* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font-family: "Segoe UI", sans-serif;
    background-color: #f5f7fa;
    color: #222;
    padding: 2rem;
    transition: background 0.3s, color 0.3s;
  }
  
  .container {
    max-width: 850px;
    margin: auto;
    background: #fff;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.08);
  }
  
  h1, h2 {
    text-align: center;
    margin-bottom: 1rem;
  }
  
  section {
    margin: 2rem 0;
  }
  
  input, select {
    padding: 10px;
    margin: 0.5rem 0;
    width: 100%;
    border-radius: 8px;
    border: 1px solid #ccc;
    font-size: 1rem;
  }
  
  button {
    background-color: #007bff;
    color: white;
    border: none;
    padding: 10px 16px;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    margin: 0.5rem 0.5rem 0 0;
    transition: background 0.3s;
  }
  
  button:hover {
    background-color: #0056b3;
  }
  
  .result {
    margin-top: 1rem;
    font-weight: bold;
    font-size: 1.2rem;
  }
  
  table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1rem;
  }
  
  th, td {
    padding: 10px;
    text-align: center;
    border-bottom: 1px solid #ddd;
  }
  
  hr {
    border: 0;
    height: 1px;
    background: #ddd;
    margin: 2rem 0;
  }
  
  /* Theme Toggle */
  .theme-toggle {
    position: fixed;
    top: 5px;
    right: 16px;
    background-color: #007bff;
    color: white;
    padding: 10px 14px;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    z-index: 100;
  }
  
  /* Dark Mode */
  body.dark {
    background-color: #1e1e1e;
    color: #eee;
  }
  body.dark .container {
    background-color: #2c2c2c;
  }
  body.dark input,
  body.dark select {
    background-color: #444;
    color: #fff;
    border: 1px solid #666;
  }
  body.dark .result {
    color: #eee;
  }
  
  /* Navbar */
.navbar {
    width: 100%;
    background-color: #0a3d62;
    color: white;
    padding: 1rem 2rem;
    display: flex;
    align-items: center;
    justify-content: start;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1000;
  }
  
  /* Add padding to body so content doesn't get hidden behind navbar */
  body {
    padding-top: 70px; /* Adjust based on navbar height */
  }
  
  .navbar .logo {
    font-size: 1.5rem;
    font-weight: bold;
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  }
  
  body.dark .navbar {
    background-color: #1e1e1e;
    color: #f0f0f0;
  }