* {
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}

html {
    background-color: rgb(177, 230, 247);
}

body {
    margin-top: 0;
}

/* Status bar */ 
#status-bar {
    display: inline-block;
    width: 100%;
    background-color: #4f73dd;
    border: 1px solid black;
    border-bottom-left-radius: 10px;
    border-bottom-right-radius: 10px;
}

#status-bar_content {
    padding: 3px 15px;
}

#status-bar_content > div {
    padding-bottom: 3px;
}

#status-bar_content > #notifications {
    float: left;
}

.notifications > ul { /* not tested, not used */
    list-style-type: none;
}

#status-bar_content > #current-time {
    float: right;
}

/* Navigation content */
.content {
    max-width: 90%;
    margin-right: 5%;
    margin-left: 5%;
    margin-top: 10px;
}

/* ClearFix */
.content::after {
    display: table;
    clear: both;
    content: '';
}

.content-group {
    /* General grid (+for mobiles) */
    width: 100%;
    line-height: 20px;
    text-align: center;
    margin-bottom: 15px;
    border: 3px solid blue;
    border-radius: 7px;
}

@media (min-width: 900px) {
    /* PCs, 3 margins 5px each, 4 columns */
    .content-group {
        width: calc((100% - 15px * 3) / 4);
        float: left;
        margin-right: 15px;
    }

    .content-group:nth-child(4n+4) {
        margin-right: 0;
        float: right;
    }
}

.group-heading {
    margin-top: 12px;
}

.group-list {
    list-style-type: none;
    padding-left: 0px;
}

.group-item {
    margin-bottom: 5px; 
}