@import url(https://fonts.googleapis.com/css?family=Raleway:300,400,700|Roboto+Slab:400,700|Lato:300,400,700|Merriweather:300i,400,400italic,700);
@import url(https://unpkg.com/ionicons@4.4.4/dist/css/ionicons.min.css);
/*$text_colour: #030379;*/
body {
  margin: 0px;
  background-color: white; }

.flexbox, .row, .collapsing-row, .col, .panel#performance-targeting .icon-holder .entry, .theory-navbar .item, .theory-navbar .item .circle, .panel, .panel#performance-targeting .icon-holder, .fundamentals-landing-text, .theory-navbar, .next-prev-side-button, .theory-content-container, .theory-content-container .content-area, .expandable-subsection-wrapper .heading, .grid-container, .grid-container .block, .grid-container .block .expand-button .section-title, .grid-container .block .block-content .collapse-img-container, .grid-container .block .block-content .full-width-img-container, .image-toggle-container .toggle-btn {
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-sizing: border-box;
  box-sizing: border-box; }

.row, .collapsing-row {
  width: 100%;
  -webkit-box-orient: horizontal;
  -webkit-box-direction: normal;
  -ms-flex-direction: row;
  flex-direction: row; }

.col, .panel#performance-targeting .icon-holder .entry, .theory-navbar .item, .theory-navbar .item .circle {
  -webkit-box-orient: vertical;
  -webkit-box-direction: normal;
  -ms-flex-direction: column;
  flex-direction: column; }

.collapsing-row {
  -ms-flex-wrap: wrap;
  flex-wrap: wrap; }

.col-1 {
  width: 8.33%; }

.col-2 {
  width: 16.66%; }

.col-3 {
  width: 25%; }

.col-4 {
  width: 33.33%; }

.col-5 {
  width: 41.66%; }

.col-6 {
  width: 50%; }

.col-7 {
  width: 58.33%; }

.col-8 {
  width: 66.66%; }

.col-9 {
  width: 75%; }

.col-10 {
  width: 83.33%; }

.col-11 {
  width: 91.66%; }

.col-12 {
  width: 100%; }

/* these are old! don't use! */
.centred-h {
  -ms-flex-pack: distribute;
  justify-content: space-around; }

.space-around {
  -ms-flex-pack: distribute;
  justify-content: space-around; }

.space-between {
  -webkit-box-pack: justify;
  -ms-flex-pack: justify;
  justify-content: space-between; }

.centre-h {
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center; }

.centred-v {
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center; }

.align-centre {
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center; }

/* convenience flexbox justify-content (main axis) */
.axmain-centre {
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center; }

.axmain-space-around {
  -ms-flex-pack: distribute;
  justify-content: space-around; }

.axmain-space-between {
  -webkit-box-pack: justify;
  -ms-flex-pack: justify;
  justify-content: space-between; }

.axmain-flex-start {
  -webkit-box-pack: start;
  -ms-flex-pack: start;
  justify-content: flex-start; }

.axmain-flex-end {
  -webkit-box-pack: end;
  -ms-flex-pack: end;
  justify-content: flex-end; }

/* convenience flexbox align-items (cross axis) */
.axcross-flex-start {
  -webkit-box-align: start;
  -ms-flex-align: start;
  align-items: flex-start; }

.axcross-flex-end {
  -webkit-box-align: end;
  -ms-flex-align: end;
  align-items: flex-end; }

.axcross-centre {
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center; }

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

.text-right {
  text-align: right; }

.shadow-raised, .grid-container .block--expanded {
  -webkit-box-shadow: 0px 4px 2px gray;
  box-shadow: 0px 4px 2px gray; }

.shadow-inset {
  -webkit-box-shadow: 0px 4px 2px gray inset;
  box-shadow: 0px 4px 2px gray inset; }

.text-black {
  color: black; }

.text-white {
  color: white; }
  .text-white a {
    color: white; }

.animated, .grid-container .block .block-content {
  -webkit-animation-duration: 1s;
  animation-duration: 1s;
  -webkit-animation-fill-mode: backwards;
  animation-fill-mode: backwards; }

@-webkit-keyframes fadeIn {
  0% {
    opacity: 0; }
  100% {
    opacity: 1; } }

@keyframes fadeIn {
  0% {
    opacity: 0; }
  100% {
    opacity: 1; } }

.fadeIn, .grid-container .block .block-content {
  -webkit-animation-name: fadeIn;
  animation-name: fadeIn; }

