:root {
    --primary: #0F4C81;
    --secondary: #EAEAEA;
    --accent: #FFA500;
    --text: #333333;
    --light: #FFFFFF;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  }

  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  }

  body {
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8eb 100%);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
    padding-top: 80px;
  }

  .header {
    position: fixed;
    top: 0;
    width: 100%;
    background: linear-gradient(90deg, var(--primary) 0%, #1a5a9a 100%);
    color: var(--light);
    padding: 1rem 5%;
    box-shadow: var(--shadow);
    z-index: 1000;
    display: flex;
    justify-content: space-between;
    align-items: center;
  }

  .header-title {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 1px;
  }

  .header-notice {
    background-color: var(--accent);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-size: 0.9rem;
    font-weight: 600;
  }

  .nav {
    display: flex;
    gap: 2rem;
  }

  .nav-link {
    color: var(--light);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
  }

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

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

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

  .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 5%;
  }

  .hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
    margin-bottom: 4rem;
    padding: 3rem 0;
    position: relative;
  }

  .hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 70% 30%, rgba(255, 165, 0, 0.1) 0%, transparent 50%);
    z-index: -1;
  }

  .hero-content {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
  }

  .hero-title {
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1.2;
    background: linear-gradient(90deg, var(--primary) 0%, #4b6cb7 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
  }

  .hero-text {
    font-size: 1.1rem;
    color: #555;
  }

  .hero-image {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }

  .hero-img {
    width: 100%;
    height: auto;
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: var(--transition);
  }

  .hero-img:hover {
    transform: translateY(-10px);
  }

  .section {
    margin-bottom: 5rem;
    position: relative;
  }

  .section-title {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--primary);
    position: relative;
    display: inline-block;
  }

  .section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 50%;
    height: 4px;
    background: linear-gradient(90deg, var(--accent) 0%, transparent 100%);
    border-radius: 2px;
  }

  .grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
  }

  .card {
    background: var(--light);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
  }

  .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
  }

  .card-header {
    background: linear-gradient(90deg, var(--primary) 0%, #1a5a9a 100%);
    color: var(--light);
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
  }

  .card-icon {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .card-title {
    font-size: 1.2rem;
    font-weight: 600;
  }

  .card-body {
    padding: 1.5rem;
    flex-grow: 1;
  }

  .card-text {
    margin-bottom: 1.5rem;
    color: #555;
  }

  .card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 10px;
  }

  .code-block {
    background: #282c34;
    border-radius: 10px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    overflow: auto;
    position: relative;
  }

  .code-block::before {
    content: '';
    position: absolute;
    top: 10px;
    left: 10px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #ff5f56;
    box-shadow: 20px 0 0 #ffbd2e, 40px 0 0 #27c93f;
  }

  pre {
    color: #abb2bf;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9rem;
    line-height: 1.5;
    margin: 0;
    white-space: pre-wrap;
  }

  .token.property {
    color: #e06c75;
  }

  .token.selector {
    color: #98c379;
  }

  .token.punctuation {
    color: #abb2bf;
  }

  .token.value {
    color: #d19a66;
  }

  .token.function {
    color: #61afef;
  }

  .token.comment {
    color: #5c6370;
    font-style: italic;
  }

  .footer {
    background: linear-gradient(90deg, var(--primary) 0%, #1a5a9a 100%);
    color: var(--light);
    padding: 3rem 5%;
    text-align: center;
    margin-top: 5rem;
  }

  .footer-text {
    max-width: 600px;
    margin: 0 auto;
    opacity: 0.8;
  }

  @media (max-width: 768px) {
    .hero {
      grid-template-columns: 1fr;
    }

    .nav {
      display: none;
    }

    .header {
      flex-direction: column;
      gap: 1rem;
      padding: 1rem;
    }
  }

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

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

  /* Accordion */
  .accordion {
    margin: 2rem 0;
  }

  .accordion-item {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    margin-bottom: 1rem;
  }

  .accordion-header {
    background: var(--light);
    padding: 1.5rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    transition: var(--transition);
  }

  .accordion-header:hover {
    background: #f5f5f5;
  }

  .accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
    background: #f9f9f9;
  }

  .accordion-content-inner {
    padding: 0 1.5rem 1.5rem;
  }

  .accordion-item.active .accordion-content {
    max-height: 500px;
  }

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

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