{box-sizing:border-box}
.contenedor-slider{margin:auto;width:700px;height:450px;position:relative;overflow:hidden;box-shadow:0 0 0 10px #fff,0 15px 50px;}
.slider{display: flex;width:700%}.slider__section{width:100%}
.slider__img{display: inline;width:100%;height:100%}
.btn-next,.btn-prev{width:40px;height:40px;background:rgba(255,255,255,.7);position:absolute;top:50%;transform:translateY(-50%);line-height:40px;font-size:30px;font-weight:700;text-align:center;border-radius:50%;font-family:monospace;cursor:pointer}
.btn-next:hover,.btn-prev:hover{background:#fff}.btn-prev{left:10px}.btn-next{right:10px}