:root {
  --bg: #faf8f5;
  --ink: #2b2b2b;
  --accent: #7a5c3e;
  --border: #ddd5c8;
  --warn-bg: #fbeee0;
  --warn-ink: #8a5a1f;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--ink);
}

header {
  padding: 24px 32px;
  border-bottom: 1px solid var(--border);
}

h1 {
  margin: 0 0 4px;
  font-size: 1.4rem;
}

.subtitle {
  margin: 0;
  color: #766a5a;
  font-size: 0.9rem;
}

main {
  padding: 32px;
  max-width: 900px;
  margin: 0 auto;
}

.panel {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-width: 360px;
}

.field-label {
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: 12px;
}

input[type="file"],
input[type="number"] {
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.95rem;
}

.warning {
  background: var(--warn-bg);
  color: var(--warn-ink);
  padding: 8px 10px;
  border-radius: 6px;
  font-size: 0.82rem;
  margin: 4px 0 0;
}

.hidden {
  display: none;
}

button {
  margin-top: 16px;
  padding: 10px 16px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 0.95rem;
  cursor: pointer;
}

button:disabled {
  background: #c9bfae;
  cursor: not-allowed;
}

.results {
  margin-top: 32px;
  display: flex;
  gap: 32px;
  flex-wrap: wrap;
}

.result-col {
  flex: 1;
  min-width: 280px;
}

.result-col h2 {
  font-size: 1rem;
  margin-bottom: 8px;
}

.result-col img {
  max-width: 100%;
  border: 1px solid var(--border);
  border-radius: 6px;
}

#previewCanvas {
  max-width: 100%;
  border: 1px solid var(--border);
  border-radius: 6px;
  image-rendering: pixelated;
}

#gridInfo {
  font-size: 0.85rem;
  color: #766a5a;
  margin-top: 8px;
}