#nav_bg, #setting_bg {
  position: fixed;
  z-index: 4;
  left: 0;
  top: 0;
  transition: .3s;
  width: 100%;
  height: 100%;
  display: block;
  visibility: hidden;
  background: rgba(0, 0, 0, .125);
  opacity: 0;
  filter: alpha(opacity=0)
}

#setting_bg {
  background: rgba(0, 0, 0, .1);
}

#setting_bg.on {
  visibility: visible;
  opacity: 1;
  filter: alpha(opacity=100)
}

#setting .morse,
#setting .braille {
  display: none;
}

body:not(.braille) #setting .morse,
body.braille #setting .braille {
  display: block;
}

nav {
  position: fixed;
  z-index: 5;
  top: 0;
  left: 0;
  width: 300px;
  left: -301px;
  background: #fff;
  border-right: solid 1px rgba(0, 0, 0, .12);
  height: 100%;
  overflow-y: auto;
  overflow-x: hidden;
  transition: .3s
}

nav.on {
  left: 0;
  box-shadow: 2px 0 5px rgba(0, 0, 0, .25);
}

#nav_bg.on {
  visibility: visible;
  opacity: 1;
  filter: alpha(opacity=100);
}

nav #nav {
  width: 100%;
  height: calc(100% - 46px);
  overflow-y: auto;
  overflow-x: hidden;
  transition: .3s
}

nav a {
  margin: -.5em 0;
  font-size: 16px;
  display: block;
  padding: .5em .75em;
  /*text-overflow: ellipsis;*/
  overflow: hidden;
  white-space: nowrap;
  color: rgba(0, 0, 0, .54);
  position: relative;
  text-decoration: none;
  display: flex;
  align-items: center;
}

nav i {
  margin-right: .5em;
  /* font-size: 20px!important; */
}

nav:not(.fold) a {
  text-overflow: ellipsis;
}

nav .item:not(.disabled) a:hover {
  background: rgba(158, 158, 158, .2);
  box-shadow: none;
  z-index: 1
}

nav h2 a {
  color: rgba(0, 0, 0, .38)
}

nav h2:first-of-type {
  margin-top: 1em
}

nav h3.item {
  position: relative;
  margin: .25em 0;
  padding: 0;
  font-weight: normal;
}

nav h3.item:after {
  position: absolute;
  content: ' ';
  left: 0;
  top: 0;
  height: 100%;
  width: 4px;
  background-color: #2196f3;
  opacity: 0;
  transition: opacity .25s linear;
}

nav h3.item.targeted:after {
  opacity: 1;
}

nav h4 {
  margin: .25em 0
}

nav h2 a, nav h3 a:nth-child(1) {
  padding-left: 22px;
}

nav h4 a {
  padding-left: 3em
}

nav h2 a.btn_item_fold,
nav h3 a.btn_item_open {
  position: absolute !important;
  right: 0;
  opacity: 0;
  /* color: rgba(0, 0, 0, 0.38); */
  top: .4em;
  z-index: 1;
  width: 20px;
  overflow: visible;
}

nav h2:hover>a:nth-child(2),
nav h3:hover>a:nth-child(2) {
  opacity: 1;
  background: none;
}

nav.fold h2:hover>a:nth-child(2),
nav.fold h3:hover>a:nth-child(2) {
  display: none;
}

nav #nav_header {
  display: flex;
  justify-content: space-between;
  background: #fafafa;
  box-shadow: 0 -1px 0 rgba(0, 0, 0, 0.12) inset;
  position: relative;
  color: rgba(0, 0, 0, .54);
  white-space: nowrap;
  transition: .3s;
  height: 64px;
}

nav.fold #nav_header {
  padding: 10px 0 46px;
}

#to_github {
  cursor: pointer;
  transition: .3s;
  width: 100%;
  padding: 0 8px 0 22px;
  line-height: 64px;
  color: rgba(0, 0, 0, 0.54);
  display: flex;
  align-items: center;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  /* width: calc(100% - 82px); */
  /* width: calc(100%); */
}

