:root {
  --bg: #0f1420;
  --card: #182032;
  --line: #2a3550;
  --txt: #e8edf7;
  --muted: #8b96ad;
  --acc: #4f8cff;
  --acc2: #37c978;
  --warn: #f5a623;
  --danger: #e05656;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--txt);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  min-height: 100vh;
}
.topbar { text-align: center; padding: 28px 16px 8px; }
.topbar h1 { margin: 0 0 4px; font-size: 1.5rem; }
.subtitle { margin: 0; color: var(--muted); }
.wrap { max-width: 960px; margin: 0 auto; padding: 16px; }
.muted { color: var(--muted); }
.small { font-size: .82rem; }
.hidden { display: none !important; }

/* Dropzone */
.dropzone {
  border: 2px dashed var(--line);
  border-radius: 14px;
  background: var(--card);
  padding: 36px 20px;
  text-align: center;
  cursor: pointer;
  transition: border-color .15s, background .15s;
}
.dropzone:hover, .dropzone.dragover {
  border-color: var(--acc);
  background: #1c2740;
}
.dz-icon { font-size: 2.4rem; }
.dz-inner p { margin: 8px 0; }

/* Buttons */
.btn {
  border: 1px solid var(--line);
  background: #223052;
  color: var(--txt);
  border-radius: 10px;
  padding: 10px 18px;
  font-size: .95rem;
  cursor: pointer;
}
.btn:hover { filter: brightness(1.15); }
.btn.primary { background: var(--acc); border-color: var(--acc); font-weight: 600; }
.btn.ghost { background: transparent; }
.btn.big { font-size: 1.05rem; padding: 12px 26px; }
.btn.small { padding: 6px 12px; font-size: .82rem; }
.btn:disabled { opacity: .45; cursor: not-allowed; }

/* Warning */
.warn {
  margin-top: 14px;
  background: #3a2c10;
  border: 1px solid var(--warn);
  color: #ffd98a;
  border-radius: 10px;
  padding: 12px 14px;
  font-size: .9rem;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

/* Controls */
.panel {
  margin-top: 14px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 16px;
}
.ctl-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}
.ctl-label { min-width: 64px; font-weight: 600; }
.seg { display: inline-flex; background: #101828; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.seg-btn {
  border: 0;
  background: transparent;
  color: var(--muted);
  padding: 10px 18px;
  font-size: .95rem;
  cursor: pointer;
}
.seg-btn.active { background: var(--acc); color: #fff; font-weight: 600; }
.seg-btn .tag { font-size: .68rem; opacity: .85; font-weight: 400; }

/* Quality slider */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 180px;
  height: 6px;
  border-radius: 999px;
  background: #101828;
  border: 1px solid var(--line);
  outline: none;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px; height: 20px;
  border-radius: 50%;
  background: var(--acc);
  cursor: pointer;
}
input[type="range"]::-moz-range-thumb {
  width: 20px; height: 20px;
  border-radius: 50%;
  background: var(--acc);
  border: 0;
  cursor: pointer;
}
.qval { font-weight: 700; min-width: 30px; text-align: right; }

/* Progress */
.progress { margin-top: 14px; }
.bar {
  height: 12px;
  background: #101828;
  border: 1px solid var(--line);
  border-radius: 999px;
  overflow: hidden;
}
#bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--acc), var(--acc2));
  transition: width .2s;
}

/* Preview */
.preview {
  margin-top: 14px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.pv {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 12px;
}
.pv h3 { margin: 0 0 8px; font-size: 1rem; }
.pv canvas {
  width: 100%;
  height: auto;
  border-radius: 8px;
  background: #0a0e16;
  display: block;
}
.dl-row { margin-top: 10px; text-align: center; }
.foot { text-align: center; margin: 26px 0 10px; line-height: 1.5; }

@media (max-width: 640px) {
  .preview { grid-template-columns: 1fr; }
  .topbar h1 { font-size: 1.25rem; }
  .btn.big { width: 100%; }
  .ctl-row .btn.big { margin-bottom: 4px; }
  .ctl-row .btn.ghost { width: 100%; }
}