/* Global Styles & Full Screen Centering */
    html, body {
      height: 100%;
      margin: 0;
      padding: 0;
      font-family: 'Segoe UI', 'Roboto', Arial, sans-serif;
      background-color: #f0f2f5;
      display: flex;
      justify-content: center;
      align-items: center;
      transition: background-color 0.3s, color 0.3s;
    }

    /* Main Application Container */
    main {
      background-color: white;
      border-radius: 12px;
      box-shadow: 0 8px 30px rgba(0, 0, 0, 0.364);
      padding: 2rem;
      width: 90%;
      max-width: 800px;
      max-height: 95vh;
      overflow-y: auto;
      position: relative;
    }

    /* Logo Section */
    .logo-container {
      text-align: center;
      margin-bottom: 1.5rem;
    }
    .logo-container svg {
      width: 80px;
      height: 80px;
      border-radius: 50%;
      border: #18191a 1px solid;
    }
    .header{
      background-color: #001affc3;
    }
    .header:hover {
            transform: translateY(-5px);
            box-shadow: 0 5px 10px rgba(0, 0, 0, 0.836);
        }

    
    /* Dark Mode Toggle - Placed inside the main container for context */
    #dark-mode-toggle {
      position: absolute;
      top: 20px;
      right: 20px;
      background: #f0f2f5;
      border: 1px solid #ddd;
      border-radius: 50%;
      width: 40px;
      height: 40px;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.2rem;
      transition: background-color 0.3s, color 0.3s;
    }
    #dark-mode-toggle:hover {
        background-color: #e2e6ea;
    }

    /* Dark Mode Styles */
    body.dark-mode {
      background-color: #18191a;
      color: #e4e6eb;
    }
    body.dark-mode main {
      background-color: #242526;
      box-shadow: 0 8px 30px rgba(0,0,0,0.3);
    }
    body.dark-mode section {
      background-color: #3a3b3c;
      border-color: #4a4b4c;
    }
    body.dark-mode input, body.dark-mode select {
      background-color: #4a4b4c;
      color: #e4e6eb;
      border-color: #5a5b5c;
    }
    body.dark-mode nav ul li a {
        color: #e4e6eb;
    }
    body.dark-mode nav ul li a:hover {
        color: #4dabf7;
    }
    body.dark-mode #dark-mode-toggle {
        background: #3a3b3c;
        border-color: #555;
        color: #e4e6eb;
    }
     body.dark-mode #dark-mode-toggle:hover {
        background-color: #4f5051;
    }

    /* Navbar */
    nav {
      border-bottom: 1px solid #dee2e6;
      margin-bottom: 2rem;
      padding-bottom: 1rem;
    }
    body.dark-mode nav {
        border-bottom-color: #4a4b4c;
    }
    nav ul {
      list-style-type: none;
      padding: 0;
      margin: 0;
      display: flex;
      justify-content: center;
      gap: 1.5rem;
      flex-wrap: wrap;
    }
    nav ul li a {
      color: #341010;
      text-decoration: none;
      font-weight: 700;
      font-size: 1.5em;
      transition: color 0.2s ease-in-out;
    }
    nav ul li a:hover {
      color: #ff0000;
    }


    /* Sections */
    section {
      padding: 20px;
      margin-bottom: 20px;
      background-color: #f8f9fa;
      border: 1px solid #e9ecef;
      border-radius: 8px;
    }
    
    h2 {
      text-align: center;
      margin-top: 0;
      padding-bottom: 10px;
      margin-bottom: 20px;
      border-bottom: 2px solid #007bff;
    }

    /* Forms */
    label {
      display: block;
      margin: 15px 0 5px;
      font-weight: bold;
    }
    input, select {
      padding: 10px;
      border: 1px solid #ccc;
      border-radius: 4px;
      width: 100%;
      box-sizing: border-box;
      font-size: 1em;
    }
    button {
      padding: 10px 18px;
      margin: 10px 5px 0 0;
      background-color: #007bff;
      color: white;
      border: none;
      border-radius: 4px;
      cursor: pointer;
      font-weight: bold;
      transition: background-color 0.2s;
    }
    button:hover {
      background-color: #0056b3;
    }
    button#reset, button.remove-subject {
        background-color: #dc3545;
    }
    button#reset:hover, button.remove-subject:hover {
        background-color: #c82333;
    }
    
    .subject {
      margin: 15px 0;
      padding: 15px;
      border: 1px solid #e0e0e0;
      border-radius: 6px;
      background: #fff;
    }
    body.dark-mode .subject {
        background: #2c2d2e;
        border-color: #4a4b4c;
    }

    /* Result paragraphs */
    #result, #formula, #gpa-result, #percentage-result {
        margin-top: 15px;
        font-weight: bold;
        font-size: 1.1em;
        text-align: center;
    }

    /* Responsive Design */
    @media (max-width: 600px) {
      body {
        align-items: flex-start;
        padding-top: 1rem;
      }
      main {
        padding: 1.5rem;
        max-height: 90vh;
      }
      nav ul {
        flex-direction: column;
        gap: 0.5rem;
        align-items: center;
      }
    }