I can't change style of buttons on my page

Well, on one page (home) i like change style of buttons (generated with inspector) and I use child theme

  • Type -> transparent
  • Shape -> square
  • Size -> Regular
  • class my-black-button

My Global CSS
.post .entry-wrap {
background-color: #fff;
box-shadow: none;
}

article.comment {
    background-color: #fff;
    box-shadow: none;
}

.x-colophon.top {
  background-color: #383838;
}
.x-colophon.bottom {
  background-color: #383838;
}

.x-block-grid-item h4, .x-block-grid-item h6 {
margin-top: 0px !important;
text-align: center;
color: #ffff;  
}

.white {
  color: #ffffff !important;
}
.greyblack {
  color: #383838
}
.greylight {
  color: #cacaca
}
.redsna {
  color: #760300
}
.black {
  color: #000000
}

.my-black-button {
  background-color: black;
  color: black;
  border-color: black;
}
.my-black-button:hover {
  background-color: white;
  color: white;
  border-color: white;
}


[type="submit"] {
    background: none;
    border-radius: 0px;
    box-shadow: none;
    font-size: 19px;
    color: black;
    text-shadow: none;
}

select, textarea, input[type="text"], 
input[type="password"], input[type="datetime"], input[type="datetime-local"], input[type="date"], input[type="month"], input[type="time"], input[type="week"], input[type="number"], input[type="email"], input[type="url"], 
input[type="search"], input[type="tel"], input[type="color"], .uneditable-input {
    background-color: #f9f1f1;
}

.contactFormSendButton {
  margin-bottom: 0;
  border-width: 3px;
  text-shadow: none;
  text-transform: uppercase;
  background-color: transparent;
  box-shadow: none;
  border-radius: 0;
  padding: 0.563em 1.125em 0.813em 1.125;
  font-size:16px;
}

This made according https://theme.co/apex/forum/t/customizations-implementing-additional-button-colors/206 and I tyr several options, such on css, .x-btn.my-black-button and x-btn.my-black-button:hover, and others.

But not work… also now I see a original button instead transparent button.

My site is : http://seguimundonavarro.com

Hi There,

Check on Cornerstone if your buttons are set to default or if you have any inline ode on the buttons element.

Make your CSS more specific in order to affect your items, for example

a.x-btn.my-black-button {
  color: #760300
}

Hope it helps!