:root {
    --primary-color: #1E3A8A;
    --secondary-color: #8B5CF6;
    --neutral-color: #F3F4F6;
    --accent-color: #F97316;
    --text-color: #1F2937;
    --light-gray: #E5E7EB;
    --dark-gray: #4B5563;
    --white: #FFFFFF;
  }

  @font-face {
    font-family: 'Roboto';
    src: url('https://fonts.gstatic.com/s/roboto/v30/KFOmCnqEu92Fr1Mu4mxK.woff2') format('woff2');
    font-weight: 400;
    font-style: normal;
  }

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

  body {
    font-family: 'Roboto', 'Helvetica', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: linear-gradient(135deg, var(--neutral-color) 0%, var(--white) 100%);
    padding-top: 80px;
  }

  .header-notice {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: var(--primary-color);
    color: white;
    padding: 10px 0;
    text-align: center;
    font-size: 14px;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  }

  .navbar {
    position: fixed;
    top: 40px;
    width: 100%;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(10px);
    padding: 15px 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 15px rgba(0,0,0,0.05);
    z-index: 999;
  }

  .nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
  }

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

  .nav-link {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    position: relative;
    padding: 5px 0;
    transition: color 0.3s;
  }

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

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

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

  .hero {
    height: 400px;
    background: linear-gradient(45deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-align: center;
    padding: 0 20px;
    margin-bottom: 60px;
    clip-path: polygon(0 0, 100% 0, 100% 85%, 0 100%);
  }

  .hero-content {
    max-width: 800px;
  }

  .hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
  }

  .hero p {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 30px;
  }

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

  article {
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    padding: 40px;
    margin-bottom: 60px;
  }

  article h2 {
    color: var(--primary-color);
    font-size: 2.2rem;
    margin-bottom: 30px;
    position: relative;
    padding-bottom: 15px;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--secondary-color), var(--accent-color));
    border-radius: 2px;
  }

  article h3 {
    color: var(--secondary-color);
    font-size: 1.8rem;
    margin: 40px 0 20px;
  }

  article p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 20px;
    color: var(--dark-gray);
  }

  pre {
    background: #282c34;
    border-radius: 10px;
    padding: 20px;
    margin: 30px 0;
    overflow-x: auto;
    box-shadow: inset 0 0 10px rgba(0,0,0,0.3);
  }

  code {
    font-family: 'Courier New', monospace;
    color: #abb2bf;
    font-size: 0.95rem;
  }

  .code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #21252b;
    padding: 8px 15px;
    border-radius: 10px 10px 0 0;
    margin-bottom: -10px;
    color: #9da5b4;
    font-size: 0.9rem;
  }

  .code-copy {
    cursor: pointer;
    transition: color 0.2s;
  }

  .code-copy:hover {
    color: var(--accent-color);
  }

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

  .gallery-image {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
  }

  .gallery-image:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.15);
  }

  .gallery-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
  }

  .footer {
    background: var(--primary-color);
    color: white;
    padding: 40px 0;
    text-align: center;
  }

  .footer-content {
    max-width: 800px;
    margin: 0 auto;
  }

  .footer p {
    margin-bottom: 20px;
    opacity: 0.8;
  }

  .footer-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 30px;
  }

  .footer-link {
    color: white;
    text-decoration: none;
    transition: opacity 0.3s;
  }

  .footer-link:hover {
    opacity: 0.7;
  }

  @media (max-width: 768px) {
    .navbar {
      padding: 15px 20px;
    }

    .nav-links {
      gap: 15px;
    }

    .hero h1 {
      font-size: 2.2rem;
    }

    .hero p {
      font-size: 1rem;
    }

    article {
      padding: 30px 20px;
    }

    article h2 {
      font-size: 1.8rem;
    }

    article h3 {
      font-size: 1.5rem;
    }
  }

  @media (max-width: 480px) {
    .nav-links {
      display: none;
    }

    .hero {
      height: 300px;
    }

    .hero h1 {
      font-size: 1.8rem;
    }

    .image-gallery {
      grid-template-columns: 1fr;
    }
  }

  /* Animations */
  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
  }

  .animate-fade {
    animation: fadeIn 0.8s ease-out forwards;
  }

  .delay-1 { animation-delay: 0.2s; }
  .delay-2 { animation-delay: 0.4s; }
  .delay-3 { animation-delay: 0.6s; }

  /* Tooltip */
  .tooltip {
    position: relative;
    display: inline-block;
    border-bottom: 1px dotted var(--secondary-color);
    cursor: help;
  }

  .tooltip .tooltiptext {
    visibility: hidden;
    width: 200px;
    background-color: var(--secondary-color);
    color: #fff;
    text-align: center;
    border-radius: 6px;
    padding: 5px;
    position: absolute;
    z-index: 1;
    bottom: 125%;
    left: 50%;
    transform: translateX(-50%);
    opacity: 0;
    transition: opacity 0.3s;
  }

  .tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
  }

  /* Accordion */
  .accordion {
    margin: 20px 0;
  }

  .accordion-item {
    border: 1px solid var(--light-gray);
    border-radius: 8px;
    margin-bottom: 10px;
    overflow: hidden;
  }

  .accordion-header {
    padding: 15px 20px;
    background: var(--neutral-color);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 500;
  }

  .accordion-header:hover {
    background: #e2e8f0;
  }

  .accordion-content {
    padding: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
  }

  .accordion-item.active .accordion-content {
    padding: 20px;
    max-height: 1000px;
  }

  .accordion-icon {
    transition: transform 0.3s;
  }

  .accordion-item.active .accordion-icon {
    transform: rotate(180deg);
  }