/* ==========================================================================
   盧恩星國大圖書館 (The Grand Rune Archive) - 核心設計系統樣式
   特色：深邃星空、符文金輝光暈、玻璃擬態、典雅版型與沉浸閱讀器
   ========================================================================== */

:root {
  /* 色彩體系 - 深空玄夜與星軌金芒 */
  --bg-space: #070913;
  --bg-deep: #0b0f20;
  --bg-card: rgba(18, 24, 48, 0.75);
  --bg-card-hover: rgba(28, 38, 74, 0.88);
  --bg-glass: rgba(14, 20, 42, 0.6);
  --border-rune: rgba(212, 175, 55, 0.25);
  --border-rune-glow: rgba(212, 175, 55, 0.6);

  /* 主題金輝與微光色調 */
  --gold-primary: #f5d77f;
  --gold-light: #fff2b2;
  --gold-dark: #b8860b;
  --rune-cyan: #5eead4;
  --rune-purple: #c084fc;
  --rune-blue: #60a5fa;

  /* 文字階層色彩 */
  --text-main: #f0f4fc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;

  /* 字體規範 */
  --font-serif: "Cinzel", "Noto Serif TC", "Songti TC", Georgia, serif;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "PingFang TC", "Microsoft JhengHei", sans-serif;
  --font-rune: "Segoe UI Symbol", "Noto Sans Runic", sans-serif;

  /* 動畫與效果 */
  --transition-smooth: all 0.28s cubic-bezier(0.4, 0, 0.2, 1);
  --glow-gold: 0 0 20px rgba(245, 215, 127, 0.35);
  --glow-rune: 0 0 25px rgba(94, 234, 212, 0.4);
  --box-shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.6);
}

/* 閱讀器主題覆寫（動態切換） */
body.theme-sepia {
  --reader-bg: #f5edd6;
  --reader-text: #2d261d;
  --reader-border: #d8cbb0;
}
body.theme-parchment {
  --reader-bg: #1c1815;
  --reader-text: #e6dac6;
  --reader-border: #3d342a;
}
body.theme-dark {
  --reader-bg: #090d19;
  --reader-text: #e2e8f0;
  --reader-border: rgba(212, 175, 55, 0.2);
}

/* 基礎重置與排版 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background-color: var(--bg-space);
  color: var(--text-main);
  font-family: var(--font-sans);
  min-height: 100vh;
  line-height: 1.7;
  overflow-x: hidden;
  position: relative;
}

/* 星空粒子與極光背景 */
.cosmos-background {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background: 
    radial-gradient(circle at 15% 20%, rgba(192, 132, 252, 0.08) 0%, transparent 40%),
    radial-gradient(circle at 85% 80%, rgba(94, 234, 212, 0.08) 0%, transparent 40%),
    radial-gradient(circle at 50% 50%, rgba(245, 215, 127, 0.05) 0%, transparent 60%);
}

#starCanvas {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  pointer-events: none;
  opacity: 0.8;
}

/* 應用程式容器 */
.app-container {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* 頂部導航欄 (Header) */
.library-navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2.5rem;
  background: rgba(7, 9, 19, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-rune);
  transition: var(--transition-smooth);
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 1rem;
  cursor: pointer;
  text-decoration: none;
}

.brand-emblem {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1.5px solid var(--gold-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  color: var(--gold-light);
  background: radial-gradient(circle, rgba(245, 215, 127, 0.2) 0%, rgba(11, 15, 32, 0.8) 100%);
  box-shadow: var(--glow-gold);
  transition: var(--transition-smooth);
}

.brand-wrapper:hover .brand-emblem {
  transform: rotate(45deg) scale(1.08);
  box-shadow: 0 0 25px rgba(245, 215, 127, 0.6);
}

.brand-title {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--gold-light);
  line-height: 1.2;
}

.brand-subtitle {
  font-size: 0.75rem;
  color: var(--rune-cyan);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  gap: 1.8rem;
  list-style: none;
}

.nav-link-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  padding: 0.5rem 0.8rem;
  border-radius: 6px;
  transition: var(--transition-smooth);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.nav-link-btn:hover,
.nav-link-btn.active {
  color: var(--gold-light);
  background: rgba(245, 215, 127, 0.1);
}

