:root {
    --color-text: #343a40;
    --color-text-link: #6c757d;
    --color-text-link-hovered: #343a40;
    --color-input-border: #ced4da;
}

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

html,
input,
button {
    font-family: sans-serif;
    font-size: 16px;
    line-height: 1.5rem;
    font-weight: 400;
    color: var(--color-text);
}

input,
button {
    display: block;
    padding: 0.25rem 0.5rem;
    width: 100%;
}

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

    &:hover {
        color: var(--color-text-link-hovered);
        text-decoration: underline;
    }
}

body {
    max-width: 640px;
    margin: 0 auto;
    padding: 1rem;
}

button {
    border: 1px solid;
    background-color: var(--color-gray-300);
}

footer {
    font-size: 0.75rem;
    line-height: 1rem;

    &>nav {
        display: flex;
        flex-wrap: wrap;
        column-gap: 0.5rem;
    }
}

form {
    width: 100%;
    max-width: 320px;
    margin: 0 auto;
}

h2 {
    font-size: 1.5rem;
    line-height: 2rem;
    font-weight: 700;
    margin-top: 1rem;
    margin-bottom: 1rem;
}

h3 {
    font-size: 1.25rem;
    line-height: 1.75rem;
    font-weight: 700;
    margin-top: 1rem;
    margin-bottom: 1rem;
}

h4,
h5,
h6 {
    font-size: 1rem;
    line-height: 1.5rem;
    font-weight: 700;
    margin-top: 1rem;
    margin-bottom: 1rem;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
}

input {
    border: 1px solid var(--color-input-border);

    &:focus-visible {
        outline: 1px solid var(--color-input-border);
    }
}

img {
    max-width: 100%;
    max-height: 320px;
}

main {
    margin-top: 2rem;
    margin-bottom: 2rem;
}

ol {
    padding-left: 2rem;
}

ul {
    padding-left: 2rem;
}

:not(li)>ul {
    margin: 1rem 0
}

.my-4 {
    margin-top: 1rem;
    margin-bottom: 1rem;
}

.my-8 {
    margin-top: 2rem;
    margin-bottom: 2rem;
}

.text-right {
    text-align: right;
}