html {
    font-family:Arial, Helvetica, sans-serif;
}
header {
    text-align: center;
}
.headimg {
    max-width: 80%;
}

.colcontainer {
    padding-top: 4rem;
    display: flex;
    max-width: 1200px;
    margin: 0 auto;
}
.col {
    padding: 1.6rem;
}
.col span {
    font-size: 1.3rem;
    font-weight: 600;
}
footer {
    text-align: center;
}

@media only screen and (max-width: 1024px) {
.colcontainer {
    display: block;
}
.col {
    width: 48%;
    display: inline-block;
    box-sizing: border-box;
}
}

@media only screen and (max-width: 600px) {
.col {
    display: block;
    width: 100%;
}
}