/* =========================================================
   《宋词之境 · 词画合集》 Core Stylesheet
   Design Philosophy: Song Dynasty Aesthetic (Ru Ware, Pine Ink & Xuan Paper)
   ========================================================= */

:root {
  /* Color Palette - Day (Ru Ware Celadon & Xuan Paper) */
  --paper-bg: #f4f0e8;
  --paper-card: #fcfaf6;
  --paper-card-hover: #ffffff;
  --paper-card-subtle: #ece5d8;
  --paper-border: #e2d7c5;
  --paper-border-dark: #cbbfa7;
  
  --ink-primary: #151a1d;
  --ink-secondary: #384248;
  --ink-muted: #6b7780;
  --ink-faint: #9ba6af;
  --ink-wash: rgba(21, 26, 29, 0.04);
  
  /* Song Dynasty Ru Ware Celadon & Cinnabar Accents */
  --celadon: #2d5a63;
  --celadon-light: #447b86;
  --celadon-bg: #e6eff0;
  --celadon-border: #bfd5d9;
  
  --cinnabar: #b53824;
  --cinnabar-hover: #962816;
  --cinnabar-bg: #faedea;
  --cinnabar-border: #f0c3bc;
  
  --sandalwood: #8c532b;
  --sandalwood-bg: #f9f1e8;
  --gold-accent: #c49a45;
  
  --shadow-sm: 0 2px 8px rgba(25, 20, 15, 0.05);
  --shadow-md: 0 8px 24px rgba(25, 20, 15, 0.08);
  --shadow-lg: 0 16px 40px rgba(25, 20, 15, 0.12);
  --shadow-active: 0 4px 18px rgba(45, 90, 99, 0.18);
  --shadow-focus: 0 0 0 3px rgba(45, 90, 99, 0.22);
  
  --font-serif: "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", "SimSun", serif;
  --font-kai: "Kaiti SC", "STKaiti", "KaiTi", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  
  --transition-fast: 0.18s ease;
  --transition-smooth: 0.32s cubic-bezier(0.2, 0.8, 0.2, 1);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
}

/* Night / Ink Rubbing Mode (幽夜静思) */
body.theme-night {
  --paper-bg: #121518;
  --paper-card: #1a1e23;
  --paper-card-hover: #22272e;
  --paper-card-subtle: #1e2329;
  --paper-border: #2a313a;
  --paper-border-dark: #37414d;
  
  --ink-primary: #eff3f6;
  --ink-secondary: #c6d0d9;
  --ink-muted: #85929e;
  --ink-faint: #56636f;
  --ink-wash: rgba(255, 255, 255, 0.04);
  
  --celadon: #5398a6;
  --celadon-light: #70b3c2;
  --celadon-bg: #16282d;
  --celadon-border: #223e46;
  
  --cinnabar: #db5640;
  --cinnabar-hover: #ee6852;
  --cinnabar-bg: #381a16;
  --cinnabar-border: #5e261e;
  
  --sandalwood: #d49355;
  --sandalwood-bg: #2b1e13;
  --gold-accent: #e5b95f;
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
  --shadow-active: 0 4px 18px rgba(83, 152, 166, 0.25);
  --shadow-focus: 0 0 0 3px rgba(83, 152, 166, 0.3);
}

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

html, body {
  min-height: 100vh;
  background-color: var(--paper-bg);
  color: var(--ink-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  transition: background-color var(--transition-smooth), color var(--transition-smooth);
}

/* Subtle Xuan Paper Texture Overlay */
.paper-texture {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9999;
  opacity: 0.035;
  background-image: radial-gradient(var(--ink-primary) 0.75px, transparent 0.75px);
  background-size: 14px 14px;
}

/* =========================================================
   App Header & Brand
   ========================================================= */

.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--paper-bg);
  border-bottom: 1px solid var(--paper-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header-inner {
  max-width: 1480px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand-section {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-shrink: 0;
}

.bookshelf-back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background-color: var(--paper-card);
  border: 1px solid var(--paper-border);
  border-radius: var(--radius-sm);
  color: var(--ink-secondary);
  font-size: 0.88rem;
  font-weight: 500;
  text-decoration: none;
  transition: all var(--transition-fast);
}

.bookshelf-back:hover {
  background-color: var(--paper-card-hover);
  border-color: var(--celadon);
  color: var(--celadon);
  transform: translateX(-2px);
}

