/* ─── Theme Variables ───────────────────────────────────────────── */

:root {
  --font-body: 'Lora', Georgia, serif;
  --font-ui: 'DM Sans', system-ui, sans-serif;

  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;

  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-pill: 999px;

  --header-height: 56px;

  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
}

[data-theme="light"] {
  --color-bg: #FAFAF8;
  --color-bg-subtle: #F0EFEc;
  --color-bg-card: #F5F4F1;
  --color-text: #1A1A18;
  --color-text-muted: #6B6A66;
  --color-accent: #7C6A52;
  --color-accent-hover: #6A5A44;
  --color-border: #E0DFDB;
  --color-header-bg: rgba(250, 250, 248, 0.92);
}

[data-theme="sepia"] {
  --color-bg: #F5F0E8;
  --color-bg-subtle: #EDE8DE;
  --color-bg-card: #EDE7DA;
  --color-text: #2C2416;
  --color-text-muted: #7A6E5A;
  --color-accent: #8B6914;
  --color-accent-hover: #735809;
  --color-border: #D8D0C0;
  --color-header-bg: rgba(245, 240, 232, 0.92);
}

[data-theme="dark"] {
  --color-bg: #1A1A1A;
  --color-bg-subtle: #242424;
  --color-bg-card: #2A2A2A;
  --color-text: #D4CEBF;
  --color-text-muted: #8A8476;
  --color-accent: #A08C6E;
  --color-accent-hover: #B89E82;
  --color-border: #333330;
  --color-header-bg: rgba(26, 26, 26, 0.92);
}

/* ─── Base ──────────────────────────────────────────────────────── */

html {
  font-family: var(--font-ui);
  font-size: 16px;
  color: var(--color-text);
  background-color: var(--color-bg);
  scroll-behavior: smooth;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  transition: background-color var(--transition-base), color var(--transition-base);
}

/* ─── Header ────────────────────────────────────────────────────── */

.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-lg);
  background-color: var(--color-header-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.app-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-ui);
  font-weight: 600;
  font-size: var(--font-size-lg);
  color: var(--color-accent);
}

.app-nav {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav-link {
  font-family: var(--font-ui);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
  padding: var(--space-xs) 0;
  border-bottom: 2px solid transparent;
}

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

.nav-link.active {
  border-bottom-color: var(--color-accent);
}

/* ─── Main Content ──────────────────────────────────────────────── */

#main-content {
  flex: 1;
  width: 100%;
}

/* View transitions */
#main-content.view-exit {
  opacity: 0;
  transform: translateY(4px);
  transition: opacity 120ms ease, transform 120ms ease;
}

#main-content.view-enter {
  opacity: 0;
  transform: translateY(4px);
}

#main-content:not(.view-exit):not(.view-enter) {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 180ms ease, transform 180ms ease;
}

@media (prefers-reduced-motion: reduce) {
  #main-content.view-exit,
  #main-content.view-enter,
  #main-content:not(.view-exit):not(.view-enter) {
    transition: none;
    transform: none;
  }
}

/* ─── Search View ───────────────────────────────────────────────── */

.search-view {
  padding: var(--space-2xl) var(--space-lg);
  max-width: 720px;
  margin: 0 auto;
}

.search-hero {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.search-hero-title {
  font-family: var(--font-body);
  font-size: clamp(2.925rem, 7.8vw, 4.39rem);
  font-weight: 400;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
  line-height: 1.3;
}

.search-hero-subtitle {
  font-family: var(--font-ui);
  font-size: var(--font-size-base);
  color: var(--color-text-muted);
}

.search-form {
  position: relative;
  margin-bottom: var(--space-2xl);
}

.search-input {
  width: 100%;
  padding: var(--space-md) var(--space-lg);
  padding-right: 3.5rem;
  font-family: var(--font-ui);
  font-size: var(--font-size-lg);
  color: var(--color-text);
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  -webkit-appearance: none;
  appearance: none;
}

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

.search-input:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-accent) 20%, transparent);
}

.search-clear {
  position: absolute;
  right: var(--space-md);
  top: 50%;
  transform: translateY(-50%);
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  border-radius: var(--radius-pill);
  transition: color var(--transition-fast), background-color var(--transition-fast);
  opacity: 0;
  pointer-events: none;
}

.search-clear.visible {
  opacity: 1;
  pointer-events: auto;
}

.search-clear:hover {
  color: var(--color-text);
  background-color: var(--color-bg-subtle);
}

/* ─── Search Status ─────────────────────────────────────────────── */

.search-status {
  font-family: var(--font-ui);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-lg);
  min-height: 1.4em;
}

/* ─── Book Cards ─────────────────────────────────────────────────── */

.book-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.book-card {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-md);
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  min-height: 44px;
  text-align: left;
}

.book-card:hover,
.book-card:focus-visible {
  border-color: var(--color-accent);
  box-shadow: 0 2px 8px color-mix(in srgb, var(--color-accent) 12%, transparent);
  outline: none;
}

.book-cover {
  flex-shrink: 0;
  width: 60px;
  height: 88px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  background-color: var(--color-bg-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.book-cover-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: 1.5rem;
}

.book-meta {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: var(--space-xs);
  min-width: 0;
}

.book-title {
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.3;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.book-author {
  font-family: var(--font-ui);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.book-year {
  font-family: var(--font-ui);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

/* ─── Loading / Error / Empty States ───────────────────────────── */

.state-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-3xl) var(--space-lg);
  text-align: center;
  gap: var(--space-md);
}

.state-block-icon {
  font-size: 2.5rem;
  opacity: 0.4;
}

.state-block-title {
  font-family: var(--font-body);
  font-size: var(--font-size-lg);
  color: var(--color-text);
}