@-webkit-keyframes fadeOut {
  0% {
    opacity: 1; }
  100% {
    opacity: 0; } }

@keyframes fadeOut {
  0% {
    opacity: 1; }
  100% {
    opacity: 0; } }

.fadeOut {
  -webkit-animation-name: fadeOut;
  animation-name: fadeOut; }

@-webkit-keyframes expand {
  0% {
    -webkit-transform: scale3d(0, 0, 0);
    transform: scale3d(0, 0, 0);
    opacity: 0; }
  100% {
    -webkit-transform: scale3d(1, 1, 1);
    transform: scale3d(1, 1, 1);
    opacity: 1; } }

@keyframes expand {
  0% {
    -webkit-transform: scale3d(0, 0, 0);
    transform: scale3d(0, 0, 0);
    opacity: 0; }
  100% {
    -webkit-transform: scale3d(1, 1, 1);
    transform: scale3d(1, 1, 1);
    opacity: 1; } }

.expand {
  -webkit-transform-origin: left top;
  -ms-transform-origin: left top;
  transform-origin: left top;
  -webkit-animation-name: expand;
  animation-name: expand; }

@-webkit-keyframes fadeInLeft {
  0% {
    opacity: 0.0;
    -webkit-transform: translate3d(-100%, 0, 0);
    transform: translate3d(-100%, 0, 0); }
  100% {
    opacity: 1.0;
    -webkit-transform: none;
    transform: none; } }

@keyframes fadeInLeft {
  0% {
    opacity: 0.0;
    -webkit-transform: translate3d(-100%, 0, 0);
    transform: translate3d(-100%, 0, 0); }
  100% {
    opacity: 1.0;
    -webkit-transform: none;
    transform: none; } }

.fadeInLeft {
  -webkit-animation-name: fadeInLeft;
  animation-name: fadeInLeft; }

@-webkit-keyframes fadeInUp {
  0% {
    opacity: 0.0;
    -webkit-transform: translate3d(0, 100%, 0);
    transform: translate3d(0, 100%, 0); }
  100% {
    opacity: 1.0;
    -webkit-transform: none;
    transform: none; } }

@keyframes fadeInUp {
  0% {
    opacity: 0.0;
    -webkit-transform: translate3d(0, 100%, 0);
    transform: translate3d(0, 100%, 0); }
  100% {
    opacity: 1.0;
    -webkit-transform: none;
    transform: none; } }

.fadeInUp {
  -webkit-animation-name: fadeInUp;
  animation-name: fadeInUp; }

@-webkit-keyframes fadeInDown {
  0% {
    opacity: 0.0;
    -webkit-transform: translate3d(0, -100%, 0);
    transform: translate3d(0, -100%, 0); }
  100% {
    opacity: 1.0;
    -webkit-transform: none;
    transform: none; } }

@keyframes fadeInDown {
  0% {
    opacity: 0.0;
    -webkit-transform: translate3d(0, -100%, 0);
    transform: translate3d(0, -100%, 0); }
  100% {
    opacity: 1.0;
    -webkit-transform: none;
    transform: none; } }

.fadeInDown {
  -webkit-animation-name: fadeInDown;
  animation-name: fadeInDown; }

@-webkit-keyframes slideInDown {
  0% {
    -webkit-transform: translate3d(0, -100%, 0);
    transform: translate3d(0, -100%, 0); }
  100% {
    -webkit-transform: none;
    transform: none; } }

@keyframes slideInDown {
  0% {
    -webkit-transform: translate3d(0, -100%, 0);
    transform: translate3d(0, -100%, 0); }
  100% {
    -webkit-transform: none;
    transform: none; } }

.slideInDown {
  -webkit-animation-name: slideInDown;
  animation-name: slideInDown; }

.btx-popup {
  width: 50%;
  max-width: 400px;
  margin: 0.5em auto 2.5em auto;
  position: relative; }
  .btx-popup .base {
    -o-object-fit: contain;
    object-fit: contain;
    width: 100%; }

@-webkit-keyframes structure-appear {
  0% {
    opacity: 0; }
  100% {
    opacity: 1; } }

