Vertical scrollbar not working in CSS

Question

I am making a fancy CSS theme for my tumblr. But my vertical scrollbar has vanished, and pressing "page down" has no effect. It is like the lower half of my page no longer exists, or the page is forced to be the size my browser window is. Indeed - if I resize my browser window, suddenly I see that amount of content and can't scroll down to see the stuff I could see a moment ago.

I have read some things on the internet already to solve this problem, such as adding "overflow:auto" or "overflow:scroll", but either I have have added them in the wrong place or they do not solve the problem I have. I have also tried manually adding a scrollbar in the html {} tag. If I do that, the scrollbar reappears - but it doesn't actually work. It appears all blocked in gray, as if you are already viewing the whole page, while displaying my content cut-off.

Very frustrated as the page is, apart from this, done. Any obvious ideas?

<!--CSS customization here. -->

<style type="text/css">

html {overflow-y: scroll;}
#text {
margin-bottom:50px;
margin-top:100px;
margin-top:5px;
text-transform:uppercase;
font-size:1em;
font-famiy:serif;
letter-spacing:2px;
text-align:center;}


/*main structure*/
blockquote {
padding:5px 0 5px 30px;
border-left:1px solid #eee;
margin:10px 30px;
overflow: auto;
}

body {
background-repeat:repeat-y;
background-size: cover;
font-family:serif;
font-weight:100;
font-size:1em;
text-align:left;
margin:0;
line-height:18px;
overflow:auto;
}

a {
color:black;
text-decoration:none;
    -webkit-transition:all 0.2s;
    -moz-transition:all 0.2s;
    -ms-transition:all 0.2s;
    -o-transition:all 0.2s;
    transition:all 0.2s; }
a:hover {
color:#45b69d;
}

img{
border:1px solid #fff;
border-radius:6px;
}

p {
margin-top:5px;
margin-bottom:5px}


#divider{
top:25px;
left:305px;
position:fixed;
width:420px;
position:absolute;
}

#dividerr{
bottom:20px;
left:37px;
width:420px;
position:fixed;
}

/*container*/
#con {
width:80%;
margin:0 10%;
position:fixed;
overflow:auto;
}



/*posts*/

.posts {
width:45%;
height:300px;
padding:4px;
background:white;
float:left;
margin:20px 20px;
border:1px solid #ffcec7;
border-radius:6px;
z-index:3;
}

#image {
position:absolute;
padding-top:8px;
padding-left:5px;
margin-right:5px;
}

#image img {
width:190px;
border:1px solid #fff;
border-radius:6px;
margin-right:8px;
}

.info {
margin-left:205px;
width:65%;
text-transform:none;
}

.tit {
font-weight:bold;
text-align:right;
font-family:georgia;
color:#ffa79b;
font-size:1.5em;
letter-spacing:1px;
text-transform:uppercase;
}

.lank {
border-bottom:1px dashed #ffcec7;
margin-bottom:5px;
padding-bottom:5px;}

.about ul {margin-left:-10px}

.quest {
    font-size:1.25em;
    font-family:Helvetica;
    font-variant:small-caps;
}

.answ {
    margin-top:10px;
    margin-left:40px;
    font-family:Georgia;

}

.grave {
    text-align:center;
    font-weight:bold;
    margin-top:10px;
    font-family:georgia;
    font-size:1.5em;
    letter-spacing:1px;
    font-style:italic;
    color:#cdba96;
}


.credit {
width:45%;
height:auto;
padding:4px;
background:white;
float:left;
margin:20px 20px;
border:1px solid #ffcec7;
border-radius:6px;
z-index:3;
} 
/*header*/

.headertext {
color:beige;
font-size:6em;
letter-spacing:1em;
text-align:center;
font-family:Helvetica,sans-serif;
line-height: 80%;
height: auto;
}

.l {
background:#fff;
margin-top:20px;
margin-left:auto;
margin-right:auto;
padding:2px;
text-align:center;
font-family:inconsolata;
text-transform:uppercase;
border:1px solid #ffcec7;
border-radius:6px;
}

#title {
width:50%
font-size:14px;
margin:auto 0;
text-align:center;
letter-spacing:1px;
text-transform:uppercase;
color:#ffcec7;
background:#f8f8f8;
padding:15px;
border-bottom:1px solid #eee;}

.links {
color:#ffa79b;
font-family:georgia;
padding-top:10px;
text-align:center;
padding-bottom:5px;
border-bottom:1px dashed #ffcec7;
}

.links a {
margin:10px 5px;
padding:2px 5px;
border:none;
}

.links a:hover {
background:#f8f8f8;
border-radius:6px;
}

.desc {
text-transform:none;
margin:10px 25px;
font-family:Georgia;
}

Answer 1

Alrighty, so I managed to fix the thing by taking one element at a time. The problem was in

container {position:fixed;}

but I'm not sure why. I was using the position:fixed to center my background. Leaving this in case it helps someone in future.