/* Set the minimum height and width of the app to 100% of the viewport */
html, body {
    height: 100%;
    min-height: 100%;
    min-width: 100%;
}

/* Set the height and width of the app container */
#app1 {
    height: 100%;
    width: 100%;
    display: flex;
    flex-direction: column;
}

#app {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

/* Set the height and background color of the header bar */
#header {
    background-color: #333;
    padding:40px;
    text-align: center;
    color:white;
}

/* Set the width and background color of the left bar */
#left-bar {
    width: 250px;
    background-color: #555;
    float:left;
}

/* Divide the center area into two equal parts using flexbox */
#content {
    flex: 1;
    display: flex;
    flex-direction:row;
}

/* Set the width and background color of the left part of the center area */
#left-content {
    flex:1;
    background-color: green;
}

/* Set the width and background color of the right part of the center area */
#right-content {
    flex:1;
    background-color: yellow;
}