@keyframes structure-appear {
  0% {
    opacity: 0; }
  100% {
    opacity: 1; } }
  .btx-popup .animate-appear {
    -webkit-animation-name: structure-appear;
    animation-name: structure-appear;
    -webkit-animation-duration: 1000ms;
    animation-duration: 1000ms;
    -webkit-animation-fill-mode: forwards;
    animation-fill-mode: forwards; }
  .btx-popup .reactor-structure {
    -o-object-fit: contain;
    object-fit: contain;
    position: absolute;
    opacity: 0; }
  .btx-popup img#struc-1 {
    width: 30%;
    top: 30%;
    left: 0;
    -webkit-animation-delay: 0.5s;
    animation-delay: 0.5s; }
  .btx-popup img#struc-2 {
    width: 30%;
    top: 5%;
    right: 0%;
    -webkit-animation-delay: 2.5s;
    animation-delay: 2.5s; }
  .btx-popup img#struc-3 {
    width: 40%;
    bottom: 0%;
    left: 70%;
    -webkit-animation-delay: 1s;
    animation-delay: 1s; }
  .btx-popup img#struc-4 {
    width: 40%;
    bottom: -15%;
    left: 38%;
    -webkit-animation-delay: 3s;
    animation-delay: 3s; }
  .btx-popup img#struc-5 {
    width: 40%;
    bottom: -5%;
    left: 5%;
    -webkit-animation-delay: 2s;
    animation-delay: 2s; }
  .btx-popup img#struc-6 {
    width: 30%;
    top: 5%;
    left: 17%;
    -webkit-animation-delay: 1.5s;
    animation-delay: 1.5s; }
  @media (max-width: 450px) {
    .btx-popup {
      width: 80%; } }

