* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Roboto", -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen",
    "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background-color: #f5f5f5;
}

code {
  font-family: source-code-pro, Menlo, Monaco, Consolas, "Courier New", monospace;
}

.main_cont {
  width: 100vw;
  height: 100vh;
  background-color: #f5f5f5;
  display: flex;
  justify-content: center;
  align-items: center;
}

.main_cont_inner {
  min-width: 45%;
  min-height: 100px;
  display: block;
}

@media (min-width: 1440px) {
  .main_cont_inner {
    min-width: 0;
    width: 650px;
  }
}

@media (max-width: 1347px) {
  .main_cont_inner {
    min-width: 60%;
  }
}

@media (max-width: 1060px) {
  .main_cont_inner {
    min-width: 80%;
  }
}

@media (max-width: 800px) {
  .main_cont_inner {
    min-width: 95%;
  }
}

.main_cont_about {
  width: 100%;
  display: flex;
  justify-content: space-between;
}

.main_cont_about_inner {
  text-align: right;
  width: 49%;
  height: 100%;
}

.main_cont_text_about_me {
  height: 200px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.main_cont_about img {
  width: 200px;
  height: 200px;
  border-radius: 50%;
}

.main_cont_about_inner h1 {
  font-family: "Roboto", sans-serif;
  font-weight: bold;
  font-size: 36px;
  margin: 0;
  padding: 0;
}

.main_cont_about_inner h2 {
  font-family: "Roboto", sans-serif;
  font-weight: 200;
  font-size: 24px;
  color: #7d7d7d;
}

.main_cont_about_inner_icons {
  gap: 0;
  display: flex;
  justify-content: right;
}

.main_cont_about_inner a {
  margin: 0;
  padding: 0;
  color: black;
  font-size: 40px;
  height: 40px;
  margin-left: 20px;
  gap: 0;
}

.main_cont_about_inner a i {
  margin: 0;
  padding: 0;
  text-decoration: none;
  line-height: 1;
  display: inline-block;
  gap: 0;
  transition: 0.3s all;
}

.main_cont_about_inner a i:hover {
  transform: scale(1.2);
  color: #4682b4;
}

.main_cont_about_inner .cv_icon_text {
  font-family: "Roboto", sans-serif;
  font-size: 40px;
  font-weight: 500;
  letter-spacing: 0.2px;
  width: 40px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: 0.3s all;
}

.main_cont_about_inner .cv_icon_text:hover {
  transform: scale(1.2);
  color: #4682b4;
}

.main_cont_about_inner a i::before {
  margin: 0;
  padding: 0;
  vertical-align: middle;
}

.main_cont_routs {
  width: 100%;
  background-color: #dbdbdb;
  margin-top: 20px;
  padding: 12px 30px;
  display: flex;
  justify-content: space-between;
  border-radius: 21px;
}

.main_cont_routs .main_header_a {
  position: relative;
  text-decoration: none;
  color: black;
  transition: 0.3s;
  padding: 0;
  line-height: 1;
  font-family: "Roboto", sans-serif;
  font-weight: bold;
}

.main_cont_routs .main_header_a:hover {
  cursor: pointer;
}

.main_cont_routs .main_header_a::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: black;
  transition: width 0.3s ease;
}

.main_cont_routs .main_header_a:hover::after {
  width: 100%;
}

.main_cont_routs .main_cont_routs_active::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: black;
  transition: width 0.3s ease;
  width: 100%;
}

@media (max-width: 650px) {
  .main_cont {
    padding: 10px;
  }

  .main_cont_inner {
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .main_cont_about {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    text-align: center;
    width: calc(100% - 30px);
  }

  .main_cont_about img {
    width: 150px;
    height: 150px;
  }

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

  .main_cont_about_inner_icons {
    margin-top: 10px;
    justify-content: space-between;
    width: 100%;
  }

  .main_cont_about_inner_icons a {
    margin: 0;
  }

  .main_cont_about_inner h1 {
    text-align: center;
    margin-top: 10px;
    font-size: 24px;
  }

