/*CHECKLIST: comment added for readability */
:root {
    --main-color: rgb(251, 0, 255); /* CHECKLIST: CSS variable */
}

/* CHECKLIST: grid layout */
main {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;                
    grid-template-rows: auto; 
    justify-items: center;    
    align-items: center;      
}

/* CHECKLIST: background-color, hsl, padding (longhand), margin shorthand */
body {
    background-color: hsl(302, 58%, 32%);
    font-family:'Courier New', Courier, monospace;
    margin: 10mm auto;
    color: #000000; /* CHECKLIST: hex color */
    text-decoration: underline dotted; /* CHECKLIST: text-decoration */
    text-decoration-thickness: 1px;
    padding-top: 1cm;
    padding-bottom: 1cm;
    padding-left: 1cm;
    padding-right: 1cm;
}

/* CHECKLIST: wider-gamut color + rem unit */
h1 {
    color: color(display-p3 0.1 0.5 0.8);
    font-size: 2rem;
}

/* CHECKLIST: color-mix */
h2 {
    color: color-mix(in srgb, rgb(0, 0, 0) 60%, rgb(74, 74, 74) 40%);
}

/* CHECKLIST: variable with fallback, border longhand, position sticky */
header {
    background-color: var(--main-color, #ff00d9);
    padding: 20px; /* CHECKLIST: padding shorthand */
    text-align: center; /* CHECKLIST: text-align */
    border-top: 5px dashed black;
    border-bottom: 5px dashed black;
    border-left: 5px dashed black;
    border-right: 5px dashed black;
    border-radius: 60px; /* CHECKLIST: border-radius */
    position: sticky;
    top: 0;
    min-height: 420px; /* CHECKLIST: sizing */
    height: auto;
}

/* hover animation */
header:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 25px rgba(0,0,0,0.2);
}

/* CHECKLIST: margin longhand, padding shorthand, border properties, % unit */
section {
    transition: 0.3s;
    position: static; /* CHECKLIST: position static */
    margin-top: 10mm;
    margin-bottom: 10mm;
    margin-left: auto; /* CHECKLIST: auto margin */
    margin-right: auto;
    width: 100%;
    max-width: 100%;
    padding: 5px 15px 15px 15px;
    background-color: #ff00d9;
    border-style: dashed;
    border-width: .06in;
    border-color: rgb(0, 0, 0);
    border-radius: 60px;
    color: rgb(0, 0, 0); /* CHECKLIST: rgb color */
}

section:hover {
    background-color: #ff99ee;
}

/* CHECKLIST: flexbox (display flex + properties) + nested selectors */
nav {
    & ol {
        list-style: none;
        padding: 0;
        display: flex;
        justify-content: center;
        gap: 12px;
        flex-wrap: wrap;
    }

    & li {
        display: inline-block; /* CHECKLIST: display inline-block */
    }
}

/* CHECKLIST: :has() selector */
section:has(form) {
    border-color: blue;
}

/* CHECKLIST: universal selector */
* {
    box-sizing: border-box;
}

/* CHECKLIST: sizing + display block */
video{
    width: 300px;
    display: block;
    margin: auto;
}

/* CHECKLIST: max-width, min-width */
img {
    max-width: 100%;
    min-width: 120px;
    height: auto;
    display: block;
    margin: auto;
}

/* CHECKLIST: ID selector */
#unfinishedbusiness {
    background-color: pink;
}

/* CHECKLIST: class selector */
.highlight {
    color: orange; /* CHECKLIST: color name */
}

/* CHECKLIST: attribute selector */
input[type="text"] {
    background-color: white;
}

/* CHECKLIST: pseudo-class */
a:hover {
    color: blue;
    text-decoration: underline wavy;
}

a:active {
    color: red;
}

/* CHECKLIST: selector list */
h1, h2 {
    text-align: center;
}

/* CHECKLIST: descendant combinator */
nav ol li {
    font-weight: bold;
}

/* CHECKLIST: child combinator */
nav > ol {
    border: 2px solid black;
    padding: 10px;
}

/* CHECKLIST: general sibling combinator */
h2 ~ ul {
    font-size: 1em;
}

/* CHECKLIST: adjacent sibling combinator */
h2 + h3 {
    color: darkblue;
}

/* CHECKLIST: combining selectors */
section.card {
    background-color: #ff99ee;
}

/* CHECKLIST: border shorthand */
footer {
    margin: 10mm 10mm 10mm 10mm;
    font-size: 1.50em; /* CHECKLIST: em unit */
    text-align: center;
    color: black;
    font-family: "Bebas Neue", sans-serif; /* CHECKLIST: google font */
    border: 5px dashed black;
}

/* CHECKLIST: media query / responsiveness */
@media (max-width: 700px) {
    section {
        width: 100%;
        margin: 10px auto;
    }
    nav ol {
        flex-direction: column;
        align-items: center;
    }
    h1 {
        font-size: 1.5rem;
    }
    main {
    grid-template-columns: 1fr;
    }
}