* { box-sizing: border-box; }
:root { color-scheme: light dark; }
body { margin: 0; font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; line-height: 1.5; }
header, footer { padding: 1rem; text-align: center; }
main { max-width: 900px; margin: 0 auto; padding: 1rem; }

/* Mobile-first responsive adjustments */
@media (max-width: 768px) {
  header h1 { font-size: 1.8rem; margin-bottom: 0.5rem; }
  header p { font-size: 0.95rem; margin-top: 0; }
  main { padding: 0.75rem; }
}

form { display: grid; gap: 0.75rem; background: color-mix(in oklab, Canvas, CanvasText 2%); padding: 1rem; border-radius: 12px; border: 1px solid color-mix(in oklab, CanvasText, transparent 85%); }
label { font-weight: 600; }
textarea { width: 100%; resize: vertical; padding: 0.5rem; border-radius: 8px; border: 1px solid color-mix(in oklab, CanvasText, transparent 80%); font-size: 1rem; }
select, button { padding: 0.6rem 0.8rem; border-radius: 8px; border: 1px solid color-mix(in oklab, CanvasText, transparent 80%); font-size: 1rem; }
button { cursor: pointer; }
button[disabled] { opacity: 0.7; cursor: not-allowed; }

@media (max-width: 768px) {
  form { padding: 0.75rem; gap: 1rem; }
  textarea { padding: 0.75rem; font-size: 1rem; min-height: 120px; }
  select, button { padding: 0.75rem 1rem; font-size: 1rem; }
}

.row { display: grid; grid-template-columns: 1fr auto; gap: 0.75rem; align-items: end; }
.col.end { display: flex; justify-content: flex-end; }
.hint { color: color-mix(in oklab, CanvasText, transparent 40%); margin: 0; font-size: 0.9rem; }

.option-group { display: flex; gap: 1rem; align-items: center; flex-wrap: wrap; margin-top: 0.25rem; }
.option-group label { display: inline-flex; align-items: center; gap: 0.4rem; font-weight: 500; }
.option-group input[type="radio"] { accent-color: #2a7; }

@media (max-width: 768px) {
  .row { grid-template-columns: 1fr; gap: 1rem; }
  .col.end { justify-content: stretch; }
  .col.end button { width: 100%; padding: 1rem; font-weight: 600; }
  .hint { font-size: 0.85rem; line-height: 1.4; }
}

#loading { margin-top: 1rem; text-align: center; }

.loader-container {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  padding: 2rem;
  background: color-mix(in oklab, Canvas, CanvasText 2%);
  border-radius: 12px;
  border: 1px solid color-mix(in oklab, CanvasText, transparent 85%);
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid color-mix(in oklab, CanvasText, transparent 85%);
  border-top-color: #2a7;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loader-text {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  min-height: 3rem;
  align-items: center;
}

.loader-stage {
  opacity: 0.3;
  font-size: 0.95rem;
  transition: opacity 0.4s ease, transform 0.3s ease;
  transform: scale(0.95);
}

.loader-stage.active {
  opacity: 1;
  font-weight: 600;
  transform: scale(1);
  color: #2a7;
}

@media (max-width: 768px) {
  .loader-container { padding: 1.5rem; }
  .spinner { width: 40px; height: 40px; }
  .loader-stage { font-size: 0.9rem; }
}

#error { margin-top: 1rem; padding: 0.75rem; border-radius: 8px; color: #8a1c1c; background: #ffdada; border: 1px solid #f2bdbd; }
.hidden { display: none; }

#result { margin-top: 1rem; }
.toolbar { display: flex; gap: 0.5rem; justify-content: flex-end; margin-bottom: 0.5rem; flex-wrap: wrap; }
.image-wrap { display: grid; place-items: center; background: color-mix(in oklab, Canvas, CanvasText 2%); padding: 1rem; border-radius: 12px; border: 1px solid color-mix(in oklab, CanvasText, transparent 85%); }
.image-wrap img { max-width: 100%; height: auto; border-radius: 8px; }

@media (max-width: 768px) {
  .toolbar { justify-content: stretch; gap: 0.75rem; }
  .toolbar button { flex: 1; padding: 0.75rem 1rem; font-weight: 600; }
  .image-wrap { padding: 0.75rem; }
}

@media (max-width: 480px) {
  header h1 { font-size: 1.6rem; }
  header p { font-size: 0.9rem; padding: 0 0.5rem; }
  main { padding: 0.5rem; }
  form { padding: 0.5rem; border-radius: 8px; }
  textarea { min-height: 100px; }
  .toolbar { flex-direction: column; }
  .toolbar button { width: 100%; }
}

/* Improved touch targets */
@media (hover: none) and (pointer: coarse) {
  button, select { min-height: 44px; }
  textarea { min-height: 120px; }
}

/* Large screens optimization */
@media (min-width: 1200px) {
  main { padding: 2rem; }
  form { padding: 1.5rem; }
  .image-wrap { padding: 1.5rem; }
}