.btn-demo {
    border-radius: 30px;
    background: #642afc;
    padding: 10px 30px;
    color: #fff;
    text-align: center;
    font-size: 16px;
}

.btn-demo:hover {
    color: #fff;
}

p {
  font-family: 'Roboto', sans-serif !important;
  font-weight: 400 !important;
  font-size: 16px !important;
  line-height: 1.7 !important;
  font-weight: 400 !important;
  letter-spacing: 0px !important;  
}


h1 {
  font-size: 33px !important;
  font-family: 'Roboto', sans-serif !important;
  font-weight: 700 !important;

}
h1.special {
  font-size: 40px !important;
}

h2 {
  font-size: 22px !important;
  font-family: 'Roboto', sans-serif !important;
  font-weight: 600 !important;
}


span {
  font-size: 16px !important;
}
.overlay {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0,0,0,0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  transition: opacity 0.3s ease;
}

.overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

.overlay .contact-form {
  animation: popup 0.4s ease;
}

@keyframes popup {
  from { transform: scale(0.8); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}


#successAlert {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 20000; /* cao hơn overlay */
}

.contact-form h3 span{
  font-size: 28px !important;
  font-family: 'Roboto', sans-serif !important;
  font-weight: 600 !important;
  margin-bottom: 20px;
}

.is-invalid {
  border: 1px solid red !important;
  background-color: #fff5f5;
}