classic.css

:root {
  --body-bg-color: #455164;
}

#viewport {
  padding: 4px;
  padding-left: 0;
}

#viewport.menu-open {
  /* On desktop view, .menu-open means menu is closed... */
  padding-left: 4px;
}

#viewport #loading, /* ... except on pages without a menu */
#viewport #sign-in {
  margin-left: 4px;
}

/* Sidebar and footer */

#sidebar .scrollable-area {
  padding-top: 10px;
}

#sidebar .chan {
  transition: color 0.2s;
}

#footer {
  background: rgba(0, 0, 0, 0.06);
  margin: 0 4px;
  border-radius: 2px;
}

#footer button {
  color: #9ca5b4;
}

#sidebar .chan:hover,
#footer button:hover,
#sidebar .active,
#sidebar .active:hover {
  background: transparent;
}

/* End sidebar and footer */

#windows .window::before {
  background: #f4f4f4;
  background-image: linear-gradient(#f4f4f4, #ececec);
  border-bottom: 1px solid #d7d7d7;
  content: " ";
  height: 10px;
  flex-shrink: 0;
}

#windows .window {
  border-radius: 2px;
}

#windows {
  border-radius: 2px;
  overflow: hidden;
}

/* Message input */

#form {
  background: #eee;
  border-top: 1px solid #ddd;
  padding: 5px;
}

#windows #form .input {
  border: 1px solid #ddd;
  border-radius: 2px;
  padding: 0;
}

#form #nick {
  display: block;
}

#form #submit {
  color: #9ca5b4;
}

/* End message input */

/* Header icon buttons */

#viewport .lt,
#viewport .rt,
#chat button.menu {
  color: #ccc;
}

/* End header icon buttons */

/* Previews */

#chat .toggle-content {
  border-radius: 2px;
  box-shadow: none;
}

#chat .toggle-thumbnail,
#chat .toggle-content .toggle-text {
  padding: 6px;
}

#chat .toggle-content .toggle-text {
  padding-left: 0;
}

#chat .toggle-content .thumb {
  max-width: 48px;
  max-height: 38px;
}

/* End previews */

kbd {
  background-color: #fcfcfc;
  background-image: none;
  border: solid 1px #ccc;
  border-bottom-color: #bbb;
  border-radius: 3px;
  box-shadow: inset 0 -1px 0 #bbb;
  color: #555;
  font-size: 12px;
  min-width: 20px;
  padding: 3px;
}

@media (max-width: 768px) {
  #viewport,
  #viewport.menu-open {
    padding: 0;
  }

  #viewport #loading,
  #viewport #sign-in {
    margin: 0;
  }

  #footer {
    margin: 0;
    border-radius: 0;
  }

  #windows .window::before {
    display: none;
  }

  #windows .window {
    border-radius: 0;
  }
}