.outside_case {
    background-color: rgba(0, 191, 242, 0.2);
    /*	height: 4800px;*/
    width: 100%;
    padding: 50px 0px;
}

/***********************限制宽为1170px*********************************/

.mathworld_case {
    width: 1170px;
    margin: 0 auto;
    padding: 0;
    position: relative;
    font-size: 23px;
    font-weight: 400;
    font-style: normal;
    text-decoration: none;
    font-family: "微软雅黑";
    color: rgb(54, 54, 54);
}


/***********************mathworld*********************************/

.topic {
    height: 68px;
    font-size: 50px;
    font-weight: 700;
    margin:50px 0px;
}

.littletopic {
    font-size: 24px;
    font-weight: 700;
    margin-top: -35px;
}

.topic_text {
    margin-top: -40px;
    margin-bottom: 60px;
}

.computer {
    float: right;
    margin-top: -180px;
    width: 450px;
}

.circle {
    width: 560px;
    height: 560px;
    border-radius: 50%;
    background: #fa6658;
}

.circle_content_topic {
    width: 290px;
    margin: 0px auto;
    padding-top: 100px;
    padding-bottom: 10px;
}

.circle span,
.circle p {
    color: rgb(255, 255, 255);
    margin: 0px auto;
}

.circle span {
    font-size: 32px;
    font-weight: 700;
}

.circle_content_text {
    width: 460px;
    margin: 20px auto;
    padding-bottom: 20px;
}

.circle_content_text p {
    width: 470px;
}

.redBigCircle {
    margin-left: 40px;
}

.link a {
    width: 212px;
    font-size: 18px;
    font-weight: 700;
    color: rgb(255, 255, 255);
}

.link {
    width: 212px;
    margin: 0 auto;
}

.redsmallCircle {
    width: 70px;
    height: 70px;
    margin: 0 auto;
    margin-top: -70px;
}

.orangeBigCircle {
    background: #ff9900;
    margin-left: 608px;
    margin-top: -110px;
}

.orangesmallCircle {
    width: 70px;
    height: 70px;
    background: #ff9900;
    margin: 0 auto;
    margin-top: -90px;
}

.blueBigCircle {
    background: #0099cc;
    margin-top: -50px;
    margin-left: 40px;
}

.bluesmallCircle {
    width: 70px;
    height: 70px;
    margin: 0 auto;
    background: #0099cc;
    margin-top: -70px;
}

.greenBigCircle {
    background: #7fc140;
    margin-left: 608px;
    margin-top: -110px;
}

.greenBigCircle img {
    width: 180px;
    display: block;
    margin: 0 auto;
}