(define sixhat
  (λ (dave)
    (display 'ideas)))

styles for clean bw slides in marp

<style>
    * {
        color: black!important;
        font-family: "ibm plex serif", serif;
        background: white;
    }
    pre {
        border: 2px solid;
        background: white;
        border-radius: 0.3rem;
    }
    blockquote {
        border: 2px dashed;
        margin: 0 3em;
        padding: 0.3em 0.6em;
        border-radius: 0.3rem;
    }
    h1, h2, h3 {
        margin-top: 0;
    }
    section {
        justify-content: flex-start;
    }
    code {
        background: white;
    }
    ul {
        list-style-type: '⁍  ';
    }
    section.title {
        justify-content: center;
    }
    section.f-2 {font-size: 2em;}
    section.f-3 {font-size: 3em;}
    section.f-4 {font-size: 4em;}
    section.f-5 {font-size: 5em;}
    section.f-6 {font-size: 6em;}
    section.f-8 {font-size: 8em;}
    section.f-10 {font-size: 10em;}
    section.f-14 {font-size: 14em;}
    section.f-20 {font-size: 20em;}
    section.center {text-align: center;}
</style>