:root {
  --primary-color: #0056b3;
  --secondary-color: #f0f0f0;
  --border-color: #ccc;
  --today-color: #e1ff04;
}

body {
  font-family: Arial, sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
  background-color: var(--secondary-color);
}

.calendar-container {
  background-color: #1df2eb;
  border-radius: 8px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
  width: 90%;
  max-width: 700px;
  padding: 20px;
}

.calendar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.calendar-header h2 {
  margin: 0;
  font-style: italic;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  font-weight: bolder;
  font-size: 1.5rem;
  color: var(--primary-color);
}

.calendar-header button {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 10px 15px;
  cursor: pointer;
  border-radius: 4px;
  font-size: 1rem;
  transition: background-color 0.2s;
}

.calendar-header button:hover {
  background-color: #007bff;
}

.weekdays {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  text-align: center;
  font-weight: bold;
  color: #555;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 10px;
  margin-bottom: 5px;
}

.calendar-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 5px;
}

.day {
  padding: 10px 5px;
  text-align: center;
  border-radius: 4px;
  cursor: pointer;
  transition: background-color 0.1s;
  height: 40px;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 0.9rem;
  border: 1px solid #eee; /* Subtle border for better separation */
}

.day:hover:not(.empty-day) {
  background-color: var(--secondary-color);
}

.today {
  background-color: var(--today-color);
  font-weight: bold;
  color: #333;
  border: 2px solid var(--today-color);
}

.empty-day {
  visibility: hidden;
}