Mailspring/app/internal_packages/open-tracking/styles/main.less

@import "ui-variables";
@import "ui-mixins";

@open-tracking-color: #7C19CC;

.open-tracking-icon img {
  vertical-align: initial;
}

.open-tracking-icon img.content-mask.unopened {
  background-color: fadeout(@open-tracking-color, 80%);
  cursor: default;
}
.open-tracking-icon img.content-mask.opened {
  background-color: @open-tracking-color;
  cursor: pointer;
}

.list-item.focused, .list-item.selected {
  .open-tracking-icon img.content-mask.unopened {
    background-color: fadeout(@text-color-inverse, 70%);
  }
  .open-tracking-icon img.content-mask.opened {
    background-color: @text-color-inverse;
  }
}

.open-tracking-icon .open-count {
  display: inline-block;
  position: relative;
  left: -16px;
  text-align: center;

  background-color: @text-color-link;
  font-size: 12px;
  font-weight: bold;
}

.open-tracking-icon {
  width: 15px;
  margin: 0 2px;
}

.open-tracking-message-status {
  color: @text-color-very-subtle;
  margin-left: 10px;
  &.unopened {
    img.content-mask {
      background-color: @text-color-very-subtle;
    }
  }
  &.opened {
    cursor: pointer;
    img.content-mask {
      background-color: @open-tracking-color;
    }
  }
}

.open-tracking-message-popover {
  width: 200px;
  max-height: 240px;
  .open-tracking-header {
    padding: @padding-base-vertical @padding-base-horizontal 0 @padding-base-horizontal;
    text-align: center;
    color: @text-color-subtle;
    font-weight: 600;
  }
  .open-history-container {
    max-height: 216px;
    padding: 0 @padding-base-horizontal @padding-base-vertical @padding-base-horizontal;
    overflow: auto;
    .open-action {
      color: @text-color-subtle;
      .recipient {
        text-overflow: ellipsis;
        overflow: hidden;
      }
      .spacer {
        flex: 1 1 0;
      }
      .timestamp {
        color: @text-color-very-subtle;
        flex-shrink: 0;
      }
    }
  }
}