body, html {
    margin: 0;
    padding: 0;
    font-family: 'Roboto', sans-serif;
    color: #fff;
    overflow-x: hidden;
}

body {
    background: linear-gradient(to bottom, #001f3f, #0074D9);
    height: auto;
    min-height: 100vh;
}

header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

header h1 {
    font-size: 24px;
    font-weight: bold;
    color: #FFA500;
    text-transform: uppercase;
    letter-spacing: 1px;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
}

nav ul li a {
    text-decoration: none;
    color: #fff;
    font-size: 16px;
    position: relative;
    transition: color 0.3s ease;
}

nav ul li a:hover {
    color: #FFA500;
}

nav ul li a::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 2px;
    background-color: #FFA500;
    left: 0;
    bottom: -5px;
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

nav ul li a:hover::after {
    transform: scaleX(1);
}

.main-visual {
    position: relative;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    overflow: hidden;
}

.main-visual::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center center/cover;
    opacity: 0.3;
    z-index: -1;
    animation: parallax 10s linear infinite;
}

@keyframes parallax {
    0% { transform: translateY(0); }
    100% { transform: translateY(-50%); }
}

.main-visual h2 {
    font-size: 48px;
    font-weight: bold;
    color: #fff;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
    margin-bottom: 20px;
}

.main-visual p {
    font-size: 18px;
    line-height: 1.6;
    max-width: 600px;
    margin: 0 auto 30px;
}

.cta-button {
    background-color: #FFA500;
    color: #fff;
    padding: 15px 30px;
    border: none;
    border-radius: 5px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.cta-button:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 8px rgba(0, 0, 0, 0.15);
}

.section {
    padding: 80px 20px;
    text-align: center;
    position: relative;
    overflow: hidden;
    animation: fadeIn 1s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.section:nth-child(even) {
    background: linear-gradient(to right, #001f3f, #0074D9);
}

.section:nth-child(odd) {
    background: linear-gradient(to left, #001f3f, #0074D9);
}

.section h3 {
    font-size: 36px;
    font-weight: bold;
    margin-bottom: 20px;
    color: #FFA500;
}

.section p {
    font-size: 16px;
    line-height: 1.6;
    max-width: 800px;
    margin: 0 auto 30px;
}

.card-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    margin-top: 30px;
}

.card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    padding: 20px;
    width: calc(33.33% - 40px);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 6px 10px rgba(0, 0, 0, 0.15);
}

.card img {
    width: 100px;
    height: 100px;
    margin-bottom: 15px;
}

.card h4 {
    font-size: 20px;
    font-weight: bold;
    margin-bottom: 10px;
}

.card p {
    font-size: 14px;
    line-height: 1.4;
}

.article-section {
    background: #fff;
    color: #000;
    padding: 60px 20px;
}

.article-section h2 {
    font-size: 36px;
    font-weight: bold;
    margin-bottom: 20px;
    color: #0074D9;
}

.article-section pre {
    background: #f4f4f4;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
    margin: 20px 0;
}

.article-section code {
    font-family: 'Courier New', Courier, monospace;
    font-size: 14px;
    color: #0074D9;
}

.article-section table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

.article-section th, .article-section td {
    border: 1px solid #ddd;
    padding: 10px;
    text-align: left;
}

.article-section th {
    background: #0074D9;
    color: #fff;
}

.footer {
    background: #001f3f;
    color: #fff;
    padding: 40px 20px;
    text-align: center;
}

.footer p {
    font-size: 14px;
    margin-bottom: 10px;
}

@media (max-width: 768px) {
    .card {
        width: calc(50% - 40px);
    }

    .main-visual h2 {
        font-size: 36px;
    }

    .section h3 {
        font-size: 30px;
    }
}

@media (max-width: 480px) {
    .card {
        width: 100%;
    }

    header h1 {
        font-size: 20px;
    }

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