Aligning loader to center of page and adding text to it - html

Question

I have loader designed and I positioned it to center with top:0 left:0 z:10 and text-align:center. Its not positioning to center of the page. I also added a text called Loading But its's not showing up.
#container-sleftpinner {
background: #ffffff;
color: #666666;
position: fixed;
height: 100%;
width: 100%;
z-index: 10;
top: 0;
left: 0;
text-align: center;
opacity: .80;
}
.loader,
.loader:before,
.loader:after {
background: grey;
-webkit-animation: load1 1s infinite ease-in-out;
animation: load1 1s infinite ease-in-out;
width: 1em;
height: 4em;
}
.loader {
color: grey;
background-repeat: no-repeat;
background-position: center;
position: fixed;
display: block;
left: 0;
right: 0;
top: 0;
bottom: 0;
text-indent: -9999em;
margin: 88px auto;
position: relative;
font-size: 11px;
-webkit-transform: translateZ(0);
-ms-transform: translateZ(0);
transform: translateZ(0);
-webkit-animation-delay: -0.16s;
animation-delay: -0.16s;
}
.loader:before,
.loader:after {
position: absolute;
top: 0;
content: '';
}
.loader:before {
left: -1.5em;
-webkit-animation-delay: -0.32s;
animation-delay: -0.32s;
}
.loader:after {
left: 1.5em;
}
.loader p {
position: absolute;
left: 0;
right: 0;
bottom: 50%;
display: inline-block;
text-align: center;
margin-bottom: -5em;
}
#-webkit-keyframes load1 {
0%,
80%,
100% {
box-shadow: 0 0;
height: 4em;
}
40% {
box-shadow: 0 -2em;
height: 5em;
}
}
#keyframes load1 {
0%,
80%,
100% {
box-shadow: 0 0;
height: 4em;
}
40% {
box-shadow: 0 -2em;
height: 5em;
}
}
<div id="container-spinner" style="display:block;">
<div class="loader">
<p>Loading...</p>
</div>
</div>

Answer 1

Based upon your code.
give the .container-spinner class the following and the content will center.
I changed the display to be flex and made sure to give it hight:100vh to fill the page and all that left is to center it vertically and horizontally using justify-content and align-items ( don't forget to remove the inline style to get this to work)
.container-spinner {
display: flex;
justify-content: center;
align-items: center;
width: 100%;
height: 100vh;
}
Edit
based upon your request. Here is the working code with the text showing up and all the changes to the HTML and CSS.
.container-spinner {
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
text-align: center;
height: 100vh;
}
#container-sleftpinner {
background: #ffffff;
color: #666666;
position: fixed;
height: 100%;
width: 100%;
z-index: 10;
top: 0;
left: 0;
text-align: center;
opacity: 0.8;
}
.loader,
.loader:before,
.loader:after {
background: grey;
-webkit-animation: load1 1s infinite ease-in-out;
animation: load1 1s infinite ease-in-out;
width: 1em;
height: 4em;
}
.loader {
color: grey;
background-repeat: no-repeat;
background-position: center;
text-indent: -9999em;
margin: 10px auto;
font-size: 11px;
-webkit-transform: translateZ(0);
-ms-transform: translateZ(0);
transform: translateZ(0);
-webkit-animation-delay: -0.16s;
animation-delay: -0.16s;
}
.loader:before,
.loader:after {
position: absolute;
top: 0;
content: "";
}
.loader:before {
left: -1.5em;
-webkit-animation-delay: -0.32s;
animation-delay: -0.32s;
}
.loader:after {
left: 1.5em;
}
.container-spinner p {
text-align: center;
}
#-webkit-keyframes load1 {
0%,
80%,
100% {
box-shadow: 0 0;
height: 4em;
}
40% {
box-shadow: 0 -2em;
height: 5em;
}
}
#keyframes load1 {
0%,
80%,
100% {
box-shadow: 0 0;
height: 4em;
}
40% {
box-shadow: 0 -2em;
height: 5em;
}
}
<div class="container-spinner">
<div class="loader">
</div>
<p>Loading...</p>
</div>
If that doesn't work please let me know.