.course-card:nth-child(5n+1) .course-placeholder{background:linear-gradient(135deg,#05345f,#00a7a7)}
.course-card:nth-child(5n+2) .course-placeholder{background:linear-gradient(135deg,#126476,#76b82a)}
.course-card:nth-child(5n+3) .course-placeholder{background:linear-gradient(135deg,#402b72,#d85b83)}
.course-card:nth-child(5n+4) .course-placeholder{background:linear-gradient(135deg,#8c3f24,#f4a641)}
.course-card:nth-child(5n) .course-placeholder{background:linear-gradient(135deg,#004b82,#38a0dd)}