@charset "utf-8";
/* - sample과 동일한 그누보드 기본 스타일 (리셋·테이블·버튼·폼·게시판·페이징) */
/* 기본 폰트: Pretendard */
@import url('https://cdn.jsdelivr.net/gh/orioncactus/pretendard@v1.3.9/dist/web/static/pretendard.min.css');

html {
  overflow-x: hidden;
  height: 100vh;
}

body {
  margin: 0;
  padding: 0;
  font-size: 0.75em;
  font-family: "Pretendard", -apple-system, BlinkMacSystemFont, system-ui, Roboto, "Helvetica Neue", "Segoe UI", "Apple SD Gothic Neo", "Noto Sans KR", "Malgun Gothic", sans-serif;
  background: #fff;
  word-break: keep-all;
  overflow-x: hidden;
}

html,
h1,
h2,
h3,
h4,
h5,
h6,
form,
fieldset,
img {
  margin: 0;
  padding: 0;
  border: 0;
  word-break: keep-all;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-size: 1em;
  font-family: inherit;
}

article,
aside,
details,
figcaption,
figure,
footer,
header,
hgroup,
menu,
nav,
section {
  display: block;
}

ul,
li,
dl,
dt,
dd {
  margin: 0;
  padding: 0;
  list-style: none;
}

legend {
  position: absolute;
  margin: 0;
  padding: 0;
  font-size: 0;
  line-height: 0;
  text-indent: -9999em;
  overflow: hidden;
}

label,
input,
button,
select,
img {
  vertical-align: middle;
  font-size: 1em;
}

input,
button {
  margin: 0;
  padding: 0;
  font-family: inherit;
  font-size: 1em;
}

input[type="submit"] {
  cursor: pointer;
}

button {
  cursor: pointer;
}

textarea,
select {
  font-family: inherit;
  font-size: 1em;
}

select {
  margin: 0;
}

p {
  margin: 0;
  padding: 0;
  word-break: break-all;
}

hr {
  display: none;
}

pre {
  overflow-x: scroll;
  font-size: 1.1em;
}

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

*,
:after,
:before {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}

input[type="text"],
input[type="password"],
textarea {
  -webkit-transition: all 0.3s ease-in-out;
  -moz-transition: all 0.3s ease-in-out;
  -ms-transition: all 0.3s ease-in-out;
  -o-transition: all 0.3s ease-in-out;
  outline: none;
}

input[type="text"]:focus,
input[type="password"]:focus,
textarea:focus,
select:focus {
  -webkit-box-shadow: 0 0 5px #9ed4ff;
  -moz-box-shadow: 0 0 5px #9ed4ff;
  box-shadow: 0 0 5px #9ed4ff;
  border: 1px solid #558ab7 !important;
}

.placeholdersjs {
  color: #aaa !important;
}

.clearfix:after {
  content: " ";
  visibility: hidden;
  display: block;
  height: 0;
  clear: both;
}

.inner {
  max-width: 1600px;
  margin: 0 auto;
  padding: 0 30px;
}

span {
  word-break: keep-all;
}

#wrapper {
  min-width: 0;
  width: 100%;
  box-sizing: border-box;
}

/* 데스크톱에서만 최소 너비 유지 (모바일/태블릿은 플렉시블) */
@media (min-width: 1025px) {
  #wrapper {
    min-width: 1200px;
  }
}

#contents {
  max-width: 1600px;
  margin: 0 auto 100px auto;
}

#container_wr {
  max-width: 100%;
}

#container_wr:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

#container_wr {
  margin: 0 auto;
  height: 100%;
  zoom: 1;
}

#aside {
  float: right;
  width: 235px;
  padding: 0;
  height: 100%;
  margin: 20px 0 20px 20px;
}

#container {
  position: relative;
  float: left;
  min-height: 500px;
  height: auto !important;
  margin: 0;
  font-size: 1em;
  width: 100%;
  /* max-width: 1200px; */
  zoom: 1;
}

#container:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

#container_title {
  font-size: 1.333em;
  margin: 0 auto;
  font-weight: bold;
}

#container_title span {
  margin: 0 auto 10px;
  display: block;
  line-height: 30px;
}

