* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: Arial, sans-serif;
}

body {
  background: #f4f6f9;
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 100vh;
}

header {
  width: 100%;
  padding: 20px;
  background: #111;
  color: white;
  text-align: center;
  font-size: 20px;
  font-weight: bold;
}

.controls {
  margin: 20px;
  background: white;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

.controls input {
  padding: 10px;
  border-radius: 8px;
  border: 1px solid #ddd;
  outline: none;
}

.controls button {
  padding: 10px 15px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  background: #111;
  color: white;
  transition: 0.3s;
}

.controls button:hover {
  background: #444;
}

.device-buttons button {
  background: #eee;
  color: #111;
}

.device-buttons button:hover {
  background: #ddd;
}

.preview-wrapper {
  background: #222;
  padding: 20px;
  border-radius: 20px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.2);
  transition: all 0.3s ease;
  overflow: auto;
}

iframe {
  border: none;
  background: white;
  border-radius: 12px;
  transition: 0.3s ease;
}

.footer {
  margin-top: auto;
  padding: 15px;
  font-size: 14px;
  color: #777;
  display: flex;
  gap: 1rem;
}