body {
  box-sizing: border-box;
  margin: 0;
}

#document {
  width: 100%;
  display: flex;
}

/* table of content or navigatiio section */
#navbar {
  /* sticking the nav section position  */
  position: sticky; 
  top: 0;
  width: 400px;
  height: 100vh;
  /* specify for scroll effectiveness */
  background-color: rgb(80, 80, 70);
  overflow-y: auto;
  /*to make vertical-scroller if the it require*/
  border-right: 2px solid gray;
}

#content-heading {
  margin-top: 0;
  margin-bottom: 0;
  position: sticky;
  /*to make stick at the top of the page*/
  top: 0;
  background-color: #b3e7b9;
  padding: 4px 40px;
  height: 98px;
  align-content: center;
  font-size: 25px;
  font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
}

.nav-link {
  padding: 4px 40px;
  align-content: center;
  display: block;
  text-decoration: none;
  color: rgb(247, 234, 234);
  height: 60px;
  font-size: 20px;
  font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
  border-top: 1px solid gray;
  background-color: rgb(80, 80, 70);
}

/* to select the last element which has "content" id  */
.nav-link:last-child {
  border-bottom: 1px solid gray;
  margin-bottom: 100px;
}

.nav-link:hover {
  background-color: gray;
  color: white;
  user-select: none;
}


/* for content section  */
#content {
  /* to make the content section use the rest parent section (#document) */
  flex: 1;
  padding-right: 20px;
  background-color: rgb(212, 208, 208);
  padding-left: 40px;
}

#html-intro {
  margin-top: 40px;
}

/* style for inline-code  */
#inline-code {
  color: rgb(221, 5, 5);
  font-weight: lighter;
  font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
}

/* style for multi-line-code  */
#multi-line-code {
  background-color: rgb(168, 124, 209);
  width: 250px;
  padding: 12px 6px;
}

/* style for multi-line-code tag name  */
#tag-name {
  color: rgb(92, 92, 228);
}

th,
td {
  border: 1px solid black;
  border-style: solid;
  padding: 2px 6px;
}

table {
  margin-top: 12px;
  border-collapse: collapse;
  margin-bottom: 12px;
}

th {
  background-color: rgb(206, 211, 224);
}

tr:nth-child(odd) {
  background-color: rgb(110, 241, 128);
}

/* style for note  */
#note {
  background-color: rgb(10, 168, 241);
  padding: 4px 10px;
}

/* style for code attribute*/
#attribute {
  color: green;
}

/* style for attribute value */
#attr-value {
  color: rgb(243, 16, 16);
}

/* style for output in the browser */
#output-in-browser {
  padding: 12px;
  background-color: rgb(82, 79, 79);
  color: rgb(233, 221, 221);
  margin: 0 0 12px 0px;
}

#reference {
  margin-bottom: 40px;
}

#ref {
  text-decoration: none;
  color: rgb(238, 40, 5);
}

#reference>h4 {
  margin-bottom: 0;
  padding-bottom: 0;
}


/* making repsonsive for small device  */
@media only screen and (min-width: 701px) and (max-width: 900px) {
  #content {
    width: 100%;
    margin-left: 0;
    padding: 2px 20px;
    font-size: 12px;
  }

  #navbar {
    display: none;
  }

  #multi-line-code {
    background-color: rgb(168, 124, 209);
    width: 250px;
    padding: 12px 6px;
  }
}

@media only screen and (min-width: 500px) and (max-width: 700px) {
  #content {
    width: 100%;
    margin-left: 0;
    padding: 2px 20px;
    font-size: 10px;
  }

  #navbar {
    display: none;
  }
}

@media only screen and (min-width: 400px) and (max-width: 500px) {
  #content {
    width: 100%;
    margin-left: 0;
    padding: 2px 6px;
    font-size: 10px;
  }

  #navbar {
    display: none;
  }
}

@media only screen and (min-width: 301px) and (max-width: 500px) {
  #content {
    width: 100%;
    margin-left: 0;
    padding: 2px 6px;
    font-size: 8px;
  }

  #navbar {
    display: none;
  }
}

@media only screen and (max-width: 300px) {
  #content {
    width: 100%;
    margin-left: 0;
    padding: 2px 6px;
    font-size: 6px;
  }

  #navbar {
    display: none;
  }
}