* {
  margin: 0;
  padding: 0;
  border: 0;
}

html,
body {
  background-image: url("../img/bg.jpg");
  height: 100%;
}

nav {
  background-color: rgba(255, 255, 255, 0.8);
  height: 98px;
  display: flex;
  align-items: center;
  padding: 0 24px;
  color: #000;
}

nav .menu_btn {
  display: none;
  font-weight: bold;
  font-size: 18px;
  border: 1px solid #000;
  padding: 4px;
  box-sizing: border-box;
  border-radius: 5px;
}

nav .menu_btn:hover {
  cursor: pointer;
  background-color: rgba(121, 85, 72, 0.28);
  color: #4a3026;
  transition: all 0.5s;
}

nav #toc_arr .toc_ul {
  list-style: none;
}

nav #toc_arr .toc_ul:first-child > .toc_li {
  float: left;
}

nav #toc_arr > .toc_ul > .toc_li {
  cursor: pointer;
  margin-right: 18px;
  font-size: 22px;
}
nav #toc_arr .toc_ul .toc_li {
  cursor: pointer;
  margin-right: 0;
  font-size: 22px;
}

nav .homeBtn {
  text-decoration: none;
  color: #000;
}

.close_mask {
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.28);
  position: fixed;
  display: none;
  transition: display 0.5s;
}

.open_mask {
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.28);
  position: fixed;
  display: block;
  transition: display 0.5s;
  top: 0;
}

.article {
  width: 100%;
  display: flex;
  height: calc(100% - 105px);
}

#sidebar {
  display: flex;
  flex-direction: column;
  width: 300px;
  /* height: calc(100% - 85px); */
  height: 100%;
  position: fixed;
  top: 0;
  left: -300px;
  transition: left 0.5s;
  z-index: 999;
}

#sidebar.sidebar_show {
  left: 2px;
  transition: all 0.5s;
}

.sidebar div {
  width: 100%;
}

.s_body {
  flex: 1;
  background-color: #fff;
}
.s_body #m_toc_arr {
  padding: 0 50px;
}
.s_body #m_toc_arr .toc_ul {
  display: none;
}
.s_body #m_toc_arr > .toc_ul {
  display: block;
}
.s_body #m_toc_arr .toc_li.active > .toc_text {
  color: #ff4400;
}
.s_body #m_toc_arr .toc_li {
  padding: 10px 2px 10px 5px;
  /* margin: 5px 0; */

  list-style: none;
}
.s_body #m_toc_arr .toc_li.active > .toc_ul {
  display: block;
}

.my_iframe {
  background-color: rgba(255, 255, 255, 0.8);
  margin: 24px 16px;
  flex: 1;
  border-radius: 15px;
}

#toc_arr .toc_ul {
  display: none;
  position: absolute;
  white-space: nowrap;
  background-color: #fff;
  /* box-shadow: 2px 2px 0px #d9bdbd; */
  border-right: 2px solid #fff;
  border-left: 2px solid transparent;
  border-bottom: 2px solid #fff;
  text-align: center;
  top: 0;
  right: -1px;
  transform: translate(100%);
  box-sizing: border-box;
}
#toc_arr > .toc_ul > .toc_li > .toc_ul {
  left: 50%;
  top: auto;
  right: auto;
  transform: translate(-50%);
}
#toc_arr > .toc_ul {
  display: block;
  position: relative;
  transform: translate(0);
  box-shadow: none;
  left: 0;
  background-color: transparent;
  transform: translate(0);
}
#toc_arr > .toc_ul {
  display: block;
  position: relative;
  transform: translate(0);
  box-shadow: none;
  left: 0;
  border: none;
  background-color: transparent;
  transform: translate(0);
}
#toc_arr .toc_li {
  position: relative;
  margin-right: 0;
  padding: 0 15px;
}
#toc_arr .toc_li:hover > .toc_ul {
  display: block;
}

#toc_arr .toc_li .toc_text,
#toc_arr > .toc_ul > .toc_li > .toc_text,
#toc_arr > .toc_ul > .toc_li:hover > .toc_text,
#toc_arr .toc_li > .toc_text {
  color: #000;
}
#toc_arr .toc_li:hover > .toc_text {
  color: #ff4400;
}

@media screen and (max-width: 768px) {
  nav .menu_btn {
    display: block;
  }
  nav #toc_arr {
    display: none;
  }

  .my_iframe {
    margin: 8px;
    border-radius: 0;
  }
}

footer {
  width: 100%;
  position: fixed;
  bottom: 10px;
  text-align: center;
}

footer a {
  text-decoration: none;
  color: #000;
  background-color: #fff;
}