/* ─── Design Tokens ─────────────────────────────────────────────────── */
:root {
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

  /* Light */
  --bg:            #f5f4f1;
  --bg-card:       #ffffff;
  --bg-glass:      rgba(255,255,255,0.72);
  --bg-input:      #f0eeea;
  --border:        rgba(0,0,0,0.08);
  --border-focus:  rgba(0,0,0,0.3);
  --text-primary:  #0f0f0f;
  --text-secondary:#5a5a5a;
  --text-muted:    #9a9a9a;
  --accent:        #1a1a1a;
  --accent-hover:  #333333;
  --accent-fg:     #ffffff;
  --shadow-sm:     0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md:     0 4px 12px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg:     0 12px 32px rgba(0,0,0,0.10), 0 4px 8px rgba(0,0,0,0.06);
  --shadow-xl:     0 24px 64px rgba(0,0,0,0.12), 0 8px 16px rgba(0,0,0,0.06);
  --radius-sm:     8px;
  --radius-md:     12px;
  --radius-lg:     16px;
  --radius-xl:     24px;
  --transition:    0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg:            #0c0c0c;
  --bg-card:       #161616;
  --bg-glass:      rgba(22,22,22,0.80);
  --bg-input:      #1e1e1e;
  --border:        rgba(255,255,255,0.08);
  --border-focus:  rgba(255,255,255,0.3);
  --text-primary:  #f0f0f0;
  --text-secondary:#a0a0a0;
  --text-muted:    #606060;
  --accent:        #f0f0f0;
  --accent-hover:  #ffffff;
  --accent-fg:     #0c0c0c;
  --shadow-sm:     0 1px 3px rgba(0,0,0,0.3);
  --shadow-md:     0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg:     0 12px 32px rgba(0,0,0,0.5);
  --shadow-xl:     0 24px 64px rgba(0,0,0,0.6);
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text-primary);
  transition: background var(--transition-slow), color var(--transition-slow);
  min-height: 100vh;
  line-height: 1.5;
}

img, canvas { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; border: none; background: none; }
ul { list-style: none; }

/* ─── Typography ─────────────────────────────────────────────────────── */
.text-xs    { font-size: 0.72rem; line-height: 1.4; }
.text-sm    { font-size: 0.875rem; line-height: 1.5; }
.text-base  { font-size: 1rem; line-height: 1.6; }
.text-lg    { font-size: 1.125rem; line-height: 1.5; }
.text-xl    { font-size: 1.25rem; line-height: 1.4; }
.text-2xl   { font-size: 1.5rem; line-height: 1.3; font-weight: 600; }
.text-3xl   { font-size: 1.875rem; line-height: 1.2; font-weight: 700; }
.text-4xl   { font-size: 2.25rem; line-height: 1.15; font-weight: 700; }

.weight-400 { font-weight: 400; }
.weight-500 { font-weight: 500; }
.weight-600 { font-weight: 600; }
.weight-700 { font-weight: 700; }

.text-secondary { color: var(--text-secondary); }
.text-muted     { color: var(--text-muted); }

/* ─── Layout ─────────────────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ─── Navigation ─────────────────────────────────────────────────────── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  background: var(--bg-glass);
  border-bottom: 1px solid var(--border);
  transition: background var(--transition-slow), border-color var(--transition-slow);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
  gap: 16px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -0.02em;
  flex-shrink: 0;
}

.nav-logo-icon {
  width: 28px;
  height: 28px;
  background: var(--accent);
  border-radius: 7px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.nav-logo-icon svg { width: 16px; height: 16px; fill: var(--accent-fg); }

.nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}

.nav-link:hover,
.nav-link.active {
  color: var(--text-primary);
  background: var(--bg-input);
}

/* ─── Buttons ─────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 9px 18px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  transition: all var(--transition);
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--accent);
  color: var(--accent-fg);
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background: var(--accent-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.btn-primary:active { transform: translateY(0); }

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

.btn-secondary:hover {
  background: var(--border);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  color: var(--text-primary);
  background: var(--bg-input);
}

.btn-icon {
  width: 36px;
  height: 36px;
  padding: 0;
  border-radius: var(--radius-sm);
  background: var(--bg-input);
  color: var(--text-secondary);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: all var(--transition);
}

.btn-icon:hover {
  background: var(--bg-card);
  color: var(--text-primary);
  box-shadow: var(--shadow-sm);
}

.btn-icon svg { width: 16px; height: 16px; }

.btn-lg {
  padding: 13px 28px;
  font-size: 1rem;
  border-radius: var(--radius-md);
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none !important;
}

/* ─── Cards ───────────────────────────────────────────────────────────── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), border-color var(--transition), transform var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

/* ─── Book Cards ──────────────────────────────────────────────────────── */
.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 20px;
}

