body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background-color: #f4f6f8;
  color: #333;
}

.container {
  width: 80%;
  margin: 0 auto;
  max-width: 900px;
}

header {
  background-color: #006666;
  color: white;
  padding: 20px 0;
  text-align: center;
}

header h1 {
  margin: 0;
}

nav {
  background-color: #004d4d;
  overflow: hidden;
}

nav a {
  float: left;
  display: block;
  color: white;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

nav a:hover:not(.active) {
  background-color: #ddd;
  color: black;
}

nav a.active {
  background-color: #003333;
  color: white;
}

.main-content {
  background-color: white;
  padding: 20px;
  margin-top: 20px;
  border-radius: 5px;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

.footer {
  text-align: center;
  margin-top: 20px;
  padding: 20px;
  background-color: #ddd;
  color: #333;
}

.button {
  background-color: #006666;
  color: white;
  padding: 10px 20px;
  text-decoration: none;
  border: none;
  border-radius: 3px;
  cursor: pointer;
  font-size: 16px;
  display: inline-block;
  margin-top: 10px;
}

.button:hover {
  background-color: #004d4d;
}

.card {
  border: 1px solid #ccc;
  padding: 15px;
  margin-bottom: 15px;
  border-radius: 5px;
  background-color: #fafafa;
}

.result {
  margin-top: 20px;
  padding: 15px;
  background-color: #e6f2ff;
  border: 1px solid #b3d9ff;
  border-radius: 5px;
  display: none;
}

/* Mobile Responsiveness */
@media screen and (max-width: 600px) {
  .container {
    width: 95%;
  }

  nav a {
    float: none;
    display: block;
    width: 100%;
    text-align: left;
    box-sizing: border-box;
  }

  .main-content {
    padding: 15px;
  }
}