:root {
    --primary-color: #1e3c72;
    --secondary-color: #2a5298;
    --accent-color: #ff7e5f;
    --text-light: #ffffff;
    --text-muted: #dcdcdc;
    --bg-gradient: linear-gradient(135deg, #1e3c72, #2a5298, #8e2de2, #4a00e0);
    --card-bg: rgba(255, 255, 255, 0.1);
    --transition: all 0.3s ease;
  }

  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }

  body {
    font-family: 'Roboto', sans-serif;
    background: var(--bg-gradient);
    color: var(--text-light);
    line-height: 1.6;
    overflow-x: hidden;
  }

  .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
  }

  header {
    text-align: center;
    padding: 40px 0;
    position: relative;
    overflow: hidden;
  }

  header::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 200px;
    height: 3px;
    background: var(--accent-color);
    border-radius: 3px;
  }

  h1, h2, h3, h4 {
    font-family: 'Open Sans', sans-serif;
    margin-bottom: 20px;
    font-weight: 600;
  }

  h1 {
    font-size: 2.5rem;
    background: linear-gradient(90deg, #ff7e5f, #feb47b);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    text-shadow: 0 2px 10px rgba(0,0,0,0.1);
  }

  h2 {
    font-size: 1.8rem;
    color: var(--text-light);
    position: relative;
    padding-bottom: 10px;
  }

  h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 2px;
    background: var(--accent-color);
  }

  h3 {
    font-size: 1.5rem;
    margin-top: 30px;
    color: var(--text-light);
  }

  p {
    margin-bottom: 20px;
    color: var(--text-muted);
    font-size: 1.1rem;
  }

  .notice {
    background: rgba(255,255,255,0.1);
    padding: 15px;
    border-radius: 5px;
    margin: 30px 0;
    border-left: 3px solid var(--accent-color);
  }

  .grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin: 40px 0;
  }

  .card {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 30px;
    transition: var(--transition);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    position: relative;
    overflow: hidden;
  }

  .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.2);
  }

  .card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: var(--accent-color);
  }

  .card img {
    width: 100%;
    border-radius: 5px;
    margin-bottom: 20px;
    transition: var(--transition);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
  }

  .card:hover img {
    transform: scale(1.03);
  }

  .code-block {
    background: rgba(0,0,0,0.3);
    border-radius: 5px;
    padding: 20px;
    margin: 30px 0;
    overflow-x: auto;
    font-family: 'Courier New', monospace;
    position: relative;
  }

  .code-block::before {
    content: 'CSS';
    position: absolute;
    top: 0;
    left: 0;
    background: var(--accent-color);
    color: white;
    padding: 2px 10px;
    border-radius: 0 0 5px 0;
    font-size: 0.8rem;
  }

  pre {
    margin: 0;
    white-space: pre-wrap;
  }

  code {
    color: #f8f8f2;
    font-size: 0.9rem;
  }

  .nav-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 15px;
    margin: 40px 0;
  }

  .nav-link {
    padding: 10px 20px;
    background: rgba(255,255,255,0.1);
    border-radius: 30px;
    color: var(--text-light);
    text-decoration: none;
    transition: var(--transition);
    border: 1px solid rgba(255,255,255,0.2);
  }

  .nav-link:hover {
    background: var(--accent-color);
    transform: translateY(-2px);
  }

  .footer {
    text-align: center;
    padding: 30px 0;
    margin-top: 60px;
    border-top: 1px solid rgba(255,255,255,0.1);
  }

  @media (max-width: 768px) {
    h1 {
      font-size: 2rem;
    }
    h2 {
      font-size: 1.5rem;
    }
    .grid {
      grid-template-columns: 1fr;
    }
  }

  /* Animations */
  @keyframes float {
    0%, 100% {
      transform: translateY(0);
    }
    50% {
      transform: translateY(-10px);
    }
  }

  .floating {
    animation: float 3s ease-in-out infinite;
  }

  @keyframes pulse {
    0%, 100% {
      opacity: 1;
    }
    50% {
      opacity: 0.7;
    }
  }

  .pulse {
    animation: pulse 2s ease-in-out infinite;
  }

  /* Aurora background animation */
  @keyframes aurora {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
  }

  .aurora-bg {
    background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab);
    background-size: 400% 400%;
    animation: aurora 15s ease infinite;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    opacity: 0.3;
  }