body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
}

.main-container {
    width: 900px;
    margin: auto;
    padding: 20px;
}

h1 {
    font-size: 2em;
    margin-bottom: 20px;
}

.flex-container {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
}

.flex-item {
    flex: auto;
    border: solid black 1px;
    margin-right: 20px;
    padding: 10px;
}

.font-included {
    font-family: 'Helvetica', sans-serif;
}

@font-face {
    font-family: 'CustomFont';
    src: url('path/to/your/custom-font.woff2') format('woff2'),
         url('path/to/your/custom-font.woff') format('woff');
}

.font-imported {
    font-family: 'CustomFont', sans-serif;
}

.font-from-service {
    font-family: 'Roboto', sans-serif;
}

.font-play {
    font-weight: bold;
    font-style: italic;
}

.font-variants {
    font-variant: small-caps;
    text-decoration: underline;
}

.line-height {
    line-height: 2;
}