html, body {
  margin: 0;
  padding: 0;
  max-width: 100%;
  overflow-x: hidden;
  font-family: 'Arial', sans-serif;
  background-color: #f9f9f9;
}

.container {
  max-width: 430px;
  margin: 0 auto;
  background-color: #fff;
  min-height: 100vh;
  padding: 20px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
}

.footer {
  margin-top: 40px;
  padding: 20px;
  text-align: center;
  font-size: 14px;
  color: #888;
}

img, video, iframe {
  max-width: 100%;
  height: auto;
  display: block;
}