.boton4{

background-color: #848B8B;
-webkit-border-radius: 5%;
-moz-border-radius: 40%;
border-radius: 50%;
color: #000000;
display: inline-block;
font-family: ‘Pacifico’, Arial, sans-serif;
font-size: 80%;
line-height: 1;
padding: 1% 1%;
text-decoration: none;
text-shadow: 0 -1% 1% rgba(25, 123, 29, .7);
}


.cursos2018{
	width: 150px;
	height: 200px;
	display: inline-block;
	vertical-align: top;
	margin-left: 10px;
	margin-top: 5%;
	color: #4a4a4a;
	font-weight: bolder;
	font-size: 0.8rem;
	padding: 40px;
	-webkit-box-shadow: 0px 0px 10px rgba(240, 240, 240, 0.75);
	-moz-box-shadow:    0px 0px 10px rgba(240, 240, 240, 0.75);
	box-shadow:         0px 0px 10px rgba(240, 240, 240, 0.75);
	-webkit-transition: all 1s ease-in-out;
	-moz-transition: all 1s ease-in-out;
	z-index:10;
}


.curso2020{

    width: 300px;
	height: 230px;
	display: inline-block;
	vertical-align: top;
	margin-left: 10px;
	margin-top: 20px;
    color: #4a4a4a;
    padding: 40px;
    z-index:10;


}



.cursos2018 img{
	width: 150px;
	height: 150px;
	margin: 1px;
	border-radius: 5%;
	-webkit-box-shadow: 0px 0px 10px rgba(74, 74, 74, 0.75);
	-moz-box-shadow:    0px 0px 10px rgba(74, 74, 74, 0.75);
	box-shadow:         0px 0px 10px rgba(74, 74, 74, 0.75);
	-webkit-transition: all 1s ease-in-out;
	-moz-transition: all 1s ease-in-out;
	z-index:5;
}


.cursos2018 img:hover{
	
	z-index:8;
}
.cursos2018 a{
	background-color: #4a4a4a;
	padding: 0px;
	margin-top:5px;
	color: white;
	width: 15px;
	padding-left: 5px;
	padding-right: 5px;
	border-radius: 2%;
	z-index:10;
        font-size:0.8rem;

}


#erorcur #erorcur2 p{ 
    
    font-style: verdana;
    text-align:center;
    font-size:1rem;
    color:#000000;
    
    
    
}



    #erorcur {
      width: 220px;
      height: 60px;
      margin-left:350px;
      margin-top:-60px;
      background: red;
      position: relative;
      -moz-border-radius: 10px;
      -webkit-border-radius: 10px;
      border-radius: 10px;
    }
    #erorcur:before {
      content: "";
      position: absolute;
      right: 100%;
      top: 26px;
      margin-top:-12px;
      width: 0;
      height: 0;
      border-top: 13px solid transparent;
      border-right: 26px solid red;
      border-bottom: 13px solid transparent;
    }
    
    
    @media screen and (max-width:800px){
        
        
#erorcur #erorcur2 p{ 
    
    font-style: verdana;
    text-align:center;
    font-size:0.5rem;
    color:#000000;
    
    
    
}



    #erorcur {
      width: 120px;
      height: 50px;
      margin-left:200px;
      margin-top:-50px;
      background: red;
      position: relative;
      -moz-border-radius: 10px;
      -webkit-border-radius: 10px;
      border-radius: 10px;
    }
    #erorcur:before {
      content: "";
      position: absolute;
      right: 100%;
      top: 26px;
      margin-top:-12px;
      width: 0;
      height: 0;
      border-top: 13px solid transparent;
      border-right: 26px solid red;
      border-bottom: 13px solid transparent;
    }  
        
        
    }
    
    




	    <style type="text/css">
    <!--
        .boton4{
            background:red;
        }
        .boton4:hover{
            background:blue;
        }
        .boton4:active{
            background:white;
        }
    -->
    </style>