body { margin: 24px 40px 60px; line-height: 1.5; }
img, video { max-width: min(100%, 640px); height: auto; display: block; margin: 8px 0; }
video { max-width: min(100%, 420px); }
small { color: #555; }
@media (max-width: 600px) { body { margin: 16px 18px 40px; } }