.lt_wr {
  width: 32%;
}

.lt_wr:nth-child(3n + 1) {
  clear: both;
}

.latest_wr {
  margin-bottom: 20px;
}

.latest_wr:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

.latest_top_wr {
  margin: 0 -10px 20px;
}

.latest_top_wr:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

/* 팝업레이어 */
#hd_pop {
  z-index: 1000;
  position: relative;
  margin: 0 auto;
  height: 0;
}

#hd_pop h2 {
  position: absolute;
  font-size: 0;
  line-height: 0;
  overflow: hidden;
}

.hd_pops {
  position: absolute;
  border: 1px solid #e9e9e9;
  background: #fff;
}

.hd_pops img {
  max-width: 100%;
}

.hd_pops_footer {
  padding: 0;
  background: #000;
  color: #fff;
  text-align: left;
  position: relative;
}

.hd_pops_footer:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

.hd_pops_footer button {
  padding: 10px;
  border: 0;
  color: #fff;
}

.hd_pops_footer .hd_pops_reject {
  background: #000;
  text-align: left;
  width: 100%;
}

.hd_pops_footer .hd_pops_close {
  background: #393939;
  position: absolute;
  top: 0;
  right: 0;
}

/* 화면낭독기 사용자용 */
#hd_login_msg {
  position: absolute;
  top: 0;
  left: 0;
  font-size: 0;
  line-height: 0;
  overflow: hidden;
}

.msg_sound_only,
.sound_only {
  display: inline-block !important;
  position: absolute;
  top: 0;
  left: 0;
  width: 0;
  height: 0;
  margin: 0 !important;
  padding: 0 !important;
  font-size: 0;
  line-height: 0;
  border: 0 !important;
  overflow: hidden !important;
}

#skip_to_container a {
  z-index: 100000;
  position: absolute;
  top: 0;
  left: 0;
  width: 1px;
  height: 1px;
  font-size: 0;
  line-height: 0;
  overflow: hidden;
}

#skip_to_container a:focus,
#skip_to_container a:active {
  width: 100%;
  height: 75px;
  background: #21272e;
  color: #fff;
  font-size: 2em;
  font-weight: bold;
  text-align: center;
  text-decoration: none;
  line-height: 3.3em;
}

.img_fix {
  width: 100%;
  height: auto;
}

/* 캡챠 - 루트 img 사용 */
#captcha {
  display: inline-block;
  position: relative;
}

#captcha legend {
  position: absolute;
  margin: 0;
  padding: 0;
  font-size: 0;
  line-height: 0;
  text-indent: -9999em;
  overflow: hidden;
}

#captcha #captcha_img {
  height: 40px;
  border: 1px solid #898989;
  vertical-align: top;
  padding: 0;
  margin: 0;
}

#captcha #captcha_mp3,
#captcha #captcha_reload {
  margin: 0;
  padding: 0;
  width: 40px;
  height: 40px;
  border: 0;
  background: transparent;
  vertical-align: middle;
  overflow: hidden;
  cursor: pointer;
  text-indent: -999px;
  border-radius: 3px;
}

#captcha #captcha_key {
  margin: 0 0 0 3px;
  padding: 0 5px;
  width: 90px;
  height: 40px;
  border: 1px solid #ccc;
  background: #fff;
  font-size: 1.333em;
  font-weight: bold;
  text-align: center;
  border-radius: 3px;
  vertical-align: top;
}

#captcha #captcha_info {
  display: block;
  margin: 5px 0 0;
  font-size: 0.95em;
  letter-spacing: -0.1em;
}

/* ckeditor */
.cke_sc {
  margin: 0 0 5px;
  text-align: right;
}

.btn_cke_sc {
  display: inline-block;
  padding: 0 10px;
  height: 23px;
  border: 1px solid #ccc;
  background: #fafafa;
  color: #000;
  text-decoration: none;
  line-height: 1.9em;
  vertical-align: middle;
  cursor: pointer;
}

.cke_sc_def {
  margin: 0 0 5px;
  padding: 10px;
  border: 1px solid #ccc;
  background: #f7f7f7;
  text-align: center;
}