.state-block-body {
  font-family: var(--font-ui);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  max-width: 30ch;
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-accent);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ─── Library ────────────────────────────────────────────────────── */

.library-view .book-grid {
  width: 100%;
}

.library-view .book-card {
  width: 100%;
}

.library-card {
  position: relative;
}

.library-remove-btn {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  border-radius: var(--radius-pill);
  background-color: var(--color-bg-subtle);
  opacity: 0;
  transition: opacity var(--transition-fast), color var(--transition-fast);
  z-index: 1;
}

.library-card:hover .library-remove-btn,
.library-card:focus-within .library-remove-btn {
  opacity: 1;
}

.library-remove-btn:hover {
  color: var(--color-text);
  background-color: var(--color-border);
}

.library-progress-bar {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background-color: var(--color-border);
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  overflow: hidden;
}

.library-progress-fill {
  height: 100%;
  background-color: var(--color-accent);
  transition: width var(--transition-base);
}

.library-progress-label {
  color: var(--color-accent);
  font-weight: 500;
}

/* ─── Settings Trigger ──────────────────────────────────────────── */

.nav-settings-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-pill);
  color: var(--color-text-muted);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-settings-btn:hover {
  color: var(--color-text);
  background-color: var(--color-bg-subtle);
}

/* ─── Settings Panel ─────────────────────────────────────────────── */

.settings-panel {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 300;
}

.settings-panel.open {
  display: block;
}

.settings-backdrop {
  position: absolute;
  inset: 0;
  background-color: color-mix(in srgb, #000 40%, transparent);
  animation: fade-in var(--transition-base) forwards;
}

@keyframes fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

.settings-drawer {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(320px, 90vw);
  background-color: var(--color-bg);
  border-left: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  animation: slide-in var(--transition-base) forwards;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

@keyframes slide-in {
  from { transform: translateX(100%); }
  to { transform: translateX(0); }
}

.settings-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  background-color: var(--color-bg);
  z-index: 1;
}

.settings-title {
  font-family: var(--font-ui);
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-text);
}

.settings-close {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  border-radius: var(--radius-pill);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.settings-close:hover {
  color: var(--color-text);
  background-color: var(--color-bg-subtle);
}

.settings-body {
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.settings-section {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.settings-section-title {
  font-family: var(--font-ui);
  font-size: var(--font-size-sm);
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

.settings-option-group {
  display: flex;
  gap: var(--space-xs);
  flex-wrap: wrap;
}

.settings-option-btn {
  flex: 1;
  min-width: 0;
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-ui);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast);
  min-height: 44px;
  text-align: center;
}

.settings-option-btn:hover {
  color: var(--color-text);
  border-color: var(--color-text-muted);
}

.settings-option-btn.active {
  color: var(--color-accent);
  border-color: var(--color-accent);
  background-color: color-mix(in srgb, var(--color-accent) 8%, var(--color-bg-card));
}

.settings-section--danger {
  padding-top: var(--space-md);
  border-top: 1px solid var(--color-border);
}

.settings-danger-btn {
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-ui);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  background-color: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  min-height: 44px;
  text-align: left;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.settings-danger-btn:hover {
  color: #c0392b;
  border-color: #c0392b;
}

/* ─── Discovery ─────────────────────────────────────────────────── */

.discovery {
  display: flex;
  flex-direction: column;
  gap: var(--space-2xl);
}

.discovery-section {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.discovery-title {
  font-family: var(--font-ui);
  font-size: var(--font-size-sm);
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

.discovery-chips {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.discovery-chip {
  font-family: var(--font-ui);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  padding: var(--space-xs) var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background-color: var(--color-bg-card);
  transition: color var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast);
  white-space: nowrap;
}

.discovery-chip:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
  background-color: color-mix(in srgb, var(--color-accent) 6%, var(--color-bg));
}

.discovery-books {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  margin: 0 calc(-1 * var(--space-lg));
  padding: 0 var(--space-lg) var(--space-sm);
}

.discovery-books::-webkit-scrollbar {
  display: none;
}

.discovery-books-row {
  display: flex;
  flex-direction: row;
  gap: var(--space-md);
  width: max-content;
}

.discovery-section-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.discovery-section-header .discovery-title {
  flex: 1;
}

.discovery-books-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg-card);
  cursor: pointer;
  color: var(--color-text-muted);
  flex-shrink: 0;
  transition: color var(--transition-fast), border-color var(--transition-fast), opacity var(--transition-fast);
}

.discovery-books-arrow:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.discovery-books-arrow.hidden {
  opacity: 0;
  pointer-events: none;
}

.book-card--compact {
  flex-direction: column;
  gap: var(--space-sm);
  padding: var(--space-sm);
  width: 100px;
  align-items: flex-start;
}

.book-card--compact .book-cover {
  width: 100%;
  height: 136px;
}

.book-card--compact .book-title {
  font-size: 0.75rem;
  font-weight: 500;
  -webkit-line-clamp: 3;
}

/* ─── Load More ─────────────────────────────────────────────────── */

.search-load-more {
  display: block;
  width: 100%;
  margin-top: var(--space-lg);
  padding: var(--space-md);
  font-family: var(--font-ui);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.search-load-more:hover:not(:disabled) {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.search-load-more:disabled {
  opacity: 0.5;
  cursor: default;
}

/* ─── Desktop ────────────────────────────────────────────────────── */

@media (min-width: 768px) {
  .search-view {
    padding: var(--space-3xl) var(--space-xl);
  }

  .book-grid {
    gap: var(--space-sm);
  }

  .book-cover {
    width: 72px;
    height: 104px;
  }

  .library-remove-btn {
    opacity: 0;
  }
}