:root {
    --radius: 5px;
    --text-font-size: 16px;
    --background: hsl(220, 60%, 100%);
    --button-background: hsl(0, 0%, 92%);
    /* Never use black (https://huijzer.xyz/posts/design) */
    --text: hsl(212, 90%, 7%);
    --border: hsl(0, 0%, 60%);
    --header: hsl(212, 90%, 18%);
    --accent: hsl(212, 91%, 60%);
    --visited: hsl(271, 68%, 32%);
}

body {
    /* Avoid horizontal scroll on mobile. */
    padding: 0.2rem;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, sans-serif;
    line-height: 150%;
    text-rendering: optimizeLegibility;
    background-color: var(--background);
    color: var(--text);
    font-size: var(--text-font-size);
    margin: 0px;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--header);
    text-align: center;
    margin-top: 1.8em;
    line-height: 1.2;
}

a {
    color: var(--accent);
    text-decoration: none;
}

.container {
    display: flex;
    justify-content: center;
    align-items: stretch;
    min-height: 98vh;
}

.middle {
    width: 100%;
    max-width: 70ch;
    padding: 0px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

input {
    box-sizing: border-box;
    background-color: var(--button-background);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 4px;
    margin-top: 4px;
    margin-bottom: 10px;
    font-size: var(--small-font-size);
}

input[type="file"] {
    max-width: 100%;
}

input[type="submit"] {
    border: 1px solid var(--border);
    padding: 7px 20px;
    line-height: 1.3;
    margin: 12px 6px;
}

input[type="submit"]:hover {
    cursor: pointer;
}

input[type="submit"]:disabled {
    opacity: 0.5;
}

.body-output-container {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 10px;
    margin-bottom: 30px;
    justify-content: center;
    align-items: center;
}

.body-output-fieldset {
    flex-wrap: wrap;
    gap: 10px 10px;
    justify-content: center;
    align-items: center;
}

.body-output {
    display: inline-block;
    margin-left: 0;
    margin-right: 10px;
    margin-bottom: 10px;
}