* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: #f5f5f5;
  font-family: system-ui, -apple-system, sans-serif;
}

main {
  text-align: center;
  background: white;
  padding: 3rem 4rem;
  border-radius: 1rem;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  max-width: 400px;
  width: 100%;
}

h1 {
  font-size: 2rem;
  font-weight: 600;
  color: #1e293b;
  margin-bottom: 1.5rem;
}

.slider-container {
  margin-bottom: 2rem;
}

.slider-container label {
  display: block;
  font-size: 1rem;
  color: #1e293b;
  margin-bottom: 0.5rem;
}

.slider-container input[type="range"] {
  width: 100%;
  cursor: pointer;
}

#zapBtn {
  font-size: 1.5rem;
  padding: 0.75rem 2.5rem;
  border: none;
  border-radius: 0.5rem;
  background: #646464;
  color: white;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s;
  width: 100%;
}

#zapBtn:hover {
  background: #646464;
}

#zapBtn:active {
  transform: scale(0.96);
}

#zapBtn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

#status {
  margin-top: 1.5rem;
  font-size: 1.1rem;
  color: #374151;
  min-height: 1.8rem;
}