.stage {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  display: grid;
  place-items: center;
  position: relative;
  min-height: 420px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
  margin-bottom: 14px;
}
.canvas {
  background: #0f1218;
  border: 1px solid var(--border);
  border-radius: 10px;
  width: 100%;
  height: auto;
  max-width: 900px;
  aspect-ratio: 3 / 2;
}
.hint {
  position: absolute;
  bottom: 12px;
  left: 16px;
  color: var(--muted);
  font-size: 12px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 14px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 12px;
}
.panel-section {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px;
}
.panel-section h2 {
  font-size: 13px;
  margin: 0 0 8px 0;
  color: #cfd6e6;
  letter-spacing: 0.2px;
}
label {
  display: block;
  margin: 8px 0;
  color: var(--muted);
}
select,
input[type="range"],
button {
  width: 100%;
  background: #0f1218;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 10px;
}

.btn-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 8px;
}
button {
  cursor: pointer;
}
button:hover {
  border-color: #3a82f6;
}
.download-link {
  display: inline-block;
  margin-top: 8px;
  color: var(--accent);
}

.demo-grid {
  display: grid;
  grid-template-columns: 1fr 360px;
  gap: 16px;
  align-items: start;
}
@media (max-width: 1100px) {
  .demo-grid {
    grid-template-columns: 1fr 340px;
  }
}
@media (max-width: 900px) {
  .demo-grid {
    grid-template-columns: 1fr;
  }
}

.status {
  margin-top: 10px;
  margin-bottom: 10px;
  padding: 8px;
  background: rgba(0, 0, 0, 0.1);
  border-radius: 4px;
  font-size: 12px;
  font-family: monospace;
  color: #666;
}

.filter-hint {
  font-size: 12px;
  color: #666;
  margin-bottom: 10px;
  font-style: italic;
}

/* upload pill */
.file {
  position: relative;
  display: flex; /* 原本 inline-flex → flex */
  align-items: center;
  justify-content: center; /* 置中文字 */
  gap: 10px;
  width: 100%;
  padding: 5px 10px;
  background: #0f1218;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
}
.file:hover {
  border-color: #3a82f6;
}
.file input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}
/* 可選：確保 span 也撐滿並置中（多一層保險）*/
.file > span {
  width: 100%;
  text-align: center;
}

/* make btn-row nicer on small screens */
.btn-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.btn-row button {
  flex: 1;
  min-width: 80px;
}