.brand-seal {
  width: 38px;
  height: 38px;
  background-color: var(--celadon);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-family: var(--font-kai);
  font-size: 1.4rem;
  font-weight: bold;
  box-shadow: inset 0 0 0 1.5px rgba(255, 255, 255, 0.35);
  user-select: none;
}

.brand-titles {
  display: flex;
  flex-direction: column;
}

.brand-titles h1 {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--ink-primary);
  line-height: 1.2;
}

.brand-sub {
  font-size: 0.76rem;
  color: var(--ink-muted);
  letter-spacing: 0.04em;
}

/* Search Bar */
.search-section {
  flex: 1;
  max-width: 520px;
  position: relative;
}

.search-box {
  display: flex;
  align-items: center;
  position: relative;
  background-color: var(--paper-card);
  border: 1px solid var(--paper-border);
  border-radius: var(--radius-md);
  padding: 6px 14px;
  transition: all var(--transition-fast);
}

.search-box:focus-within {
  border-color: var(--celadon);
  box-shadow: var(--shadow-focus);
  background-color: var(--paper-card-hover);
}

.search-icon {
  font-size: 0.95rem;
  margin-right: 8px;
  opacity: 0.6;
}

.search-input {
  flex: 1;
  border: none;
  background: transparent;
  font-size: 0.9rem;
  color: var(--ink-primary);
  outline: none;
  font-family: inherit;
}

.search-input::placeholder {
  color: var(--ink-faint);
  font-size: 0.85rem;
}

.clear-search-btn {
  display: none;
  border: none;
  background: transparent;
  color: var(--ink-muted);
  font-size: 0.85rem;
  padding: 4px;
  cursor: pointer;
}

.clear-search-btn.visible {
  display: block;
}

.search-shortcut {
  font-size: 0.72rem;
  padding: 2px 6px;
  background: var(--paper-card-subtle);
  border: 1px solid var(--paper-border);
  border-radius: 4px;
  color: var(--ink-muted);
  margin-left: 6px;
  user-select: none;
}

/* Search Results Dropdown */
.search-results-panel {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  right: 0;
  background: var(--paper-card);
  border: 1px solid var(--paper-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  max-height: 480px;
  overflow-y: auto;
  z-index: 200;
}

.search-results-header {
  padding: 10px 14px;
  border-bottom: 1px solid var(--paper-border);
  font-size: 0.8rem;
  color: var(--ink-muted);
  display: flex;
  justify-content: space-between;
  background: var(--paper-card-subtle);
}

.search-result-item {
  padding: 12px 14px;
  border-bottom: 1px solid var(--paper-border);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.search-result-item:hover,
.search-result-item.focused {
  background: var(--paper-card-hover);
}

.search-result-title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1rem;
  color: var(--celadon);
  margin-bottom: 4px;
}

.search-result-meta {
  font-size: 0.82rem;
  color: var(--ink-muted);
  margin-bottom: 4px;
}

.search-result-match {
  font-family: var(--font-kai);
  font-size: 0.95rem;
  color: var(--ink-primary);
  background: var(--paper-card-subtle);
  padding: 4px 8px;
  border-radius: 4px;
  margin-top: 4px;
}

.search-result-match mark {
  background: var(--gold-accent);
  color: #fff;
  padding: 0 2px;
  border-radius: 2px;
}

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.action-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 13px;
  background-color: var(--paper-card);
  border: 1px solid var(--paper-border);
  border-radius: var(--radius-sm);
  color: var(--ink-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.action-btn:hover {
  background-color: var(--paper-card-hover);
  border-color: var(--celadon);
  color: var(--celadon);
}

.action-btn[aria-pressed="false"],
.action-btn.is-muted {
  opacity: 0.55;
}

.action-btn .btn-icon {
  font-weight: bold;
}

/* Author Filter Chips Bar */
.author-filter-bar {
  max-width: 1480px;
  margin: 0 auto;
  padding: 8px 24px;
  display: flex;
  align-items: center;
  gap: 10px;
  border-top: 1px solid var(--paper-border);
  overflow-x: auto;
}

.filter-label {
  font-size: 0.8rem;
  color: var(--ink-muted);
  white-space: nowrap;
}

.author-chips-scroll {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 2px;
}

.author-chip {
  padding: 4px 11px;
  background: var(--paper-card);
  border: 1px solid var(--paper-border);
  border-radius: 20px;
  font-size: 0.8rem;
  color: var(--ink-secondary);
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.author-chip:hover {
  background: var(--paper-card-hover);
  border-color: var(--celadon);
  color: var(--celadon);
}

