body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: #f6f7f9;
  color: #111;
}

main {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.card {
  width: min(900px, 100%);
  background: #fff;
  border-radius: 14px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.08);
  padding: 20px;
}

h1 {
  margin: 0 0 14px;
  font-size: 1.4rem;
  text-align: center;
}

.video-wrap {
  position: relative;
  width: 100%;
  padding-top: 56.25%; /* 16:9 ratio */
  border-radius: 12px;
  overflow: hidden;
  background: #000;
}

.video-wrap iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.note {
  margin-top: 12px;
  text-align: center;
  font-size: 0.95rem;
  color: #555;
}
.next-container {
  margin-top: 20px;
  display: flex;
  justify-content: flex-end;
}

.next-arrow {
  text-decoration: none;
  font-size: 1rem;
  font-weight: 600;
  padding: 10px 16px;
  background: #111;
  color: #fff;
  border-radius: 8px;
  transition: 0.2s ease;
}

.next-arrow:hover {
  background: #333;
  transform: translateX(3px);
}