.error404 .container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}
.error404 .container .mymain {
  width: 100%;
  padding: 2rem 1.6rem;
}
.error404 .not-found {
  text-align: center;
  padding: 6rem 2rem;
}
.error404 .not-found h1 {
  font-size: 2.5rem;
  font-weight: bold;
  margin-bottom: 4rem;
  color: #333;
}
.error404 .not-found p {
  font-size: 1.4rem;
  color: #666;
  margin-bottom: 2.6rem;
}
.error404 .not-found p a {
  color: #0073aa;
  text-decoration: underline;
}
.error404 .not-found p a:hover {
  color: #005177;
}
.error404 .not-found .btn-back-home {
  display: inline-block;
  padding: 0.8rem 2rem;
  background: #0073aa;
  color: #fff;
  border-radius: 0.5rem;
  font-size: 1.4rem;
  text-decoration: none;
  transition: background 0.3s;
}
.error404 .not-found .btn-back-home:hover {
  background: #005177;
}