body {
  margin: 0;
  font-family: "Segoe UI", sans-serif;
  background: #f3f4f6;
  color: #111827;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.container {
  width: 100%;
  max-width: 400px;
  padding: 2rem;
  text-align: center;
}

h1 {
  font-size: 1.8rem;
  margin-bottom: 1.5rem;
}

.card {
  background: #ffffff;
  padding: 2rem;
  border-radius: 16px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
}

label {
  display: block;
  text-align: left;
  margin-bottom: 0.3rem;
  font-weight: 600;
}

input[type="date"] {
  width: 100%;
  padding: 10px;
  margin-bottom: 1.2rem;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  font-size: 1rem;
}

button {
  width: 100%;
  padding: 12px;
  background-color: #3b82f6;
  color: white;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

button:hover {
  background-color: #2563eb;
}

.result {
  margin-top: 1.5rem;
  font-size: 1rem;
  text-align: left;
}

.hidden {
  display: none;
}