.author-chip.active {
  background: var(--celadon);
  border-color: var(--celadon);
  color: #ffffff;
}

.chip-count {
  font-size: 0.72rem;
  opacity: 0.8;
}

/* =========================================================
   Main Reader Stage
   ========================================================= */

.reader-stage {
  max-width: 1480px;
  margin: 20px auto 70px;
  padding: 0 24px;
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  gap: 28px;
  align-items: start;
}

/* =========================================================
   Left Column: Ci Card & Text Container
   ========================================================= */

.lyrics-column {
  min-width: 0;
}

.ci-card {
  background: var(--paper-card);
  border: 1px solid var(--paper-border);
  border-radius: var(--radius-lg);
  padding: 32px 36px;
  box-shadow: var(--shadow-md);
  position: relative;
}

.ci-header {
  border-bottom: 1px solid var(--paper-border);
  padding-bottom: 20px;
  margin-bottom: 20px;
}

.ci-badge-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
}

.ci-dynasty-badge {
  background: var(--celadon-bg);
  color: var(--celadon);
  border: 1px solid var(--celadon-border);
  font-size: 0.74rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 4px;
}

.ci-form-badge {
  background: var(--sandalwood-bg);
  color: var(--sandalwood);
  border: 1px solid #ebd0be;
  font-size: 0.74rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 4px;
}

.ci-tags-list {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.ci-tag {
  font-size: 0.72rem;
  color: var(--ink-muted);
  background: var(--paper-card-subtle);
  padding: 2px 6px;
  border-radius: 3px;
}

.ci-title {
  font-family: var(--font-serif);
  font-size: 1.85rem;
  font-weight: 700;
  color: var(--ink-primary);
  margin-bottom: 8px;
  letter-spacing: 0.04em;
  line-height: 1.6;
}

.ci-author-row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-kai);
  font-size: 1.05rem;
  color: var(--ink-secondary);
}

.author-seal {
  display: inline-block;
  font-size: 0.75rem;
  color: #fff;
  background-color: var(--cinnabar);
  padding: 1px 5px;
  border-radius: 2px;
  font-family: var(--font-serif);
}

/* Ci Preface (小序) */
.ci-preface {
  margin-top: 14px;
  padding: 10px 14px;
  background: var(--paper-card-subtle);
  border-left: 3px solid var(--celadon);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-family: var(--font-kai);
  font-size: 0.92rem;
  color: var(--ink-secondary);
  line-height: 1.7;
}

.ci-preface .preface-label {
  font-weight: bold;
  color: var(--celadon);
  display: inline;
  margin-right: 4px;
}

.ci-preface .preface-text {
  display: inline;
}

/* Stanza Tabs Bar (Quick Switch between Stanzas) */
.stanza-tabs-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px dashed var(--paper-border);
}

.stanza-tab-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  background: var(--paper-card-subtle);
  border: 1px solid var(--paper-border);
  border-radius: 20px;
  font-size: 0.84rem;
  color: var(--ink-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.stanza-tab-pill:hover {
  background: var(--paper-card-hover);
  border-color: var(--celadon);
  color: var(--celadon);
}

.stanza-tab-pill.active {
  background: var(--celadon-bg);
  border-color: var(--celadon);
  color: var(--celadon);
  font-weight: 600;
}

/* Ci Text Container (Scrollable & Focus-aligned) */
.ci-text-container {
  max-height: 600px;
  overflow-y: auto;
  padding-right: 8px;
  margin-bottom: 20px;
  scroll-behavior: smooth;
}

.ci-text-container::-webkit-scrollbar {
  width: 6px;
}

.ci-text-container::-webkit-scrollbar-thumb {
  background: var(--paper-border-dark);
  border-radius: 3px;
}

/* Stanza Block Container */
.stanza-block {
  margin-bottom: 24px;
  padding: 14px 18px;
  background: rgba(240, 245, 245, 0.35);
  border: 1px solid var(--paper-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast);
}

body.theme-night .stanza-block {
  background: rgba(26, 32, 38, 0.45);
}

.stanza-block.current-stanza {
  border-color: var(--celadon-border);
}

.stanza-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  font-family: var(--font-kai);
  font-size: 0.95rem;
  font-weight: bold;
  color: var(--celadon);
}

.stanza-header-line {
  flex: 1;
  height: 1px;
  background: linear-gradient(to right, var(--celadon-border), transparent);
}

/* Sentence Unit (画意大句单元) */
.sentence-unit {
  position: relative;
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 14px 16px;
  margin-bottom: 12px;
  background: var(--paper-card);
  border: 1.5px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  opacity: 0.72;
}