.cke_sc_def dl:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

.cke_sc_def dt,
.cke_sc_def dd {
  float: left;
  margin: 0;
  padding: 5px 0;
  border-bottom: 1px solid #e9e9e9;
}

.cke_sc_def dt {
  width: 20%;
  font-weight: bold;
}

.cke_sc_def dd {
  width: 30%;
}

#bo_v_con ul {
  display: block;
  list-style-type: disc;
  margin: 1em 0;
  padding-left: 40px;
}

#bo_v_con ol {
  display: block;
  list-style-type: decimal;
  margin: 1em 0;
  padding-left: 40px;
}

#bo_v_con li {
  display: list-item;
}

/* 버튼 */
a.btn,
.btn {
  line-height: 35px;
  height: 35px;
  padding: 0 10px;
  text-align: center;
  font-weight: bold;
  border: 0;
  font-size: 1.4em;
  transition: background-color 0.3s ease-out;
}

a.btn01,
button.btn01 {
  display: inline-block;
  padding: 7px;
  border: 1px solid #ccc;
  background: #fafafa;
  color: #000;
  text-decoration: none;
}

a.btn02,
button.btn02 {
  display: inline-block;
  padding: 7px;
  border: 1px solid #3b3c3f;
  background: #4b545e;
  color: #fff;
  text-decoration: none;
}

.btn_confirm {
  text-align: right;
}

.btn_submit {
  border: 0;
  background: #3a8afd;
  color: #fff;
  cursor: pointer;
  border-radius: 3px;
}

.btn_submit:hover {
  background: #2375eb;
}

.btn_close {
  border: 1px solid #dcdcdc;
  cursor: pointer;
  border-radius: 3px;
  background: #fff;
}

a.btn_close {
  text-align: center;
  line-height: 50px;
}

a.btn_cancel,
button.btn_cancel {
  display: inline-block;
  background: #969696;
  color: #fff;
  text-decoration: none;
}

.btn_cancel:hover {
  background: #aaa;
}

a.btn_frmline,
button.btn_frmline {
  display: inline-block;
  width: 128px;
  padding: 0 5px;
  height: 40px;
  border: 0;
  background: #434a54;
  border-radius: 3px;
  color: #fff;
  text-decoration: none;
  vertical-align: top;
}

/* 게시판용 버튼 */
a.btn_b01,
.btn_b01 {
  display: inline-block;
  color: #bababa;
  text-decoration: none;
  vertical-align: middle;
  border: 0;
  background: transparent;
}

.btn_b01:hover {
  color: #000;
}

a.btn_b02,
.btn_b02 {
  display: inline-block;
  background: #253dbe;
  padding: 0 10px;
  color: #fff;
  text-decoration: none;
  border: 0;
  vertical-align: middle;
}

a.btn_b02:hover {
  background: #0025eb;
}

a.btn_b03,
.btn_b03 {
  display: inline-block;
  background: #fff;
  border: 1px solid #b9bdd3;
  color: #646982;
  text-decoration: none;
  vertical-align: middle;
}

a.btn_b03:hover {
  background: #ebedf6;
}

a.btn_b04,
.btn_b04 {
  display: inline-block;
  background: #fff;
  border: 1px solid #ccc;
  color: #707070;
  text-decoration: none;
  vertical-align: middle;
}

a.btn_b04:hover {
  color: #333;
  background: #f9f9f9;
}

a.btn_admin,
.btn_admin {
  display: inline-block;
  color: #d13f4a;
  text-decoration: none;
  vertical-align: middle;
}

.btn_admin:hover,
a.btn_admin:hover {
  color: #ff3746;
}

/* 기본테이블 */
.tbl_wrap table {
  width: 100%;
  border-collapse: collapse;
  border-spacing: 0 5px;
  background: #fff;
  border-top: 1px solid #ececec;
  border-bottom: 1px solid #ececec;
}

.tbl_wrap caption {
  padding: 10px 0;
  font-weight: bold;
  text-align: left;
}

.tbl_head01 {
  margin: 0 0 10px;
}

.tbl_head01 caption {
  padding: 0;
  font-size: 0;
  line-height: 0;
  overflow: hidden;
}

