body, html {
    margin: 0;
    padding: 0;
    font-family: 'Roboto', sans-serif;
    color: #ffffff;
    background: radial-gradient(circle, rgb(25, 31, 53), rgb(8, 14, 27));
    overflow-x: hidden;
    height: 100%;
}
header {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    overflow: hidden;
}
header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 215, 0, 0.2), transparent);
    animation: aurora-move 15s linear infinite;
    transform-origin: center;
}
@keyframes aurora-move {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}
header h1 {
    font-size: 4rem;
    z-index: 10;
    text-shadow: 0 4px 10px rgba(0, 0, 0, 0.5);
}
.container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    padding: 40px;
    max-width: 1400px;
    margin: auto;
}
.card {
    background: linear-gradient(135deg, #1e3c72, #2a5298);
    border-radius: 15px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
}
.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.4);
}
.card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}
.card-content {
    padding: 20px;
}
.card-title {
    font-size: 1.5rem;
    margin-bottom: 10px;
}
.card-text {
    font-size: 1rem;
    line-height: 1.6;
}
pre {
    background: rgba(0, 0, 0, 0.5);
    color: #ffffff;
    padding: 15px;
    border-radius: 8px;
    overflow-x: auto;
}
code {
    font-family: 'Courier New', Courier, monospace;
    color: #ffeb3b;
}
@media (max-width: 768px) {
    header h1 {
        font-size: 2.5rem;
    }
    .container {
        grid-template-columns: 1fr;
        padding: 20px;
    }
    pre {
        font-size: 0.9rem;
    }
}
.tip {
    text-align: center;
    margin: 20px 0;
    font-size: 1.2rem;
    color: #ffeb3b;
    font-weight: bold;
}