.panel {
  -webkit-box-orient: vertical;
  -webkit-box-direction: normal;
  -ms-flex-direction: column;
  flex-direction: column;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  padding: 2em 3em;
  margin-top: 5em; }
  .panel#intro img {
    display: block;
    -o-object-fit: contain;
    object-fit: contain;
    width: 60%;
    max-width: 550px;
    min-width: 240px;
    margin: 2em auto; }
  .panel#intro .footnote {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-orient: horizontal;
    -webkit-box-direction: normal;
    -ms-flex-direction: row;
    flex-direction: row;
    margin: 2em auto;
    padding: 0 0.5em;
    border: 1px solid pink; }
    .panel#intro .footnote i {
      font-size: 1em;
      font-style: normal;
      margin-top: 1em;
      margin-left: 1em; }
    .panel#intro .footnote p {
      font-size: 0.8em;
      margin-left: 0.3em; }
  .panel#rns {
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center; }
    .panel#rns .question {
      text-align: center;
      font-family: "Merriweather", serif;
      font-weight: lighter;
      font-style: italic;
      font-size: 1.2em;
      color: #372f2f;
      margin: 0em auto 3.5em auto; }
      .panel#rns .question span {
        font-weight: bold; }
      .panel#rns .question i {
        font-size: 1.6em;
        margin-left: 0.1em;
        vertical-align: sub; }
      .panel#rns .question .fig-container {
        display: -webkit-box;
        display: -ms-flexbox;
        display: flex;
        -webkit-box-orient: horizontal;
        -webkit-box-direction: normal;
        -ms-flex-direction: row;
        flex-direction: row;
        -ms-flex-wrap: wrap;
        flex-wrap: wrap;
        -webkit-box-pack: center;
        -ms-flex-pack: center;
        justify-content: center; }
        .panel#rns .question .fig-container .fig {
          display: inline-block;
          text-align: center;
          color: #372f2f;
          font-style: normal;
          font-family: "Raleway", sans-serif;
          font-weight: bold;
          font-size: 0.9em;
          margin-top: 1em; }
          .panel#rns .question .fig-container .fig img {
            display: block;
            -o-object-fit: contain;
            object-fit: contain;
            max-width: 250px;
            height: auto;
            margin: 0 auto; }
    @media screen and (max-width: 640px) {
      .panel#rns h1 {
        text-align: center; }
      .panel#rns .icon-holder {
        -webkit-box-orient: vertical;
        -webkit-box-direction: normal;
        -ms-flex-direction: column;
        flex-direction: column; }
        .panel#rns .icon-holder .entry {
          -webkit-box-orient: horizontal;
          -webkit-box-direction: normal;
          -ms-flex-direction: row;
          flex-direction: row;
          -webkit-box-pack: center;
          -ms-flex-pack: center;
          justify-content: center; } }
  .panel#performance-targeting {
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
    -ms-flex-direction: column;
    flex-direction: column;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center; }
    .panel#performance-targeting .icon-holder {
      -webkit-box-orient: horizontal;
      -webkit-box-direction: normal;
      -ms-flex-direction: row;
      flex-direction: row;
      -webkit-box-align: center;
      -ms-flex-align: center;
      align-items: center;
      -webkit-box-pack: center;
      -ms-flex-pack: center;
      justify-content: center;
      width: 100%;
      max-width: 640px; }
      .panel#performance-targeting .icon-holder .entry {
        -webkit-box-pack: center;
        -ms-flex-pack: center;
        justify-content: center;
        -webkit-box-align: center;
        -ms-flex-align: center;
        align-items: center; }
        .panel#performance-targeting .icon-holder .entry img {
          -o-object-fit: contain;
          object-fit: contain;
          max-width: 250px;
          height: auto; }
    @media screen and (max-width: 640px) {
      .panel#performance-targeting h1 {
        text-align: center; }
      .panel#performance-targeting .icon-holder {
        -webkit-box-orient: vertical;
        -webkit-box-direction: normal;
        -ms-flex-direction: column;
        flex-direction: column; }
        .panel#performance-targeting .icon-holder .entry {
          -webkit-box-orient: horizontal;
          -webkit-box-direction: normal;
          -ms-flex-direction: row;
          flex-direction: row;
          -webkit-box-pack: center;
          -ms-flex-pack: center;
          justify-content: center; } }
  .panel#ar {
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
    -ms-flex-direction: column;
    flex-direction: column;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center; }
    .panel#ar #AR-static {
      -o-object-fit: contain;
      object-fit: contain;
      width: 50%;
      max-width: 500px;
      min-width: 250px; }
    @media screen and (max-width: 640px) {
      .panel#ar h1 {
        text-align: center; }
      .panel#ar .icon-holder {
        -webkit-box-orient: vertical;
        -webkit-box-direction: normal;
        -ms-flex-direction: column;
        flex-direction: column; }
        .panel#ar .icon-holder .entry {
          -webkit-box-orient: horizontal;
          -webkit-box-direction: normal;
          -ms-flex-direction: row;
          flex-direction: row;
          -webkit-box-pack: center;
          -ms-flex-pack: center;
          justify-content: center; } }
  .panel#summary {
    -webkit-box-align: center;
    -ms-flex-align: center;
    align-items: center;
    background-color: #175880;
    padding: 3em;
    position: relative;
    width: 100%; }
    .panel#summary h2, .panel#summary p, .panel#summary a {
      color: white; }
    .panel#summary h2 {
      font-size: 3em; }
    .panel#summary::before {
      content: "";
      position: absolute;
      top: 0;
      left: 50%;
      top: -20px;
      -webkit-transform: translateX(-20px);
      -ms-transform: translateX(-20px);
      transform: translateX(-20px);
      background-color: transparent;
      width: 0px;
      border-bottom: 20px solid #175880;
      border-top: 0;
      border-left: 20px solid transparent;
      border-right: 20px solid transparent; }
  @media (max-width: 640px) {
    .panel {
      padding: 1em; }
      .panel#intro .footnote i {
        margin-left: 0; }
      .panel#rns .question {
        font-size: 0.9em; }
      .panel#summary {
        padding: 1em; } }

.fundamentals-landing-text {
  -webkit-box-orient: horizontal;
  -webkit-box-direction: normal;
  -ms-flex-direction: row;
  flex-direction: row;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  margin: -2em 2em 0 2em; }
  .fundamentals-landing-text i {
    font-size: 3em; }
  @media (max-width: 350px) {
    .fundamentals-landing-text i {
      display: none; } }

