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

a {
	text-decoration: none;
}

/* 布局工具类 */
.flex {
	display: flex;
}

.flex--row {
	flex-direction: row;
}

.flex--wrap {
	flex-wrap: wrap;
}

.flex--center {
	justify-content: center;
}

.flex--align-center {
	align-items: center;
}

.position--absolute {
	position: absolute;
}

.position--relative {
	position: relative;
}