.tbl_head01 thead th {
  padding: 20px 0;
  font-weight: normal;
  text-align: center;
  border-bottom: 1px solid #ececec;
  height: 40px;
}

.tbl_head01 thead th input {
  vertical-align: top;
}

.tbl_head01 tfoot th,
.tbl_head01 tfoot td {
  padding: 10px 0;
  border-top: 1px solid #c1d1d5;
  border-bottom: 1px solid #c1d1d5;
  background: #d7e0e2;
  text-align: center;
}

.tbl_head01 tbody th {
  padding: 8px 0;
  border-bottom: 1px solid #e8e8e8;
}

.tbl_head01 td {
  color: #666;
  padding: 10px 5px;
  border-top: 1px solid #ecf0f1;
  border-bottom: 1px solid #ecf0f1;
  line-height: 1.4em;
  height: 60px;
  word-break: break-all;
}

.tbl_head01 tbody tr:hover td {
  background: #fafafa;
}

.tbl_head01 a:hover {
  text-decoration: underline;
}

.tbl_head02 {
  margin: 0 0 10px;
}

.tbl_head02 caption {
  padding: 0;
  font-size: 0;
  line-height: 0;
  overflow: hidden;
}

.tbl_head02 thead th {
  padding: 5px 0;
  border-top: 1px solid #d1dee2;
  border-bottom: 1px solid #d1dee2;
  background: #e5ecef;
  color: #383838;
  font-size: 0.95em;
  text-align: center;
  letter-spacing: -0.1em;
}

.tbl_head02 thead th input {
  vertical-align: top;
}

.tbl_head02 tfoot th,
.tbl_head02 tfoot td {
  padding: 10px 0;
  border-top: 1px solid #c1d1d5;
  border-bottom: 1px solid #c1d1d5;
  background: #d7e0e2;
  text-align: center;
}

.tbl_head02 tbody th {
  padding: 5px 0;
  border-top: 1px solid #e9e9e9;
  border-bottom: 1px solid #e9e9e9;
  background: #fff;
}

.tbl_head02 td {
  padding: 5px 3px;
  border-top: 1px solid #e9e9e9;
  border-bottom: 1px solid #e9e9e9;
  background: #fff;
  line-height: 1.4em;
  word-break: break-all;
}

/* 폼 테이블 */
.tbl_frm01 {
  margin: 0 0 20px;
}

.tbl_frm01 table {
  width: 100%;
  border-collapse: collapse;
  border-spacing: 0;
}

.tbl_frm01 th {
  width: 70px;
  padding: 7px 13px;
  border: 1px solid #e9e9e9;
  border-left: 0;
  background: #f5f8f9;
  text-align: left;
}

.tbl_frm01 td {
  padding: 7px 10px;
  border-top: 1px solid #e9e9e9;
  border-bottom: 1px solid #e9e9e9;
  background: transparent;
}

.wr_content textarea,
.tbl_frm01 textarea,
.form_01 textarea,
.frm_input {
  border: 1px solid #d0d3db;
  background: #fff;
  color: #000;
  vertical-align: middle;
  border-radius: 3px;
  padding: 5px;
  box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075);
}

.tbl_frm01 textarea {
  padding: 2px 2px 3px;
}

.frm_input {
  height: 40px;
}

.full_input {
  width: 100%;
}

.half_input {
  width: 49.5%;
}

.twopart_input {
  width: 385px;
  margin-right: 10px;
}

.tbl_frm01 textarea,
.write_div textarea {
  width: 100%;
  height: 100px;
}

.tbl_frm01 .frm_file {
  display: block;
  margin-bottom: 5px;
}

.tbl_frm01 .frm_info {
  display: block;
  padding: 0 0 5px;
  line-height: 1.4em;
}

.list_01 ul {
  border-top: 1px solid #ececec;
}

.list_01 li {
  border-bottom: 1px solid #ececec;
  background: #fff;
  padding: 10px 15px;
  list-style: none;
  position: relative;
}