  .main_cont_about_inner h2 {
    text-align: center;
    margin-top: 10px;
    font-size: 16px;
  }

  .main_cont_routs {
    flex-direction: row;
    align-items: center;
    padding: 15px;
    transition: all 0.5s ease-in-out;
  }

  .main_cont_routs .main_header_a {
    margin: 5px 0;
    font-size: 14px;
  }

  #main_go_to_main {
    display: none;
  }
}

.header_main_cont {
  width: 100vw;
  display: flex;
  justify-content: center;
  align-items: center;
}

.header_main_cont_inner {
  min-width: 45%;
  display: block;
}

@media (min-width: 1440px) {
  .header_main_cont_inner {
    min-width: 0;
    width: 650px;
  }
}

@media (max-width: 1347px) {
  .header_main_cont_inner {
    min-width: 60%;
  }
}

@media (max-width: 1060px) {
  .header_main_cont_inner {
    min-width: 80%;
  }
}

@media (max-width: 800px) {
  .header_main_cont_inner {
    min-width: 95%;
  }
}

.lect_notes_main_cont {
  width: 100vw;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.lect_notes_main_cont_inner {
  padding: 0 30px;
  min-width: 45%;
  display: block;
  text-align: left;
}

@media (min-width: 1440px) {
  .lect_notes_main_cont_inner {
    min-width: 0;
    width: 650px;
  }
}

@media (max-width: 1347px) {
  .lect_notes_main_cont_inner {
    min-width: 60%;
  }
}

@media (max-width: 1060px) {
  .lect_notes_main_cont_inner {
    min-width: 80%;
  }
}

@media (max-width: 800px) {
  .lect_notes_main_cont_inner {
    min-width: 95%;
  }
}

.lect_notes_page-title {
  margin-top: 20px;
  font-size: 36px;
  text-align: center;
  color: #333;
}

.lect_notes_page-sub_title {
  font-size: 24px;
  text-align: center;
  margin-bottom: 30px;
  color: #5d5c5c;
}

.section {
  margin-bottom: 40px;
}

.section-title {
  font-size: 28px;
  margin-bottom: 20px;
  color: #555;
  border-bottom: 2px solid #ddd;
  padding-bottom: 5px;
}

.subsection {
  margin-bottom: 30px;
}

.subsection-title {
  font-size: 22px;
  color: #666;
  margin-bottom: 15px;
}

.notes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}

.note-card {
  background-color: #fdfdfd;
  border: 1px solid #ddd;
  border-radius: 8px;
  padding: 20px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.note-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.note-content h4 {
  font-size: 18px;
  margin-bottom: 10px;
  color: #333;
}

.note-link {
  font-size: 14px;
  color: #4682b4;
  text-decoration: none;
  font-weight: bold;
}

.note-link:hover {
  text-decoration: underline;
}

@media (max-width: 768px) {
  .page-title {
    font-size: 28px;
  }

  .section-title {
    font-size: 24px;
  }

  .subsection-title {
    font-size: 20px;
  }
}

.lect_notes_content-container {
  width: 100%;
  display: block;
}

.lect_notes_sections {
  width: 100%;
  display: block;
}

.table-of-contents {
  margin-bottom: 40px;
  padding: 20px;
  background: linear-gradient(135deg, #f8f9fa, #ffffff);
  border: 1px solid #ddd;
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.table-of-contents h3 {
  font-size: 22px;
  margin-bottom: 15px;
  color: #333;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: bold;
}

.table-of-contents ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.table-of-contents li {
  margin-bottom: 10px;
}

.table-of-contents button {
  font-size: 16px;
  font-weight: 500;
  color: #4682b4;
  background: none;
  border: none;
  text-align: left;
  cursor: pointer;
  transition: color 0.3s ease, transform 0.2s ease;
  padding: 8px 12px;
  border-radius: 8px;
}

.table-of-contents button:hover {
  color: #ffffff;
  background-color: #4682b4;
  transform: translateX(5px);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.table-of-contents li:last-child button {
  margin-bottom: 0;
}

.contact-page {
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
  font-family: "Roboto", Arial, sans-serif;
  text-align: center;
}

