body {
    background-color: rgb(35, 64, 136);
}
.index_block_introduce {
    line-height:1.5em; 
    min-height:3em;
}

.register {
    margin-left: 15%;
    margin-right: 15%;
}
.register_btn {
   width: 30%;
   margin: auto;
}

.register_btn button {
    background: none;
    border: none;
    padding: 0px;
}

.register_btn img {
    width: 100%;
}

h1.primary {
    color: rgb(35, 64, 136);
}
.index_block h2 {
    line-height:1em; 
    min-height:2em;
}

.index_block {
    margin-left: 15%;
    margin-right: 15%;
}

.index_block img, .introduce img {
    width: 100%;
}

.index_logo {
    width: 25%
}

.p1 {
    padding: 15px 10% 15px ;
}

.m2 {
    margin: 5px 20% 5px;
}

.register_form {
    padding-top:50px;
}

.register_form h2 {
    padding: 0 10% 0;
}

.register_form a {
    color: white;
}

.form-group {
    margin-bottom:10px;
}

@media screen and (max-width:768px) {
    .index_logo {
        width: 50%
    }

    .register_btn {
        width: 100%;
     }

     .register {
        margin-left: 0;
        margin-right: 0;
    }
}