.list_01 li:nth-child(odd) {
  background: #f6f6f6;
}

.list_01 li:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

.list_01 li:hover {
  background: #f9f9f9;
}

.list_01 li.empty_li {
  text-align: center;
  padding: 20px 0;
  color: #666;
}

.form_01 h2 {
  font-size: 1.167em;
}

.form_01 li {
  margin-bottom: 10px;
}

.form_01 ul:after,
.form_01 li:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

.form_01 .left_input {
  float: left;
}

.form_01 .margin_input {
  margin-right: 1%;
}

.form_01 textarea {
  height: 100px;
  width: 100%;
}

.form_01 .frm_label {
  display: inline-block;
  width: 130px;
}

.empty_table {
  padding: 50px 0 !important;
  text-align: center;
}

.empty_list {
  padding: 20px 0 !important;
  color: #666;
  text-align: center;
}

.required,
textarea.required {
  background-image: url("../img/require.png") !important;
  background-repeat: no-repeat !important;
  background-position: right top !important;
}

.td_board {
  width: 80px;
  text-align: center;
}

.td_category {
  width: 80px;
  text-align: center;
}

.td_chk {
  width: 30px;
  text-align: center;
}

.td_date {
  width: 60px;
  text-align: center;
}

.td_datetime {
  width: 110px;
  text-align: center;
}

.td_group {
  width: 80px;
  text-align: center;
}

.td_mb_id {
  width: 100px;
  text-align: center;
}

.td_mng {
  width: 80px;
  text-align: center;
}

.td_name {
  width: 100px;
  text-align: left;
}

.td_nick {
  width: 100px;
  text-align: center;
}

.td_num {
  width: 50px;
  text-align: center;
}

.td_numbig {
  width: 80px;
  text-align: center;
}

.td_stat {
  width: 60px;
  text-align: center;
}

.txt_active {
  color: #5d910b;
}

.txt_done {
  color: #e8180c;
}

.txt_expired {
  color: #ccc;
}

.txt_rdy {
  color: #8abc2a;
}

#copymove .win_desc {
  text-align: center;
  display: block;
}

#copymove .tbl_wrap {
  margin: 20px;
}

#copymove .win_btn {
  padding: 0 20px 20px;
}

.copymove_current {
  float: right;
  background: #ff3061;
  padding: 5px;
  color: #fff;
  border-radius: 3px;
}

.copymove_currentbg {
  background: #f4f4f4;
}

.new_win {
  position: relative;
}

.new_win .tbl_wrap {
  margin: 0 20px;
}

.new_win #win_title {
  font-size: 1.3em;
  height: 50px;
  line-height: 30px;
  padding: 10px 20px;
  background: #fff;
  color: #000;
  box-shadow: 0 1px 10px rgba(0, 0, 0, 0.1);
}

.new_win .win_ul:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

.new_win .win_ul li {
  float: left;
  background: #fff;
  text-align: center;
  padding: 0 10px;
  border: 1px solid #d6e9ff;
  border-radius: 30px;
  margin-left: 5px;
}

.new_win .win_ul li:first-child {
  margin-left: 0;
}

.new_win .win_ul li a {
  display: block;
  padding: 8px 0;
  color: #6794d3;
}

.new_win .win_ul .selected {
  background: #3a8afd;
  border-color: #3a8afd;
  color: #fff;
  font-weight: bold;
}

.new_win .win_ul .selected a {
  color: #fff;
}

.new_win .win_desc {
  margin: 10px;
  border-radius: 5px;
  font-size: 1em;
  background: #f2838f;
  color: #fff;
  line-height: 50px;
  text-align: left;
  padding: 0 20px;
  position: relative;
}

.new_win .win_desc:after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 4px;
  height: 50px;
  background: #da4453;
  border-radius: 3px 0 0 3px;
}

.new_win .frm_info {
  font-size: 0.92em;
  color: #919191;
}

.new_win .win_total {
  float: right;
  display: inline-block;
  line-height: 30px;
  font-weight: normal;
  font-size: 0.75em;
  color: #3a8afd;
  background: #f6f6f6;
  padding: 0 10px;
  border-radius: 5px;
}

