@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
  /* Light Theme (Default) */
  --bg-primary: #f5f7fa;
  --bg-secondary: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.7);
  --bg-card-hover: rgba(255, 255, 255, 0.9);
  --glass-border: rgba(0, 0, 0, 0.08);
  --glass-border-hover: rgba(0, 0, 0, 0.15);
  --accent: #5c4de0;
  --accent-glow: rgba(92, 77, 224, 0.2);
  --accent-hover: #4a3cba;
  --accent-2: #24a187;
  --accent-2-glow: rgba(36, 161, 135, 0.2);
  --text-primary: #1a1b26;
  --text-secondary: #4a5066;
  --text-muted: #737a91;
  --danger: #e03152;
  --danger-glow: rgba(224, 49, 82, 0.2);
  --success: #24a187;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --dark-cover-bg: linear-gradient(135deg, #e3e6f0, #f0f2f8);
  --dark-input-bg: #ffffff;
  --toast-bg: #ffffff;
  --toast-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
  --modal-overlay: rgba(255, 255, 255, 0.6);
}

[data-theme="dark"] {
  /* Dark Theme */
  --bg-primary: #0d0f17;
  --bg-secondary: #131624;
  --bg-card: rgba(255, 255, 255, 0.04);
  --bg-card-hover: rgba(255, 255, 255, 0.07);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-border-hover: rgba(255, 255, 255, 0.18);
  --accent: #7c6af7;
  --accent-glow: rgba(124, 106, 247, 0.35);
  --accent-hover: #9985ff;
  --accent-2: #3ecfb2;
  --accent-2-glow: rgba(62, 207, 178, 0.3);
  --text-primary: #eaeaf0;
  --text-secondary: #8b8fa8;
  --text-muted: #545873;
  --danger: #f0516e;
  --danger-glow: rgba(240, 81, 110, 0.3);
  --success: #3ecfb2;
  --dark-cover-bg: linear-gradient(135deg, #2a2d4a, #1a1d30);
  --dark-input-bg: rgba(255, 255, 255, 0.04);
  --toast-bg: #1e2235;
  --toast-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  --modal-overlay: rgba(0, 0, 0, 0.6);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ── Background orbs ── */
body::before,
body::after {
  content: '';
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
  z-index: 0;
}

body::before {
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(124, 106, 247, 0.15) 0%, transparent 70%);
  top: -200px;
  left: -200px;
}

body::after {
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(62, 207, 178, 0.1) 0%, transparent 70%);
  bottom: -150px;
  right: -100px;
}

/* ── Layout ── */
.container {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

/* ── Header ── */
.header {
  text-align: center;
  margin-bottom: 48px;
  position: relative;
}

.theme-toggle {
  position: absolute;
  top: 0;
  right: 0;
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.1rem;
  transition: all var(--transition);
}

.theme-toggle:hover {
  background: var(--bg-card-hover);
  border-color: var(--glass-border-hover);
  transform: translateY(-2px);
}

.header .logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.header .logo-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  box-shadow: 0 8px 32px var(--accent-glow);
}

.header h1 {
  font-size: 2.4rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--text-primary) 30%, var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.5px;
}

.header p {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-top: 8px;
}

/* ── Glass Card ── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  padding: 28px;
  transition: border-color var(--transition);
}

.card:hover {
  border-color: var(--glass-border-hover);
}

.section-title {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

/* ── Drop Zone ── */
#drop-zone {
  border: 2px dashed var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 56px 24px;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

#drop-zone::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--accent-glow), transparent 60%);
  opacity: 0;
  transition: opacity var(--transition);
}

#drop-zone:hover,
#drop-zone.drag-over {
  border-color: var(--accent);
  background: rgba(124, 106, 247, 0.06);
}

#drop-zone:hover::before,
#drop-zone.drag-over::before {
  opacity: 1;
}

#drop-zone.drag-over {
  transform: scale(1.01);
}

.drop-icon {
  font-size: 3rem;
  margin-bottom: 16px;
  display: block;
  position: relative;
  z-index: 1;
  filter: drop-shadow(0 0 20px var(--accent-glow));
  animation: float 3s ease-in-out infinite;
}

@keyframes float {

  0%,
  100% {
    transform: translateY(0);
  }

  50% {
    transform: translateY(-8px);
  }
}

.drop-title {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
  position: relative;
  z-index: 1;
  margin-bottom: 6px;
}

.drop-subtitle {
  font-size: 0.85rem;
  color: var(--text-secondary);
  position: relative;
  z-index: 1;
}

.drop-btn {
  display: inline-block;
  margin-top: 20px;
  padding: 10px 24px;
  background: linear-gradient(135deg, var(--accent), #5c4de0);
  color: white;
  border-radius: 100px;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  position: relative;
  z-index: 1;
  box-shadow: 0 4px 20px var(--accent-glow);
  border: none;
}

.drop-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px var(--accent-glow);
}

#file-input {
  display: none;
}

/* ── Book List ── */
#book-list-section {
  margin-top: 28px;
  display: none;
}