.sentence-unit:hover {
  opacity: 0.92;
  background: var(--paper-card-hover);
  border-color: var(--paper-border-dark);
  transform: translateX(2px);
}

.sentence-unit.active {
  opacity: 1;
  background: var(--paper-card-hover);
  border-color: var(--celadon);
  box-shadow: var(--shadow-active);
  transform: translateX(4px);
}

.sentence-num-stamp {
  flex-shrink: 0;
  width: 26px;
  height: 26px;
  background: var(--paper-card-subtle);
  border: 1px solid var(--paper-border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.76rem;
  font-family: var(--font-serif);
  color: var(--ink-muted);
  margin-top: 4px;
  transition: all var(--transition-fast);
}

.sentence-unit.active .sentence-num-stamp {
  background: var(--celadon);
  border-color: var(--celadon);
  color: #fff;
  font-weight: bold;
}

.sentence-body-wrap {
  flex: 1;
  font-family: var(--font-serif);
  font-size: 1.45rem;
  letter-spacing: 0.08em;
  line-height: 2.1;
  color: var(--ink-secondary);
}

.sentence-unit.active .sentence-body-wrap {
  color: var(--ink-primary);
  font-weight: 600;
}

/* Ruby Pinyin Styles */
ruby {
  ruby-position: over;
}

rt {
  font-family: var(--font-sans);
  font-size: 0.52em;
  color: var(--ink-muted);
  user-select: none;
  font-weight: 400;
  letter-spacing: 0;
  transform: translateY(2px);
}

body:not(.pinyin-enabled) rt {
  display: none;
}

/* Stanza-Segmented Stepper Box */
.stanzas-stepper-box {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 18px;
  padding: 12px 16px;
  background: var(--paper-card-subtle);
  border-radius: var(--radius-md);
  margin-bottom: 20px;
}

.stanza-step-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.stanza-step-label {
  font-family: var(--font-kai);
  font-size: 0.8rem;
  font-weight: bold;
  color: var(--celadon);
}

.stanza-dots-row {
  display: flex;
  gap: 6px;
}

.step-dot {
  width: 10px;
  height: 10px;
  background: var(--paper-border-dark);
  border-radius: 50%;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.step-dot:hover {
  background: var(--celadon-light);
  transform: scale(1.3);
}

.step-dot.active {
  background: var(--celadon);
  transform: scale(1.4);
  box-shadow: 0 0 0 3px var(--celadon-bg);
}

/* Appreciation Details */
.ci-appreciation-details {
  border: 1px solid var(--paper-border);
  border-radius: var(--radius-md);
  background: var(--paper-card-subtle);
  margin-bottom: 20px;
  overflow: hidden;
}

.appreciation-summary {
  padding: 12px 16px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--ink-secondary);
  display: flex;
  align-items: center;
  gap: 8px;
  user-select: none;
}

.appreciation-summary:hover {
  color: var(--celadon);
}

.summary-icon {
  color: var(--gold-accent);
}

.summary-arrow {
  margin-left: auto;
  transition: transform var(--transition-fast);
}

.ci-appreciation-details[open] .summary-arrow {
  transform: rotate(180deg);
}

.appreciation-body {
  padding: 0 16px 16px;
  font-size: 0.92rem;
  color: var(--ink-secondary);
  line-height: 1.8;
  font-family: var(--font-sans);
}

/* Pager Controls */
.ci-footer-pager {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 16px;
  border-top: 1px solid var(--paper-border);
}

.pager-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: var(--paper-card);
  border: 1px solid var(--paper-border);
  border-radius: var(--radius-sm);
  color: var(--ink-secondary);
  font-size: 0.88rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.pager-btn:hover {
  background: var(--paper-card-hover);
  border-color: var(--celadon);
  color: var(--celadon);
}

.ci-counter {
  font-family: var(--font-serif);
  font-size: 0.92rem;
  color: var(--ink-muted);
}

/* =========================================================
   Right Column: Artwork & In-Depth Explanation
   ========================================================= */

.artwork-column {
  position: sticky;
  top: 96px;
}

.artwork-card {
  background: var(--paper-card);
  border: 1px solid var(--paper-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.artwork-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 3 / 2;
  background: #111;
  overflow: hidden;
}

.artwork-loading {
  position: absolute;
  inset: 0;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  color: rgba(255, 255, 255, 0.9);
  background: rgba(17, 17, 17, 0.72);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.12s ease, visibility 0.12s ease;
}

