how to leave the div fixed in a location

.menu {
  width: 100%;
  height: 55px;
  position: relative;
  background: #fff;
  border-bottom: 1px solid #59ab66;
}

.menu ul {
  margin-left: 3%;
  margin-top: 10px;
  position: relative;
}

.menu ul li {
  display: block;
  text-align: center;
  float: left;
  margin-left: 1%;
  width: 8%;
}

.menu ul li a {
  margin-top: -5px;
}

.menu li a:hover {
  border-bottom: #64c3ea solid 2px;
}

.menu li img {
  border-bottom: none;
  float: none;
  margin: 4%;
}

.menu li ul {
  display: none;
}

.menu input {
  padding: 5px;
}

.user ul li {
  width: 4%;
  float: left;
  position: relative;
}

.user ul li a,
.user ul li a:hover {
  background: none;
  border: none;
  float: none;
}

.user .usuario {
  display: block;
  position: absolute;
  margin-left: 75%;
}

.user .subuser {
  display: none;
  margin-top: 5px;
  height: 200px;
  width: 250% !important;
  padding: 5px;
  background-color: #64c3aa;
}

.user .subuser li {
  background: #fff;
  width: 85%;
}

.user .subuser li a:hover {
  color: #2B6FB6;
}

.user ul li ul li {
  margin-top: 10px;
  margin-left: 10px;
  float: none;
}

.user ul li ul a {
  background: none;
  text-align: left;
  width: 100%;
  white-space: nowrap;
}

.user ul li ul a:hover {
  background: none;
  color: #fff;
}

.user img {
  width: 40px;
  height: 35px;
  border: 1px solid;
  border-radius: 100%;
}

.img_user {
  width: 100px;
  border: none !important;
  border-radius: 0 !important;
}

.noborder img {
  border: none !important;
}

.user .acao {
  display: block;
  position: absolute;
  margin-left: 70%;
}

.user .subacao {
  display: none;
  overflow: auto;
  width: 700%;
  height: 500px;
  float: left;
  margin-left: -300%;
  background-color: #64c3ea;
}

.user .subacao img {
  border-radius: 0%;
}

.user .subacao p {
  text-align: left;
}

.sem {
  display: none;
}

.points {
  margin-right: 32% !important;
  position: relative;
  float: right !important;
}

.ocult {
  display: none;
}


/*Relacionados*/

.relac {
  width: 150px;
  margin-right: 5%;
  height: 100px;
  background: #eee;
  margin-top: 20px;
  margin-bottom: 40px;
  float: left;
}

.relac p {
  text-align: center;
}

.channels {
  width: 25%;
  margin-right: 5%;
  height: 100px;
  background: #eee;
  margin-top: 20px;
  margin-bottom: 40px;
  float: left;
}

.channels p {
  text-align: center;
}

.about {
  width: 100%;
  float: left;
  margin-top: 20px;
}

.img_about {
  width: 150px !important;
  height: 100px;
}


/*Descrição*/

.exibir_desc {
  margin-left: 20%;
  width: 60%;
  background: #eee;
  margin-top: 20px;
  margin-bottom: 25px;
  padding: 15px;
}

.desc {
  margin-left: 20%;
  width: 60%;
  background: #eee;
  margin-top: -25px;
  margin-bottom: 40px;
  padding: 15px;
}

.desc p {
  text-align: center;
  margin-top: 5px;
}

div.hRule {
  height: 0;
  margin: 0;
  padding: 0;
  overflow: hidden;
  border-top: 5px dashed #ccc;
  margin-bottom: 5px;
}

div.hRule hr {
  display: none;
}


/* Footer */

footer a {
  color: #59aed1;
}

footer a:hover {
  text-decoration: underline;
}


/* Paginação */

.pag a {
  color: #000
}

.pag a:hover {
  color: #fff;
}


/* Viwer */

.afastar {
  margin-left: 1%;
}

.afastar_right {
  margin-right: 3%;
}

.afastarcom {
  margin-left: 22% !important;
  height: 35px !important;
  background: #b26a6a;
  color: #fff !important;
}

.comentar {
  width: 100%;
  margin-top: 25px;
  margin-bottom: 25px;
}

.coment {
  width: 70%;
  background: #eee;
  margin-left: 15%;
  margin-bottom: 25px;
  float: left;
  min-height: 150px;
  position: relative;
}

.coment p {
  margin-bottom: 5px;
}

.coment img {
  width: 80px;
  margin-left: 2%;
  margin-top: 20px;
  margin-right: 2%;
  height: 80px;
}

.coment small {
  color: red;
}

.localvideo {
  width: 100%;
  margin-top: 25px;
  background: #eee;
  float: left;
  min-height: 150px;
}

.localvideo img {
  margin-left: 1%;
  width: 80px;
  margin-top: 10px;
  float: left;
  margin-right: 2%;
  height: 80px;
}

.descer {
  display: inline;
}

textArea {
  width: 100% !important;
  background: #00D4FF;
  border: 2px solid #000;
  height: 250px;
}

