<div class="container">
    <iframe width="560" height="315" src="https://www.youtube.com/embed/68NGKdaNVi4?si=H_E_Hm3jtOUP9m8j" frameborder="0" allowfullscreen></iframe>
</div>
html {
    padding: 20px;
}

.container {
    position: relative;
    overflow: hidden;
    width: 100%;
    height: 0;
    padding-bottom: 56.25%; /* 9 ÷ 16 x 100% para mantener la proporción 16:9 */
}

.container > * {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
}

External CSS

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External JavaScript

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