body {
  font-family: 'Segoe UI', sans-serif;
  background: #f3f5f7;
  margin: 0;
  padding: 0;
  color: #333;
}

.container {
  max-width: 800px;
  margin: auto;
  padding: 20px;
}

h1, h2 {
  text-align: center;
  color: #2b2b2b;
}

input[type="file"], input[type="text"] {
  display: block;
  margin: 10px auto;
  padding: 10px;
  width: 90%;
  max-width: 500px;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 16px;
}

button {
  display: block;
  margin: 10px auto;
  padding: 10px 20px;
  font-size: 16px;
  background: #0066cc;
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

button:hover {
  background: #004d99;
}

video, .yt-frame iframe {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  margin: 15px auto;
  border-radius: 8px;
  border: none;
}

.yt-frame iframe {
  height: 315px;
}

#chartBox {
  margin: 20px auto;
  width: 100%;
  max-width: 100%;
}

.totals {
  text-align: center;
  font-weight: bold;
  font-size: 18px;
}