body {
    font-family: 'Roboto', sans-serif;
    margin: 0;
    padding: 20px;
    background-color: #f5f5f5;
}

.mdc-layout-grid {
    max-width: 1200px;
    margin: 0 auto;
}

.ppt-container {
    position: relative;
    width: 100%;
    height: 600px;
    border: 1px solid #ccc;
    background-color: #fff;
    overflow: hidden;
}

.toolbar {
    margin-top: 20px;
    text-align: center;
}

.mdc-button {
    margin: 0 10px;
}

.mdc-circular-progress {
    margin: 20px auto;
    display: none;
}

.mdc-circular-progress--indeterminate {
    display: block;
}