.landing-page {
  text-align: center;
  max-width: 500px;
  margin: 0 auto;
}

body {
  background: #FAFAFA;
}
body .flex {
  display: flex;
  justify-content: space-between;
}
@media (max-width: 320px) {
  body .flex {
    flex-direction: column;
  }
}
body .flex .column {
  padding: 3px;
}
body .flex .column .row {
  text-align: center;
  margin: 10px auto;
}

.box {
  flex: 1;
  border: 2px solid #999;
  border-radius: 10px;
  margin: 0.5rem;
  min-height: 100px;
  padding: 10px;
  background: #FAFAFA;
}

input {
  text-align: center;
}

.container {
  max-width: 700px;
  margin: 0 auto;
  text-align: center;
}
.container #choose {
  background: #E1E1E1;
  padding: 10px;
}
.container #choose:before, .container #input:before, .container #output:before, .container #latex:before {
  font-weight: 600;
}
.container #output:before {
  content: "Output: ";
}
.container #latex:before {
  content: "LaTeX Code: ";
}
.container #latex {
  font-family: monospace;
}
.container .question {
  background: #E1E1E1;
  margin: 1em auto;
  padding: 12px;
  border-radius: 10px;
}

.menu {
  background: pink;
}

.toolbar {
  background: #2E3641;
  display: flex;
}
.toolbar button, .toolbar .dropdown {
  float: left;
  background: #2E3641;
  border-right: 1px solid #434f5f;
  color: #C1CFD9;
}
.toolbar button:hover, .toolbar .dropdown:hover {
  background: #394250;
  color: #b1c3cf;
}

.dropdown {
  position: relative;
  width: 150px;
}
.dropdown button {
  width: 75px;
  border: none;
  border-right: 1px solid #434f5f;
  border-bottom: 1px solid #434f5f;
}

.dropdown-text {
  cursor: pointer;
  position: relative;
  text-indent: 10px;
  line-height: 32px;
  border-radius: 3px;
  width: 100%;
}
.dropdown-text:after {
  position: absolute;
  right: 6px;
  top: 15px;
  content: "";
  width: 0px;
  height: 0px;
  border-style: solid;
  border-width: 5px 4px 0 4px;
  border-color: #555 transparent transparent transparent;
}

.dropdown-toggle {
  font-size: 0;
  z-index: 1;
  cursor: pointer;
  position: absolute;
  top: 0;
  border: none;
  padding: 0;
  margin: 0 0 0 1px;
  background: transparent;
  text-indent: -10px;
  height: 34px;
  width: 100%;
}
.dropdown-toggle:focus {
  outline: 0;
}

.dropdown-content {
  transition: all 0.25s ease;
  list-style-type: none;
  position: absolute;
  z-index: 100;
  top: 32px;
  padding: 0;
  margin: 0;
  opacity: 0;
  visibility: hidden;
  line-height: 32px;
  background-color: pink;
  width: 150px;
}
.dropdown-content a {
  display: block;
}
.dropdown-toggle:focus ~ .dropdown-text {
  z-index: 2;
}
.dropdown-toggle:focus ~ .dropdown-text:after {
  border-width: 0 4px 5px 4px;
  border-color: transparent transparent #555 transparent;
}

.dropdown-content:hover, .dropdown-toggle:focus ~ .dropdown-content {
  opacity: 1;
  visibility: visible;
  top: 42px;
}
.dropdown-content:hover ul li, .dropdown-toggle:focus ~ .dropdown-content ul li {
  background: #2E3641 !important;
}