body, html {
    margin: 0 auto;
    padding: 0;
    width: 100%;
    height: 100%;
}
 /* Header */
.header-container, .footer-container {
    height: 15%;
    color: #fff;
}

.header-container .logo {
    height: -webkit-fill-available;
}

/* Navbar */
nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: rgba(51, 51, 51, 0.71);
}

nav li {
    float: left;
}

nav li a {
    display: block;
    color: white;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
}

nav li a:hover {
    background-color: #ffffff;
    color: #333;
}

/* Content */
.content-container {
    width: 100%;
    display: flex;
}

.content-container .menu-left,
.content-container .content-right{
    flex: 1 0 10%;
}
.content-container .content-area{
    flex: 1 0 70%;
}

@media (max-width: 992px) {
    .content-container {
        flex-direction: column;
    }
}
.menu-left ul{
    padding: 0 10px;
}
.menu-left ul li:hover {
    background-color: #333;
    color: #fff;
}
.menu-left li{
    line-height: 3rem;
    border: 1px green solid;
    text-align: center;
}

.menu-left li a{
    text-decoration: none;
    font-size: 1.4rem;
}
.menu-left li a:hover{
    color: white;
}
.content-area {
    animation: fadeInAnimation 1s ease-in-out;
    -webkit-animation: fadeInAnimation 1s ease-in-out;
    -moz-animation: fadeInAnimation 1s ease-in-out;
    -o-animation: fadeInAnimation 1s ease-in-out;
    visibility: visible;
    text-align: center;
    padding-top: 10px;
}
.content-area .card-container{
    width: 100%;
    display: flex;
    flex-wrap: wrap;
}
.content-area .card-container > * {
    width: calc(100% / 3);
}
.column {
    align-content: center;
    flex: 1 0 21%;
    padding: 1em;
}
@media (max-width: 1200px) {
    .content-area .card-container > * {
        width: calc(100% / 2);
    }
}

@media (max-width: 992px) {
    .column {
        flex: 1 0 100%;
    }
}
@media (max-width: 768px) {
    .content-area .card-container > * {
        width: 100%;
    }
}
/* Footer */
.footer-columns {
    display: flex;
    flex-wrap: wrap;
}

.footer-columns .column h4{
    color: black;
}

.footer-columns .column img{
    width: 50%;
}
@media (max-width: 600px) {
    .column {
        flex: 1 0 100%;
    }
}

@keyframes fadeInAnimation {
    0% {opacity: 0; visibility: hidden;}
    100% {opacity: 1; visibility: visible;}
}