.artwork-loading.is-visible { opacity: 1; visibility: visible; transition: none; }
.artwork-loading-spinner {
  width: 26px;
  height: 26px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: artworkSpin 0.7s linear infinite;
}
.artwork-loading-label { font-size: 0.85rem; }
@keyframes artworkSpin { to { transform: rotate(360deg); } }

.sentence-illustration-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: opacity 0.28s ease, transform 0.4s ease;
}

.sentence-illustration-img.is-loading,
.sentence-illustration-img.fade-out { opacity: 0; }

.sentence-illustration-img.fade-out {
  opacity: 0;
  transform: scale(1.02);
}

@media (prefers-reduced-motion: reduce) {
  .artwork-loading-spinner { animation: none; }
  .artwork-loading, .sentence-illustration-img { transition: none; }
}

.artwork-overlay {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 20px 20px 14px;
  background: linear-gradient(to top, rgba(12, 16, 20, 0.88), transparent);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.artwork-sentence-badge {
  background: var(--celadon);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 600;
  padding: 3px 9px;
  border-radius: 4px;
  white-space: nowrap;
}

.artwork-poetic-focus {
  color: #f7f9fa;
  font-family: var(--font-kai);
  font-size: 1.05rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Sentence Explanation Card */
.sentence-explanation-card {
  padding: 24px;
}

.explanation-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--paper-border);
}

.exp-seal {
  width: 32px;
  height: 32px;
  background: var(--cinnabar);
  color: #fff;
  font-family: var(--font-kai);
  font-size: 1.1rem;
  font-weight: bold;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.exp-title-group {
  min-width: 0;
}

.exp-caption {
  font-size: 0.74rem;
  color: var(--ink-muted);
  letter-spacing: 0.04em;
}

.exp-sentence-text {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--ink-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.exp-content {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.exp-section-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  font-weight: bold;
  color: var(--celadon);
  margin-bottom: 8px;
}

.exp-section-title .dot {
  width: 6px;
  height: 6px;
  background: var(--celadon);
  border-radius: 50%;
}

.exp-translation {
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--ink-primary);
  background: var(--paper-card-subtle);
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--gold-accent);
}

.exp-words {
  font-size: 0.88rem;
  line-height: 1.75;
  color: var(--ink-secondary);
}

.exp-words p {
  margin-bottom: 6px;
}

/* =========================================================
   Bottom Floating Keyboard Hint Bar
   ========================================================= */

.keyboard-nav-bar {
  position: fixed;
  bottom: 14px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(28, 34, 40, 0.92);
  color: #eff3f6;
  padding: 8px 20px;
  border-radius: 30px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  z-index: 90;
  font-size: 0.8rem;
  border: 1px solid rgba(255, 255, 255, 0.12);
  white-space: nowrap;
}

.nav-hint-group {
  display: flex;
  align-items: center;
  gap: 10px;
}

.keyboard-nav-bar kbd {
  background: rgba(255, 255, 255, 0.18);
  padding: 1px 6px;
  border-radius: 3px;
  font-family: inherit;
  font-size: 0.75rem;
  border: 1px solid rgba(255, 255, 255, 0.25);
}

.hint-divider {
  opacity: 0.4;
}

/* =========================================================
   Catalog Drawer Modal
   ========================================================= */

.catalog-drawer {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  justify-content: flex-end;
}

.catalog-drawer[hidden] {
  display: none;
}

.drawer-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
}

.drawer-content {
  position: relative;
  width: 100%;
  max-width: 620px;
  height: 100%;
  background: var(--paper-bg);
  box-shadow: -8px 0 32px rgba(0, 0, 0, 0.25);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  z-index: 1001;
}

.drawer-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--paper-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.drawer-title-group h2 {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  color: var(--ink-primary);
}

.drawer-subtitle {
  font-size: 0.8rem;
  color: var(--ink-muted);
}

.close-drawer-btn {
  border: none;
  background: transparent;
  font-size: 1.3rem;
  color: var(--ink-muted);
  cursor: pointer;
  padding: 6px;
}

.drawer-filter-pills {
  padding: 12px 24px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  border-bottom: 1px solid var(--paper-border);
  background: var(--paper-card);
}

.drawer-pill {
  padding: 4px 12px;
  border-radius: 20px;
  border: 1px solid var(--paper-border);
  background: var(--paper-card);
  font-size: 0.8rem;
  color: var(--ink-secondary);
  cursor: pointer;
  white-space: nowrap;
}

