:root {
    --bg-color: #ffffff;
    --text-color: #1d1d1f;
    --card-bg-color: #f9f9f9;
    --accent-color: #0071e3;
    --button-bg: var(--accent-color);
    --button-text: white;
  }
  
  body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    text-rendering: optimizeLegibility;
    transition: background-color 0.3s ease, color 0.3s ease;
  }
  
  body.dark-mode {
    --bg-color: #121212;
    --text-color: #f5f5f5;
    --card-bg-color: #1e1e1e;
    --accent-color: #90caf9;
    --button-bg: var(--text-color);
    --button-text: var(--bg-color);
  }
  
  /* Links */
  a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
  }
  
  a:hover {
    text-decoration: underline;
  }
  
  /* Scrollbar progress bar */
  #scroll-bar {
    position: fixed;
    top: 0;
    left: 0;
    height: 5px;
    background-color: var(--accent-color);
    width: 0%;
    z-index: 1000;
    transition: width 0.1s ease;
  }
  
  /* Header */
  #header {
    background-color: var(--bg-color);
    color: var(--text-color);
    border-bottom: 1px solid #d2d2d7;
    padding: 20px 0;
    text-align: center;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
    text-shadow: none;
  }
  
  #header h1 {
    font-size: 2.5rem;
    font-weight: 600;
    margin: 0;
  }
  
  /* Container */
  #container {
    padding: 40px 20px;
    max-width: 800px;
    margin: 40px auto;
    background-color: var(--bg-color);
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    color: var(--text-color);
  }
  
  #container h2 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    border-bottom: 2px solid #d2d2d7;
    padding-bottom: 10px;
    color: var(--text-color);
  }
  
  #container p {
    line-height: 1.8;
  }
  
  /* Case Studies */
  #case-studies ul {
    list-style: none;
    padding: 0;
  }
  
  #case-studies li {
    margin-bottom: 20px;
    padding: 15px;
    background-color: var(--card-bg-color);
    color: var(--text-color);
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }
  
  #case-studies li:hover {
    transform: translateY(-10px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
  }
  
  #case-studies h3 {
    font-size: 1.5rem;
    margin-top: 40px;
    color: var(--accent-color);
    border-left: 5px solid var(--accent-color);
    padding-left: 10px;
  }
  
  /* Buttons */
  .case-study-button {
    display: inline-block;
    margin-top: 10px;
    padding: 10px 15px;
    background-color: var(--button-bg);
    color: var(--button-text);
    font-weight: bold;
    text-decoration: none;
    border-radius: 6px;
    transition: background-color 0.3s ease, transform 0.2s ease;
  }
  
  .case-study-button:hover {
    background-color: #005bb5;
    transform: translateY(-2px);
  }
  
  /* Featured tag */
  .featured-tag {
    background-color: #ffcc00;
    color: #1d1d1f;
    font-size: 0.65rem;
    padding: 2px 6px;
    border-radius: 4px;
    margin-left: 8px;
    font-weight: bold;
    text-transform: uppercase;
  }
  
  /* Skills and Lists */
  ul {
    list-style-type: disc;
    padding-left: 20px;
    margin: 20px 0;
  }
  
  li {
    margin-bottom: 10px;
    line-height: 1.6;
  }
  
  /* Social Icons */
  .social-icons {
    text-align: center;
    margin-top: 20px;
  }
  
  .social-icons a {
    margin: 0 10px;
    font-size: 3.5rem;
    color: var(--accent-color);
    transition: color 0.2s, transform 0.3s ease;
  }
  
  .social-icons a:hover {
    color: #005bb5;
    transform: translateY(-5px);
  }
  
  /* Dark Mode Toggle Button */
  #dark-mode-toggle {
    position: fixed;
    top: 10px;
    right: 10px;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    z-index: 1000;
    color: var(--text-color);
  }
  
  /* Responsive */
  @media (max-width: 768px) {
    #container {
      padding: 20px;
    }
  
    #header h1 {
      font-size: 2rem;
    }
  
    #container h2 {
      font-size: 1.5rem;
    }
  
    .social-icons a {
      font-size: 1.2rem;
    }
  }

  #portfolio-logo {
    width: 5%;
    height: auto;
  }