#to_github i {
  fill: rgba(0, 0, 0, .54);
}

#to_github:hover {
  background: rgba(158, 158, 158, .2);
}

nav.fold #to_github {
  width: 100%;
  text-overflow: clip;
}

@keyframes setting_bt_unfold {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

nav #nav_item_list {
  box-shadow: 0 -1px 0 rgba(0, 0, 0, 0.12) inset;
  padding-bottom: 16px;
  will-change: transform;
}

nav hr {
  box-shadow: 0 -1px 0 rgba(0, 0, 0, 0.12) inset;
  margin: 16px 0;
  border: none;
  height: 1px;
}

nav #nav_menu {
  padding-top: 14px;
}

dl#setting {
  padding: 1em;
  box-shadow: 0 2px 4px rgba(0, 0, 0, .2);
  background: #fff;
  width: calc(100% - 2em);
  transition: .25s, background 0s, color 0s;
  /* border-top: 1px rgba(0, 0, 0, .12) solid; */
}

#setting dt {
  font-size: 16px;
  /*color: #777;*/
  color: rgba(0, 0, 0, .65);
  display: inline;
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
}

#setting dd {
  font-size: .9em;
  color: rgba(0, 0, 0, .5);
  white-space: normal;
}

#setting i {
  margin-right: .5em;
  height: 22px;
  vertical-align: text-bottom;
}

#setting input[checked]+dt {
  font-weight: 700;
  color: #000;
  text-decoration: none;
}

#setting_bt {
  border-left: 1px solid rgba(0, 0, 0, 0.1);
  height: 24px;
  width: 92px;
  padding: 20px 0;
  display: inline-block;
  transition: 0s;
  text-align: center;
  cursor: pointer;
  animation-name: setting_bt_unfold;
  animation-duration: .3s;
}

#setting_bt i {
  transition: .3s;
  position: absolute;
  right: 0;
  margin-right: 18px;
}

#setting_bt:hover i:not(.setting_arrow) {
  transform: rotate(-30deg);
  right: 8px;
}

#setting_bt i.setting_arrow {
  visibility: hidden;
  opacity: 0;
}

#setting_bt:hover i.setting_arrow {
  visibility: visible;
  opacity: 1;
  right: -12px;
}

nav.fold #nav_header {
  /*display: block;*/
}

nav #nav_header span {
  opacity: 1;
  transition: .3s;
}

nav.fold #nav_header span {
  opacity: 0;
}

@keyframes setting_bt_fold {
  0% {
    opacity: 0;
    margin-top: -28px;
  }

  25% {
    opacity: 0;
    margin-top: -28px;
  }

  100% {
    opacity: 1;
    margin-top: 0;
  }
}

nav.fold #setting_bt {
  width: 68px;
  top: 46px;
  position: absolute;
  left: 0;
  animation-name: setting_bt_fold;
  animation-duration: .3s;
}

nav.fold #setting_bt i {
  right: 14px;
}

nav.fold #setting_bt:hover i:not(.setting_arrow) {
  right: 22px;
}

nav.fold #setting_bt:hover i.setting_arrow {
  right: 4px;
}

nav.fold #setting_bt:hover {
  background: rgba(158, 158, 158, .2);
}

/* ------------------------------------------------------------------- */
/* ***** nav ***** */
/* ------------------------------------------------------------------- */
#setting {
  background: #fff;
  box-shadow: 0 2px 4px -1px rgba(0, 0, 0, 0.2), 0 4px 5px 0 rgba(0, 0, 0, 0.14), 0 1px 10px 0 rgba(0, 0, 0, 0.12) !important;
  z-index: 5;
  max-width: calc(450px - 2em);
  margin: auto;
  transition: .25s opacity !important;
  opacity: 1;
  visibility: visible;
  position: fixed;
  padding: 1em 0 .5em !important;
}

#setting:not(.on) {
  /*height: 0;*/
  display: block !important;
  opacity: 0;
  visibility: hidden;
}

#setting .header,
.contents.sub .header {
  display: none;
}

#setting .setting_item {
  cursor: pointer;
  padding: .5em 1em;
  transition: .25s;
}

