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

:root {
  --purple: #7c3aed;
  --purple-dark: #6d28d9;
  --bg: #f4f4f6;
  --panel: #ffffff;
  --border: #e2e2e8;
  --text: #1f2430;
  --muted: #8a8f9e;
  --danger: #dc2626;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  display: flex;
  height: 100vh;
  background: var(--bg);
  color: var(--text);
  overflow: hidden;
}

.hidden { display: none !important; }
.muted { color: var(--muted); font-size: 0.85rem; }

/* ---------- lock screen ---------- */
#lock-screen {
  position: fixed;
  inset: 0;
  z-index: 100;
  background: var(--bg);
  display: flex;
  align-items: center;
  justify-content: center;
}
.lock-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
  width: 320px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  text-align: center;
}
.lock-card p { font-size: 0.95rem; }
.lock-card input { text-align: center; font-size: 1.2rem; letter-spacing: 0.4em; }
.lock-error { color: var(--danger); font-size: 0.85rem; min-height: 1em; }

/* ---------- left sidebar ---------- */
#sidebar {
  width: 340px;
  min-width: 340px;
  background: var(--panel);
  border-right: 1px solid var(--border);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  overflow-y: auto;
}

.logo { font-size: 1.2rem; }

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.panel.grow { flex: 1; }
.panel h2 { font-size: 0.95rem; }

label { display: flex; flex-direction: column; gap: 4px; font-size: 0.85rem; }

input[type="text"], input[type="number"], select, textarea {
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.9rem;
  width: 100%;
  font-family: inherit;
}
textarea { resize: vertical; }
input:focus, select:focus, textarea:focus { outline: 2px solid var(--purple); border-color: var(--purple); }

.req { color: var(--danger); }
.tip { font-size: 0.78rem; color: var(--muted); line-height: 1.35; }

/* option card grids (art style, line thickness, trim size) */
.opt-group { display: flex; flex-direction: column; gap: 6px; }
.opt-label { font-size: 0.85rem; font-weight: 600; }
.opt-grid { display: grid; gap: 8px; }
.opt-grid.cols-2 { grid-template-columns: 1fr 1fr; }
.opt-grid.cols-3 { grid-template-columns: 1fr 1fr 1fr; }
.opt-card {
  display: flex;
  flex-direction: column;
  gap: 2px;
  align-items: flex-start;
  text-align: left;
  padding: 8px 10px;
  border: 2px solid var(--border);
  border-radius: 8px;
  background: #fff;
}
.opt-card b { font-size: 0.8rem; }
.opt-card span { font-size: 0.7rem; color: var(--muted); line-height: 1.25; }
.opt-card:hover { border-color: var(--purple); }
.opt-card.selected { border-color: var(--purple); background: #f6f0ff; }

/* page-count stepper */
.stepper-row { display: flex; align-items: center; gap: 10px; }
.stepper { display: flex; align-items: center; gap: 0; }
.stepper button {
  width: 34px;
  height: 36px;
  padding: 0;
  font-size: 1rem;
  border-radius: 8px;
}
.stepper input {
  width: 60px;
  margin: 0 6px;
  text-align: center;
  /* hide number spinners */
  appearance: textfield;
  -moz-appearance: textfield;
}
.stepper input::-webkit-outer-spin-button,
.stepper input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }

button {
  padding: 8px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  cursor: pointer;
  font-size: 0.9rem;
}
button:hover { background: #f0f0f4; }
button:disabled { opacity: 0.5; cursor: default; }
button.primary { background: var(--purple); color: #fff; border-color: var(--purple); }
button.primary:hover { background: var(--purple-dark); }
button.danger { color: var(--danger); border-color: #f3c1c1; }
button.danger:hover { background: #fdf0f0; }

.book-list { display: flex; flex-direction: column; gap: 8px; overflow-y: auto; }
.book-item {
  display: flex;
  gap: 10px;
  align-items: center;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
}
.book-item:hover { border-color: var(--purple); }
.book-item.active { border-color: var(--purple); background: #f6f0ff; }
.book-item img { width: 44px; height: 60px; object-fit: cover; border-radius: 4px; background: #eee; }
.book-item .info { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.book-item .info b { font-size: 0.85rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.book-item .del {
  margin-left: auto;
  border: none;
  background: none;
  color: var(--muted);
  padding: 4px;
}
.book-item .del:hover { color: var(--danger); background: none; }

/* ---------- main ---------- */
#main { flex: 1; display: flex; flex-direction: column; min-width: 0; }

.empty {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  font-size: 1.05rem;
}

#book-view { flex: 1; display: flex; flex-direction: column; min-height: 0; }

#toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 20px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.book-meta h2 { font-size: 1.1rem; }
.toolbar-actions { display: flex; align-items: center; gap: 10px; }
.checkbox { flex-direction: row; align-items: center; gap: 6px; white-space: nowrap; }

#page-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 20px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.edit-box { display: flex; gap: 8px; flex: 1; min-width: 260px; }

#viewer {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  min-height: 0;
  position: relative;
}
#viewer-img {
  max-width: 100%;
  max-height: 100%;
  background: #fff;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.12);
  border-radius: 4px;
}

.spinner {
  width: 42px;
  height: 42px;
  border: 4px solid var(--border);
  border-top-color: var(--purple);
  border-radius: 50%;
  animation: spin 0.9s linear infinite;
  position: absolute;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ---------- right rail ---------- */
#rail {
  width: 170px;
  min-width: 170px;
  background: var(--panel);
  border-left: 1px solid var(--border);
  padding: 12px;
  overflow-y: auto;
}
#rail h3 { font-size: 0.9rem; margin-bottom: 10px; }

#thumbs { display: flex; flex-direction: column; gap: 10px; }
.thumb {
  position: relative;
  border: 2px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  cursor: pointer;
  background: #fff;
  aspect-ratio: 2 / 3;
  display: flex;
  align-items: center;
  justify-content: center;
}
.thumb:hover { border-color: var(--purple); }
.thumb.active { border-color: var(--purple); box-shadow: 0 0 0 2px rgba(124, 58, 237, 0.25); }
.thumb img { width: 100%; height: 100%; object-fit: cover; }
.thumb .num {
  position: absolute;
  bottom: 4px;
  right: 4px;
  background: var(--purple);
  color: #fff;
  font-size: 0.7rem;
  border-radius: 4px;
  padding: 1px 6px;
}
.thumb .state { font-size: 1.3rem; color: var(--muted); }
.thumb.error { border-color: var(--danger); }
.thumb.error .state { color: var(--danger); font-size: 0.8rem; padding: 6px; text-align: center; }