.center {
    display: block;
    margin: 0 auto;
    text-align: center;
}

.hide {
    display: none !important;
}

.top-bg {
    background-color: #f5f6f6;
    padding-bottom: 60px;
    padding-top: 5%;
    background-size: contain;
    background-position-x: 0%;
    background-repeat: no-repeat;
    background-image: url('https://static.dingtalk.com/media/lALOlKt03c0CNc0CXA_604_565.png');
}

* {
    box-sizing: border-box;
    font-family: "HelveticaNeueLTPro", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

body, html {
    background: #fff;
    margin: 0;
    padding: 0;
}

h1, h2 {
    margin: 10px 0;
    font-weight: normal;
}

h1 {
    font-size: 40px;
    margin-top: 0;
    color: #272727;
}

h1::after {
    content: "";
    display: block;
    margin: 1px auto;
    width: 16px;
    border: 1px solid #000;
}

h2 {
    font-size: 20px;
    color: #272727;
}

.red {
    text-decoration: none;
    color: #de2c28;
}

.video {
    margin-top: 54px;
    width: 480px;
    height: 258px;
    position: relative;
    transition: all 0.6s ease-out;
}

.video.shadow {
    box-shadow: 0 10px 20px 0 rgba(185, 192, 202, 0.4);
}

.toolbar {
    position: absolute;
    top: -10px;
    right: -26px;
    width: 190px;
    height: 30px;
    transition: box-shadow 0.4s;
}

.toolbar.shadow {
    box-shadow: 0 4px 12px 0 rgba(12, 181, 251, 0.5);
}

.toolbar .anchor {
    position: relative;
}

.toolbar .container {
    width: 100%;
    height: 100%;
    position: relative;
    overflow: hidden;
}

.toolbar.light .dark, .toolbar.dark .light {
    opacity: 0;
}

.toolbar img {
    position: absolute;
    top: 0;
    left: 0;
    transition: opacity 0.7s;
}

.youtube {
    position: absolute;
    top: 90px;
    left: 180px;
    transition: margin-left 0.4s;
}

.right-arrow, .down-arrow {
    border-radius: 50%;
    position: absolute;
    background-size: cover;
    transition: opacity 0.2s ease-out;
    background: url('./img/down-arrow.png') no-repeat;
}

.right-arrow {
    width: 26px;
    height: 26px;
    top: 102px;
    left: 300px;
    background-color: #333;
}

.right-arrow:hover {
    background-color: #e02d28;
}

.right-arrow img {
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}

.down-arrow {
    right: -16px;
    bottom: -16px;
    background-color: #3d9bff;
    width: 66px;
    height: 66px;
}

.feature {
    display: inline-block;
    margin: 36px 50px;
    position: relative;
}

.feature:hover .detail {
    opacity: 1;
    bottom: 110%;
}

.feature .detail {
    width: 220px;
    background-color: #333;
    color: #fff;
    position: absolute;
    bottom: 90%;
    margin: 0;
    transition: all 0.4s;
    left: -60px;
    font-size: 14px;
    padding: 18px 28px;
    text-align: left;
    opacity: 0;
}

.feature p {
    color: #222;
    font-size: 12px;
}

.tip {
    position: absolute;
}

.tip span {
    font-style: italic;
    vertical-align: top;
    line-height: 32px;
    color: #72767b;
    font-size: 14px;
}

.tip.v1 {
    left: -220px;
    top: 120px;
}

.tip.v2 {
    top: 25px;
    right: -220px;
}

.tip span.dash {
    margin: 0 5px;
    width: 35px;
    height: 16px;
    display: inline-block;
    border-bottom: 1px solid #72767b;
}

.tip.v2 span.dash {
    width: 50px;
}

.tip.v3 {
    right: -200px;
    bottom: 10px;
}

.section-title {
    margin-top: 0;
    transition: padding-top 0.4s ease-out;
}

.section-video, .features {
    transition: opacity 0.5s ease-out;
}

body.s1 .top-bg {
    background: #fff;
}

body.s1 .section-title {
    padding-top: 170px;
}

body.s1 .features, body.s1 .section-video, body.s1 .video {
    opacity: 0;
}

body.s1 .video {
    transform: translate(0, 80px);
}

body.s3 .youtube {
    margin-left: 10px;
}

body.s3 .right-arrow {
    opacity: 0;
}
