html, body {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-top: .5em;
  font-family: sans-serif;
}

body > header {
  font-size: 1.25em;
  font-weight: bold;
  line-height: 1.25em;
  margin-bottom: 2em;
  color: dimgray;
}

body > header > span {
  display: inline-block;
  width: 1em;
  height: 1em;
  line-height: 1em;
  margin-left: 0;
  margin-right: 0;
}
body > header > span:nth-child(1) {
  background-color: dimgray;
}
body > header > span:nth-child(2) {
  background-color: darkgray;
}
body > header > span:nth-child(3) {
  background-color: gainsboro;
  margin-right: .5em;
}

body > section {
  display: flex;
}

.hidden {
  display: none !important;
}

#bmc-wbtn {
  width: 40px !important;
  height: 40px !important;
}
#bmc-wbtn > img {
  width: 28px !important;
  height: 28px !important;
}
#bmc-wbtn + div {
  right: 60px !important;
  padding: 12px !important;
  max-width: 220px !important;
  font-size: 16px !important;
}

.loading, .user-inputs, .zones, .measurements {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.loading {
  color: gray;
}

.user-inputs {
  margin-left: 2em;
}
.zones {
  margin-left: 3em;
}

.user-inputs {
  align-items: flex-start;
  justify-content: center;
}

.user-inputs > select {
  font-size: 1em;
  min-width: 8.25em;
  height: 2em;
  margin-top: .25em;
  font-weight: bold;
  color: black;
}

.user-inputs > label[for=select-measurement-kind]
{
  font-size: .95em;
  margin-top: -.25em;
  font-weight: bold;
  color: dimgray;
}

.zones > div {
  width: 2em;
  height: 2em;
  line-height: 2em;
  border: 2px solid gray;
  text-align: center;
  margin: 1px;
  cursor: help;
}

.measurements > div {
  min-width: 5.5rem;
  height: 2em;
  line-height: 2em;
  border: 2px solid transparent;
  text-align: left;
  margin: 1px;
}

.measurements > div.measured, .measurements > div.midpoint.measured {
  cursor: pointer;
}
.measurements > div.measured::after, .measurements > div.midpoint.measured::after {
  content: "x";
  display: inline-block;
  padding: .05rem;
  height: .875rem;
  width: .875rem;
  line-height: .8rem;
  vertical-align: .1rem;
  margin-left: .25rem;
  font-size: 1rem;
  font-weight: normal;
  text-align: center;
  color: crimson;
  border: solid 1px crimson;
  cursor: pointer;
}

.zones > div.outside-zone-minus {
  border: 2px solid orangered;
  color: hsl(16, 100%, 65%);
  background-color: black;
}
.zones > div.outside-zone-plus {
  border: 2px solid orangered;
  color: orangered;
  background-color: white;
}

.zones > div.min, .zones > div.max {
  border: 2px solid orangered;
}
.zones > div.almost-min, .zones > div.almost-max {
  border: 2px solid orange;
}

.zones > div.midpoint {
  width: 2.25em;
  height: 2.25em;
  line-height: 2.25em;
  font-size: 1.1em;
  font-weight: bold;
  border-color: green;
  border-width: 2px;
}

.measurements > div.midpoint {
  height: 2.25em;
  line-height: 2.25em;
  font-size: 1.1em;
  font-weight: bold;
  color: green;
}

.btn {
  min-width: 6.5em;
  margin-top: .75em;
  padding: .5em .75em;
  background-color: green;
  color: white;
  font-weight: bold;
  border-radius: .25em;
  border-width: 2px;
  border-style: solid;
  border-top-color: #ddd;
  border-right-color: #222;
  border-bottom-color: #222;
  border-left-color: #ddd;
  text-align: center;
  text-decoration: none;
}

.btn:active {
  border-top-color: #222;
  border-right-color: #ddd;
  border-bottom-color: #ddd;
  border-left-color: #222;
}

.btn.darker {
  background-color: #333;
  color: white;
  margin-top: 4em;
}
.btn.lighter {
  background-color: #eee;
  color: black;
}
.btn.reset {
  background-color: gray;
  color: white;
}

.btn.del {
  background-color: #CC5500;
  color: white;
}

.btn.del-all {
  background-color: darkred;
  color: white;
}

.tooltip {
  position: relative;
}
.tooltip > .tooltiptext {
  visibility: hidden;
  position: absolute;
  z-index: 1;
  width: 12rem;
  bottom: 110%;
  left: 50%;
  margin-left: -6rem;
  background-color: rgba(0, 0, 0, .75);
  color: #fff;
  text-align: center;
  font-size: .8rem;
  font-weight: normal;
  line-height: 1.25rem;
  padding: .25rem .5rem;
  border-radius: .25rem;
}
.tooltip .tooltiptext::after {
  position: absolute;
  content: " ";
  top: 100%;
  left: 46.5%;
  margin-left: -5px;
  border-width: 5px;
  border-style: solid;
  border-color: black transparent transparent transparent;
}
.tooltip > .tooltiptext.visible {
  visibility: visible;
}