removed duplicate css properties

src/main/resources/static/index.css

@@ -247,123 +247,3 @@ tbody tr:hover {
 select {
     min-width: 200px;
 }
-
-
-.hamburger-menu {
-    position: relative;
-    width: 30px;
-    height: 21.5px;
-    cursor: pointer;
-    margin: 16px;
-  }
-
-  .hamburger-line {
-    position: absolute;
-    width: 100%;
-    height: 4px;
-    background-color: white;
-    border-radius: 4px;
-    transition: transform 0.3s, opacity 0.3s;
-  }
-
-  .hamburger-line:nth-child(2) {
-    top: 50%;
-    transform: translateY(-50%);
-  }
-
-  .hamburger-line:nth-child(3) {
-    bottom: 0;
-  }
-
-  .hamburger-menu.open .line-1 {
-    transform: rotate(-45deg) translate(-6px, 6px);
-  }
-
-  .hamburger-menu.open .line-2 {
-    opacity: 0;
-  }
-
-  .hamburger-menu.open .line-3 {
-    transform: rotate(45deg) translate(-6px, -6px);
-  }
-
-  .navigation-menu {
-    position: fixed;
-    top: 0;
-    left: 0;
-    width: 100%;
-    height: 100%;
-    background-color: var(--nav-menu-background-color);
-    display: flex;
-    flex-direction: column;
-    align-items: center;
-    justify-content: center;
-    z-index: 9999;
-    opacity: 0;
-    pointer-events: none;
-    transition: opacity 0.3s;
-  }
-
-  .navigation-menu.show {
-    opacity: 1;
-    pointer-events: auto;
-  }
-
-  .close-button {
-    position: absolute;
-    top: 1px;
-    left: 1px;
-    font-size: 24px;
-    color: var(--header-font-color);
-    cursor: pointer;
-  }
-
-  .links {
-    list-style: none;
-    padding: 0;
-    display: flex;
-    flex-direction: column;
-    align-items: center;
-  }
-
-  .links li {
-    margin: 10px 0;
-  }
-
-  .links a {
-    color: var(--header-font-color);
-    text-decoration: none;
-    font-size: 18px;
-  }
-
-  .navbar {
-    background-color: var(--header-background-color);
-    padding: 10px;
-    padding-top: 0;
-    padding-bottom: 0;
-    text-align: center;
-    width: 100%;
-    height: 58px;
-    display: flex;
-    position: fixed;
-    top: 0;
-    z-index: 1;
-  }
-
-  @media only screen and (max-width: 650px) and (min-width: 375px) {
-    .nav-links {
-      display: none;
-    }
-    .hamburger-menu {
-      display: block;
-    }
-  }
-
-  @media only screen and (max-width: 375px) and (min-width: 0px) {
-    .nav-links {
-      display: none;
-    }
-    .hamburger-menu {
-      display: block;
-    }
-  }