[css] Simple CSS Animation Loop – Fading In & Out "Loading" Text

To make more than one element fade in/out sequentially such as 5 elements fade each 4s,

1- make unique animation for each element with animation-duration equal to [ 4s (duration for each element) * 5 (number of elements) ] = 20s

animation-name: anim1 , anim2, anim3 ... 
animation-duration : 20s, 20s, 20s ... 

2- get animation keyframe for each element.

100% (keyframes percentage) / 5 (elements) = 20% (frame for each element)

3- define starting and ending point for each animation:

each animation has 20% frame length and @keyframes percentage always starts from 0%, so first animation will start from 0% and end in his frame(20%), and each next animation will starts from previous animation ending point and end when it reach his frame (+20% ),

@keyframes animation1 { 0% {}, 20% {}}
@keyframes animation2 { 20% {}, 40% {}}
@keyframes animation3 { 40% {}, 60% {}}
and so on

now we need to make each animation fade in from 0 to 1 opacity and fade out from 1 to 0,

so we will add another 2 points (steps) for each animation after starting and before ending point to handle the full opacity(1)

http://codepen.io/El-Oz/pen/WwPPZQ

.slide1 {
    animation: fadeInOut1 24s ease reverse forwards infinite
}

.slide2 {
    animation: fadeInOut2 24s ease reverse forwards infinite
}

.slide3 {
    animation: fadeInOut3 24s ease reverse forwards infinite
}

.slide4 {
    animation: fadeInOut4 24s ease reverse forwards infinite
}

.slide5 {
    animation: fadeInOut5 24s ease reverse forwards infinite
}

.slide6 {
    animation: fadeInOut6 24s ease reverse forwards infinite
}

@keyframes fadeInOut1 {
    0% { opacity: 0 }
    1% { opacity: 1 }
    14% {opacity: 1 }
    16% { opacity: 0 }
}

@keyframes fadeInOut2 {
    0% { opacity: 0 }
    14% {opacity: 0 }
    16% { opacity: 1 }
    30% { opacity: 1 }
    33% { opacity: 0 }
}

@keyframes fadeInOut3 {
    0% { opacity: 0 }
    30% {opacity: 0 }
    33% {opacity: 1 }
    46% { opacity: 1 }
    48% { opacity: 0 }
}

@keyframes fadeInOut4 {
    0% { opacity: 0 }
    46% { opacity: 0 }
    48% { opacity: 1 }
    64% { opacity: 1 }
    65% { opacity: 0 }
}

@keyframes fadeInOut5 {
    0% { opacity: 0 }
    64% { opacity: 0 }
    66% { opacity: 1 }
    80% { opacity: 1 }
    83% { opacity: 0 }
}

@keyframes fadeInOut6 {
    80% { opacity: 0 }
    83% { opacity: 1 }
    99% { opacity: 1 }
    100% { opacity: 0 }
}