.book-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  cursor: pointer;
}

.book-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.book-cover {
  aspect-ratio: 3/4;
  overflow: hidden;
  position: relative;
  background: var(--bg-input);
}

.book-cover img,
.book-cover canvas {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.book-card:hover .book-cover img,
.book-card:hover .book-cover canvas {
  transform: scale(1.04);
}

.book-cover-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  background: linear-gradient(135deg, var(--bg-input), var(--bg));
}

.book-cover-placeholder svg {
  width: 36px;
  height: 36px;
  opacity: 0.25;
}

.book-category-badge {
  position: absolute;
  top: 10px;
  left: 10px;
  background: var(--bg-glass);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 3px 10px;
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-secondary);
}

.book-info {
  padding: 14px 16px 16px;
}

.book-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.35;
  margin-bottom: 3px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book-author {
  font-size: 0.78rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.book-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.book-pages {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-weight: 500;
}

.btn-open {
  font-size: 0.78rem;
  font-weight: 600;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: var(--accent-fg);
  transition: all var(--transition);
  border: none;
}

.btn-open:hover {
  opacity: 0.85;
  transform: translateY(-1px);
}

/* ─── Form Elements ───────────────────────────────────────────────────── */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  letter-spacing: 0.01em;
}

.form-input,
.form-select,
.form-textarea {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  color: var(--text-primary);
  font-size: 0.9rem;
  transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
  outline: none;
  width: 100%;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(128,128,128,0.12);
  background: var(--bg-card);
}

.form-textarea {
  resize: vertical;
  min-height: 80px;
  line-height: 1.5;
}

.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23666' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

/* ─── Radio Group ─────────────────────────────────────────────────────── */
.radio-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.radio-option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  background: var(--bg-input);
}

.radio-option:hover {
  border-color: var(--border-focus);
  background: var(--bg-card);
}

.radio-option input[type="radio"] {
  width: 17px;
  height: 17px;
  accent-color: var(--accent);
  flex-shrink: 0;
  margin-top: 1px;
  cursor: pointer;
}

.radio-option input[type="radio"]:checked + .radio-label-wrap {
  color: var(--text-primary);
}

.radio-option:has(input:checked) {
  border-color: var(--border-focus);
  background: var(--bg-card);
}

.radio-label-wrap { display: flex; flex-direction: column; gap: 2px; }
.radio-label { font-size: 0.875rem; font-weight: 600; }
.radio-desc  { font-size: 0.78rem; color: var(--text-secondary); }

/* ─── File Drop Zone ──────────────────────────────────────────────────── */
.drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius-lg);
  padding: 36px 24px;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition);
  background: var(--bg-input);
  position: relative;
}

.drop-zone:hover,
.drop-zone.drag-over {
  border-color: var(--border-focus);
  background: var(--bg-card);
}

.drop-zone.drag-over {
  box-shadow: 0 0 0 4px rgba(128,128,128,0.1);
}

.drop-zone input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  width: 100%;
  height: 100%;
}

.drop-icon {
  width: 44px;
  height: 44px;
  margin: 0 auto 12px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
}

.drop-icon svg { width: 22px; height: 22px; color: var(--text-muted); }

.drop-text { font-size: 0.875rem; font-weight: 500; margin-bottom: 4px; }
.drop-subtext { font-size: 0.78rem; color: var(--text-muted); }

/* ─── File List ───────────────────────────────────────────────────────── */
.file-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-top: 12px;
}

.file-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  animation: slideIn 0.2s ease;
}

@keyframes slideIn {
  from { opacity: 0; transform: translateY(-6px); }
  to   { opacity: 1; transform: translateY(0); }
}

.file-icon {
  width: 32px;
  height: 32px;
  background: var(--bg-input);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.file-icon svg { width: 16px; height: 16px; color: var(--text-secondary); }

.file-details { flex: 1; min-width: 0; }
.file-name { font-size: 0.825rem; font-weight: 500; truncate: ellipsis; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.file-size { font-size: 0.72rem; color: var(--text-muted); }

.file-remove {
  width: 26px;
  height: 26px;
  border-radius: 6px;
  background: none;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: all var(--transition);
}

.file-remove:hover {
  background: rgba(220,38,38,0.1);
  color: #dc2626;
}

.file-remove svg { width: 14px; height: 14px; }

/* ─── Progress ────────────────────────────────────────────────────────── */
.progress-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
}

.progress-overlay.active {
  opacity: 1;
  pointer-events: all;
}

.progress-box {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 36px 40px;
  width: 380px;
  max-width: calc(100vw - 48px);
  box-shadow: var(--shadow-xl);
  text-align: center;
}

