:root {
  --bg: #0f1220;
  --surface: #1a1f35;
  --surface-2: #242a44;
  --border: #2f3656;
  --text: #e7eaf5;
  --muted: #9aa3c7;
  --accent: #6c8cff;
  --accent-hover: #8aa2ff;
  --danger: #ff5b7a;
  --success: #3ddc97;
  --whiteout: rgba(255, 255, 255, 0.92);
  --delete: rgba(255, 91, 122, 0.35);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Helvetica Neue", Arial, sans-serif;
  min-height: 100vh;
}

header {
  padding: 2rem 2rem 1rem;
  border-bottom: 1px solid var(--border);
}

h1 { margin: 0; font-size: 1.75rem; letter-spacing: 0.2px; }
h2 { margin: 0 0 0.75rem; font-size: 1.05rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.08em; }
.subtitle { color: var(--muted); margin: 0.25rem 0 0; }

main { padding: 1.5rem 2rem 3rem; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
}

.hidden { display: none !important; }

/* Upload dropzone */
.dropzone {
  display: block;
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 2.5rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 150ms ease, background 150ms ease;
}
.dropzone:hover, .dropzone.dragover {
  border-color: var(--accent);
  background: var(--surface-2);
}
.dropzone-inner strong { display: block; font-size: 1.1rem; }
.dropzone-inner span { color: var(--muted); }

.card-title {
  margin-top: 0;
}

.library-row {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  align-items: center;
}
.library-row select {
  flex: 1;
  min-width: 180px;
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.55rem 0.7rem;
  font-size: 0.95rem;
}
.library-row select:focus {
  outline: none;
  border-color: var(--accent);
}
.library-row select[disabled] { opacity: 0.6; }

#library-section + #upload-section {
  margin-top: 1rem;
}

.divider {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--muted);
  font-size: 0.8rem;
  margin: 1rem 0 0.75rem;
}
.divider::before,
.divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border);
}

.url-row {
  display: flex;
  gap: 0.5rem;
}
.url-row input[type="url"] {
  flex: 1;
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.55rem 0.7rem;
  font-size: 0.95rem;
}
.url-row input[type="url"]:focus {
  outline: none;
  border-color: var(--accent);
}

.status {
  margin-top: 0.75rem;
  color: var(--muted);
  min-height: 1.2em;
  font-size: 0.9rem;
}
.status.error { color: var(--danger); }
.status.success { color: var(--success); }

/* Layout */
.layout {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 1.25rem;
  align-items: flex-start;
}
@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; }
}

.controls { position: sticky; top: 1rem; }

.field { display: flex; flex-direction: column; gap: 0.3rem; margin-bottom: 0.75rem; }
.field label { font-size: 0.85rem; color: var(--muted); }
.field input, .field select {
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.5rem 0.6rem;
  font-size: 0.95rem;
}
.field input:focus, .field select:focus {
  outline: none;
  border-color: var(--accent);
}

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem 0.75rem;
}

hr { border: none; border-top: 1px solid var(--border); margin: 1rem 0; }

.row { display: flex; gap: 0.5rem; flex-wrap: wrap; }
button {
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 0.55rem 0.9rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
  transition: background 120ms ease, border-color 120ms ease;
}
button:hover { background: #2b3254; }
button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #0a0e22;
  font-weight: 600;
}
button.primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
button:disabled { opacity: 0.5; cursor: not-allowed; }

.hint { color: var(--muted); font-size: 0.85rem; margin: 0 0 0.5rem; }
.summary { font-size: 0.9rem; color: var(--muted); margin-top: 0.5rem; }

/* Big preview */
.big-preview {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  margin-bottom: 1.25rem;
  overflow: hidden;
}

.big-preview-toolbar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 0.75rem;
  border-bottom: 1px solid var(--border);
  background: var(--surface-2);
}
.big-preview-toolbar .spacer { flex: 1; }
.big-page-label {
  font-size: 0.9rem;
  color: var(--muted);
  min-width: 8ch;
  text-align: center;
}
.nav-btn {
  min-width: 2.1rem;
  font-size: 1.2rem;
  line-height: 1;
  padding: 0.35rem 0.6rem;
}

.big-preview-wrap {
  padding: 1rem;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  background: #0c0f1c;
  max-height: 70vh;
  overflow: auto;
}
.big-thumb {
  position: relative;
  display: inline-block;
  background: #fff;
  max-width: 100%;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
  line-height: 0;
}
.big-thumb img {
  display: block;
  max-width: 100%;
  max-height: 66vh;
  width: auto;
  height: auto;
  background: #fff;
}

/* Pages grid */
.preview { min-width: 0; }
.pages-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 1rem;
}

.page-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  cursor: pointer;
  position: relative;
  transition: transform 120ms ease, border-color 120ms ease;
}
.page-card:hover { transform: translateY(-2px); border-color: var(--accent); }
.page-card.deleted { border-color: var(--danger); }
.page-card.active { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(108, 140, 255, 0.35); }

.page-remove {
  position: absolute;
  top: 6px;
  right: 6px;
  z-index: 2;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: rgba(15, 18, 32, 0.85);
  color: var(--text);
  font-size: 14px;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  padding: 0;
  transition: background 120ms ease, color 120ms ease, border-color 120ms ease;
}
.page-remove:hover {
  background: var(--danger);
  color: #fff;
  border-color: var(--danger);
}
.page-card.deleted .page-remove {
  background: var(--danger);
  color: #fff;
  border-color: var(--danger);
}

.page-thumb {
  position: relative;
  width: 100%;
  background: #fff;
  aspect-ratio: var(--aspect, 0.707);
  overflow: hidden;
}
.page-thumb img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: contain;
  background: #fff;
}

/* White-out overlays sit on top of the thumbnail */
.whiteout-box {
  position: absolute;
  background: var(--whiteout);
  border: 1px solid rgba(0, 0, 0, 0.08);
  pointer-events: none;
}

.delete-overlay {
  position: absolute;
  inset: 0;
  background: var(--delete);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.85rem;
  pointer-events: none;
}

.page-meta {
  padding: 0.5rem 0.6rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
}
.page-meta .num { color: var(--text); font-weight: 600; }