/*
基础样式。
只负责变量、重置、排版和全局行为，不承载页面布局细节。
*/

:root {
	--color-background: #1b1f22;
	--color-border: #ffffff;
	--color-border-active: rgba(255, 255, 255, 0.175);
	--color-border-hover: rgba(255, 255, 255, 0.075);
	--color-text: #ffffff;
	--duration-fast: 0.2s;
	--duration-intro: 0.75s;
	--duration-section: 0.325s;
	--font-family-base: "Source Sans Pro", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
	--font-family-fixed: "Courier New", monospace;
	--font-letter-spacing: 0.2rem;
	--font-letter-spacing-title: 0.5rem;
	--font-weight-base: 300;
	--font-weight-bold: 600;
	--radius-base: 4px;
	--space-section: 3.5rem;
	--space-stack: 2rem;
}

html {
	box-sizing: border-box;
	font-size: 16pt;
}

*,
*::before,
*::after {
	box-sizing: inherit;
}

html,
body,
div,
span,
applet,
object,
iframe,
h1,
h2,
h3,
h4,
h5,
h6,
p,
blockquote,
pre,
a,
abbr,
acronym,
address,
big,
cite,
code,
del,
dfn,
em,
img,
ins,
kbd,
q,
s,
samp,
small,
strike,
strong,
sub,
sup,
tt,
var,
b,
u,
i,
center,
dl,
dt,
dd,
ol,
ul,
li,
fieldset,
form,
label,
legend,
table,
caption,
tbody,
tfoot,
thead,
tr,
th,
td,
article,
aside,
canvas,
details,
embed,
figure,
figcaption,
footer,
header,
hgroup,
menu,
nav,
output,
ruby,
section,
summary,
time,
mark,
audio,
video {
	margin: 0;
	padding: 0;
	border: 0;
	font: inherit;
	font-size: 100%;
	vertical-align: baseline;
}

article,
aside,
details,
figcaption,
figure,
footer,
header,
hgroup,
menu,
nav,
section {
	display: block;
}

body {
	background: var(--color-background);
	color: var(--color-text);
	font-family: var(--font-family-base);
	font-size: 1rem;
	font-weight: var(--font-weight-base);
	line-height: 1.65;
	-webkit-text-size-adjust: none;
}

body.is-preload *,
body.is-preload *::before,
body.is-preload *::after {
	animation: none !important;
	transition: none !important;
}

ol,
ul {
	list-style: none;
}

blockquote,
q {
	quotes: none;
}

blockquote::before,
blockquote::after,
q::before,
q::after {
	content: "";
}

table {
	border-collapse: collapse;
	border-spacing: 0;
}

img {
	display: block;
	max-width: 100%;
}

input,
select,
textarea,
button {
	color: inherit;
	font: inherit;
}

a {
	color: inherit;
	text-decoration: none;
	transition:
		color var(--duration-fast) ease-in-out,
		background-color var(--duration-fast) ease-in-out,
		border-color var(--duration-fast) ease-in-out;
}

strong,
b {
	font-weight: var(--font-weight-bold);
}

em,
i {
	font-style: italic;
}

p {
	margin: 0 0 var(--space-stack) 0;
}

h1,
h2,
h3,
h4,
h5,
h6 {
	color: var(--color-text);
	font-weight: var(--font-weight-bold);
	letter-spacing: var(--font-letter-spacing);
	line-height: 1.5;
	margin: 0 0 calc(var(--space-stack) * 0.25) 0;
	text-transform: uppercase;
}

h1 {
	font-size: 2.25rem;
	letter-spacing: var(--font-letter-spacing-title);
	line-height: 1.3;
}

::-webkit-scrollbar {
	width: 0;
}

@-ms-viewport {
	width: device-width;
}

@media screen and (max-width: 1680px) {
	html {
		font-size: 12pt;
	}
}

@media screen and (max-width: 736px) {
	html {
		font-size: 11pt;
	}

	h1 {
		font-size: 1.75rem;
		line-height: 1.4;
	}
}

@media screen and (max-width: 480px) {
	html,
	body {
		min-width: 320px;
	}
}

@media screen and (max-width: 360px) {
	html {
		font-size: 10pt;
	}
}