.panel {
  position: relative;
  display: flex;
  flex-direction: column;
  z-index: 0;
  background-color: $fallback--bg;
  background-color: var(--bg, $fallback--bg);

  &::after,
  & {
    border-radius: $fallback--panelRadius;
    border-radius: var(--panelRadius, $fallback--panelRadius);
  }

  &::after {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 100;
    box-shadow: 1px 1px 4px rgba(0, 0, 0, 0.6);
    box-shadow: var(--panelShadow);
    pointer-events: none;
  }
}

.panel-body:empty::before {
  content: "¯\\_(ツ)_/¯"; // Could use words but it'd require translations
  display: block; margin: 1em;
  text-align: center;
}

.panel-heading {
  position: relative;
  box-sizing: border-box;
  display: flex;
  flex: none;
  border-radius: $fallback--panelRadius $fallback--panelRadius 0 0;
  border-radius: var(--panelRadius, $fallback--panelRadius) var(--panelRadius, $fallback--panelRadius) 0 0;
  background-size: cover;
  padding: 0.6em 0.6em;
  text-align: left;
  line-height: 28px;
  color: var(--panelText);
  background-color: $fallback--bg;
  background-color: var(--bg, $fallback--bg);
  align-items: baseline;
  height: var(--panelHeadingHeight);
  z-index: -2;

  --panelHeadingHeight: 45px;

  &.-flexible-height {
    --panelHeadingHeight: auto;

    &::after,
    &::before {
      display: none;
    }
  }

  &.-sticky {
    position: sticky;
    top: 0;
    z-index: 2;
  }

  &::after,
  &::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    right: 0;
    left: 0;
    pointer-events: none;
  }

  &::after {
    background-color: $fallback--fg;
    background-color: var(--panel, $fallback--fg);
    z-index: -2;
    border-radius: $fallback--panelRadius $fallback--panelRadius 0 0;
    border-radius: var(--panelRadius, $fallback--panelRadius) var(--panelRadius, $fallback--panelRadius) 0 0;
    box-shadow: var(--panelHeaderShadow);
  }

  &::before {
    bottom: -20px;
    z-index: -1;
    border-radius: $fallback--panelRadius $fallback--panelRadius 0 0;
    border-radius: var(--panelRadius, $fallback--panelRadius) var(--panelRadius, $fallback--panelRadius) 0 0;
    mask: linear-gradient(to bottom, white var(--panelHeadingHeight), transparent var(--panelHeadingHeight));
  }

  .title {
    flex: 1 0 auto;
    font-size: 1.3em;
  }

  .faint {
    background-color: transparent;
    color: $fallback--faint;
    color: var(--panelFaint, $fallback--faint);
  }

  .faint-link {
    color: $fallback--faint;
    color: var(--faintLink, $fallback--faint);
  }

  .alert {
    white-space: nowrap;
    text-overflow: ellipsis;
    overflow-x: hidden;
  }

  .button-default,
  .alert {
    // height: 100%;
    line-height: 21px;
    min-height: 0;
    box-sizing: border-box;
    margin: 0;
    margin-left: 0.5em;
    min-width: 1px;
    align-self: stretch;
  }

  .button-default {
    flex-shrink: 0;

    &,
    i[class*=icon-] {
      color: $fallback--text;
      color: var(--btnPanelText, $fallback--text);
    }

    &:active {
      background-color: $fallback--fg;
      background-color: var(--btnPressedPanel, $fallback--fg);
      color: $fallback--text;
      color: var(--btnPressedPanelText, $fallback--text);
    }

    &:disabled {
      color: $fallback--text;
      color: var(--btnDisabledPanelText, $fallback--text);
    }

    &.toggled {
      color: $fallback--text;
      color: var(--btnToggledPanelText, $fallback--text);
    }
  }

  a,
  .-link {
    color: $fallback--link;
    color: var(--panelLink, $fallback--link);
  }
}

.panel-heading.stub {
  border-radius: $fallback--panelRadius;
  border-radius: var(--panelRadius, $fallback--panelRadius);
}

/* TODO Should remove timeline-footer from here when we refactor panels into
 * separate component and utilize slots
 */
.panel-footer {
  display: flex;
  border-radius: 0 0 $fallback--panelRadius $fallback--panelRadius;
  border-radius: 0 0 var(--panelRadius, $fallback--panelRadius) var(--panelRadius, $fallback--panelRadius);
  flex: none;
  padding: 0.6em 0.6em;
  text-align: left;
  line-height: 28px;
  align-items: baseline;
  border-width: 1px 0 0 0;
  border-style: solid;
  border-color: var(--border, $fallback--border);

  .faint {
    color: $fallback--faint;
    color: var(--panelFaint, $fallback--faint);
  }

  a,
  .-link {
    color: $fallback--link;
    color: var(--panelLink, $fallback--link);
  }
}

.panel-body > p {
  line-height: 18px;
  padding: 1em;
  margin: 0;
}