@charset "utf-8";



	/* ----------------------------------- Button ----------------------------------- */

.btn, section a.btn, .btn-toref {
    font-size: 14px;
    border: none;
    border-radius: 5px;
    display: inline-block;
    padding: 12px 18px;
    vertical-align: middle;
    overflow: hidden;
    text-decoration: none;
    text-align: center;
    cursor: pointer;
    white-space: nowrap;
	color: #000;
	background-color: #e0e0e0;
	transition: background-color 0.3s ease;
}

.btn:hover, section a.btn:hover, .btn-toref:hover {
	background-color: #d5d5d5;
}

section.intro .btn {
    background-color: #007A63;
	color: #fff;
}

section.intro .btn:hover {
    background-color: #006552;
	color: #fff;
}

.theme {
    color: #fff !important;
    background-color: #04AA6D !important;
}

.theme:hover {
    color: #fff !important;
    background-color: #059862 !important;
}

.nav-toref {
	padding: 30px 0;
	border-bottom: 1px solid #E1E1E1;
}

article > .nav-toref:nth-of-type(2) {
	border: 0;
	padding-bottom: 0;
}

.nav-toref a:nth-child(2) {
	margin-left: 10px;
}


	/* ----------------------------------- Logo ----------------------------------- */

.header-logo-container {
    width: 260px;
	height: 100%;
	display: flex;
	justify-content: center;
	align-items: center;
	margin-left: 15px;
    }

.header-logo
    {
    position: relative;
	text-indent: -9999px;
    overflow:hidden;
	text-decoration: none;
    display: block;	
    width: 260px;
	height: 100%;
    background : transparent url("/i/ui/w3school.svg") no-repeat;
    background-position: center center;
    }

.header-logo::after {
    content: '';
    position: absolute;
    bottom: 16px;
    left: 0;
    width: 100%;
    height: 5px;
    background-color: transparent;
    transition: background-color 0.3s ease;
    }

.header-logo:hover::after {
    background-color: #BD2D30;
    }

@media screen and (max-width: 720px) {

.header-logo-container {
    width: 200px;
    }

.header-logo
    {
    width: 200px;
	height: 100%;
	background-size: 200px 100%;
    }

.header-logo::after {
    bottom: 12px;
    height: 3px;
    }
}



	/* ----------------------------------- Menu Toggle Button ----------------------------------- */

.menu-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background-color 0.2s ease;
	}

.menu-toggle:hover {
    background-color: #f5f5f5;
	}

.menu-toggle::before {
    content: '\f0c9';
    font: normal normal 900 14px/1 FontAwesome;
	text-rendering: auto;
    color: #BD2D30;
	letter-spacing: 1px;
	}

.menu-toggle.active::before {
    content: '\f00d';
    font: normal normal 900 14px/1 FontAwesome;
	text-rendering: auto;
    color: #BD2D30;
	letter-spacing: 1px;
	}

@media screen and (max-width: 720px) {
.menu-toggle {
    display: flex;
	width: 40px;
    height: 40px;
	}
}

@media screen and (min-width: 721px) and (max-width: 1079px) {
.menu-toggle {
    display: flex;
	width: 50px;
    height: 50px;
	}
}




.nav-top-menu {
    overflow-x: auto;
    -ms-overflow-style: none;
    scrollbar-width: none;
    flex: 1;
    cursor: grab;
    user-select: none;
    list-style: none;
    display: flex;
	align-items: stretch;
    }

.nav-top-menu::-webkit-scrollbar {
    display: none;
    }

/* 列表项样式 */
.nav-top-menu li {
    flex-shrink: 0;
    display: flex;
	align-items: center;
	justify-content: center;
	transition: all 0.3s ease;
	cursor: pointer;
}

/* 链接样式 */
.nav-top-menu li a {
    position: relative;
    display: flex;
	align-items: center;
	justify-content: center;
	width: 100%;
	height: 100%;
    color: #777;
    text-align: center;
    text-decoration: none;
    font-size: 16px;
    white-space: nowrap;
    transition: all 0.3s ease;
	font-family: 'Source Sans Pro Topnav', sans-serif;
	padding: 0 14px;
}

/* 红色下划线伪元素 */
.nav-top-menu li a::after {
    content: '';
    position: absolute;
    bottom: 10px;
    left: 14px; /* 与链接内边距保持一致 */
    right: 14px; /* 与链接内边距保持一致 */
    height: 3px; /* 横条高度 */
    background-color: transparent;
    transition: background-color 0.3s ease;
}

/* 悬停效果 */
.nav-top-menu li:hover {
    background-color: #E1E1E1;
}

.nav-top-menu li:hover a {
    background-color: transparent;
    color: inherit;
}

/* 悬停时显示红色下划线 */
.nav-top-menu li:hover a::after {
    background-color: red;
}

/* 激活状态 */
.nav-top-menu li a.active {
    background-color: #E1E1E1;
    color: #000;
}

/* 激活状态下的红色下划线 */
.nav-top-menu li a.active::after {
    background-color: #BD2D30;
}