.nav-link-btn.active {
  border-bottom: 2px solid var(--gold-primary);
}

/* 英雄首頁區塊 (Hero) */
.hero-section {
  padding: 4.5rem 2rem 3rem;
  text-align: center;
  max-width: 900px;
  margin: 0 auto;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--border-rune);
  background: rgba(212, 175, 55, 0.08);
  color: var(--gold-primary);
  font-size: 0.85rem;
  margin-bottom: 1.5rem;
  letter-spacing: 0.05em;
}

.hero-title {
  font-family: var(--font-serif);
  font-size: 3rem;
  font-weight: 700;
  color: var(--gold-light);
  text-shadow: 0 2px 15px rgba(0, 0, 0, 0.8), 0 0 30px rgba(245, 215, 127, 0.25);
  margin-bottom: 1.2rem;
  letter-spacing: 0.06em;
}

.hero-desc {
  font-size: 1.12rem;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 2.2rem;
}

/* 搜尋與篩選列 */
.search-filter-bar {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
  max-width: 800px;
  margin: 0 auto 3rem;
  padding: 0 1.5rem;
}

.search-input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 1.2rem;
  color: var(--gold-primary);
  font-size: 1.2rem;
  pointer-events: none;
}

.search-input {
  width: 100%;
  padding: 1rem 1.2rem 1rem 3.2rem;
  border-radius: 999px;
  background: rgba(18, 24, 48, 0.8);
  border: 1.5px solid var(--border-rune);
  color: var(--text-main);
  font-size: 1.05rem;
  outline: none;
  transition: var(--transition-smooth);
  backdrop-filter: blur(10px);
}

.search-input:focus {
  border-color: var(--gold-primary);
  box-shadow: var(--glow-gold);
  background: rgba(24, 32, 64, 0.95);
}

.category-tags-row {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.cat-btn {
  padding: 0.45rem 1.1rem;
  border-radius: 20px;
  font-size: 0.88rem;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: rgba(18, 24, 48, 0.6);
  color: var(--text-muted);
  cursor: pointer;
  transition: var(--transition-smooth);
}

.cat-btn:hover,
.cat-btn.active {
  background: rgba(245, 215, 127, 0.2);
  border-color: var(--gold-primary);
  color: var(--gold-light);
  box-shadow: 0 0 12px rgba(245, 215, 127, 0.2);
}

/* 主內容區塊 */
.main-view-container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 2rem 5rem;
  width: 100%;
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--border-rune);
  padding-bottom: 0.8rem;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 1.6rem;
  color: var(--gold-light);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

/* 書籍格狀展示 (Book Grid) */
.book-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 2rem;
}

.book-card {
  background: var(--bg-card);
  border: 1px solid var(--border-rune);
  border-radius: 14px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition-smooth);
  box-shadow: var(--box-shadow-card);
  backdrop-filter: blur(12px);
  position: relative;
  cursor: pointer;
}

.book-card:hover {
  transform: translateY(-8px);
  border-color: var(--gold-primary);
  box-shadow: 0 15px 35px -5px rgba(0, 0, 0, 0.8), 0 0 25px rgba(245, 215, 127, 0.25);
  background: var(--bg-card-hover);
}

.book-card-cover {
  height: 190px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  overflow: hidden;
}

.rune-glow-badge {
  font-size: 4.5rem;
  font-family: var(--font-rune);
  color: rgba(255, 255, 255, 0.9);
  text-shadow: 0 0 20px rgba(255, 255, 255, 0.8), 0 0 40px var(--gold-primary);
  transition: var(--transition-smooth);
}

.book-card:hover .rune-glow-badge {
  transform: scale(1.15) rotate(5deg);
}

.book-card-badge {
  position: absolute;
  top: 1rem;
  right: 1rem;
  padding: 0.25rem 0.65rem;
  border-radius: 6px;
  font-size: 0.75rem;
  font-weight: 600;
  background: rgba(0, 0, 0, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: var(--gold-primary);
  backdrop-filter: blur(4px);
}

.book-card-body {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.book-category-tag {
  font-size: 0.8rem;
  color: var(--rune-cyan);
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-bottom: 0.4rem;
}

.book-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  color: var(--text-main);
  line-height: 1.4;
  margin-bottom: 0.5rem;
}

.book-author {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.9rem;
}

.book-desc {
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.6;
  margin-bottom: 1.2rem;
  flex-grow: 1;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 0.8rem;
  font-size: 0.8rem;
  color: var(--text-dim);
}

