body {
    margin: 0;
    font-family: Arial
}

div.one-third {
    width: 47.5%;
}

div.one-third-second {
    margin: 0;
}

div.one-third-last {
    clear: both;
    float: none;
    width: auto;
    padding: 20px 0 0 0;
}
.p_header {
    font-size: 26px;
    text-align: center;
    color: Gray;
}

.p_content {
    font-size: 16px;
    text-align: left;
}

@media screen and (max-width: 500px) {
    .topnav a:not(:first-child), .dropdown .dropbtn {
        display: none;
    }

    .topnav a.icon {
        float: right;
        display: block;
    }

    div.mobile-collapse {
        width: auto;
        float: none;
        margin-right: 0;
    }

    .hide-mobile {
        display: none;
    }

    .topnav.responsive {
        position: relative;
    }

    .topnav.responsive .icon {
        position: absolute;
        right: 0;
        top: 0;
    }

    .topnav.responsive a {
        float: none;
        display: block;
        text-align: left;
    }

    .topnav.responsive .dropdown {
        float: none;
    }

    .topnav.responsive .dropdown-content {
        position: relative;
    }

    .topnav.responsive .dropdown .dropbtn {
        display: block;
        width: 100%;
        text-align: left;
    }

}