.drawer-pill.active {
  background: var(--celadon);
  border-color: var(--celadon);
  color: #fff;
}

.catalog-grid {
  flex: 1;
  overflow-y: auto;
  padding: 20px 24px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 14px;
}

.catalog-item-card {
  padding: 14px;
  background: var(--paper-card);
  border: 1px solid var(--paper-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.catalog-item-card:hover {
  background: var(--paper-card-hover);
  border-color: var(--celadon);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.catalog-item-card.current {
  border-color: var(--celadon);
  background: var(--celadon-bg);
}

.catalog-item-title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--ink-primary);
  margin-bottom: 4px;
}

.catalog-item-author {
  font-size: 0.82rem;
  color: var(--celadon);
  margin-bottom: 6px;
}

.catalog-item-snippet {
  font-family: var(--font-kai);
  font-size: 0.85rem;
  color: var(--ink-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* =========================================================
   Game & Memory Quiz Mode Styles
   ========================================================= */

/* Header Mode Toggle Button */
.mode-toggle-btn {
  border-color: var(--ochre);
  color: var(--ochre);
  font-weight: 500;
  transition: all var(--transition-fast);
}

.mode-toggle-btn:hover {
  background: var(--ochre-bg);
  border-color: var(--ochre);
  color: var(--ochre);
}

.mode-toggle-btn.is-active,
.mode-toggle-btn[aria-pressed="true"] {
  background: var(--cinnabar);
  border-color: var(--cinnabar);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(184, 59, 38, 0.25);
}

.mode-toggle-btn.is-active:hover {
  background: var(--cinnabar-hover);
  color: #ffffff;
}

/* Poem / Ci Mastery Badge */
.poem-mastery-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-size: 0.76rem;
  font-weight: 600;
  border: 1px solid currentColor;
  transition: all var(--transition-fast);
}

.poem-mastery-badge.mastered {
  color: var(--celadon);
  background: var(--celadon-bg);
  border-color: rgba(43, 97, 75, 0.3);
}

.poem-mastery-badge.vague {
  color: var(--ochre);
  background: var(--ochre-bg);
  border-color: rgba(181, 122, 34, 0.3);
}

.poem-mastery-badge.forgot {
  color: var(--cinnabar);
  background: var(--cinnabar-bg);
  border-color: rgba(184, 59, 38, 0.3);
}

.quiz-control-bar[hidden],
.quiz-suboptions[hidden],
.quiz-mastery-bar[hidden],
.poem-mastery-badge[hidden] {
  display: none !important;
}

/* Quiz Control Bar */
.quiz-control-bar {
  margin: 16px 0 20px 0;
  padding: 16px 18px;
  background: var(--paper-card-subtle);
  border: 1px dashed var(--paper-border-dark);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  gap: 14px;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.02);
  animation: quizBarFadeIn 0.24s cubic-bezier(0.16, 1, 0.3, 1);
}

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

.quiz-modes-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.quiz-mode-selector {
  display: inline-flex;
  background: var(--paper-card);
  border: 1px solid var(--paper-border);
  border-radius: var(--radius-md);
  padding: 3px;
  gap: 3px;
}

.quiz-tab-btn {
  appearance: none;
  background: transparent;
  border: none;
  padding: 6px 14px;
  font-size: 0.85rem;
  font-family: inherit;
  font-weight: 500;
  color: var(--ink-secondary);
  border-radius: 6px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all var(--transition-fast);
}

.quiz-tab-btn:hover {
  color: var(--ink-primary);
  background: rgba(0, 0, 0, 0.03);
}

.quiz-tab-btn.active {
  background: var(--paper-bg);
  color: var(--cinnabar);
  font-weight: 600;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
}

/* Context Sub-options Pills */
.quiz-suboptions {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
}

.subopt-label {
  color: var(--ink-muted);
  white-space: nowrap;
}

.subopt-pills {
  display: flex;
  gap: 6px;
}

.subopt-pill {
  appearance: none;
  background: var(--paper-card);
  border: 1px solid var(--paper-border);
  border-radius: 14px;
  padding: 3px 10px;
  font-size: 0.78rem;
  font-family: inherit;
  color: var(--ink-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.subopt-pill:hover {
  border-color: var(--ochre);
  color: var(--ochre);
}

.subopt-pill.active {
  background: var(--ochre-bg);
  border-color: var(--ochre);
  color: var(--ochre);
  font-weight: 600;
}