.theory-navbar {
  -webkit-box-orient: horizontal;
  -webkit-box-direction: normal;
  -ms-flex-direction: row;
  flex-direction: row;
  width: 100%;
  -webkit-box-pack: justify;
  -ms-flex-pack: justify;
  justify-content: space-between;
  position: relative;
  padding: 2em;
  margin: 0 auto;
  max-width: 800px; }
  .theory-navbar .progress-line {
    position: absolute;
    top: 0px;
    left: 0px;
    height: calc(50px + 3em + 10px);
    width: 100%;
    border-bottom: 1px dashed gray;
    border-right: 1px dashed none;
    opacity: 0.5;
    z-index: 1; }
  .theory-navbar .item {
    -webkit-box-align: center;
    -ms-flex-align: center;
    align-items: center;
    -webkit-box-pack: justify;
    -ms-flex-pack: justify;
    justify-content: space-between;
    width: 20%;
    background-color: none;
    font-family: "Roboto Slab", serif;
    opacity: 0.5;
    -webkit-transition-duration: 0.2s;
    -o-transition-duration: 0.2s;
    transition-duration: 0.2s;
    z-index: 2; }
    .theory-navbar .item:hover {
      cursor: pointer; }
      .theory-navbar .item:hover .small-circle {
        background-color: gray;
        -webkit-transition-duration: inherit;
        -o-transition-duration: inherit;
        transition-duration: inherit; }
    .theory-navbar .item .title {
      text-align: center;
      height: 50px; }
    .theory-navbar .item .circle {
      -webkit-box-pack: center;
      -ms-flex-pack: center;
      justify-content: center;
      -webkit-box-align: center;
      -ms-flex-align: center;
      align-items: center;
      width: 20px;
      height: 20px;
      border-radius: 50%;
      border: 1px solid gray;
      background-color: white;
      margin: 1em;
      -webkit-transition-duration: inherit;
      -o-transition-duration: inherit;
      transition-duration: inherit; }
      .theory-navbar .item .circle .small-circle {
        width: 10px;
        height: 10px;
        border-radius: 50%;
        background-color: none;
        -webkit-transition-duration: inherit;
        -o-transition-duration: inherit;
        transition-duration: inherit; }
    .theory-navbar .item--selected {
      opacity: 1; }
      .theory-navbar .item--selected .circle .small-circle {
        background-color: gray; }
  @media screen and (max-width: 32em) {
    .theory-navbar {
      padding-left: 0;
      padding-right: 0;
      overflow: hidden; }
      .theory-navbar .item .title {
        font-size: 0.75em;
        -webkit-transform-origin: top left;
        -ms-transform-origin: top left;
        transform-origin: top left;
        -webkit-transform: rotate(-60deg) translate(-40px, 30px);
        -ms-transform: rotate(-60deg) translate(-40px, 30px);
        transform: rotate(-60deg) translate(-40px, 30px);
        text-align: left;
        overflow: hidden; } }

.footnote-icon {
  display: inline;
  -webkit-transition: 0.5s;
  -o-transition: 0.5s;
  transition: 0.5s;
  font-weight: bold;
  color: inherit;
  position: relative; }
  .footnote-icon:hover {
    -webkit-transition: 0.5s;
    -o-transition: 0.5s;
    transition: 0.5s;
    cursor: pointer;
    background: #175880;
    color: white; }
  .footnote-icon:before {
    display: inline-block;
    content: "";
    width: 20px;
    height: 20px;
    position: absolute;
    top: -35%;
    left: -15%;
    border: 2px solid cornflowerblue;
    border-radius: 50%;
    background: transparent;
    -webkit-transform: scale(0, 0);
    -ms-transform: scale(0, 0);
    transform: scale(0, 0);
    opacity: 0.5;
    -webkit-animation-name: ping;
    animation-name: ping;
    -webkit-animation-duration: 10s;
    animation-duration: 10s;
    -webkit-animation-fill-mode: forwards;
    animation-fill-mode: forwards;
    -webkit-animation-iteration-count: infinite;
    animation-iteration-count: infinite;
    -webkit-animation-timing-function: ease-out;
    animation-timing-function: ease-out; }

@-webkit-keyframes ping {
  15% {
    -webkit-transform: scale(2, 2);
    transform: scale(2, 2);
    opacity: 0.0; }
  100% {
    opacity: 0.0; } }

@keyframes ping {
  15% {
    -webkit-transform: scale(2, 2);
    transform: scale(2, 2);
    opacity: 0.0; }
  100% {
    opacity: 0.0; } }

.footnote-content {
  overflow: hidden;
  border-top: 0px solid gray;
  border-bottom: 0px solid gray;
  background-color: none;
  max-height: 0px;
  margin: 0px;
  padding: 0px;
  -webkit-transition-duration: 500ms;
  -o-transition-duration: 500ms;
  transition-duration: 500ms;
  -webkit-transition-timing-function: ease-in-out;
  -o-transition-timing-function: ease-in-out;
  transition-timing-function: ease-in-out; }
  .footnote-content--selected {
    border-top: 1px solid gray;
    border-bottom: 1px solid gray;
    margin: 2em 0;
    padding: 1em 0;
    max-height: 1500px; }

