:root {
   --maincolor: #cc0000;
   --maincolor-hover: #990033;
   --secondcolor: #777777;
   --thirdcolor: #af0000;
}
.periods{
    display:block;
    
}
html, body {
  height: 100%;
  width: 100%;
}
body {
  display: table;
  margin: 0;
}

body {
    margin: 0 auto;
    width: 100%;
    font-family: "Arial";
    color: white;
    background: black;
    background-attachment: fixed !important;
    background: -webkit-linear-gradient(black, var(--maincolor-hover));
    background: -o-linear-gradient(black, var(--maincolor-hover));
    background: -moz-linear-gradient(black, var(--maincolor-hover));
    background: linear-gradient(black, var(--maincolor-hover));
}

button {
    color: white;
    background-color: var(--maincolor);
    border: none;
    border-radius: 5px;
    font-size: 20px;
  
}

button:hover {
    background-color: var(--maincolor-hover);
}

#navbar {
    z-index: 100;
    position: fixed;
    list-style-type: none;
    margin-top: 0;
    padding: 0px;
    background-color: black;
    overflow: hidden;
    width: 100%;
}
#navbar li{
    float: left;
}
#navbar li button{
    display: block;
    color: white;
    text-align: center;
    padding: 14px 16px;
    background-color: black;
    border: none;
    border-radius: 0px;
    font-size: 13.3333px;
}
#title {
    position: relative;
    margin-top: 50px;
    width: 100%;
    top: -7px;
    text-align: center;
    background-color: var(--maincolor);
    clear: both;
    height: 80px;
}
#title h1 {
    position: relative;
    color: white;
    top: 20px;
    overflow: hidden;
}

#navbar li button:hover{
    background-color: var(--maincolor);
}

#navbar #navbar_sel button {
    background-color: var(--maincolor-hover);
}

#navbar #navbar_sel button:hover{
    background-color: var(--maincolor);
}

#navbar #navbar_about {
    position: relative;
    float: right;
    right: 1.2%;
}

#sidebar {
    margin-top: 0px;
    clear: left;
    float: left;
    background-color: var(--secondcolor);
    height: 90%;
    padding: 0px;
    width: 15%;
    overflow: auto;
    border-radius: 8px 0px 0px 0px;
    text-align: center;
}

#sidebar > * {
   margin: 6px;
}

.middlecontent > * {
   margin: 6px;
}

#sidebar #sidebar_toptitle {
    margin: 0px;
    border-radius: 8px 0px 0px 0px;
}

#sidebar .contenttitle {
    margin: 0px;
}

.contenttitle {
    margin-top: 0px;
    text-align: center;
    border: 10px solid var(--thirdcolor);
    background-color: var(--thirdcolor);
    border-radius: 0px 0px 0px 0px;
}

#bottom-footer {
    background: black;
    padding: 4px;
    clear: both;
}

.middlecontent {
   margin-top: 0px;
   margin-left: 10px;
   float: left;
   background-color: var(--secondcolor);
   width: 83.3%;
   border-radius: 0px 0px 0px 0px;
}

#middlecontent_top {
   border-radius: 0px 8px 0px 0px;
} 

.middlecontent > * {
   margin: 6px;
}

.middlecontent .contenttitle {
   margin: 0px;
   border-radius: 0px 0px 0px 0px;
}

#middlecontent_top .contenttitle {
   border-radius: 0px 8px 0px 0px;
}

.middlecontent .middlecontent_footer {
   float: right;
   color: #E5E7E9;
   font-size: 13px;
}