.contact-us-button {
    position: relative;
    color: #000;
    width: 160px;
    height: 60px;
    outline: none;
    border: none;
    cursor: pointer;
    overflow: hidden;
    font-size: 20px;
    font-weight: bold;
    text-align: center;
    background-color: transparent;
    transition: 0.5s ease-in-out;
    margin-bottom: 40px;
}
.contact-us-button::before,
.contact-us-button::after {
    content: "";
    position: absolute;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, #000);
}
.contact-us-button::before {
    top: 0;
    left: -100%;
    animation: contact-us-button-animation1 20s linear infinite 1s;
}
.contact-us-button::after {
    bottom: 0;
    right: -100%;
    animation: contact-us-button-animation1 20s linear infinite 5s;
}
@keyframes contact-us-button-animation1 {
    0% {
      left: -100%;
      right: 100%;
    }
    50% {
      left: 100%;
      right: -100%;
    }
    100% {
      left: -100%;
      right: 100%;
    }
}
@keyframes contact-us-button-animation2 {
    0% {
      top: -100%;
      bottom: 100%;
    }
    50% {
      top: 100%;
      bottom: -100%;
    }
    100% {
      top: -100%;
      bottom: 100%;
    }
}

@media (max-width: 800px) {
    .contact-us-button {
        margin-top: 50px;
    }
}