@import url('https://fonts.googleapis.com/css?family=Source+Sans+Pro:300,400,600,700,900&display=swap');

html, body{min-height: 100%; height: 100%}

.main-wrapper{background:url(../images/main-bg.jpg) no-repeat; background-size:cover; height:100vh;  display:flex; flex-direction:column; justify-content:space-between;}
header{padding:35px 0}

.left-img, .right-img{transition: filter .5s ease-in-out;
  -webkit-filter: grayscale(0%); /* Ch 23+, Saf 6.0+, BB 10.0+ */
  filter: grayscale(0%); /* FF 35+ */}
  .left-img:hover, .right-img:hover{-webkit-filter: grayscale(100%); /* Ch 23+, Saf 6.0+, BB 10.0+ */
  filter: grayscale(100%); /* FF 35+ */}
.img-sec h2{font:400 30px 'Source Sans Pro', sans-serif; color:#fff; margin:30px 0 0}
.img-sec h2 img{margin:0 30px 0 0;}
footer{padding:30px 0}
footer p{font:300 14px 'Source Sans Pro'; color:#fff; margin:0}