* {
  margin: 0;
  padding: 0;

  bax-sizing: border-box;
}

html, body {
  width: 100%;
  height: 100%;
}

ol, ul {
  list-style: none;
}

a {
  text-decoration: none;
}

img {
  vertical-align: top;
}

button {
  background-color: transparent;
  border: none;
}

input {
  outline: none;
  border: none;
}

input:focus {
  outline: none;
}



/* 영역 잡기 */
#wrapper {
  position: relative;
  width: 100%;
  height: 100%;
  min-width: 1320px;
}

#top_nav {
  position: fixed;

  width: 100%;
  height: 56px;
  background-color: #212121;
}

#left_nav {
  overflow-y: auto;
  overflow-x: hidden;
  position: fixed;

  width: 240px;

  top: 56px;
  bottom: 0;
  left: 0;
  background-color: #212121;
}

#left_content {
  position: absolute;
  width: 225px;
  height: 100%;
  background-color: grey;
}

#main { 
  position: absolute;
  left: 240px;
  top: 56px;
  right: 0;
  bottom: 0;
  background-color: grey;
}