body {
  font-family: sans-serif;
  background: #f8fafc;
  margin: 0;
  padding: 2rem;
}
.container {
  max-width: 600px;
  margin: auto;
  background: #fff;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}
h1 {
  text-align: center;
}
button {
  margin-top: 1rem;
  padding: 0.5rem 1rem;
  font-size: 16px;
}
.habit {
  margin: 0.5rem 0;
  padding: 1rem;
  border: 1px solid #ccc;
  border-radius: 8px;
  cursor: pointer;
}
.habit.done {
  background-color: #d1fae5;
  border-color: #10b981;
}
.progress-bar {
  background: #e5e7eb;
  height: 20px;
  border-radius: 10px;
  margin-top: 1rem;
}
#progress {
  height: 100%;
  background: #10b981;
  width: 0%;
  border-radius: 10px;
  transition: width 0.3s ease;
}