.next-prev-side-button {
  -webkit-box-orient: vertical;
  -webkit-box-direction: normal;
  -ms-flex-direction: column;
  flex-direction: column;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  visibility: hidden;
  position: fixed;
  z-index: 5;
  width: 20%;
  height: 25%;
  right: 0px;
  background-color: transparent;
  overflow: hidden; }
  .next-prev-side-button .button-icon {
    opacity: 0.5;
    position: relative;
    width: 35px;
    height: 35px;
    border-radius: 50%;
    border: 1px solid black;
    -webkit-transform: translateX(60px);
    -ms-transform: translateX(60px);
    transform: translateX(60px);
    opacity: 0;
    -webkit-transition: all 700ms cubic-bezier(0.52, 0.01, 0.57, 1.6);
    -o-transition: all 700ms cubic-bezier(0.52, 0.01, 0.57, 1.6);
    transition: all 700ms cubic-bezier(0.52, 0.01, 0.57, 1.6); }
    .next-prev-side-button .button-icon i {
      display: inline-block;
      font-size: 1em;
      line-height: 0;
      text-align: center;
      position: absolute;
      top: 50%;
      left: 50%;
      -webkit-transform: translate(-50%, -50%);
      -ms-transform: translate(-50%, -50%);
      transform: translate(-50%, -50%); }
    .next-prev-side-button .button-icon:hover {
      cursor: pointer; }
  .next-prev-side-button.is-shown {
    visibility: visible; }
    .next-prev-side-button.is-shown .button-icon {
      -webkit-transform: translateX(0px);
      -ms-transform: translateX(0px);
      transform: translateX(0px);
      opacity: 0.4; }
  .next-prev-side-button#next {
    bottom: 0px; }
    .next-prev-side-button#next .button-icon:hover {
      -webkit-transform: translateX(5px);
      -ms-transform: translateX(5px);
      transform: translateX(5px); }
  .next-prev-side-button#prev {
    top: calc(0px + 50px); }
    .next-prev-side-button#prev .button-icon:hover {
      -webkit-transform: translateX(-5px);
      -ms-transform: translateX(-5px);
      transform: translateX(-5px); }

.theory-content-container {
  -webkit-box-orient: vertical;
  -webkit-box-direction: normal;
  -ms-flex-direction: column;
  flex-direction: column;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  margin: 0 auto;
  width: 100%; }
  .theory-content-container .content-area {
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center;
    overflow: hidden;
    top: 50px;
    width: 100%;
    max-width: 50em;
    padding-left: 2em;
    padding-right: 2em; }
    .theory-content-container .content-area .content-page {
      width: 100%;
      padding-bottom: 1em; }
      .theory-content-container .content-area .content-page #conc-vec-eg2 {
        display: -webkit-box;
        display: -ms-flexbox;
        display: flex;
        -webkit-box-orient: horizontal;
        -webkit-box-direction: normal;
        -ms-flex-direction: row;
        flex-direction: row;
        -ms-flex-wrap: wrap;
        flex-wrap: wrap;
        -webkit-box-align: center;
        -ms-flex-align: center;
        align-items: center;
        -webkit-box-pack: center;
        -ms-flex-pack: center;
        justify-content: center; }
        .theory-content-container .content-area .content-page #conc-vec-eg2 p {
          margin: 0 auto; }
        @media (max-width: 600px) {
          .theory-content-container .content-area .content-page #conc-vec-eg2 {
            -webkit-box-orient: vertical;
            -webkit-box-direction: normal;
            -ms-flex-direction: column;
            flex-direction: column; } }
      .theory-content-container .content-area .content-page .to-top-btn {
        width: 45%;
        max-width: 200px;
        min-width: 150px;
        margin: 1em auto;
        padding: 0.5em 1em;
        font-family: "Merriweather", serif;
        text-align: center;
        color: #372f2f;
        border: 2px solid #372f2f;
        border-radius: 5px;
        -webkit-transition-duration: 0.2s;
        -o-transition-duration: 0.2s;
        transition-duration: 0.2s; }
        .theory-content-container .content-area .content-page .to-top-btn:before {
          content: "\02191";
          margin: 0 0.3em 0 0;
          font-size: 1.5em; }
        .theory-content-container .content-area .content-page .to-top-btn:hover {
          cursor: pointer;
          color: white;
          background-color: #372f2f;
          -webkit-transition-duration: 0.2s;
          -o-transition-duration: 0.2s;
          transition-duration: 0.2s; }
    .theory-content-container .content-area .content-page-selected {
      display: block; }
    .theory-content-container .content-area .content-page-hidden {
      display: none; }
    @media screen and (max-width: 32em) {
      .theory-content-container .content-area {
        padding: 0; } }

