/* Lyrics text diff — layout & diff-specific UI (shell from tool-ui.css) */

:root {
  --diff-line: 24px;
  --diff-pad-y: 12px;
  --diff-pad-top: 26px;
  --diff-pad-x: 16px;
  --diff-pane-header-h: 40px;
  --diff-editor-h: min(64vh, 720px);
  --diff-scrollbar-track: rgba(10, 10, 12, 0.92);
  --diff-scrollbar-thumb: rgba(100, 116, 139, 0.45);
  --diff-scrollbar-thumb-hover: rgba(148, 163, 184, 0.55);
}

/* Wider shell — side-by-side lyric columns need room */
.text-diff-page .container {
  max-width: min(1320px, calc(100vw - 32px));
}

.text-diff-page .tool-shell {
  max-width: none;
  width: 100%;
}

/* Page flex chain so editor can grow / fill in Focus mode */
.text-diff-page main {
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.text-diff-page main > .container {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
  padding-bottom: 48px;
}

.text-diff-page .tool-shell {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.text-diff-page .diff-workspace {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

/* Scrollbars — dark, thin, rounded */
.text-diff-page .diff-textarea,
.text-diff-page .diff-metrics-scroll {
  scrollbar-width: thin;
  scrollbar-color: var(--diff-scrollbar-thumb) var(--diff-scrollbar-track);
}

.text-diff-page .diff-textarea::-webkit-scrollbar,
.text-diff-page .diff-metrics-scroll::-webkit-scrollbar {
  width: 7px;
  height: 7px;
}

.text-diff-page .diff-textarea::-webkit-scrollbar-track,
.text-diff-page .diff-metrics-scroll::-webkit-scrollbar-track {
  background: var(--diff-scrollbar-track);
  border-radius: 100px;
}

.text-diff-page .diff-textarea::-webkit-scrollbar-thumb,
.text-diff-page .diff-metrics-scroll::-webkit-scrollbar-thumb {
  background: var(--diff-scrollbar-thumb);
  border-radius: 100px;
  border: 2px solid transparent;
  background-clip: padding-box;
}

.text-diff-page .diff-textarea::-webkit-scrollbar-thumb:hover,
.text-diff-page .diff-metrics-scroll::-webkit-scrollbar-thumb:hover {
  background: var(--diff-scrollbar-thumb-hover);
  border: 2px solid transparent;
  background-clip: padding-box;
}

.text-diff-page .diff-textarea::-webkit-scrollbar-corner,
.text-diff-page .diff-metrics-scroll::-webkit-scrollbar-corner {
  background: var(--diff-scrollbar-track);
}

/* Toolbar card */
.diff-toolbar-card {
  flex-shrink: 0;
  margin-bottom: 12px;
}

.diff-toolbar-card .tool-optbar {
  border-top: none;
}

.diff-toolbar-card .tool-spacer {
  flex: 1;
  min-width: 8px;
}

.diff-toolbar-toggles {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.diff-toolbar .tool-toggle span {
  min-height: 34px;
  padding: 6px 14px;
  white-space: nowrap;
}

.diff-immersive-btn[aria-pressed="true"] {
  border-color: rgba(255, 255, 255, 0.36);
  color: #fff;
  background: rgba(255, 255, 255, 0.13);
}

/* Three equal-height columns — flex is more reliable than grid here */
.diff-layout {
  display: flex;
  align-items: stretch;
  gap: 12px;
  flex: 0 0 auto;
  width: 100%;
  height: var(--diff-editor-h);
  min-height: 360px;
  margin-bottom: 12px;
}

.diff-layout > .tool-card,
.diff-layout > .tool-card + .tool-card {
  display: flex;
  flex-direction: column;
  min-height: 0;
  min-width: 0;
  overflow: hidden;
  margin: 0;
}

.diff-layout > .diff-pane {
  flex: 1 1 0;
}

.diff-layout > .diff-metrics {
  flex: 0 0 clamp(148px, 14vw, 188px);
}

@media (max-width: 960px) {
  .diff-layout {
    flex-direction: column;
    height: auto;
  }

  .diff-layout > .diff-pane {
    flex: none;
    height: 300px;
  }

  .diff-layout > .diff-metrics {
    flex: none;
    height: 240px;
  }
}

/* Shared header — identical on all three columns */
.text-diff-page .diff-pane-header.tool-card-head {
  flex: 0 0 var(--diff-pane-header-h);
  height: var(--diff-pane-header-h);
  min-height: var(--diff-pane-header-h);
  max-height: var(--diff-pane-header-h);
  padding: 0 16px;
  box-sizing: border-box;
  background: rgba(0, 0, 0, 0.28);
  border-bottom: 1px solid rgba(255, 255, 255, 0.07);
}

.diff-pane-stats {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.diff-pane-stats span {
  margin-left: 12px;
}

