style.css

@font-face {
  font-family: "Learning Curve";
  src: url("./assets/learning_curve_regular_ot_tt-webfont.woff2")
      format("woff2"),
    url("./assets/learning_curve_regular_ot_tt-webfont.woff")
      format("woff");
  font-weight: normal;
  font-style: normal;
}

html {
  height: 100%;
  box-sizing: border-box;
}
*,
*:before,
*:after {
  box-sizing: inherit;
}

body {
  display: flex;
  flex-direction: row;
  flex-wrap: nowrap;
  margin: 0;
  padding: 0;
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
    Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
}
nav {
  width: 310px;
  flex: 0 0 auto;
  padding: 20px;
  background-color: #155d3c;
  color: rgba(146, 84, 84, 0.9);
  font-size: 15px;
  line-height: 20px;
}
nav a,
nav a:visited {
  color: rgba(255, 255, 255, 0.9);
}
main {
  flex: 1 1 auto;
  align-self: stretch;
  background-image: url("assets/ug-bg.jpg");
  background-size: cover;
  overflow: scroll;

}
main img {
  max-width: 100%;
  height: auto;
}
main section {
  font-family: "Learning Curve", serif;
  margin: 100px auto;
  font-size: 34px;
  width: 600px;
  background-color: #fffae7;
  border-top-right-radius: 30px;
  border-bottom-right-radius: 30px;
  position: relative;
}

main section:before {
  content: "";
  display: block;
  position: absolute;
  background: #e7847e;
  width: 2px;
  left: 60px;
  height: 100%;
  z-index: 200;
  top: 0;
}
.to-do-heading {
  padding: 46px 0 0 84px;
  height: 60px;
  line-height: 0;
  display: block;
  border-bottom: 2px solid #7aafff;
  margin-bottom: 6px;
}
.to-do-items {
  display: flex;
  padding-left: 84px;
  border-bottom-right-radius: 30px;
  flex-wrap: nowrap;
  flex-direction: column;
  align-items: flex-start;
  width: 100%;
  border-top: 2px solid #7aafff;
  padding-top: 0px;
  position: relative;
}
.to-do-items:before {
  background-position: center -6px;
  background-image: repeating-linear-gradient(
    180deg,
    #fffae7 0px,
    #fffae7 42px,
    #7aafff 42px,
    #7aafff 44px
  );
  content: "";
  display: block;
  position: absolute;
  height: 100%;
  width: 100%;
  top: 0;
  left: 0;
  z-index: 100;
  border-bottom-right-radius: 30px;
}
.item {
  flex-grow: 1;
  flex-shrink: 1;
  flex-basis: auto;
  position: relative;
  height: 44px;
  z-index: 300;
  padding-top: 10px;
}
.item:first-child {
  height: 36px;
  padding-top: 4px;
}
.item span {
  line-height: 0;
  margin-left: -10px;
}
.item span:empty:after {
  content: "";
  display: inline-block;
  width: 460px;
}
.item span:not(:empty):before {
  content: "●";
  font-family: helvetica, arial, sans-serif;
  font-style: italic;
  font-size: 10px;
  margin-right: 14px;
  display: inline-block;
}
main section div {
  display: inline-block;
}
input {
  position: absolute;
  left: -60px;
  top: 0px;
  opacity: 0;
  width: 30px;
  height: 30px;
}
input:hover {
  opacity: 1;
}
input:checked ~ label:after {
  content: "";
  display: inline-block;
  position: absolute;
  border-bottom: 2px solid black;
  width: 100%;
  top: 32px;
  left: 5px;
}
.item:first-child input:checked ~label:after {
  top: 26px;
}
footer {
  margin: 0 auto;
  width: 800px;
  font-family: Helvetica Neue, Helvetica, Arial, sans-serif;
  margin-top: 20px;
}

.child-item {
  margin-left: 40px;
}

#bell {
  position: absolute;
  z-index: 1;
  top: 40%;
  left: 50%;
  max-width: 20%;
  height: auto;
  -webkit-transform: translate(-50%, -50%);
  -moz-transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
  -o-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}