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

body {
  font-family: system-ui, sans-serif;
  background: #0f172a;
  color: #e2e8f0;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 100vh;
  padding: 2rem 1rem;
}

.container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  width: 100%;
  max-width: 640px;
}

h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: #7dd3fc;
}

video {
  width: 100%;
  border-radius: 12px;
  border: 2px solid #334155;
  background: #1e293b;
}

.controls {
  display: flex;
  gap: 1rem;
}

button {
  padding: 0.6rem 1.4rem;
  border: none;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.2s;
}

button:disabled { opacity: 0.35; cursor: not-allowed; }

#startBtn { background: #22c55e; color: #fff; }
#stopBtn  { background: #ef4444; color: #fff; }

.status-box {
  width: 100%;
  background: #1e293b;
  border: 1px solid #334155;
  border-radius: 10px;
  padding: 1rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.95rem;
}

.status-box span { font-weight: 600; color: #7dd3fc; }

#changeLabel.changed    { color: #f97316; }
#changeLabel.no-change  { color: #22c55e; }