index.html

<style>
    html, body {
        height: 100%;
        margin: 0;
        padding: 0;
        font-family: 'Roboto', sans-serif;
        background-color: #f0f0f0;
    }

    .header {
        background-color: #007bff;
        color: white;
        padding: 20px;
        text-align: center;
        border-bottom: 5px solid #0056b3;
    }

    .header a {
        color: #ff9900;
    }

    .container {
        height: calc(100vh - 160px); /* 100% chiều cao - header + tab + footer */
        max-width: 100%;
        padding: 0;
        margin: 0 auto;
    }

    .tab-content {
        height: 100%;
    }

    .tab-pane {
        height: 100%;
    }

    .tab-pane iframe {
        width: 100%;
        height: 100%;
        border: none;
    }

    footer {
        background-color: #343a40;
        color: #fff;
        text-align: center;
        padding: 10px;
        position: fixed;
        left: 0;
        bottom: 0;
        width: 100%;
        font-size: 1em;
        opacity: 0.6;
        transition: opacity 0.5s ease-in-out;
    }

    footer:hover {
        opacity: 1;
    }
</style>