@media screen and (max-width: 750px) {
    html {
        font-size: calc(100vw / 7.5);
    }
}

@media screen and (min-width: 750px) {
    html {
        font-size: calc(450px / 7.5);
    }
}
.free-code-con {
    width: 7.5rem;
    margin: 0 auto;
}

.bottom-img {
    width: 100%;
    min-height: 100vh;
    background: url('../img/experienceBg1.png') no-repeat;
    background-size: contain;
}

.center-pic {
    position: absolute;
    top: 10.6rem;
    left: 0.31rem;
}
.recv-btn {
    margin: 0 auto;
    width: 6.88rem;
    height: 1.21rem;
}
.btn-bg-style {
    width: 100%;
    height: 1.21rem;
    text-align: center;
    line-height: 1.21rem;
    position: absolute;
    top: 0;
    left: 0;
    letter-spacing: 2px;
    font-size: 0.28rem;
    color: #fff;
}
.btn-bg-style img {
    width: 0.3rem;
    height: 0.3rem;
}