/* Body fills remaining card height */
.text-diff-page .diff-col-body {
  flex: 1 1 0;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: rgba(0, 0, 0, 0.35);
}

.text-diff-page .diff-pane .diff-col-body {
  position: relative;
}

/* 24px line rhythm — absolute fill avoids flex/height:auto shrink */
.text-diff-page textarea.diff-textarea {
  position: absolute;
  inset: 0;
  box-sizing: border-box;
  width: 100%;
  height: 100%;
  margin: 0;
  padding: var(--diff-pad-top) var(--diff-pad-x) var(--diff-pad-y);
  border: none;
  resize: none;
  font-family: var(--mono);
  font-size: 0.875rem;
  line-height: var(--diff-line);
  color: var(--text-main);
  background: transparent;
  outline: none;
  white-space: pre;
  overflow-x: auto;
  overflow-y: auto;
  tab-size: 4;
}

.text-diff-page textarea.diff-textarea::placeholder {
  color: var(--text-dim);
  font-family: var(--font);
}

.text-diff-page textarea.diff-textarea.guides {
  background-color: transparent;
  background-image: linear-gradient(
    transparent calc(var(--diff-line) - 1px),
    rgba(255, 255, 255, 0.06) var(--diff-line)
  );
  background-size: 100% var(--diff-line);
  background-attachment: local;
  background-position: 0 var(--diff-pad-top);
}

/* Metrics — colhead matches textarea top pad */
.text-diff-page .diff-metrics-colhead {
  flex: 0 0 var(--diff-pad-top);
  height: var(--diff-pad-top);
  min-height: var(--diff-pad-top);
  display: grid;
  grid-template-columns: 2rem minmax(1.75rem, 1fr) minmax(1.75rem, 1fr) 2.25rem;
  column-gap: 4px;
  align-items: center;
  padding: 0 8px;
  font-family: var(--mono);
  font-size: 0.6rem;
  line-height: 1;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 1px solid rgba(255, 255, 255, 0.07);
  box-sizing: border-box;
}

.diff-metrics-colhead > span {
  text-align: center;
  min-width: 0;
  white-space: nowrap;
}

.text-diff-page .diff-metrics-scroll {
  flex: 1 1 0;
  min-height: 0;
  overflow: auto;
  scrollbar-gutter: stable;
}

.diff-metrics-empty {
  padding: 16px 12px;
  text-align: center;
  font-size: 0.82rem;
  color: var(--text-dim);
  line-height: 1.5;
}

.diff-metrics-row {
  display: grid;
  grid-template-columns: 2rem minmax(1.75rem, 1fr) minmax(1.75rem, 1fr) 2.25rem;
  column-gap: 4px;
  align-items: center;
  box-sizing: border-box;
  height: var(--diff-line);
  min-height: var(--diff-line);
  max-height: var(--diff-line);
  padding: 0 8px;
  font-family: var(--mono);
  font-size: 0.72rem;
  line-height: 1;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.diff-metrics-row .ln {
  color: var(--text-dim);
  text-align: center;
  min-width: 0;
}

.diff-metrics-row .num {
  text-align: center;
  color: var(--text-muted);
  min-width: 0;
  font-variant-numeric: tabular-nums;
}

.diff-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 18px;
}

.diff-mark-icon {
  position: relative;
  display: block;
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.diff-mark-ok .diff-mark-icon::after {
  content: "";
  position: absolute;
  left: 2px;
  top: 1px;
  width: 4px;
  height: 8px;
  border: solid #4ade80;
  border-width: 0 1.5px 1.5px 0;
  transform: rotate(45deg);
  box-sizing: border-box;
}

.diff-delta {
  display: inline-block;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  line-height: 1;
}

.diff-delta-plus {
  color: #4ade80;
}

.diff-delta-minus,
.diff-delta-zero {
  color: #f87171;
}

.diff-metrics-row.match {
  background: transparent;
}

.diff-metrics-row.diff {
  background: rgba(255, 0, 204, 0.06);
}

.diff-metrics-row.missing-left {
  background: rgba(251, 191, 36, 0.08);
}

.diff-metrics-row.missing-right {
  background: rgba(96, 165, 250, 0.08);
}

/* —— Immersive (Focus) mode —— */
html.diff-immersive,
body.diff-immersive {
  overflow: hidden;
}

body.diff-immersive .diff-immersive-hide {
  display: none !important;
}

body.diff-immersive .diff-workspace {
  position: fixed;
  inset: 0;
  z-index: 120;
  padding: 12px 16px 16px;
  background: var(--bg-dark);
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

body.diff-immersive .diff-layout {
  flex: 1 1 auto;
  min-height: 0;
  height: auto;
  max-height: none;
  margin-bottom: 0;
}

body.diff-immersive .diff-toolbar-card {
  flex-shrink: 0;
  margin-bottom: 10px;
}