/* ---------- theme ---------- */
:root {
  --bg: #f4f5f7;
  --panel: #ffffff;
  --fg: #1b1e24;
  --muted: #667085;
  --line: #e1e4ea;
  --field: #f8f9fb;
  --accent: #2b59d9;
  --accent-hover: #2249b5;
  --warn: #b45309;
  --radius: 10px;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.06);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121418;
    --panel: #1b1e24;
    --fg: #e9ebef;
    --muted: #98a1b0;
    --line: #2f343d;
    --field: #14171c;
    --accent: #6c93f0;
    --accent-hover: #86a6f4;
    --warn: #e5a35c;
    --shadow: none;
    color-scheme: dark;
  }
}

/* ---------- base ---------- */
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  padding: 24px 20px 40px;
  background: var(--bg);
  color: var(--fg);
  font:
    14px/1.5 system-ui,
    -apple-system,
    'Segoe UI',
    Roboto,
    sans-serif;
}
header,
.wrap {
  max-width: 1200px;
  margin-inline: auto;
}
h1 {
  margin: 0 0 6px;
  font-size: 40px;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  background: linear-gradient(90deg, var(--accent), #9b5de5);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.sub {
  margin: 0;
  max-width: 70ch;
  font-size: 15px;
  color: var(--muted);
}
header {
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--line);
}

/* ---------- layout ---------- */
.wrap {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
  gap: 20px;
  align-items: start;
}
@media (max-width: 900px) {
  .wrap {
    grid-template-columns: 1fr;
  }
}

/* ---------- cards ---------- */
.box {
  margin-bottom: 16px;
  padding: 16px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.box h2 {
  margin: 0 0 12px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}
.row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  align-items: center;
  margin-bottom: 10px;
}
.row:last-child {
  margin-bottom: 0;
}
.controls {
  margin-top: 12px;
}
.hint {
  margin: 0 0 10px;
}
.status {
  margin-top: 8px;
}

/* ---------- form controls ---------- */
label {
  display: flex;
  align-items: center;
  gap: 6px;
}
input[type='number'],
select {
  padding: 6px 8px;
  background: var(--field);
  color: var(--fg);
  border: 1px solid var(--line);
  border-radius: 6px;
  font: inherit;
}
input[type='number'] {
  width: 80px;
}
input[type='number']:focus,
select:focus,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}
input[type='range'] {
  flex: 1;
  min-width: 120px;
  accent-color: var(--accent);
}
input[type='checkbox'] {
  accent-color: var(--accent);
}
input[type='file'] {
  font: inherit;
}

/* ---------- buttons ---------- */
button {
  padding: 7px 12px;
  background: var(--panel);
  color: var(--fg);
  border: 1px solid var(--line);
  border-radius: 6px;
  font: inherit;
  font-weight: 500;
  cursor: pointer;
  transition:
    background 0.15s,
    border-color 0.15s;
}
button:hover:not(:disabled) {
  background: var(--field);
  border-color: var(--muted);
}
button.primary {
  padding: 10px 20px;
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  font-weight: 600;
}
button.primary:hover:not(:disabled) {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}
button:disabled {
  opacity: 0.45;
  cursor: default;
}

/* ---------- sliders ---------- */
.slider {
  display: grid;
  grid-template-columns: 110px 1fr 52px;
  gap: 10px;
  align-items: center;
  margin-bottom: 8px;
}
.slider span {
  text-align: right;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
}
.num {
  min-width: 4ch;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
}

/* ---------- canvases + preview ---------- */
#pv {
  display: block;
  width: 100%;
  max-height: 60vh;
  object-fit: contain;
  background: #000;
  border-radius: 6px;
  touch-action: none;
  cursor: crosshair;
}
#out {
  max-width: 100%;
  max-height: 200px;
  background: #000;
  border: 1px solid var(--line);
  border-radius: 6px;
}
.flip-stage {
  display: grid;
  place-items: center;
  min-height: 80px;
  padding: 10px;
  text-align: center;
  background: var(--field);
  border: 1px dashed var(--line);
  border-radius: 6px;
}
.flip-stage img {
  max-width: 100%;
  max-height: 320px;
  border-radius: 4px;
}

/* ---------- text + status ---------- */
.muted {
  color: var(--muted);
}
.warn {
  color: var(--warn);
}
#info {
  font-variant-numeric: tabular-nums;
}
progress {
  width: 100%;
  height: 10px;
  accent-color: var(--accent);
}

/* The video element must exist but stay invisible; frames are drawn on canvases. */
#vid {
  position: absolute;
  width: 2px;
  height: 2px;
  opacity: 0;
  pointer-events: none;
}