.contact-page h1 {
  font-size: 36px;
  margin-bottom: 10px;
  color: #333;
}

.contact-description {
  font-size: 18px;
  color: #666;
  margin-bottom: 30px;
}

.contact-details {
  margin-bottom: 40px;
}

.contact-item {
  display: flex;
  align-items: center;
  margin-bottom: 20px;
  font-size: 18px;
  color: #333;
}

.contact-item i {
  font-size: 24px;
  color: #4682b4;
  margin-right: 15px;
}

.contact-item a {
  color: #4682b4;
  text-decoration: none;
  font-weight: bold;
}

.contact-item a:hover {
  text-decoration: underline;
}

.social-links {
  margin-top: 20px;
}

.social-links h3 {
  font-size: 22px;
  margin-bottom: 15px;
  color: #333;
}

.icons {
  display: flex;
  justify-content: center;
  gap: 20px;
}

.icons a {
  font-size: 24px;
  color: #333;
  transition: color 0.3s ease, transform 0.3s ease;
}

.icons a:hover {
  color: #4682b4;
  transform: scale(1.2);
}

.map-container {
  margin-top: 40px;
}

.map-container h3 {
  font-size: 22px;
  margin-bottom: 15px;
  color: #333;
}

.map-container iframe {
  border: 1px solid #ddd;
  border-radius: 8px;
}

.name_about_me {
  padding-bottom: 15px;
  text-align: center;
}

.lisn-link {
  color: black;
}

.dj_photo {
  width: 80%;
  border-radius: 15px;
}

.dj_div {
  padding-top: 10px;
  width: 100%;
  display: block;
}

.dj_inner {
  width: 100%;
  display: flex;
  justify-content: center;
}

.dj_div-caption {
  text-align: center;
}

.aboutme-bg {
  background: linear-gradient(135deg, #f5f5f5, #ffffff);
  padding: 20px 0;
}

.first-text-about-me {
  margin-top: 20px;
}

.aboutme-content {
  background-color: #fff;
  padding: 30px;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  margin: 20px auto;
}

.aboutme-header {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 30px;
}

.aboutme-photo {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
}

.aboutme-title {
  font-family: "Roboto", sans-serif;
  font-weight: bold;
  color: #333;
}

.aboutme-section {
  margin-bottom: 40px;
  border-bottom: 1px solid #ddd;
  padding-bottom: 20px;
}

.aboutme-section-title {
  font-size: 24px;
  color: #4682b4;
  margin-bottom: 15px;
}

.aboutme-text {
  font-size: 16px;
  line-height: 1.6;
  color: #555;
  margin-bottom: 10px;
}

.projects-container {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.project-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px;
  border: 1px solid #eee;
  border-radius: 8px;
  transition: box-shadow 0.3s ease;
}

.project-item:hover {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.project-info {
  font-size: 16px;
  color: #555;
}

.project-link {
  text-decoration: none;
  background-color: #4682b4;
  color: #fff;
  padding: 8px 12px;
  border-radius: 6px;
  font-size: 14px;
  transition: background-color 0.3s ease;
  display: inline-block;
  min-width: 130px;
  text-align: center;
}

.project-link:hover {
  background-color: #2a5d8f;
}

@media (max-width: 480px) {
  .project-item {
    flex-direction: column;
    align-items: stretch;
  }

  .project-info {
    margin-bottom: 10px;
    text-align: center;
  }

  .project-link {
    min-width: 100%;
  }
}

@media (max-width: 768px) {
  .aboutme-content {
    padding: 20px;
  }

  .aboutme-title {
    font-size: 28px;
  }

  .aboutme-section-title {
    font-size: 22px;
  }

  .aboutme-text,
  .project-info {
    font-size: 14px;
  }
}

@media (max-width: 768px) {
  .dj_photo {
    width: 97%;
  }
}

.main-text {
  font-weight: 800;
  font-size: 1.8rem;
}

.lecture-notes-status {
  text-align: center;
  color: #555;
  margin-bottom: 20px;
}

.lecture-notes-status.error {
  color: #b44a4a;
}