* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #14171c;
  --panel: #1d2229;
  --panel-2: #262c35;
  --text: #e8eaed;
  --muted: #9aa3ad;
  --accent: #e8825a;
  --accent-2: #f0a06f;
  --border: #333b46;
  --error: #ff6b6b;
}

html, body { height: 100%; }

body {
  font-family: "Sukhumvit Set", "Noto Sans Thai", -apple-system, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
}

.app {
  display: flex;
  height: 100vh;
}

.panel {
  width: 340px;
  flex-shrink: 0;
  background: var(--panel);
  border-right: 1px solid var(--border);
  padding: 20px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

h1 { font-size: 1.4rem; }

.subtitle { color: var(--muted); font-size: 0.85rem; margin-top: -8px; }

.dropzone {
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 18px 14px;
  text-align: center;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.85rem;
  color: var(--muted);
  transition: border-color 0.15s, background 0.15s;
}

.dropzone:hover, .dropzone.dragover {
  border-color: var(--accent);
  background: var(--panel-2);
}

.dropzone b { color: var(--accent-2); }

.dz-icon { font-size: 1.6rem; }

.file-name {
  color: var(--text);
  font-size: 0.8rem;
  word-break: break-all;
}

.error {
  background: rgba(255, 107, 107, 0.12);
  border: 1px solid var(--error);
  color: var(--error);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 0.82rem;
}

.controls h2 {
  font-size: 0.95rem;
  margin-bottom: 10px;
  color: var(--accent-2);
}

.row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  margin-bottom: 12px;
  font-size: 0.82rem;
}

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

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

.row {
  grid-template-columns: 1fr 70px;
  align-items: center;
}

.row > span { grid-column: 1 / -1; }

.row input[type="number"], .row select {
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  padding: 5px 7px;
  font-size: 0.82rem;
  width: 100%;
}

.select-row { grid-template-columns: 1fr; }

.select-row select { width: 100%; }

.check-row {
  display: flex;
  gap: 8px;
  align-items: flex-start;
  font-size: 0.82rem;
  cursor: pointer;
  margin-bottom: 4px;
}

.check-row input { accent-color: var(--accent); margin-top: 3px; }

.check-row small { color: var(--muted); display: block; }

.dims {
  background: var(--panel-2);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 0.8rem;
  color: var(--muted);
  line-height: 1.6;
}

.dims b { color: var(--text); }

.download-btn {
  background: linear-gradient(135deg, var(--accent), #d4663d);
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 13px;
  font-size: 0.95rem;
  font-family: inherit;
  font-weight: 600;
  cursor: pointer;
  transition: filter 0.15s, transform 0.1s;
}

.download-btn:hover { filter: brightness(1.1); }
.download-btn:active { transform: scale(0.98); }
.download-btn:disabled { filter: grayscale(1); cursor: not-allowed; }

.hint { font-size: 0.75rem; color: var(--muted); line-height: 1.6; }

.viewport {
  flex: 1;
  position: relative;
  min-width: 0;
}

#canvas { width: 100%; height: 100%; display: block; }

.viewport-hint {
  position: absolute;
  bottom: 12px;
  right: 16px;
  font-size: 0.75rem;
  color: var(--muted);
  pointer-events: none;
}

@media (max-width: 760px) {
  .app { flex-direction: column; height: auto; }
  .panel { width: 100%; border-right: none; border-bottom: 1px solid var(--border); }
  .viewport { height: 60vh; }
}