* {
  font-family: Arial, Helvetica, sans-serif;
}

html, body {
  margin: 0;
  border: 0;
  padding: 0;
  background-color: #fff;
}

main {
  margin: auto;
  width: 50%;
  padding: 20px;
  padding-top: 20px; /* Adjusted padding to avoid content being hidden behind the fixed header */
  padding-bottom: 20px; /* Add padding to avoid content being hidden behind the fixed footer */
}

main > h1 {
  text-align: center;
  font-size: 3.5em;
}

.flashcard {
  background-color: #f9f9f9;
  border: 1px solid #ddd;
  border-radius: 8px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
  padding: 20px;
  margin: 20px 0;
  transition: transform 0.2s;
}

.flashcard:hover {
  transform: scale(1.05);
}

ul {
  list-style-type: none;
  padding-left: 0;
}

header {
  position: fixed;
  top: 0;
  width: 100%;
  background-color: #333;
  color: white;
  text-align: center;
  padding: 10px 0;
  z-index: 1000;
}

header h1 {
  margin: 0;
}

nav {
  position: fixed;
  bottom: 0;
  width: 100%;
  background-color: #333;
  color: white;
  text-align: center;
  padding: 10px 0;
}

nav ul {
  display: flex;
  justify-content: space-around;
  padding: 0;
  margin: 0;
}

nav ul li {
  display: inline;
}

nav ul li a {
  color: white;
  text-decoration: none;
  padding: 10px 20px;
  display: block;
}

nav ul li a:hover, nav ul li a.active {
  background-color: #575757;
  border-radius: 4px;
}

.flashcard .front {
  background-color: #e0f7fa;
}

.flashcard .back {
  background-color: #ffe0b2;
}