.read-btn {
  background: linear-gradient(135deg, var(--gold-primary), var(--gold-dark));
  color: #070913;
  border: none;
  padding: 0.4rem 0.9rem;
  border-radius: 6px;
  font-weight: 700;
  font-size: 0.85rem;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.read-btn:hover {
  filter: brightness(1.15);
  box-shadow: 0 0 15px rgba(245, 215, 127, 0.5);
}

/* ==========================================================================
   符文百科手冊視圖 (Rune Codex View)
   ========================================================================== */
.runes-codex-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.5rem;
}

.rune-tile {
  background: var(--bg-card);
  border: 1px solid var(--border-rune);
  border-radius: 12px;
  padding: 1.5rem 1.2rem;
  text-align: center;
  cursor: pointer;
  transition: var(--transition-smooth);
  backdrop-filter: blur(8px);
  position: relative;
  overflow: hidden;
}

.rune-tile:hover {
  transform: translateY(-5px);
  border-color: var(--rune-cyan);
  box-shadow: 0 8px 25px rgba(94, 234, 212, 0.2);
  background: var(--bg-card-hover);
}

.rune-tile-char {
  font-size: 3.2rem;
  font-family: var(--font-rune);
  color: var(--gold-light);
  line-height: 1;
  margin-bottom: 0.6rem;
  transition: var(--transition-smooth);
}

.rune-tile:hover .rune-tile-char {
  color: var(--rune-cyan);
  text-shadow: var(--glow-rune);
}

.rune-tile-name {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.2rem;
}

.rune-tile-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.6rem;
}

.rune-tile-category {
  display: inline-block;
  font-size: 0.72rem;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.05);
  color: var(--gold-primary);
  border: 1px solid rgba(212, 175, 55, 0.2);
}

/* 符文詳細彈窗 (Modal) */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(5, 7, 15, 0.85);
  backdrop-filter: blur(14px);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-content {
  background: var(--bg-deep);
  border: 1.5px solid var(--border-rune-glow);
  border-radius: 18px;
  max-width: 540px;
  width: 100%;
  padding: 2.2rem;
  box-shadow: 0 25px 50px rgba(0, 0, 0, 0.8), var(--glow-gold);
  position: relative;
  transform: scale(0.95);
  transition: transform 0.25s ease;
}

.modal-overlay.active .modal-content {
  transform: scale(1);
}

.modal-close-btn {
  position: absolute;
  top: 1.2rem;
  right: 1.2rem;
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.modal-close-btn:hover {
  color: var(--gold-light);
  transform: rotate(90deg);
}

/* ==========================================================================
   沉浸式閱讀器 (Reader View)
   ========================================================================== */
.reader-modal {
  position: fixed;
  inset: 0;
  z-index: 300;
  background: var(--bg-space);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.reader-modal.active {
  opacity: 1;
  pointer-events: auto;
}

.reader-header {
  padding: 1rem 2rem;
  border-bottom: 1px solid var(--border-rune);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(11, 15, 32, 0.95);
  backdrop-filter: blur(12px);
  z-index: 10;
}

.reader-meta-group {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.back-to-shelf-btn {
  background: rgba(245, 215, 127, 0.1);
  border: 1px solid var(--border-rune);
  color: var(--gold-primary);
  padding: 0.5rem 1rem;
  border-radius: 8px;
  font-size: 0.9rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  transition: var(--transition-smooth);
}

.back-to-shelf-btn:hover {
  background: rgba(245, 215, 127, 0.25);
  color: #fff;
}

.reader-title-label {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  color: var(--gold-light);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 400px;
}

.reader-toolbar {
  display: flex;
  align-items: center;
  gap: 1.2rem;
}

.tool-control-group {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(255, 255, 255, 0.05);
  padding: 0.25rem 0.5rem;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.tool-btn {
  background: transparent;
  border: none;
  color: var(--text-main);
  padding: 0.35rem 0.65rem;
  border-radius: 4px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.tool-btn:hover,
.tool-btn.active {
  background: rgba(245, 215, 127, 0.2);
  color: var(--gold-light);
}

/* 閱讀主體版面 */
.reader-workspace {
  display: flex;
  flex: 1;
  overflow: hidden;
}

.reader-sidebar {
  width: 300px;
  background: rgba(11, 15, 32, 0.8);
  border-right: 1px solid var(--border-rune);
  overflow-y: auto;
  padding: 1.5rem 1rem;
  transition: var(--transition-smooth);
}

