playground.css

:root {
    /* https://tailwindcss.com/docs/customizing-colors#color-palette-reference */
    --black: #000;
    --white: #fff;
    --blueGray-50: #F8FAFC;
    --blueGray-100: #F1F5F9;
    --amber-50: #FFFBEB;
    --amber-100: #FEF3C7;
    --amber-200: #FDE68A;
    --green-500: #22C55E;
    --green-600: #16A34A;
    --blue-600: #2563EB;
}

*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    line-height: 1.15;
}

body {
    padding: 20px;
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

kbd {
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, 'Liberation Mono', 'Courier New', monospace;
}

#playground-instructions {
    border-radius: 5px;
    font-weight: 700;
    font-size: 30px;
    text-align: center;
    border-radius: 5px;
    border: 2px solid var(--black);
    padding: 20px 10px;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, 'Liberation Mono', 'Courier New', monospace;
}

main {
    max-width: 560px;
    margin: 0 auto 150px auto;
    display: flex;
    flex-direction: column;
    gap: 40px 0;
}

main h1 {
    padding: 10px;
    text-align: right;
    font-size: 18px;
    font-weight: 700;
    background-color: var(--black);
    color: var(--white);
    border-radius: 12px 2px 12px 2px;
}

section {
    outline: 2px solid var(--green-500);
    border-radius: 5px;
    padding: 30px 20px 20px 20px;
    display: flex;
    flex-direction: column;
    gap: 20px;
    position: relative;
}

section:hover:not(:focus-within) {
    background-color: var(--blueGray-50);
}

section:focus-within {
    outline: 2px solid var(--black);
    background-color: var(--blueGray-100);
}

section[data-label]::before {
    content: attr(data-label);
    position: absolute;
    top: -13px;
    left: 15px;
    height: 26px;
    display: flex;
    align-items: center;
    padding: 0 15px;
    background-color: var(--green-500);
    border: 1px solid var(--green-600);
    border-radius: 6px;
    color: #fff;
}

section[data-label]:focus-within::before {
    background-color: var(--black);
    border: 1px solid var(--black);
}

section p {
    padding: 5px;
}

section p:hover {
    background-color: var(--amber-50);
    border-radius: 5px;
}

section input {
    display: block;
    height: 40px;
    width: 100%;
    font-size: 16px;
    border: 1px solid var(--blue-600);
    border-radius: 3px;
    padding: 0 10px;
}

section select {
    display: block;
    height: 40px;
    width: 100%;
    font-size: 16px;
    border: 1px solid var(--blue-600);
    border-radius: 3px;
    padding: 0 10px;
}

section input:hover:not(:focus):not([disabled]),
section select:hover:not(:focus):not([disabled]) {
    background-color: var(--amber-50);
}

section input:focus,
section select:focus {
    outline: none;
    background-color: var(--amber-100);
}

section a {
    padding: 10px;
    font-size: 16px;
    border-radius: 5px;
}

section a:hover:not(:focus) {
    background-color: var(--amber-50);
    text-decoration: underline;
}

section a:focus {
    outline: 2px solid var(--amber-200);
    background-color: var(--amber-100);
}

section pre {
    font-size: 16px;
}

section div[tabindex] {
    padding: 10px;
    font-size: 16px;
    border-radius: 5px;
}

section div[tabindex]:hover:not(:focus) {
    background-color: var(--amber-50);
    text-decoration: underline;
}

section div[tabindex]:focus {
    outline: 2px solid var(--amber-200);
    background-color: var(--amber-100);
}

.grid-with-custom-taborder .grid {
    display: grid;
    gap: 10px 0;
    grid-template-columns: 1fr;
    grid-template-rows: repeat(4, min-content);
    grid-template-areas: 'uno' 'zwei' 'tre' 'quattro';
}

.grid-with-custom-taborder .grid > [data-grid-area="uno"] {     grid-area: uno;     }
.grid-with-custom-taborder .grid > [data-grid-area="zwei"] {    grid-area: zwei;    }
.grid-with-custom-taborder .grid > [data-grid-area="tre"] {     grid-area: tre;     }
.grid-with-custom-taborder .grid > [data-grid-area="quattro"] { grid-area: quattro; }