
    border-top-color: #1a805d;
    
    white-space: pre-line;
}

blockquote:before {
    position: absolute;
    right: 0;
    top: 0;
    padding: 6px;
    
    border-radius: 0 0 0 6px;
    background: #1a805d;
    color: #fff;
    line-height: 1;
}

#license:before {
    content: "License";
}

#attribution:before {
    content: "Attribution";
}

.buttons {
    padding: 24px 0 12px;
    
    border-top-width: 1px;
    border-top-style: solid;
    border-top-color: #1a805d;
    
    text-align: center;
}

button {
    -webkit-appearance: none;
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    background: #1a805d;
    color: #fff;
    cursor: pointer;
}

footer {
    padding: 12px 0;
    background: #1a805d;
    color: #fff;
    text-align: center;
    font-size: 10px;
}