* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

body {
  height: 100vh;
  background-color: #212121;
  color: #ffffff;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: background-color 0.5s ease;
}

.container {
  background: rgba(255, 255, 255, 0.08);
  padding: 30px 40px;
  border-radius: 12px;
  text-align: center;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

h1 {
  margin-bottom: 10px;
  font-size: 1.8rem;
}

p {
  margin-bottom: 20px;
  color: #cccccc;
}

.btn-group {
  display: flex;
  gap: 15px;
  justify-content: center;
}

.btn {
  padding: 10px 22px;
  font-size: 1rem;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.btn.start {
  background-color: #4caf50;
  color: white;
}

.btn.stop {
  background-color: #f44336;
  color: white;
}

.btn:hover {
  transform: translateY(-2px);
  opacity: 0.9;
}