:root {
  --bg: #e6e7ea;
  --panel: rgba(250, 250, 251, 0.96);
  --panel-strong: #ffffff;
  --ink: #202124;
  --muted: #5f6368;
  --accent: #4a4d55;
  --accent-soft: rgba(74, 77, 85, 0.08);
  --line: rgba(32, 33, 36, 0.14);
  --shadow: 0 8px 18px rgba(32, 33, 36, 0.08);
  --radius: 3px;
  --mono: monospace;
  --sans: sans-serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
}

body {
  font-family: var(--sans);
  color: var(--ink);
  background: var(--bg);
}

button,
input,
select {
  font: inherit;
}

.app-shell {
  display: grid;
  grid-template-columns: 360px 1fr;
  gap: 18px;
  height: 100vh;
  padding: 18px;
}

.control-panel,
.viewer-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  box-shadow: var(--shadow);
}

.control-panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 22px;
  overflow-y: auto;
}

.panel-head {
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  margin: 0 0 8px;
  font-size: 0.75rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
}

.panel-head h1 {
  margin: 0;
  font-size: 2rem;
  line-height: 1;
}

.lede {
  position: relative;
  top: 4px;
  margin: 3px 0 0;
  font-size: 0.82rem;
  color: var(--muted);
  line-height: 1.05;
  white-space: nowrap;
}

.drop-note {
  font-size: 0.82rem;
  line-height: 1.05;
  color: var(--muted);
}

.drop-lead:last-of-type {
  margin-bottom: 6px;
}

.control-group {
  display: grid;
  gap: 12px;
}

.section-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.control-group h2,
.viewer-card h2,
.collapsible summary {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
}

.header-note {
  font-weight: 400;
  color: var(--muted);
}

.collapsible summary {
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  position: relative;
  padding: 2px 0 2px 24px;
  list-style: none;
}

.collapsible summary::-webkit-details-marker {
  display: none;
}

.collapsible summary::before {
  content: "▶";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 20px;
  text-align: center;
  font-size: 1.15rem;
  line-height: 1;
  color: var(--muted);
}

.collapsible[open] summary::before {
  content: "▼";
}

.collapsible summary > span {
  flex: 1 1 auto;
}

.collapsible > :not(summary) {
  margin-top: 4px;
}

.field-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.field-grid label,
.slider-stack label {
  display: grid;
  gap: 7px;
  font-size: 0.86rem;
}

.stack-label {
  display: grid;
  gap: 7px;
  font-size: 0.86rem;
}

.field-grid span,
.slider-stack span,
.stack-label span {
  color: var(--muted);
}

.slider-stack > label > span {
  position: relative;
  top: 4px;
  margin-bottom: -4px;
}

.stack-label > span {
  position: relative;
  top: 2px;
  margin-bottom: -2px;
}

output {
  margin-left: 8px;
  font: 0.8rem/1 var(--mono);
  color: var(--accent);
}

input[type="number"],
select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 3px;
  background: var(--panel-strong);
  color: var(--ink);
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.drop-zone {
  display: grid;
  place-items: center;
  min-height: 80px;
  padding: 20px;
  border: 1px dashed rgba(74, 77, 85, 0.35);
  border-radius: 3px;
  background: var(--accent-soft);
  text-align: center;
  cursor: pointer;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.drop-zone.dragging {
  transform: translateY(-1px);
  border-color: var(--accent);
  background: rgba(74, 77, 85, 0.12);
}

#fileInput {
  display: none;
}

.control-row {
  display: flex;
  gap: 10px;
}

button,
.download-link {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  min-height: 44px;
  padding: 0 16px;
  border: 0;
  border-radius: 3px;
  background: var(--accent);
  color: #ffffff;
  text-decoration: none;
  cursor: pointer;
  transition: transform 160ms ease, opacity 160ms ease;
}

.header-button {
  min-height: 28px;
  padding: 0 10px;
  font-size: 0.85rem;
}

.summary-button {
  min-height: 24px;
  padding: 0 8px;
  font-size: 0.8rem;
  flex: 0 0 auto;
  font-weight: 400;
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

button:hover:not(:disabled),
.download-link:hover {
  transform: translateY(-1px);
}

.button-ring {
  animation: button-ring 0.82s ease-in-out;
  transform-origin: 50% 50%;
}

@keyframes button-ring {
  0% { transform: scale(1) rotate(0deg); }
  12% { transform: scale(1.06) rotate(-5deg); }
  24% { transform: scale(1.1) rotate(5deg); }
  36% { transform: scale(1.08) rotate(-4deg); }
  48% { transform: scale(1.06) rotate(4deg); }
  60% { transform: scale(1.04) rotate(-3deg); }
  72% { transform: scale(1.02) rotate(2deg); }
  100% { transform: scale(1) rotate(0deg); }
}

.toggle {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 3px;
  background: var(--panel-strong);
  font-size: 0.86rem;
}

.toggle span {
  color: var(--muted);
}

.status-group pre {
  margin: 0;
  padding: 14px;
  min-height: 92px;
  border-radius: 3px;
  background: #2a2c31;
  color: #eef0f2;
  font: 0.8rem/1.45 var(--mono);
  white-space: pre-wrap;
}

.workspace {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  grid-template-rows: minmax(0, 1fr) minmax(280px, 0.9fr);
  gap: 18px;
  min-height: 0;
}

.viewer-card {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  min-height: 0;
  padding: 18px;
  overflow: hidden;
}

.viewer-card header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.viewer-card canvas,
.viewer-card img {
  display: block;
  border-radius: 3px;
  background: #f3f4f6;
  min-width: 0;
  min-height: 0;
}

.viewer-card-wide {
  grid-column: 1 / -1;
}

.viewer-stage,
.output-preview {
  display: grid;
  place-items: stretch;
  min-height: 0;
  overflow: hidden;
  height: 100%;
  background-color: #edf0f3;
  background-image: repeating-linear-gradient(
    -45deg,
    rgba(120, 126, 136, 0.045) 0,
    rgba(120, 126, 136, 0.045) 8px,
    rgba(237, 240, 243, 0) 8px,
    rgba(237, 240, 243, 0) 18px
  );
}

body.has-loaded-image .viewer-stage,
body.has-loaded-image .output-preview {
  background-color: #f3f4f6;
  background-image: none;
}

.viewer-stage > canvas,
.output-preview > canvas {
  justify-self: stretch;
  align-self: stretch;
}

#rawCanvas,
#rectifiedCanvas,
#gifPreviewCanvas {
  width: 100%;
  height: 100%;
  background: transparent;
}

#gifImage,
.viewer-stage > img,
.output-preview > img {
  justify-self: center;
  align-self: center;
}

#gifImage {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
}

.cross-roi-grid {
  display: grid;
  grid-auto-columns: max-content;
  grid-auto-rows: max-content;
  align-content: start;
  justify-content: start;
  gap: 6px;
  min-height: 0;
  overflow: auto;
}

.cross-roi-empty {
  min-width: 24px;
  min-height: 24px;
  background: transparent;
  border: 1px dashed var(--line);
  border-style: dashed;
  opacity: 0.25;
}

.cross-roi-grid .cross-roi-tile {
  display: block;
  image-rendering: pixelated;
  width: auto;
  height: auto;
  max-width: none;
  max-height: none;
  align-self: start;
  justify-self: start;
  border: 0;
  border-radius: 0;
  background: transparent;
}

.hidden {
  display: none;
}

[hidden] {
  display: none !important;
}