assets/main-ui-style.css

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background: #ececec;
    display: flex;
    flex-direction: column;
    padding-top: 50px;
    margin: 0;
    padding: 0;
    height: 100%;
    font-family: Arial, sans-serif;
}

.btn {
    font-size: 14px;
    text-decoration: none;
    padding: 5px 10px;
    white-space: nowrap;
    margin-left: auto;
}

.btn i {
    margin-right: 5px;
}

.top {
    height: 60px;
    width: 100%;
    border-top: none;
    border-bottom: groove;
    color: #000000;
    box-sizing: border-box;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 15px;
    flex-shrink: 0;
    position: relative;
}

.top-title-container {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-grow: 1;
    position: absolute;
    left: 50%;
    transform: translateX(-15%); /* adjust for sidebar */
}

.top-title {
    font-size: 35px;
    font-family: 'Zilla Slab', serif;
    text-align: center;
    white-space: nowrap;
}

.main-content {
    display: flex;
    flex-grow: 1;
    height: calc(100% - 60px); /* Subtract the height of the top banner */
}

.main-sidebar {
    flex: 0 0 15%;
    border-right: groove;
    color: #000000;
    overflow-y: scroll;
    transition: all .3s ease-in-out;
    z-index: 100;
}

.content {
    width: 90%;
    padding: 20px;
    align-items: center;
    display: flex;
    flex-direction: column;
}

#leftside-navigation {
    ul, ul ul {
        margin: -2px 0 0;
        padding: 0;
    }
    ul {
        li {
            list-style-type: none;
            border-bottom: 1px solid rgba(255,255,255,.05);
            &.active {
                & > a {
                    color: #ececec;
                }
                ul {
                    display: block;
                }
            }
            a {
                color: #000000;
                text-decoration: none;
                display: block;
                padding: 18px 0 18px 25px;
                font-size: 14px;
                outline: 0;
                transition: all 200ms ease-in;
                &:hover {
                    color: #1abc9c;
                }
                span {
                    display: inline-block;
                }
                .arrow {
                  text-align: right;
                  display: block;
                  float: right;
                  padding-right: 15px;
                }
                i {
                    width: 20px;
                    .fa-angle-left, .fa-angle-right {
                        padding-top: 3px;
                    }
                }
            }
        }
    }
    ul ul {
        display: none;
        li {
            margin-bottom: 0;
            margin-left: 0;
            margin-right: 0;
            border-bottom: none;
            a {
                font-size: 14px;
                padding-top: 13px;
                padding-bottom: 13px;
                color: #000000;
            }
        }
    }
}