styles.css

* {
  box-sizing: border-box;
}

body {
  background: #F1F1F1;
  padding: 20px;
  font-family: 'Raleway', sans-serif;
  color: #222222;
  font-size: 14px;
}

h1, h2, h3, h4, h5 {
  font-family: 'Exo', sans-serif;
}

textarea {
  font-family: 'Raleway', sans-serif;
  font-size: 14px;
}

.editor {
  overflow: auto;
  height: 160px;
  width: 100%;
  border: 1px solid #dadada;
  border-radius: 4px;
  padding: 5px 8px;
  outline: 0 none;
  margin: 10px 0;
  background: white;
}

iframe.editor {
  padding: 0;
}

.editor:focus {
  border: 1px solid #5ABBF6;
}

.offset-y-line, .offset-x-line {
  position: absolute;
  z-index: 999;
  opacity: 0.8;
}

.offset-y-line {
  border-left: 1px dashed magenta;
  height: 100%;
  top: 0;
  left: -1px;
}

.offset-x-line {
  border-bottom: 1px dashed cyan;
  width: 100%;
  top: -1px;
  left: 0;
}

.indicators {
  position: absolute;
  background: #000;
  opacity: 0.75;
  border-radius: 6px;
  border-top-left-radius: 0;
  color: #fff;
  padding: 5px;
  margin-top: 2px;
}

.indicators > .offset-indicator {
  z-index: 999;
  padding: 0 3px;
  border-radius: 3px;
}

.indicators > .position-indicator {
  bottom: -50px;
  padding: 0 3px;
  border-radius: 3px;
}