.viwer {
  width: 100% !important;
  height: 125px !important;
  background: #59aed1;
  border: 2px solid #000;
}

.foto {
  width: 150px;
  height: 125px;
  float: left
}

.visualizaron {
  display: none;
  width: 100%;
  margin-top: 10px;
  float: left;
  text-align: center;
  background: #eee;
  height: 40px;
  height: 50px;
  padding: 5px;
}

.visualizaroff {
  width: 100%;
  margin-top: 10px;
  padding: 10px;
  float: left;
  text-align: center;
  background: #eee;
  height: 50px;
  padding: 15px;
}

.comentando {
  width: 60% !important;
  float: left;
}

.comentando {
  width: 60% !important;
  float: left;
}

.resposta {
  float: left;
  position: relative;
  left: 17%;
  width: 100%;
}

.resposta:hover {
  cursor: pointer;
}

.resp {
  left: 10%;
  width: 100%;
  float: left;
}

.resp textArea {
  height: 50px !important;
  width: 80% !important;
}


/* Links */

a:visited {
  color: #000;
}

a {
  color: #000;
}


/* Espacamento */

.cimabaixo {
  margin-top: 10px;
  margin-bottom: 10px;
}


/* minimo heigth*/

.minimo {
  min-height: 900px;
}


/* Notificações */

.notif {
  width: 100%;
  height: 100px;
  background: #eee;
  color: #000;
  margin-top: 20px;
  float: left;
  white-space: pre-wrap;
  display: block;
}

.notif small {
  width: 75%;
  float: left !important;
  text-align: left;
  margin-top: 15px;
  white-space: pre-wrap;
}

.notif img {
  width: 15%;
  height: 80px;
  float: left !important;
  border: 3px solid #fff;
}


/* Definições para todas as paginas */

.meio {
  width: 70%;
  margin: 0 15%;
  padding: 40px 0;
}

.user_menu {
  width: 10%;
  float: left;
  margin-top: 90px;
  padding: 40px 0;
}

.user_foto {
  width: 40%;
  height: 80px;
  margin-right: 10px;
  border: 2px solid #fff;
  border-radius: 10px;
}

.definicao {
  width: 32%;
  height: 5px;
  float: left;
  text-align: center;
}

.painel {
  width: 90%;
  height: 225px;
  background: #fff;
  border: 2px solid #fff;
  border-radius: 10px;
}

.notif a {
  background: none !important;
}


/* Notificação */

.contador {
  width: 45%;
  position: relative;
  margin-top: -35px;
  font-weight: bold;
  color: #fff;
  background: #333;
  border: 1px solid #eee;
  border-radius: 100%;
}

.img_notif {
  position: relative
}

.acao_foto {
  width: 20% !important;
  height: 85px;
  float: left;
  margin-left: 2%;
  margin-right: 2%;
}

.notif_fundo {
  width: 80%;
  background: #fff;
  margin-bottom: 10px;
  color: #000 !important;
  padding: 10px;
  height: 60px;
  margin-left: 10%;
}


/* Modal */

.window {
  display: none;
  width: 50%;
  height: 500px;
  position: absolute;
  left: 25% !important;
  top: 0;
  background: #eee;
  z-index: 9000;
  padding: 50px;
}

#mascara {
  display: none;
  position: absolute;
  left: 0;
  top: 0;
  z-index: 9000;
  background-color: #000;
}

.fechar {
  display: block;
  text-align: right;
}

.tit-modal {
  background: #00D4FF;
  text-align: center;
  border: 3px solid #000;
  padding: 10px;
  color: #FFF;
  font-size: 20px
}

.input-modal {
  width: 100%;
  background: #00D4FF;
  border: 2px solid #000;
  color: #fff;
}

.label-modal {
  text-align: center;
  padding: 5px;
  width: 100%;
  color: #000;
  font-size: 15px !important;
}

.btn-modal {
  margin-top: 20px;
  margin-right: 30%;
  width: 40%;
}

.window .fechar {
  position: absolute;
  left: 85%;
  top: 2%;
  padding: 5px 9px;
  background: #00D4FF;
}

.window .fechar {
  text-decoration: none;
  color: #fff;
  font-weight: 200;
}

.window .fechar:hover {
  background: #09F;
  color: #fff;
}

.window .text {
  height: 150px !important;
  color: #fff
}


/* MYDIALOG */

.dialog {
  position: fixed;
  left: 0px;
  top: 0px;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 104;
  display: none;
}

.dialog .loadsistem {
  padding: 30px;
  width: 20%;
  text-align: center;
  background: #fff;
  position: absolute;
  left: 50%;
  margin-left: -160px;
  top: 50%;
  margin-top: -50px;
}

.dialog .loadsistem {
  font-weight: bold;
  color: #069;
  text-transform: uppercase;
  font-size: 14px;
}

.dialog .loadsistem img {
  margin-bottom: 8px;
}

.dialog .msg {
  background: #fff;
  position: absolute;
  left: 50%;
  top: 50%;
  width: 400px;
  height: 160px;
  z-index: 106;
  border: 5px solid #CCC;
  display: none;
}