#setting .setting_item.disabled {
  cursor: default;
}

#setting .setting_item.disabled>* {
  color: rgba(0, 0, 0, .5) !important;
}

#setting .setting_item:hover {
  background: rgba(158, 158, 158, .2);
}

#setting .setting_item.disabled:hover {
  background: none;
}

#setting .setting_title {
  color: rgba(0, 0, 0, .75);
  padding: 0 1em;
}

#setting .setting_title {
  padding: 1em 1em 0;
}

#setting .setting_title:nth-of-type(2) {
  padding: 0em 1em;
}

nav #nav_footer {
  cursor: pointer;
  -webkit-box-flex: 0;
  -webkit-flex: 0 0 auto;
  -ms-flex: 0 0 auto;
  flex: 0 0 auto;
  height: 44px;
  padding: 0;
  margin: 0;
  width: inherit;
  left: 0;
  background: #fafafa;
  border: 0;
  bottom: 0;
  position: fixed;
  z-index: 2;
  border-top: 1px solid rgba(0, 0, 0, .1)
}

nav #nav_footer:hover {
  background-color: rgba(158, 158, 158, 0.2);
}

nav #nav_footer i {
  margin: 10px 22px;
  float: right;
  transition: .3s
}

nav.fold #nav_footer i {
  -webkit-transform: rotate(180deg);
  -ms-transform: rotate(180deg);
  transform: rotate(180deg)
}

nav.fold {
  width: 68px;
}

nav.fold #nav::-webkit-scrollbar {
  display: none
}

nav #nav a>* {
  transition: .3s;
}

nav.fold #nav a span {
  color: transparent;
}

nav #nav h2, nav #nav h3 {
  transition: .3s;
}

nav #nav h2 {
  height: 40px;
  margin: 16px 0 0;
  position: relative
}

nav.fold #nav h2 {
  margin: 16px 0 14px;
  height: 3px
}

nav.fold #nav h2:first-of-type {
  margin: 16px 0 6px;
}

nav #nav h2:not(:first-of-type):before {
  position: absolute;
  content: "";
  height: 3px;
  width: 100%
}

nav.fold #nav h2:not(:first-of-type):before {
  box-shadow: 0 1px 0 rgba(0, 0, 0, .12) inset
}

nav.fold #nav h2 a {
  opacity: 0;
  filter: alpha(opacity=0);
  width: 0
}

nav .morse,
nav .braille {
  display: none;
}

/* ------------------------------------------------------------------- */
/* ***** mobile ***** */
/* ------------------------------------------------------------------- */
@media handheld, only screen and (max-width: 1080px) {
  nav {
    z-index: 35;
    box-shadow: none;
    padding-top: 0;
    height: 100%
  }

  nav #nav {
    height: 100%;
  }

  nav #nav_footer {
    display: none;
  }

  nav #nav_item_list {
    display: none;
  }

  nav h3 {
    margin: .5em 0;
  }

  #setting {
    z-index: 35;
    top: 0 !important;
    left: 0 !important;
    padding: 0 !important;
    width: 100% !important;
    max-width: 100%;
    height: 100%;
    border-radius: 0 !important;
  }

  #setting .setting_title {
    border-top: 1px solid rgba(0, 0, 0, .12);
  }

  #setting .setting_title:nth-of-type(2) {
    border-top: none;
  }

  #setting .header,
  .contents.sub .header {
    display: block;
    margin-bottom: 1em;
    height: 56px;
    display: flex;
    align-items: center;
    box-shadow: 0 2px 6px 0 rgba(60, 64, 67, .15);
  }

  #setting .header i,
  .contents.sub .header i {
    padding: .75em;
    font-size: 24px;
  }

  #setting .header span,
  .contents.sub .header span {
    font-size: 1.25em;
    margin: 0;
    padding: 0;
  }
}

@media handheld, only screen and (max-width: 600px) {
  #to_github {
    line-height: 56px;
  }

  nav #nav_header {
    height: 57px;
  }

  #setting_bt {
    width: 78px;
    padding: 16px 0;
  }

  #setting_bt i {
    margin-right: 15px;
  }

  #nav_bg, #setting_bg {
    z-index: 31;
  }

  body.braille nav .morse,
  body:not(.braille) nav .braille {
    display: block;
  }
}