Div container

Bonjour,
J'ai fais une div contenair avec background-image et j'ai centrer une bannière mais je n'arrive pas a centrer mon menu dans la div container, si quelqu'un peut m'éclairer voici mon code:

body {
  background: black;
}
.container {
  background-image: url(images/fond.jpg);
  background-position:  center center;
  position: fixed;
  background-repeat: no-repeat;
  height: 1600px;
  width: 1200px;
  background-attachment: fixed;
}
#cssmenu,
#cssmenu ul,
#cssmenu ul li,
#cssmenu ul li a {
  margin: 0;
  padding: 0;
  border: 0;
  list-style: none;
  line-height: 1;
  display: block;
  position: relative;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
#cssmenu {
  width: auto;
  font-family: Helvetica, Arial, sans-serif;
  color: #f085fa;
  position: fixed;
  margin-left: auto;
  margin-right: auto;
}
#cssmenu.align-right ul li {
  float: right;
  border-right: 0;
  border-left: 1px solid rgba(0, 0, 0, 0.22);
}
#cssmenu.align-right ul li a {
  border-right: 0;
  border-left: 1px solid rgba(255, 255, 255, 0.15);
}
#cssmenu ul {
  background: #222222;
  /* Old browsers */

  background: -moz-linear-gradient(bottom, #000000 0%, #222222 50%, #3c3c3c 51%, #393939 78%, #888888 100%);
  background: -webkit-linear-gradient(bottom, #000000 0%, #222222 50%, #3c3c3c 51%, #393939 78%, #888888 100%);
  background: -o-linear-gradient(bottom, #000000 0%, #222222 50%, #3c3c3c 51%, #393939 78%, #888888 100%);
  background: -ms-linear-gradient(bottom, #000000 0%, #222222 50%, #3c3c3c 51%, #393939 78%, #888888 100%);
  background: linear-gradient(to top, #000000 0%, #222222 50%, #3c3c3c 51%, #393939 78%, #888888 100%);
}
#cssmenu:after,
#cssmenu ul:after {
  content: ".";
  display: block;
  clear: both;
  visibility: hidden;
  line-height: 0;
  height: 0;
}
#cssmenu ul li {
  float: left;
  display: block;
  border-right: 1px solid rgba(0, 0, 0, 0.22);
  z-index: 1;
}
#cssmenu ul li::after {
  content: "";
  width: 100%;
  height: 8px;
  position: absolute;
  border-top-left-radius: 50% 4px;
  border-top-right-radius: 50% 4px;
  background: -webkit-linear-gradient(bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0) 60%, #222222 61%, #222222 100%);
  background: -o-linear-gradient(bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0) 60%, #222222 61%, #222222 100%);
  background: -ms-linear-gradient(bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0) 60%, #222222 61%, #222222 100%);
  background: linear-gradient(to top, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0) 60%, #222222 61%, #222222 100%);
  background: -moz-linear-gradient(bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0));
  z-index: 2;
  bottom: 10px;
}
#cssmenu ul li a {
  display: block;
  padding: 10px 30px;
  text-decoration: none;
  font-size: 12px;
  text-transform: uppercase;
  color: #f085fa;
  border-right: 1px solid rgba(255, 255, 255, 0.15);
  z-index: 3;
}
#cssmenu ul li a:hover,
#cssmenu ul li.active a {
  color: #ffffff;
}
#cssmenu ul li:hover,
#cssmenu ul li.active {
  background: ##fb0bfb;
  /* Old browsers */

  background: -moz-linear-gradient(bottom, #0b4669 0%, ##fb0bfb 50%, #1794dc 51%, #1691d8 78%, #98d2f4 100%);
  background: -webkit-linear-gradient(bottom, #0b4669 0%, ##fb0bfb 50%, #1794dc 51%, #1691d8 78%, #98d2f4 100%);
  background: -o-linear-gradient(bottom, #0b4669 0%, ##fb0bfb 50%, #1794dc 51%, #1691d8 78%, #98d2f4 100%);
  background: -ms-linear-gradient(bottom, #0b4669 0%, ##fb0bfb 50%, #1794dc 51%, #1691d8 78%, #98d2f4 100%);
  background: linear-gradient(to top, #0b4669 0%, ##fb0bfb 50%, #1794dc 51%, #1691d8 78%, #98d2f4 100%);
}
#cssmenu ul li:hover::after,
#cssmenu ul li.active::after {
  background: -webkit-linear-gradient(bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0) 60%, ##fb0bfb 61%, ##fb0bfb 100%);
  background: -o-linear-gradient(bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0) 60%, ##fb0bfb 61%, ##fb0bfb 100%);
  background: -ms-linear-gradient(bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0) 60%, ##fb0bfb 61%, ##fb0bfb 100%);
  background: linear-gradient(to top, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0) 60%, ##fb0bfb 61%, ##fb0bfb 100%);
  background: -moz-linear-gradient(bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0));
}

Merci d'avance [smile]