@media screen and (max-width: 720px) {
	.nav-top-menu li a {
		padding: 0 12px;
		font-size: 15px;
	}

	.nav-top-menu li a::after {
		bottom: 7px;
		left: 12px;
		right: 12px;
		height: 2px;
	}
}


.nav-top-controls {
    display: none;
    position: absolute;
    top: 0;
    height: 100%;
    width: 40px;
    border: none;
    cursor: pointer;
    z-index: 1001;
    align-items: center;
    justify-content: center;
    font-size: 15px;
    transition: all 0.2s;
    background-color: #EDEDED;
	line-height: 1.5;
	font-family: 'Source Sans Pro Topnav', sans-serif;
	color: #BD2D30;
}

.nav-top-controls::before {
    content: '';
    position: absolute;
    top: 0;
    width: 15px;
    height: 100%;
    pointer-events: none;
}

.nav-top-controls-prev::before {
    right: -15px;
    background: linear-gradient(to right, 
        rgba(237, 237, 237, 1) 0%, 
        rgba(237, 237, 237, 0.8) 50%, 
        rgba(237, 237, 237, 0) 100%);
}

.nav-top-controls-next::before {
    left: -15px;
    background: linear-gradient(to left, 
        rgba(237, 237, 237, 1) 0%, 
        rgba(237, 237, 237, 0.8) 50%, 
        rgba(237, 237, 237, 0) 100%);
}

.nav-top-controls:hover {
    background-color: rgba(225, 225, 225, 1);
	color: red;
}

.nav-top-controls-controls.active {
    background-color: rgba(225, 225, 225, 0.9);
}

.nav-top-controls-prev {
    left: 0;
}

.nav-top-controls-next {
    right: 0;
}



.nav-left-content {
    width: 100%;
	height: 100%;
	overflow-x: hidden;
    overflow-y: scroll;
	background-color: #F7F7F7;
	border-top: 0px solid #e5e5e5;
	border-left: 2px solid #F7F7F7;
	border-right: 0px solid #e5e5e5;
	color: #4B4B4D;
}

.nav-left-content h2	{
	font-size: 16px;
	margin: 15px 0 5px 15px;
	font-weight: bold;
	}

.nav-left-content li	{
	list-style: none;
	}

.nav-left-content a {
	display: block;
	padding: 4px 0 4px 15px;
	font-size:14px;
	text-decoration:none;
	}

.nav-left-content ul a.active {
	background : #f5f5f5;
	color:#990000;
	} 
	
.nav-left-content a:link, .nav-left-content a:visited	{
	text-decoration : none;
	color:#000000;
	background : transparent;
	} 

.nav-left-content a:hover	{
	text-decoration : none;
	color : #000;
	background : #E1E1E1;
	transition: background 0.2s ease;
	}

.nav-left-content a.active	{
	text-decoration : none;
	color : #000;
	background : #E1E1E1;
	border-left: 3px solid #900b09;
	padding-left: 12px;
	transition: background 0.2s ease;
	}


/* 滚动条样式 */
.nav-left-content::-webkit-scrollbar {
    width: 2px;
}

.nav-left-content::-webkit-scrollbar-track {
    background: #F7F7F7;
	color: #000;
}

.nav-left-content::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 2px;
}

.nav-left-content::-webkit-scrollbar-thumb:hover {
    background: #a8a8a8;
}

.nav-top-menu::-webkit-scrollbar {
    height: 4px;
}

.nav-top-menu::-webkit-scrollbar-track {
    background: transparent;
}

.nav-top-menu::-webkit-scrollbar-thumb {
    background: #666;
    border-radius: 2px;
}



	/* ----------------------------------- Menu Overlay ----------------------------------- */

.menu-overlay {
    position: fixed;
    top: 120px;
    left: 0;
    width: 100%;
    height: calc(100vh - 120px);
    background-color: rgba(0,0,0,0.5);
    z-index: 998;
    opacity: 0;
    transition: all 0.3s ease;
	visibility: hidden;
    }

.menu-overlay.active {
    opacity: 1;
    visibility: visible;
	}

@media screen and (min-width: 721px) and (max-width: 1079px) {
.menu-overlay {
    top: 150px;
    height: calc(100vh - 150px);
	}
}




	/* ----------------------------------- prenext ----------------------------------- */

.nav-prenext	{
	width:100%;
	padding-top: 30px;
	padding-bottom: 30px;
	background: transparent;
	box-sizing: border-box;
    }

.nav-prenext:nth-of-type(2) {
	border: 0;
	padding-bottom: 0;
}

.nav-prenext-menu	{
	position:relative;
    height:45px;
	width:260px;
    }

.nav-prenext-menu li	{
	list-style:none;
	position:absolute;
	top:0px;
	overflow:hidden;
    display:block;
	height:45px;
    }

.nav-prenext-menu a	{
	text-indent: -9999px;
	text-decoration: none;
    display:block;
	height:45px;
    }