.dialog .msg {
  padding: 20px;
  margin-left: -220px;
  margin-top: -90px;
}

.dialog .msg .tt {
  display: block;
  margin-bottom: 10px;
  padding-bottom: 5px;
  border-bottom: 1px solid #CCC;
  font-size: 40px;
  font-weight: 600;
}

.dialog .msg p {
  font-size: 18px;
  font-weight: 400;
  margin-top: 10px;
}

.dialog .msg .closedial {
  position: absolute;
  right: 15px;
  top: 15px;
  padding: 5px 10px;
  background: #ccc;
}

.dialog .msg .closedial {
  text-decoration: none;
  color: #fff;
  font-weight: 200;
}

.dialog .msg .closedial:hover {
  background: #09F;
  color: #fff;
}

.dialog .accept {
  color: #0C0;
}

.dialog .accept .tt {
  padding-left: 45px;
  background: url(../../tpl/images/ms_icon_accept.png) center left no-repeat;
}

.dialog .alert {
  color: #F90;
}

.dialog .alert .tt {
  padding-left: 45px;
  background: url(../../tpl/images/ms_icon_alert.png) center left no-repeat;
}

.dialog .error {
  color: #900;
}

.dialog .error .tt {
  padding-left: 45px;
  background: url(../../tpl/images/ms_icon_error.png) center left no-repeat;
}

.dialog .closemodal {
  position: absolute;
  left: 50%;
  top: 38%;
  padding: 5px 9px;
  background: #ccc;
}

.dialog .closemodal {
  text-decoration: none;
  color: #fff;
  font-weight: 200;
}

.dialog .closemodal:hover {
  background: #09F;
  color: #fff;
}

@media (max-width: 1438px) {
  .viwer {
width: 60%;
  }
}

@media (max-width: 1335px) {
  .viwer {
width: 60% !important;
  }
}

@media (max-width: 1390px) {
  .min {
width: 100% !important;
  }
  .user img {
width: 40px !important;
  }
  .img_user {
width: 100px !important;
  }
  .img_about {
width: 200px !important;
height: 100px;
  }
  .viwer {
width: 60% !important;
  }
}

@media (max-width: 1348px) {
  .min {
width: 110% !important;
  }
  .user .subuser {
width: 250% !important;
  }
  .user img {
width: 40px;
  }
  .img_user {
width: 100px;
  }
  .img_about {
width: 200px !important;
height: 100px;
  }
}

@media (max-width: 1225px) {
  .min {
width: 120% !important;
  }
  .user .subuser {
width: 320% !important;
  }
  .user img {
width: 40px;
  }
  .img_user {
width: 100px;
  }
  .img_about {
width: 200px !important;
height: 100px;
  }
}

@media (max-width: 1125px) {
  .min {
width: 140% !important;
  }
  .user img {
width: 40px;
  }
  .img_user {
width: 100px;
  }
  .img_about {
width: 200px !important;
height: 100px;
  }
}

@media (max-width: 970px) {
  .min {
width: 160% !important;
  }
  .user img {
width: 40px;
  }
  .img_user {
width: 100px;
  }
  .img_about {
width: 200px !important;
height: 100px;
  }
  .user ul li {
width: 40px;
  }
}

@media (max-width: 950px) {
  .full h1 {
width: 100% !important;
  }
  .channels {
width: 50% !important;
  }
  .viwer {
width: 65% !important;
  }
  .ocult {
width: 80% !important;
display: block;
  }
  .min {
display: none;
  }
  .user img {
width: 40px;
  }
  .img_user {
width: 100px;
  }
  .img_about {
width: 200px !important;
height: 100px;
  }
}

@media (max-width: 760px) {
  .viwer {
width: 70% !important;
margin-left: 0%;
  }
  .foto {
margin-left: -15%;
  }
}

@media (max-width: 725px) {
  .coment {
width: 100%;
margin-left: 0%;
  }
  .user .usuario {
margin-left: 80%;
  }
  .ocult {
width: 90% !important;
  }
}

@media (max-width: 620px) {
  .viwer {
width: 50% !important;
  }
}

@media (max-width: 570px) {
  .viwer {
width: 15% !important;
  }
  .user {
margin-left: -40%;
  }
  .user .subuser {
margin-left: -80%;
  }
  .user .subuser li {
font-size: 14px;
  }
  .img_about {
width: 200px !important;
  }
  .relac {
width: 100px;
font-size: 10px;
  }
  .relac p {
margin-top: 8px;
  }
  .afastar {
margin-left: 8%;
  }
  .full {
white-space: nowrap;
  }
  .channels {
width: 40% !important;
font-size: 10px;
  }
  .channels p {
margin-top: 8px;
  }
}

<div class="comentando">
  <p>comentario 1</p>
</div>

<div class="comentando">
  <p>comentario 2</p>
</div>

<div class="comentando">
  <p>comentario 3</p>
</div>


<div class=' resp' style=''>
  
  <form method='post'>
<textarea>Minha resposta</textarea>
<input class='btn btn-green' type='submit' value='responder' name='responder'>
  </form>
</div>