* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: #f8f9fa;
    text-align: center;
    animation: fadeIn 1s ease-in-out;
}

.main-content {
    max-width: 600px;
    animation: fadeUp 1s ease-in-out;
}

h1 {
    font-size: 6rem;
    color: #007bff;
    display: inline-block;
    animation: shake 0.5s ease-in-out infinite alternate;
}

h2 {
    font-size: 2rem;
    margin-bottom: 10px;
}

p {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 20px;
}

a {
    display: inline-block;
    padding: 12px 24px;
    font-size: 1rem;
    color: white;
    background: #007bff;
    text-decoration: none;
    border-radius: 5px;
    transition: 0.3s;
    box-shadow: 0px 4px 6px rgba(0, 123, 255, 0.3);
}

a:hover {
    background: #0056b3;
    transform: scale(1.05);
    box-shadow: 0px 6px 10px rgba(0, 86, 179, 0.4);
}

/* Hiệu ứng fade-in */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* Hiệu ứng fade-up */
@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Hiệu ứng rung lắc chữ "404" */
@keyframes shake {
    from {
        transform: rotate(-5deg);
    }
    to {
        transform: rotate(5deg);
    }
}