Demo

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Thank You</title>

body {
font-family: Arial, sans-serif;
background: #f7f8fa;
color: #222;
}

.thank-you-page {
min-height: 100vh;
display: flex;
align-items: center;
justify-content: center;
padding: 40px 20px;
}

.thank-you-box {
width: 100%;
max-width: 650px;
background: #ffffff;
text-align: center;
padding: 60px 40px;
border-radius: 20px;
box-shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
}

.check-icon {
width: 80px;
height: 80px;
margin: 0 auto 25px;
border-radius: 50%;
background: #16a34a;
display: flex;
align-items: center;
justify-content: center;
}

.check-icon svg {
width: 42px;
height: 42px;
stroke: #fff;
stroke-width: 3;
fill: none;
}

.thank-you-box h1 {
font-size: 42px;
line-height: 1.2;
font-weight: 700;
margin-bottom: 15px;
color: #111827;
}

.thank-you-box p {
font-size: 18px;
line-height: 1.7;
color: #6b7280;
margin-bottom: 30px;
}

.home-btn {
display: inline-block;
padding: 14px 30px;
background: #111827;
color: #fff;
text-decoration: none;
border-radius: 8px;
font-size: 16px;
font-weight: 600;
transition: 0.3s ease;
}

.home-btn:hover {
background: #000;
transform: translateY(-2px);
}

@media (max-width: 767px) {
.thank-you-box {
padding: 45px 25px;
}

.thank-you-box h1 {
font-size: 32px;
}

.thank-you-box p {
font-size: 16px;
}

.check-icon {
width: 70px;
height: 70px;
}
}
</style>
</head>

<body>

<h1>Thank You!</h1>

<p>
Your message has been successfully submitted.
We appreciate you reaching out to us and will get back to you shortly.
</p>

</div>

</section>

</body>
</html>