:root {
  --bg: #f6f7f9;
  --panel: #ffffff;
  --text: #1f2328;
  --muted: #667085;
  --border: #d0d5dd;
  --accent: #1a73e8;
  --danger: #d93025;
  --sel: #1a73e8;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body {
  margin: 0;
  font-family: "Microsoft JhengHei", "Noto Sans TC", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
}
button {
  font: inherit;
  padding: 6px 12px;
  border: 1px solid var(--border);
  background: var(--panel);
  border-radius: 6px;
  cursor: pointer;
}
button:hover { background: #eef2f7; }
button:disabled { opacity: .5; cursor: default; }
button.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
button.primary:hover { background: #1765cc; }
button.danger { color: var(--danger); border-color: #f1b5b0; }
button.big { font-size: 1.1rem; padding: 10px 20px; }

.bar {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 10px 16px; background: var(--panel); border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.title { display: flex; align-items: baseline; gap: 12px; min-width: 0; }
.file-name { color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.actions { display: flex; gap: 8px; flex-wrap: wrap; }

.toolbar {
  position: sticky; top: 0; z-index: 5;
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
  padding: 8px 16px; background: var(--panel); border-bottom: 1px solid var(--border);
}
.toolbar .sep { width: 1px; height: 24px; background: var(--border); }
#selInfo { color: var(--muted); min-width: 7em; }

main { padding: 16px; }
.welcome { max-width: 640px; margin: 48px auto; text-align: center; line-height: 1.7; }
.hint { color: var(--muted); font-size: .9rem; }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 14px;
}
.card {
  background: var(--panel); border: 2px solid transparent; border-radius: 8px;
  padding: 8px; user-select: none; cursor: pointer;
  box-shadow: 0 1px 2px rgba(0,0,0,.08);
}
.card.selected { border-color: var(--sel); background: #e8f0fe; }
.card .thumb {
  height: 200px; display: flex; align-items: center; justify-content: center; overflow: hidden;
}
.card canvas { box-shadow: 0 0 0 1px var(--border); transition: transform .15s; background: #fff; }
.card .label { display: flex; justify-content: space-between; margin-top: 6px; font-size: .85rem; color: var(--muted); }
.sortable-ghost { opacity: .35; }

.status {
  position: fixed; left: 50%; bottom: 20px; transform: translateX(-50%);
  background: #323232; color: #fff; padding: 10px 18px; border-radius: 6px; max-width: 90vw;
  box-shadow: 0 2px 8px rgba(0,0,0,.3); z-index: 20;
}
.status a { color: #8ab4f8; }
.status.error { background: var(--danger); }

dialog#preview { width: min(95vw, 1000px); height: 92vh; padding: 0; border: none; border-radius: 8px; }
.preview-head { display: flex; justify-content: space-between; align-items: center; padding: 8px 12px; border-bottom: 1px solid var(--border); }
.preview-body { height: calc(100% - 50px); overflow: auto; text-align: center; background: #e5e7eb; padding: 12px; }
.preview-body canvas { max-width: 100%; height: auto; background: #fff; }

@media (max-width: 600px) {
  .grid { grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); }
  .card .thumb { height: 160px; }
}