.expandable-subsection-wrapper {
  -webkit-box-sizing: border-box;
  box-sizing: border-box; }
  .expandable-subsection-wrapper .heading {
    -webkit-box-orient: horizontal;
    -webkit-box-direction: normal;
    -ms-flex-direction: row;
    flex-direction: row;
    width: 100%;
    -webkit-box-align: center;
    -ms-flex-align: center;
    align-items: center;
    padding-left: 1em;
    margin-top: 1em;
    -webkit-transition-duration: 0.5s;
    -o-transition-duration: 0.5s;
    transition-duration: 0.5s; }
    .expandable-subsection-wrapper .heading:before {
      content: '+';
      text-align: center;
      display: inline-block;
      width: 20px;
      border: 1px solid pink;
      padding: 0 10px;
      border-radius: 5px;
      font-size: 2.0em;
      font-weight: bold;
      font-family: "Roboto Slab", serif;
      opacity: 0.5;
      -webkit-transition-duration: 0.5s;
      -o-transition-duration: 0.5s;
      transition-duration: 0.5s; }
    .expandable-subsection-wrapper .heading:hover {
      cursor: pointer;
      -webkit-transition-duration: 0.5s;
      -o-transition-duration: 0.5s;
      transition-duration: 0.5s;
      background-color: #175880; }
      .expandable-subsection-wrapper .heading:hover h2 {
        color: white; }
      .expandable-subsection-wrapper .heading:hover:before {
        color: white;
        opacity: 1.0;
        -webkit-transition-duration: 0.5s;
        -o-transition-duration: 0.5s;
        transition-duration: 0.5s; }
  .expandable-subsection-wrapper .heading--selected:before {
    content: '\2013'; }
  .expandable-subsection-wrapper .heading--selected:hover:before {
    content: '\2013'; }
  .expandable-subsection-wrapper .content {
    display: none; }
  .expandable-subsection-wrapper .content--visible {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
    -ms-flex-direction: column;
    flex-direction: column; }