/* Quiz Action Bar */
.quiz-action-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.quiz-tip-badge {
  font-size: 0.8rem;
  color: var(--ochre);
  background: var(--ochre-bg);
  border: 1px dashed rgba(184, 115, 51, 0.4);
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.quiz-btn {
  appearance: none;
  font-family: inherit;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 0.88rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.quiz-kbd {
  font-size: 0.68rem;
  padding: 1px 4px;
  background: rgba(0, 0, 0, 0.06);
  border: 1px solid rgba(0, 0, 0, 0.12);
  border-radius: 3px;
  margin-left: 2px;
}

.quiz-btn-reveal {
  background: var(--cinnabar);
  color: #ffffff;
  border: 1px solid var(--cinnabar);
  font-weight: 600;
  box-shadow: 0 2px 6px rgba(184, 59, 38, 0.2);
}

.quiz-btn-reveal:hover {
  background: var(--cinnabar-hover);
  border-color: var(--cinnabar-hover);
  transform: translateY(-1px);
}

.quiz-btn-reveal.is-active-reveal {
  background: var(--celadon);
  border-color: var(--celadon);
}

.quiz-btn-reveal .quiz-kbd {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.35);
  color: #ffffff;
}

.quiz-btn-hint {
  background: var(--paper-card);
  color: var(--ochre);
  border: 1px solid var(--paper-border-dark);
}

.quiz-btn-hint:hover {
  background: var(--ochre-bg);
  border-color: var(--ochre);
}

.quiz-btn-secondary {
  background: var(--paper-card);
  color: var(--ink-secondary);
  border: 1px solid var(--paper-border);
}

.quiz-btn-secondary:hover {
  background: var(--paper-card-hover);
  color: var(--ink-primary);
  border-color: var(--paper-border-dark);
}

/* Mastery Self-Assessment Bar */
.quiz-mastery-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 10px;
  border-top: 1px dashed var(--paper-border);
  animation: masteryBarSlideDown 0.2s ease;
}

@keyframes masteryBarSlideDown {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.mastery-label {
  font-size: 0.82rem;
  color: var(--ink-muted);
  font-weight: 500;
}

.mastery-buttons {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.mastery-btn {
  appearance: none;
  font-family: inherit;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  font-size: 0.82rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  background: var(--paper-card);
  border: 1px solid var(--paper-border);
  color: var(--ink-secondary);
  transition: all var(--transition-fast);
}

.mastery-btn .m-seal {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 3px;
  font-size: 0.68rem;
  font-family: var(--font-kai);
  font-weight: bold;
}

.mastery-btn.btn-forgot .m-seal {
  background: var(--cinnabar-bg);
  color: var(--cinnabar);
  border: 1px solid var(--cinnabar-border);
}

.mastery-btn.btn-forgot:hover {
  border-color: var(--cinnabar);
  background: var(--cinnabar-bg);
  color: var(--cinnabar);
}

.mastery-btn.btn-vague .m-seal {
  background: var(--ochre-bg);
  color: var(--ochre);
  border: 1px solid rgba(181, 122, 34, 0.3);
}

.mastery-btn.btn-vague:hover {
  border-color: var(--ochre);
  background: var(--ochre-bg);
  color: var(--ochre);
}

.mastery-btn.btn-mastered .m-seal {
  background: var(--celadon-bg);
  color: var(--celadon);
  border: 1px solid rgba(43, 97, 75, 0.3);
}

.mastery-btn.btn-mastered:hover {
  border-color: var(--celadon);
  background: var(--celadon-bg);
  color: var(--celadon);
}

.mastery-btn.is-selected {
  font-weight: 600;
  box-shadow: 0 0 0 2px currentColor;
}

/* Masked Sentences in Sentence Units */
.sentence-unit.is-masked {
  background: var(--paper-card-subtle);
  border: 1.5px dashed var(--paper-border-dark);
  cursor: pointer;
  opacity: 0.9;
  user-select: none;
}

.sentence-unit.is-masked:hover {
  background: var(--paper-card);
  border-color: var(--ochre);
}

.sentence-unit.is-masked .sentence-body-wrap {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px;
  color: var(--ink-faint);
}

.masked-char-slot {
  display: inline-block;
  min-width: 1.35em;
  height: 1.6em;
  line-height: 1.6em;
  text-align: center;
  border-bottom: 2px dashed var(--paper-border-dark);
  color: var(--ink-faint);
  font-family: var(--font-serif);
  font-size: 1.35rem;
  transition: all var(--transition-fast);
}