.progress-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.progress-subtitle {
  font-size: 0.825rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.progress-bar-wrap {
  background: var(--bg-input);
  border-radius: 99px;
  height: 6px;
  overflow: hidden;
  margin-bottom: 10px;
}

.progress-bar {
  height: 100%;
  background: var(--accent);
  border-radius: 99px;
  transition: width 0.3s ease;
  width: 0%;
}

.progress-pct {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-secondary);
}

/* ─── Toast ───────────────────────────────────────────────────────────── */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
}

.toast {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  max-width: 340px;
  pointer-events: all;
  display: flex;
  align-items: center;
  gap: 10px;
  animation: toastIn 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes toastIn {
  from { opacity: 0; transform: translateY(12px) scale(0.95); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

.toast.hiding {
  animation: toastOut 0.2s ease forwards;
}

@keyframes toastOut {
  to { opacity: 0; transform: translateY(6px); }
}

.toast-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}

.toast.success .toast-dot { background: #22c55e; }
.toast.error   .toast-dot { background: #ef4444; }
.toast.info    .toast-dot { background: #3b82f6; }

/* ─── Search & Filter ─────────────────────────────────────────────────── */
.search-filter-bar {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 28px;
}

.search-wrap {
  position: relative;
  flex: 1;
  min-width: 200px;
}

.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  color: var(--text-muted);
  pointer-events: none;
}

.search-input {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 9px 12px 9px 38px;
  color: var(--text-primary);
  font-size: 0.875rem;
  width: 100%;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.search-input:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(128,128,128,0.12);
}

.filter-chips {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.chip {
  padding: 6px 13px;
  border-radius: 99px;
  font-size: 0.78rem;
  font-weight: 500;
  border: 1px solid var(--border);
  background: var(--bg-input);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
}

.chip:hover { color: var(--text-primary); background: var(--bg-card); }
.chip.active {
  background: var(--accent);
  color: var(--accent-fg);
  border-color: var(--accent);
}

/* ─── Theme Toggle ────────────────────────────────────────────────────── */
.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: var(--bg-input);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition);
  flex-shrink: 0;
}

.theme-toggle:hover {
  background: var(--bg-card);
  box-shadow: var(--shadow-sm);
}

.theme-toggle svg { width: 16px; height: 16px; color: var(--text-secondary); }

/* ─── Empty State ─────────────────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 80px 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.empty-state-icon {
  width: 64px;
  height: 64px;
  background: var(--bg-input);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 8px;
}

.empty-state-icon svg { width: 28px; height: 28px; color: var(--text-muted); }
.empty-state h3 { font-size: 1.1rem; font-weight: 600; }
.empty-state p  { font-size: 0.875rem; color: var(--text-secondary); max-width: 360px; }

/* ─── Cover Upload Preview ────────────────────────────────────────────── */
.cover-upload-wrap {
  display: flex;
  gap: 12px;
  align-items: flex-start;
}

.cover-preview {
  width: 80px;
  height: 107px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-input);
  flex-shrink: 0;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.cover-preview-placeholder { color: var(--text-muted); }
.cover-preview-placeholder svg { width: 24px; height: 24px; }

/* ─── Page Hero ───────────────────────────────────────────────────────── */
.page-hero {
  padding: 48px 0 36px;
}

.page-hero h1 {
  font-size: clamp(1.6rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 6px;
}

.page-hero p {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 500px;
}

/* ─── Divider ─────────────────────────────────────────────────────────── */
.divider {
  height: 1px;
  background: var(--border);
  margin: 0;
}

/* ─── Misc ────────────────────────────────────────────────────────────── */
.flex { display: flex; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: 8px; }
.gap-3 { gap: 12px; }
.gap-4 { gap: 16px; }
.mb-1 { margin-bottom: 4px; }
.mb-2 { margin-bottom: 8px; }
.mb-3 { margin-bottom: 12px; }
.mb-4 { margin-bottom: 16px; }
.mb-5 { margin-bottom: 20px; }
.mb-6 { margin-bottom: 24px; }
.mb-8 { margin-bottom: 32px; }
.hidden { display: none !important; }

/* ─── Responsive ──────────────────────────────────────────────────────── */
@media (max-width: 640px) {
  .container { padding: 0 16px; }
  .books-grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 14px; }
  .page-hero { padding: 32px 0 24px; }
  .search-filter-bar { flex-direction: column; align-items: stretch; }
  .nav-link { display: none; }
}

/* ─── Skeleton Loading ────────────────────────────────────────────────── */
.skeleton {
  background: linear-gradient(90deg, var(--bg-input) 25%, var(--border) 50%, var(--bg-input) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.4s infinite;
  border-radius: var(--radius-sm);
}

@keyframes shimmer {
  from { background-position: 200% 0; }
  to   { background-position: -200% 0; }
}