.reader-sidebar.collapsed {
  margin-left: -300px;
}

.sidebar-title {
  font-family: var(--font-serif);
  font-size: 0.95rem;
  color: var(--gold-primary);
  margin-bottom: 1rem;
  padding-left: 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.chapter-nav-item {
  padding: 0.8rem 1rem;
  border-radius: 8px;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.92rem;
  margin-bottom: 0.3rem;
  transition: var(--transition-smooth);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.chapter-nav-item:hover {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
}

.chapter-nav-item.active {
  background: rgba(245, 215, 127, 0.15);
  border-left: 3px solid var(--gold-primary);
  color: var(--gold-light);
  font-weight: 600;
}

.reader-content-scroll {
  flex: 1;
  overflow-y: auto;
  padding: 3rem 1.5rem 8rem;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.reading-article-sheet {
  max-width: 780px;
  width: 100%;
  padding: 3rem 3.5rem;
  border-radius: 12px;
  background: var(--bg-deep);
  border: 1px solid var(--border-rune);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.4);
  transition: background 0.3s ease, color 0.3s ease;
}

body.theme-sepia .reading-article-sheet {
  background: #fbf0d9;
  color: #2b2319;
  border-color: #d6c4a5;
}

body.theme-parchment .reading-article-sheet {
  background: #1c1815;
  color: #ded1bd;
  border-color: #45372b;
}

.article-chapter-title {
  font-family: var(--font-serif);
  font-size: 1.85rem;
  color: var(--gold-light);
  margin-bottom: 1.8rem;
  border-bottom: 1px dashed var(--border-rune);
  padding-bottom: 1rem;
}

body.theme-sepia .article-chapter-title {
  color: #5d3d1e;
  border-color: #baa280;
}

.article-body-text {
  font-size: 1.05rem;
  line-height: 2.1;
  white-space: pre-line;
  letter-spacing: 0.03em;
}

.article-nav-actions {
  display: flex;
  justify-content: space-between;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.page-turn-btn {
  padding: 0.6rem 1.4rem;
  border-radius: 8px;
  background: rgba(245, 215, 127, 0.12);
  border: 1px solid var(--border-rune);
  color: var(--gold-light);
  font-size: 0.95rem;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.page-turn-btn:hover:not(:disabled) {
  background: rgba(245, 215, 127, 0.25);
  box-shadow: var(--glow-gold);
}

.page-turn-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

/* ==========================================================================
   世界觀互動介紹 (Worldview View)
   ========================================================================== */
.worldview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 2rem;
}

.worldview-card {
  background: var(--bg-card);
  border: 1px solid var(--border-rune);
  border-radius: 14px;
  padding: 2rem;
  backdrop-filter: blur(10px);
  transition: var(--transition-smooth);
}

.worldview-card:hover {
  transform: translateY(-5px);
  border-color: var(--gold-primary);
  box-shadow: var(--glow-gold);
}

.worldview-card-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.2rem;
}

.worldview-icon {
  font-size: 2.2rem;
}

.worldview-tag {
  font-size: 0.75rem;
  color: var(--rune-cyan);
  border: 1px solid rgba(94, 234, 212, 0.3);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
}

.worldview-card-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  color: var(--gold-light);
  margin-top: 0.3rem;
}

.worldview-card-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.8;
}

/* 頁尾 Footer */
.library-footer {
  margin-top: auto;
  border-top: 1px solid var(--border-rune);
  background: rgba(7, 9, 19, 0.95);
  padding: 2.5rem 2rem;
  text-align: center;
  color: var(--text-dim);
  font-size: 0.88rem;
}

.footer-runes {
  letter-spacing: 0.8rem;
  font-family: var(--font-rune);
  color: var(--gold-primary);
  font-size: 1.2rem;
  margin-bottom: 1rem;
  opacity: 0.7;
}

/* 響應式優化 */
@media (max-width: 768px) {
  .library-navbar {
    padding: 1rem;
    flex-direction: column;
    gap: 1rem;
  }
  .hero-title {
    font-size: 2.1rem;
  }
  .reader-workspace {
    flex-direction: column;
  }
  .reader-sidebar {
    width: 100%;
    max-height: 160px;
    border-right: none;
    border-bottom: 1px solid var(--border-rune);
  }
  .reading-article-sheet {
    padding: 1.8rem 1.4rem;
  }
}