.masked-char-slot.is-hinted {
  color: var(--ochre);
  font-weight: 600;
  border-bottom-color: var(--ochre);
  background: var(--ochre-bg);
  border-radius: 4px;
}

.masked-line-badge {
  margin-left: auto;
  font-size: 0.75rem;
  color: var(--ink-muted);
  background: var(--paper-card);
  border: 1px solid var(--paper-border);
  padding: 2px 8px;
  border-radius: 10px;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.sentence-unit.is-masked:hover .masked-line-badge {
  color: var(--ochre);
  border-color: var(--ochre);
}

.sentence-unit.just-revealed {
  animation: sentenceInkReveal 0.35s cubic-bezier(0.2, 0.8, 0.2, 1);
}

@keyframes sentenceInkReveal {
  from {
    opacity: 0.3;
    transform: translateY(3px);
    filter: blur(4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
    filter: blur(0);
  }
}

/* Artwork Masking in Quiz Mode */
.is-artwork-masked {
  filter: blur(14px) grayscale(30%) contrast(90%) !important;
  opacity: 0.85 !important;
  transform: scale(1.02);
  transition: filter 0.4s ease, opacity 0.4s ease, transform 0.4s ease !important;
}

.artwork-quiz-overlay {
  position: absolute;
  top: 14px;
  left: 14px;
  background: rgba(24, 29, 32, 0.75);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  color: #ffffff;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.78rem;
  letter-spacing: 0.5px;
  display: flex;
  align-items: center;
  gap: 6px;
  z-index: 5;
}

/* =========================================================
   Responsive Design
   ========================================================= */

@media (max-width: 1080px) {
  .reader-stage {
    grid-template-columns: minmax(0, 1fr);
    gap: 24px;
  }
  
  .artwork-column {
    position: static;
    order: -1;
    min-width: 0;
    width: 100%;
  }

  .lyrics-column {
    order: 1;
  }
}

@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
    padding: 10px 16px;
  }

  .header-actions {
    order: 2;
    width: 100%;
    min-width: 0;
    overflow-x: auto;
    overscroll-behavior-x: contain;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    touch-action: pan-x;
    padding-bottom: 2px;
  }

  .header-actions::-webkit-scrollbar {
    display: none;
  }

  .header-actions .action-btn {
    flex: 0 0 auto;
    white-space: nowrap;
  }

  .search-section {
    order: 3;
    max-width: 100%;
    width: 100%;
  }

  .brand-sub {
    display: none;
  }

  .ci-card {
    padding: 20px 18px;
    min-width: 0;
    overflow: hidden;
  }

  .ci-title {
    font-size: 1.5rem;
  }

  .sentence-body-wrap {
    font-size: 1.22rem;
    min-width: 0;
    max-width: 100%;
    overflow-wrap: anywhere;
    word-break: break-word;
  }

  .ci-text-container,
  .stanza-block,
  .stanza-sentences-group,
  .sentence-unit {
    width: 100%;
    min-width: 0;
  }

  .ci-text-container {
    overflow-x: hidden;
  }

  .sentence-unit,
  .sentence-unit:hover,
  .sentence-unit.active {
    transform: none;
  }

  .sentence-num-stamp {
    flex: 0 0 40px;
    width: 40px;
    height: 40px;
    aspect-ratio: 1;
    margin-top: 0;
    font-size: 0.7rem;
    line-height: 1;
    white-space: nowrap;
  }

  .stanzas-stepper-box,
  .stanza-step-group,
  .stanza-dots-row {
    min-width: 0;
  }

  .stanza-dots-row {
    flex-wrap: wrap;
  }

  .ci-footer-pager {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
    gap: 8px;
  }

  .ci-footer-pager .pager-btn {
    width: 100%;
    min-width: 0;
    gap: 5px;
    padding: 8px 9px;
  }

  .ci-footer-pager .pager-btn:first-child {
    justify-content: flex-start;
  }

  .ci-footer-pager .pager-btn:last-child {
    justify-content: flex-end;
  }

  .ci-footer-pager .pager-arrow,
  .ci-counter {
    flex: 0 0 auto;
    white-space: nowrap;
  }

  .ci-footer-pager .pager-text {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 0.74rem;
  }

  .ci-counter {
    font-size: 0.82rem;
    font-variant-numeric: tabular-nums;
  }

  .reader-stage {
    overflow-x: hidden;
    touch-action: pan-y;
  }

  .reader-stage img {
    pointer-events: none;
    -webkit-user-drag: none;
    user-select: none;
  }

  .keyboard-nav-bar {
    display: none;
  }
}