.btn-pre {
	left:0;
	width:120px;
	background: transparent url("/i/ui/btn-pre.svg") 0px 0px no-repeat;
	border-radius: 5px;
	background-color: #EDEDED;
    }

.btn-next {
	left:150px;
	width:120px;
	background: transparent url("/i/ui/btn-next.svg") 0px 0px no-repeat;
	border-radius: 5px;
	background-color: #EDEDED;
    }

.btn-ref {
	left:300px;
	width:146px;
	background: transparent url("/i/ui/btn-toref.svg") 0px 0px no-repeat;
	border-radius: 5px;
	background-color: #EDEDED;
    }

.btn-pre a {
	background: transparent url("/i/ui/btn-pre.svg") 0px 0px no-repeat;
	background-color: #EDEDED;
	transition: background-color 0.3s ease;
    }

.btn-pre a:hover {
	background: transparent url("/i/ui/btn-pre.svg") 0px 0px no-repeat;
	background-color: #E1E1E1;
    }

.btn-next a	{
	background: transparent url("/i/ui/btn-next.svg") 0px 0px no-repeat;
	background-color: #EDEDED;
	transition: background-color 0.3s ease;
    }

.btn-next a:hover {
	background: transparent url("/i/ui/btn-next.svg") 0px 0px no-repeat;
	background-color: #E1E1E1;
    }

.btn-ref a	{
	background: transparent url("/i/ui/btn-toref.svg") 0px 0px no-repeat;
	background-color: #EDEDED;
	transition: background-color 0.3s ease;
    }

.btn-ref a:hover {
	background: transparent url("/i/ui/btn-toref.svg") 0px 0px no-repeat;
	background-color: #E1E1E1;
    }



	/* ----------------------------------- tools ----------------------------------- */

.nav-tools {
	background:transparent url("/i/ui/nav-tools.svg") no-repeat;
	background-size: 230px 90px;
	width: 230px;
	display: flex;
	flex-direction: column;
	align-items: center;
	padding-top: 110px;
    }

.nav-tools-menu {
    display: flex;
	flex-direction: column;
	align-items: center;
	width: 190px;
    }

.nav-tools-menu li {
	list-style:none;
	width: 190px;
	height: 88px;
	margin-bottom: 15px;
    }

.nav-tools-menu a {
	display: block;
	overflow:hidden;
	text-indent: -9999px;
	width: 100%;
	height: 100%;
	text-decoration: none;
	border-radius: 10px;
    }

.btn-reference a	{
	background: #9ED78D url("/i/ui/btn-reference.svg") no-repeat;
	transition: background-color 0.3s ease;
	background-size: 190px 88px;
	}

.btn-reference a:hover	{
	background: #93D181 url("/i/ui/btn-reference.svg") no-repeat;
	background-size: 190px 88px;
	}

.btn-example a	{
	background: #D6B8E4 url("/i/ui/btn-example.svg") no-repeat;
	transition: background-color 0.3s ease;
	background-size: 190px 88px;
	}

.btn-example a:hover	{
	background: #CEACDE url("/i/ui/btn-example.svg") no-repeat;
	background-size: 190px 88px;
	}

.btn-quiz a	{
	background: #E8AE8F url("/i/ui/btn-quiz.svg") no-repeat;
	transition: background-color 0.3s ease;
	background-size: 190px 88px;
	}

.btn-quiz a:hover	{
	background: #E4A281 url("/i/ui/btn-quiz.svg") no-repeat;
	background-size: 190px 88px;
	}

.btn-tutorial a	{
	background: #9BB6F3 url("/i/ui/btn-tutorial.svg") no-repeat;
	transition: background-color 0.3s ease;
	background-size: 190px 88px;
	}

.btn-tutorial a:hover	{
	background: #90ADEF url("/i/ui/btn-tutorial.svg") no-repeat;
	background-size: 190px 88px;
	}

.btn-professional a	{
	background: #9BB6F3 url("/i/ui/btn-professional.svg") no-repeat;
	transition: background-color 0.3s ease;
	background-size: 190px 88px;
	}

.btn-professional a:hover	{
	background: #90ADEF url("/i/ui/btn-professional.svg") no-repeat;
	background-size: 190px 88px;
	}

@media screen and (min-width: 1250px) and (max-width: 1599px) {

.nav-tools {
	background:transparent url("/i/ui/nav-tools-200.svg") no-repeat;
	background-size: 200px 65px;
	width: 200px;
	padding-top: 80px;
    }

.nav-tools-menu {
	width: 160px;
    }

.nav-tools-menu li {
	width: 160px;
	height: 74px;
	margin-bottom: 10px;
    }

.nav-tools-menu a {
	border-radius: 8px;
    }

.btn-reference a, .btn-reference a:hover, .btn-example a, .btn-example a:hover, .btn-quiz a, .btn-quiz a:hover, .btn-tutorial a, .btn-tutorial a:hover, .btn-professional a, .btn-professional a:hover {
	background-size: 160px 74px;
	}
}