html {
    background: #e6e9e9;
    background-image: linear-gradient(270deg, rgb(230, 233, 233) 0%, rgb(216, 221, 221) 100%);
    -webkit-font-smoothing: antialiased;
}

p#Headline {
    border: 2px solid blue;
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
     font-size: 20px;
    color: black;
}

p#idea {
    border: none;
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
    font-size: 20px;
    text-decoration: underline;
    color: firebrick;
}
ul#navigation {
    margin: 0px;
    padding: 0px;
    list-style-type: none;
}

ul#navigation li {
    padding: 0px;
    margin: 0px;
    display: inline;
}

    ul#navigation li a:link {
        border: 1px solid #000;
        background-color:aliceblue;
        padding: 2px 15px 2px 15px;
        font-size: 15px;
        color: #000;
        font-family: Arial, Helvetica, sans-serif;
        text-decoration:none;
        font-weight: bold;
    }

    ul#navigation li a:hover {
        display:inline-block;
        border: 1px solid #54993f;
        background-color:cornflowerblue;
        color: #fff;
    }

body {
    background: #fff;
    box-shadow: 0 0 2px rgba(0, 0, 0, 0.06);
    color: #545454;
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
    font-size: 16px;
    line-height: 1.5;
    margin: 0 auto;
    max-width: 800px;
    max-height: none;
    padding: 2em 2em 4em;
}