.book-list-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.book-count {
  font-size: 0.8rem;
  background: rgba(124, 106, 247, 0.18);
  color: var(--accent-hover);
  padding: 3px 10px;
  border-radius: 100px;
  font-weight: 600;
}

#book-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.book-item {
  display: flex;
  align-items: center;
  gap: 14px;
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  transition: all var(--transition);
  animation: slideIn 0.3s ease both;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.book-item:hover {
  border-color: var(--glass-border-hover);
  background: var(--bg-card-hover);
  transform: translateX(3px);
}

.book-item.sortable-ghost {
  opacity: 0.3;
}

.book-item.sortable-drag {
  opacity: 0.9;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  border-color: var(--accent);
}

.drag-handle {
  color: var(--text-muted);
  cursor: grab;
  font-size: 1rem;
  padding: 4px;
  flex-shrink: 0;
  transition: color var(--transition);
}

.drag-handle:hover {
  color: var(--accent);
}

.drag-handle:active {
  cursor: grabbing;
}

.book-cover-thumb {
  width: 44px;
  height: 60px;
  border-radius: 6px;
  object-fit: cover;
  flex-shrink: 0;
  background: var(--dark-cover-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  border: 1px solid var(--glass-border);
  overflow: hidden;
}

.book-cover-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.book-info {
  flex: 1;
  min-width: 0;
}

.book-title-text {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.book-author-text {
  font-size: 0.78rem;
  color: var(--text-secondary);
  margin-top: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.book-meta-tags {
  display: flex;
  gap: 6px;
  margin-top: 5px;
  flex-wrap: wrap;
}

.tag {
  font-size: 0.68rem;
  padding: 2px 8px;
  border-radius: 100px;
  font-weight: 500;
}

.tag-chapters {
  background: rgba(62, 207, 178, 0.12);
  color: var(--accent-2);
}

.tag-size {
  background: rgba(124, 106, 247, 0.12);
  color: var(--accent);
}

.book-order-num {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  min-width: 28px;
  text-align: center;
  flex-shrink: 0;
}

.book-remove {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 6px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  font-size: 1rem;
  flex-shrink: 0;
}

.book-remove:hover {
  background: rgba(240, 81, 110, 0.15);
  color: var(--danger);
}

/* ── Metadata Editor ── */
#metadata-section {
  margin-top: 28px;
  display: none;
}

.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 600px) {
  .form-grid {
    grid-template-columns: 1fr;
  }
}

.form-full {
  grid-column: 1 / -1;
}

.field-label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 6px;
  display: block;
  letter-spacing: 0.3px;
}

.field-input {
  width: 100%;
  background: var(--dark-input-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: 'Inter', sans-serif;
  font-size: 0.9rem;
  padding: 10px 14px;
  transition: all var(--transition);
  outline: none;
}

.field-input:focus {
  border-color: var(--accent);
  background: rgba(124, 106, 247, 0.07);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.field-input::placeholder {
  color: var(--text-muted);
}

select.field-input option {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

/* Cover preview */
.cover-picker {
  display: flex;
  align-items: center;
  gap: 16px;
}

#cover-preview {
  width: 64px;
  height: 88px;
  border-radius: 8px;
  background: var(--dark-cover-bg);
  border: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  flex-shrink: 0;
  overflow: hidden;
}

#cover-preview img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.cover-picker-right {
  flex: 1;
}

/* ── Action Bar ── */
#action-section {
  margin-top: 28px;
  display: none;
}

.action-bar {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 100px;
  font-size: 0.9rem;
  font-weight: 600;
  font-family: 'Inter', sans-serif;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: white;
  opacity: 0;
  transition: opacity var(--transition);
}

.btn:hover::after {
  opacity: 0.06;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), #5c4de0);
  color: white;
  box-shadow: 0 4px 24px var(--accent-glow);
  flex: 1;
  justify-content: center;
}

.btn-primary:hover {
  box-shadow: 0 8px 36px var(--accent-glow);
  transform: translateY(-2px);
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.btn-secondary {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  color: var(--text-secondary);
}

.btn-secondary:hover {
  border-color: var(--glass-border-hover);
  color: var(--text-primary);
}

/* ── Progress ── */
#progress-section {
  margin-top: 20px;
  display: none;
}

.progress-bar-wrap {
  background: rgba(255, 255, 255, 0.05);
  border-radius: 100px;
  height: 6px;
  overflow: hidden;
  margin-bottom: 10px;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  border-radius: 100px;
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  width: 0%;
  box-shadow: 0 0 12px var(--accent-glow);
}

.progress-text {
  font-size: 0.82rem;
  color: var(--text-secondary);
  text-align: center;
}

/* Toast */
#toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--toast-bg);
  border: 1px solid var(--glass-border);
  border-radius: 100px;
  padding: 12px 24px;
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--toast-shadow);
  opacity: 0;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  pointer-events: none;
  white-space: nowrap;
  z-index: 1000;
}

#toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

#toast.success {
  border-color: var(--accent-2);
  color: var(--accent-2);
}

#toast.error {
  border-color: var(--danger);
  color: var(--danger);
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.2);
}