Example 1: gradient over image css
#linear-gradient-over-image{
background-image: linear-gradient(to bottom, black, white),
url('images/background.jpg');
background-size: cover;
}
Example 2: background image with color overlay gradient css
.css {
background: -moz-linear-gradient(top, rgba(0, 0, 0, 0) 0%, rgba(0, 0, 0, 0) 59%, rgba(0, 0, 0, 0.65) 100%), url('https://cdn.sstatic.net/Sites/stackoverflow/company/img/logos/so/so-icon.png?v=c78bd457575a') no-repeat;
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, rgba(0, 0, 0, 0)), color-stop(59%, rgba(0, 0, 0, 0)), color-stop(100%, rgba(0, 0, 0, 0.65))), url('https://cdn.sstatic.net/Sites/stackoverflow/company/img/logos/so/so-icon.png?v=c78bd457575a') no-repeat;
background: -webkit-linear-gradient(top, rgba(0, 0, 0, 0) 0%, rgba(0, 0, 0, 0) 59%, rgba(0, 0, 0, 0.65) 100%), url('https://cdn.sstatic.net/Sites/stackoverflow/company/img/logos/so/so-icon.png?v=c78bd457575a') no-repeat;
background: -o-linear-gradient(top, rgba(0, 0, 0, 0) 0%, rgba(0, 0, 0, 0) 59%, rgba(0, 0, 0, 0.65) 100%), url('https://cdn.sstatic.net/Sites/stackoverflow/company/img/logos/so/so-icon.png?v=c78bd457575a') no-repeat;
background: -ms-linear-gradient(top, rgba(0, 0, 0, 0) 0%, rgba(0, 0, 0, 0) 59%, rgba(0, 0, 0, 0.65) 100%), url('https://cdn.sstatic.net/Sites/stackoverflow/company/img/logos/so/so-icon.png?v=c78bd457575a') no-repeat;
background: linear-gradient(to bottom, rgba(0, 0, 0, 0) 0%, rgba(0, 0, 0, 0) 59%, rgba(0, 0, 0, 0.65) 100%), url('https://cdn.sstatic.net/Sites/stackoverflow/company/img/logos/so/so-icon.png?v=c78bd457575a') no-repeat;
height: 200px;
}
Example 3: how to add a background overlay in css
.header {
background: rgba(0, 0, 0, 0.5);
}