body {
  font-family: Arial, sans-serif;
  background: #f5f7fa;
  margin: 0;
  padding: 0;
  color: #333;
}

header {
  background: #1e293b;
  color: #fff;
  padding: 20px;
  text-align: center;
}

button {
  margin: 5px;
  padding: 10px 15px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  background: #2563eb;
  color: #fff;
}

button:hover {
  background: #1d4ed8;
}

.progress-bar {
  width: 80%;
  height: 20px;
  margin: 10px auto;
  background: #e5e7eb;
  border-radius: 10px;
  overflow: hidden;
}

.progress-bar div {
  height: 100%;
  width: 0;
  background: #22c55e;
  transition: width 0.4s ease;
}

.phase {
  background: #fff;
  border-radius: 12px;
  margin: 20px auto;
  padding: 20px;
  width: 80%;
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

.phase h2 {
  margin-top: 0;
}

.checklist {
  list-style: none;
  padding: 0;
}

.checklist li {
  margin: 8px 0;
}

.phase-progress {
  margin: 10px 0;
  font-size: 0.9em;
  color: #555;
}