.new_win .new_win_con {
  margin: 20px 0;
  padding: 20px;
}

.new_win .new_win_con:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

.new_win .btn_confirm:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

.new_win .win_btn {
  text-align: center;
}

.new_win .btn_close {
  height: 45px;
  width: 60px;
  overflow: hidden;
  cursor: pointer;
}

.new_win .btn_submit {
  padding: 0 20px;
  height: 45px;
  font-weight: bold;
  font-size: 1.083em;
}

.sch_word {
  color: #fff;
  background: #ff005a;
  padding: 2px 5px 3px;
  line-height: 18px;
  margin: 0 2px;
}

#validation_check {
  margin: 100px auto;
  width: 500px;
}

#validation_check h1 {
  margin-bottom: 20px;
  font-size: 1.3em;
}

#validation_check p {
  margin-bottom: 20px;
  padding: 30px 20px;
  border: 1px solid #e9e9e9;
  background: #fff;
}

.sv_wrap {
  position: relative;
  font-weight: normal;
}

.sv_wrap .sv {
  z-index: 1000;
  display: none;
  margin: 5px 0 0;
  font-size: 0.92em;
  background: #333;
  box-shadow: 2px 2px 3px 0 rgba(0, 0, 0, 0.2);
}

.sv_wrap .sv a {
  display: inline-block;
  margin: 0;
  padding: 0 10px;
  line-height: 30px;
  width: 100px;
  font-weight: normal;
  color: #bbb;
}

.sv_wrap .sv a:hover {
  background: #000;
  color: #fff;
}

.sv_on {
  display: block !important;
  position: absolute;
  top: 23px;
  left: 0;
  width: auto;
  height: auto;
}

/* 페이징 */
.pg_wrap {
  clear: both;
  float: left;
  display: inline-block;
}

.pg_wrap:after {
  display: block;
  visibility: hidden;
  clear: both;
  content: "";
}

.pg {
  text-align: center;
}

.pg_page,
.pg_current {
  display: inline-block;
  vertical-align: middle;
  background: #eee;
  border: 1px solid #eee;
}

.pg a:focus,
.pg a:hover {
  text-decoration: none;
}

.pg_page {
  color: #959595;
  font-size: 1.083em;
  height: 30px;
  line-height: 28px;
  padding: 0 5px;
  min-width: 30px;
  text-decoration: none;
  border-radius: 3px;
}

.pg_page:hover {
  background-color: #fafafa;
}

.pg_start,
.pg_prev,
.pg_end,
.pg_next {
  text-indent: -999px;
  overflow: hidden;
  background: #eee;
  padding: 0;
  border: 1px solid #eee;
}

.pg_start:hover,
.pg_prev:hover,
.pg_end:hover,
.pg_next:hover {
  background-color: #fafafa;
}

.pg_current {
  display: inline-block;
  background: #3a8afd;
  border: 1px solid #3a8afd;
  color: #fff;
  font-weight: bold;
  height: 30px;
  line-height: 30px;
  padding: 0 10px;
  min-width: 30px;
  border-radius: 3px;
}

.cheditor-popup-window *,
.cheditor-popup-window :after,
.cheditor-popup-window :before {
  box-sizing: content-box;
}

#device_change {
  display: block;
  margin: 0.3em;
  padding: 0.5em 0;
  border: 1px solid #eee;
  border-radius: 2em;
  background: #fff;
  color: #000;
  font-size: 2em;
  text-decoration: none;
  text-align: center;
}

/* 게시판 */
#bo_list {
  max-width: 1600px;
  margin: 0 auto 150px auto;
  padding: 0 20px;
}

#bo_gall {
  max-width: 1600px;
  margin: 0 auto 150px auto;
  padding: 0 20px;
}

#bo_w {
  max-width: 1600px;
  margin: 0 auto 150px auto;
  padding: 0 20px;
}

#bo_v {
  max-width: 1600px;
  margin: 0 auto 150px auto;
  padding: 0 20px;
}

#top_btn {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 40px;
  height: 40px;
  border: none;
  background: #333;
  color: #fff;
  cursor: pointer;
  border-radius: 50%;
  z-index: 100;
}

#top_btn:hover {
  background: #555;
}