core-style.css

@import url('https://fonts.googleapis.com/css?family=Poppins:300,400,500,600,700');
@import '../css/font-awesome.min.css';
@import '../css/pe-icon-7-stroke.css';
@import '../css/magnific-popup.css';
@import '../css/animate.css';

* {
    margin: 0;
    padding: 0;
}

*:focus {outline:none !important}
.gallery_area {
    height: 40%;
    width: 100%;
    z-index: 1;
}
.btn{
  margin:1em 1em 0 1em;
  padding: 2px 1rem!important;
  border: 1px solid #e74c3c;
  background-color: #fff;
}

.btn:focus{
  border: none;
  box-shadow: none;
  transition: border 0.9s;
}

.portfolio-menu button {
    background-color: transparent;
    font-size: 15px;
    color: #838383;
    padding: 0 0px;
    -webkit-transition-duration: 500ms;
    transition-duration: 500ms;
}

.portfolio-menu button.active,
.portfolio-menu button:hover {
    color: #1d1d1d;
}

.portfolio-menu button:focus {
    box-shadow: none;
}

.gallery_menu {
    margin-bottom: 2rem;
}
button{
  padding: 5px!important;
}
.column_single_gallery_item {
    margin-bottom: 30px;
}

.column_single_gallery_item img {
    width: 100%;
}
.hover_overlay {
    position: absolute;
    width: calc(100% - 30px);
    height: 100%;
    background-color: rgba(0, 0, 0, 0.3);
    top: 0;
    left: 15px;
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-align: center;
    -ms-flex-align: center;
    align-items: center;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center;
    opacity: 0;
    -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=0)";
    -webkit-transition-duration: 500ms;
    transition-duration: 500ms;
}

.hover_overlay a {
    font-size: 30px;
    color: #fff;
}

.column_single_gallery_item:hover .hover_overlay {
    opacity: 1;
    -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=100)";
}
img#one{
	z-index: -1;
	position: fixed;
	opacity: 0.4;
	top: 8rem;
	left: 30rem;
	width: 15vh;
}
img#two{
	position: fixed;
	opacity: 0.7;
	width: 10rem;
	bottom: 0;
	right: 0;
	z-index: -1;
}
img#three{
	position: fixed;
	width: 20rem;
	opacity: 0.4;
	padding: 0 0;
	z-index: -1;
}
img#four{
	position: fixed;
	width: 10rem;
	right: 40rem;
	bottom: 10rem;
	z-index: -1;
	opacity: 0.5;
}
#color_white{
  color: #000;
  padding: 0 2px;
  background: #ecf0f1;
  border: 1px solid #3498db;
  transition: background 0.7s;
}
#color_white:hover{
  background: #3498db;
  border:0;
  transition: background 0.7s;
}