styles.css

/* RESET */

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

html,
body {
	height: 100%;
	font-family: sans-serif;
}

html:focus-within {
	scroll-behavior: smooth;
}

body {
	line-height: 1.5;
}

a:not([class]) {
	text-decoration-skip-ink: auto;
}

img,
picture,
video,
canvas {
	display: block;
	max-width: 100%;
}

input,
button,
textarea,
select,
input[type='file']::file-selector-button {
	font: inherit;
}

label,
textarea,
progress,
input:where(
		[type='email'],
		[type='password'],
		[type='search'],
		[type='tel'],
		[type='text'],
		[type='url'],
		[type='file']
	) {
	display: block;
	width: 100%;
}

textarea {
	box-sizing: content-box;
	min-height: 5em;
	resize: block;
	resize: vertical;
}

/* THEME */

h1 {
	margin-block-end: 2rem;
}

h2,
h3 {
	margin-block-end: 1rem;
}

label {
	font-weight: 700;
	margin-block-end: 0.25rem;
}

button,
input[type='file']::file-selector-button {
	padding-inline: 0.5rem;
	padding-block: 0.2rem;
	cursor: pointer;
}

button:hover {
	filter: brightness(1.1);
}

button.--loading {
	cursor: wait;
	opacity: 0.6;
}