* { box-sizing: border-box; }
body {
  margin: 0;
  background: #0b0b0b;
  color: #fff;
  font-family: Arial, sans-serif;
}
header {
  padding: 18px 20px;
  background: #151515;
}
main { padding: 20px; }
.videos {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 16px;
}
.card {
  background: #171717;
  border-radius: 12px;
  overflow: hidden;
  padding-bottom: 14px;
}
.poster {
  height: 220px;
  display: grid;
  place-items: center;
  background: #292929;
  color: #aaa;
}
.card h3 { padding: 0 12px; }
button {
  margin-left: 12px;
  padding: 10px 16px;
  border: 0;
  border-radius: 7px;
  cursor: pointer;
}