.grid-container {
  -webkit-box-orient: horizontal;
  -webkit-box-direction: normal;
  -ms-flex-direction: row;
  flex-direction: row;
  width: 100%;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  -ms-flex-wrap: wrap;
  flex-wrap: wrap;
  overflow: hidden;
  border-top: 2px solid black;
  border-bottom: 2px solid black;
  padding-top: 2em;
  padding-bottom: 2em; }
  .grid-container .block {
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
    -ms-flex-direction: column;
    flex-direction: column;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center;
    -webkit-box-align: center;
    -ms-flex-align: center;
    align-items: center;
    height: auto;
    min-width: 280px;
    width: 33%;
    -webkit-transition: all 0.2s cubic-bezier(0.46, 0.03, 0.52, 0.96);
    -o-transition: all 0.2s cubic-bezier(0.46, 0.03, 0.52, 0.96);
    transition: all 0.2s cubic-bezier(0.46, 0.03, 0.52, 0.96); }
    .grid-container .block .expand-button {
      width: 100%;
      -webkit-box-sizing: border-box;
      box-sizing: border-box; }
      .grid-container .block .expand-button .section-title {
        -webkit-box-orient: horizontal;
        -webkit-box-direction: normal;
        -ms-flex-direction: row;
        flex-direction: row;
        -webkit-box-pack: center;
        -ms-flex-pack: center;
        justify-content: center;
        -webkit-box-align: center;
        -ms-flex-align: center;
        align-items: center;
        font-family: "Roboto Slab", serif;
        text-align: center;
        font-size: 1.5em;
        height: 10em;
        padding: 1em;
        background-color: none;
        border: 3px solid white;
        color: #372f2f;
        -webkit-transition-duration: 300ms;
        -o-transition-duration: 300ms;
        transition-duration: 300ms; }
        .grid-container .block .expand-button .section-title:before {
          content: "+";
          display: inline-block;
          border: 1px solid pink;
          border-radius: 5px;
          padding: 0 0.4em;
          margin-right: 0.5em; }
        .grid-container .block .expand-button .section-title:hover {
          cursor: pointer;
          font-weight: bold;
          border-color: #175880; }
      .grid-container .block .expand-button .expand-button-close {
        display: none; }
    .grid-container .block .expand-button-selected .section-title {
      display: none; }
    .grid-container .block .expand-button-selected .expand-button-close {
      display: block;
      -webkit-box-sizing: border-box;
      box-sizing: border-box;
      width: 100%;
      border: 2px solid #72e076;
      color: #372f2f;
      font-family: "Roboto Slab", serif;
      font-weight: bold;
      text-align: right;
      padding: 1em 1em;
      -webkit-transition-duration: 500ms;
      -o-transition-duration: 500ms;
      transition-duration: 500ms; }
      .grid-container .block .expand-button-selected .expand-button-close:hover {
        cursor: pointer;
        background-color: #72e076;
        color: white; }
    .grid-container .block .block-content {
      width: 100%;
      max-width: 40em; }
      .grid-container .block .block-content .collapse-img-container {
        -webkit-box-orient: horizontal;
        -webkit-box-direction: normal;
        -ms-flex-direction: row;
        flex-direction: row;
        -ms-flex-wrap: wrap;
        flex-wrap: wrap;
        -ms-flex-pack: distribute;
        justify-content: space-around; }
        .grid-container .block .block-content .collapse-img-container img {
          width: 50%;
          height: 100%;
          -o-object-fit: contain;
          object-fit: contain;
          min-width: 12em;
          max-width: 200px; }
      .grid-container .block .block-content .full-width-img-container {
        -webkit-box-orient: horizontal;
        -webkit-box-direction: normal;
        -ms-flex-direction: row;
        flex-direction: row;
        width: 100%;
        -webkit-box-pack: center;
        -ms-flex-pack: center;
        justify-content: center;
        height: auto; }
        .grid-container .block .block-content .full-width-img-container img {
          -o-object-fit: contain;
          object-fit: contain;
          width: 90%;
          max-width: 840px;
          height: 100%; }
  .grid-container .block--expanded {
    width: 100%;
    margin: 0.5em 1em;
    padding: 2em; }
  @media screen and (min-width: 840px) {
    .grid-container {
      -webkit-box-pack: start;
      -ms-flex-pack: start;
      justify-content: flex-start; }
      .grid-container .block#extra-credit {
        width: 66%; }
      .grid-container .block--expanded#extra-credit {
        width: 100%; } }
  @media screen and (max-width: 480px) {
    .grid-container .block {
      margin: 0.5em; }
      .grid-container .block .expand-button .section-title {
        height: 5em;
        padding: 0; }
    .grid-container .block--expanded {
      padding: 10px; } }

.image-toggle-container {
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-orient: vertical;
  -webkit-box-direction: normal;
  -ms-flex-direction: column;
  flex-direction: column;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  width: 100%; }
  .image-toggle-container .toggle-btn {
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center;
    -webkit-box-align: center;
    -ms-flex-align: center;
    align-items: center;
    width: 50%;
    height: 4em;
    border: 2px solid #72e076;
    border-radius: 0.6em;
    text-align: center;
    font-family: "Roboto Slab", serif;
    font-weight: normal;
    color: #372f2f;
    margin: 1em;
    -webkit-transition: background-color, color 500ms ease-in-out;
    -o-transition: background-color, color 500ms ease-in-out;
    transition: background-color, color 500ms ease-in-out; }
    .image-toggle-container .toggle-btn:active {
      -webkit-transform: scale(0.99);
      -ms-transform: scale(0.99);
      transform: scale(0.99); }
    .image-toggle-container .toggle-btn:hover {
      cursor: pointer;
      font-weight: bold; }
    .image-toggle-container .toggle-btn--selected {
      background-color: #72e076;
      color: white; }
  .image-toggle-container .img-holder {
    width: 75%; }
    .image-toggle-container .img-holder img {
      -o-object-fit: contain;
      object-fit: contain;
      width: 100%; }
  @media screen and (max-width: 720px) {
    .image-toggle-container {
      -webkit-box-orient: vertical;
      -webkit-box-direction: normal;
      -ms-flex-direction: column;
      flex-direction: column; }
      .image-toggle-container .toggle-btn {
        width: 100%; }
      .image-toggle-container .img-holder {
        width: 100%; } }