:root {
    --primary: #0d1b2a;
    --secondary: #1b263b;
    --accent: #00d8ff;
    --highlight: #007ea7;
    --text: #e0e1dd;
    --shadow: rgba(0, 0, 0, 0.3);
    --glow: rgba(0, 216, 255, 0.7);
  }

  @font-face {
    font-family: 'Montserrat Bold';
    src: local('Montserrat-Bold'), local('Montserrat Bold');
  }

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

  body {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--text);
    font-family: 'Open Sans', sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
  }

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

  .header {
    position: relative;
    height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
  }

  .header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at center, transparent 0%, var(--primary) 100%);
    z-index: 1;
  }

  .header-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    padding: 40px;
    background: rgba(13, 27, 42, 0.7);
    border-radius: 20px;
    backdrop-filter: blur(10px);
    box-shadow: 0 10px 30px var(--shadow);
    transform-style: preserve-3d;
    transform: perspective(1000px) rotateX(5deg);
  }

  h1, h2, h3, h4 {
    font-family: 'Montserrat Bold', sans-serif;
    margin-bottom: 20px;
    color: var(--accent);
    text-shadow: 0 0 10px var(--glow);
  }

  h1 {
    font-size: 3rem;
    background: linear-gradient(90deg, var(--accent), var(--highlight));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
  }

  h2 {
    font-size: 2.2rem;
    position: relative;
    padding-bottom: 15px;
  }

  h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100px;
    height: 3px;
    background: linear-gradient(90deg, var(--accent), transparent);
  }

  h3 {
    font-size: 1.8rem;
    margin-top: 40px;
  }

  p {
    margin-bottom: 20px;
    font-size: 1.1rem;
  }

  .notice {
    position: fixed;
    bottom: 20px;
    left: 20px;
    background: rgba(0, 216, 255, 0.2);
    padding: 10px 20px;
    border-radius: 30px;
    backdrop-filter: blur(5px);
    z-index: 1000;
    box-shadow: 0 0 20px var(--glow);
    animation: pulse 2s infinite;
  }

  @keyframes pulse {
    0% { box-shadow: 0 0 10px var(--glow); }
    50% { box-shadow: 0 0 20px var(--glow); }
    100% { box-shadow: 0 0 10px var(--glow); }
  }

  .nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(13, 27, 42, 0.9);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: 15px 0;
    box-shadow: 0 5px 20px var(--shadow);
  }

  .nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
  }

  .nav-links {
    display: flex;
    gap: 30px;
  }

  .nav-link {
    color: var(--text);
    text-decoration: none;
    font-family: 'Montserrat Bold', sans-serif;
    position: relative;
    transition: color 0.3s ease;
  }

  .nav-link:hover {
    color: var(--accent);
  }

  .nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s ease;
  }

  .nav-link:hover::after {
    width: 100%;
  }

  .content-section {
    padding: 100px 0;
    position: relative;
  }

  .content-section:nth-child(even) {
    background: rgba(27, 38, 59, 0.3);
  }

  .grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(500px, 1fr));
    gap: 30px;
    margin: 40px 0;
  }

  .grid-item {
    background: rgba(27, 38, 59, 0.5);
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 20px var(--shadow);
    transition: transform 0.5s ease, box-shadow 0.5s ease;
    backdrop-filter: blur(5px);
    border: 1px solid rgba(0, 216, 255, 0.1);
  }

  .grid-item:hover {
    transform: translateY(-10px) rotateY(10deg);
    box-shadow: 0 15px 30px var(--shadow);
    border-color: rgba(0, 216, 255, 0.3);
  }

  .card {
    perspective: 1000px;
    height: 100%;
  }

  .card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.6s;
    transform-style: preserve-3d;
  }

  .grid-item:hover .card-inner {
    transform: rotateY(180deg);
  }

  .card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 15px;
    padding: 30px;
    display: flex;
    flex-direction: column;
    justify-content: center;
  }

  .card-back {
    transform: rotateY(180deg);
    background: linear-gradient(135deg, var(--highlight), var(--accent));
  }

  .image-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin: 40px 0;
  }

  .image-box {
    position: relative;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 15px var(--shadow);
    transition: transform 0.3s ease;
  }

  .image-box:hover {
    transform: scale(1.05);
  }

  .image-box img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
  }

  .image-box:hover img {
    transform: scale(1.1);
  }

  .image-box::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, transparent 60%, rgba(0, 0, 0, 0.7));
  }

  pre {
    background: rgba(27, 38, 59, 0.7);
    border-radius: 10px;
    padding: 20px;
    margin: 20px 0;
    overflow: auto;
    border-left: 3px solid var(--accent);
    box-shadow: inset 0 0 10px var(--shadow);
    font-family: 'Courier New', monospace;
    line-height: 1.5;
    tab-size: 2;
  }

  code {
    font-family: 'Courier New', monospace;
    color: var(--accent);
    background: rgba(0, 216, 255, 0.1);
    padding: 2px 5px;
    border-radius: 3px;
  }

  .language-css {
    color: #e0e1dd;
  }

  .footer {
    background: var(--primary);
    padding: 50px 0;
    text-align: center;
    position: relative;
  }

  .footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
  }

  .scroll-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    background: var(--accent);
    color: var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.3s ease, transform 0.3s ease;
    z-index: 1000;
    box-shadow: 0 0 20px var(--glow);
  }

  .scroll-top.visible {
    opacity: 1;
  }

  .scroll-top:hover {
    transform: translateY(-5px);
  }

  @media (max-width: 768px) {
    .header {
      height: 60vh;
    }

    h1 {
      font-size: 2rem;
    }

    h2 {
      font-size: 1.8rem;
    }

    h3 {
      font-size: 1.5rem;
    }

    .grid-container {
      grid-template-columns: 1fr;
    }

    .nav-links {
      gap: 15px;
    }
  }

  @media (max-width: 480px) {
    .header {
      height: 50vh;
    }

    .header-content {
      padding: 20px;
    }

    .nav-container {
      flex-direction: column;
      gap: 10px;
    }

    .nav-links {
      flex-wrap: wrap;
      justify-content: center;
    }
  }