*{
  box-sizing: border-box;
}

body {
  font-family: Arial;
  font-size: 17px;
}

.container {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.container img {vertical-align: middle;}

.container .content {
  position: absolute;
  bottom: 0;
  background: rgb(0, 0, 0);
  background: rgba(0, 0, 0, 0.5); 
  color: #f1f1f1;
  width: 100%;
  padding: 20px;
}

.containerb {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.containerb img {
  width: 700 pm;
  height: 2500 pm;
	position: center;
}

.containerb .btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
  background-color: #43A1DC;
  color: white;
  font-size: 16px;
  padding: 12px 24px;
  border: none;
  cursor: pointer;
  border-radius: 5px;
  text-align: center;
}

.containerb .btn:hover {
  background-color: black;
}