* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    background: #777;
    font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
}

/* Navigation bar */
nav {
    height: 40px;
    background: #555;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
}

nav a {
    text-decoration: none;
    color: #000
}

.logo {
    margin-left: 20px;
}

.nav-items {
    margin-right: 20px;
}

/*Header container*/
.header-container {
    display: flex;
    justify-content: center;
    align-items: center;
    justify-content: space-around;
    border: 1px solid cyan;
}

/*Header div*/
.header {
    display: flex;
    margin-top: 50px;
    width: 700px;
    justify-content: space-around;
    border: 1px solid blue;
}
.header p {
    font: Arial;
    font-size: 80;
}

/*Main div*/
.main-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 81vh;
    border: 1px solid red;
}

.main-container p {
    color: aqua;
    text-align: left;
}

/*Left column*/
.left-column {
    display: flex;
    width: 300px;
    justify-content: space-around;
    min-height: 81vh;
    border: 1px solid blue;
}
.left-column-content {
    display: inline;
    margin: 1em;
}

/*Right Column*/
.right-column {
    display: flex;
    width: 700px;
    justify-content: space-around;
    min-height: 81vh;
    border: 1px solid green;
}
.right-column-content {
    display: inline;
    margin: 1em;
}