Is this effect what you are aiming for:
HTML
<div id="container">
<div id="content">
<h2 class="frame1">Loriam Ipisum</h2>
<h2 class="frame2">sad</h2>
</div>
</div>
CSS
body{margin: 0; padding: 0;}
#container{
width: 100%;
top: 200px;
border: 1px solid black;
text-align: center;
position: relative;
overflow: hidden;
}
#content{
width: 100%;
height: 50px;
border: 1px solid blue;
position: relative;
margin-left: auto;
margin-right: auto;
overflow: hidden;
}
#content h2{
position: absolute;
display: inline-block;
}
#content h2.frame1{
-webkit-animation-delay: 0s;
-webkit-animation-name: efeito1;
-webkit-animation-duration: 4s;
-webkit-animation-timing-function: linear;
-webkit-animation-direction: alternate;
opacity:0;
}
#content h2.frame2{
-webkit-animation-delay: 3s;
-webkit-animation-name: efeito1;
-webkit-animation-duration: 3s;
-webkit-animation-timing-function: linear;
-webkit-animation-direction: alternate;
opacity:0;
position:absolute;
}
@-webkit-keyframes efeito1{
0%{
opacity: 0;
}
100%{
opacity: 100;
}
}