/* --- 全局与主题变量 --- */
:root {
  --font-serif: "Songti SC", "SimSun", "Noto Serif CJK SC", "Source Han Serif SC", STSong, Georgia, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --reading-font: var(--font-serif);
  --content-max-width: 820px;
  --font-size: 19px;
  --line-height: 1.85;
  --paragraph-spacing: 1.25em;
  --sidebar-width: 320px;
}

[data-theme="sepia"] {
  --bg-page: #fbf0d9;
  --bg-sidebar: #f4e5c5;
  --bg-card: #ebd9b3;
  --bg-hover: #e3cfa5;
  --text-main: #3d3121;
  --text-muted: #7d6b52;
  --border-color: #dfcdab;
  --accent: #9c5c28;
  --accent-light: rgba(156, 92, 40, 0.1);
  --progress-bg: #8c5222;
}

[data-theme="light"] {
  --bg-page: #fcfcfd;
  --bg-sidebar: #f4f5f7;
  --bg-card: #eaecef;
  --bg-hover: #dfe2e6;
  --text-main: #24292f;
  --text-muted: #6e7781;
  --border-color: #e1e4e8;
  --accent: #0969da;
  --accent-light: rgba(9, 105, 218, 0.1);
  --progress-bg: #0969da;
}

[data-theme="dark"] {
  --bg-page: #1e2227;
  --bg-sidebar: #171a1e;
  --bg-card: #252a31;
  --bg-hover: #2e353e;
  --text-main: #d7dae0;
  --text-muted: #8b949e;
  --border-color: #333942;
  --accent: #58a6ff;
  --accent-light: rgba(88, 166, 255, 0.15);
  --progress-bg: #58a6ff;
}

[data-theme="oled"] {
  --bg-page: #000000;
  --bg-sidebar: #0d0d0d;
  --bg-card: #181818;
  --bg-hover: #262626;
  --text-main: #b8b8b8;
  --text-muted: #666666;
  --border-color: #242424;
  --accent: #4aa3df;
  --accent-light: rgba(74, 163, 223, 0.15);
  --progress-bg: #4aa3df;
}

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

body {
  background-color: var(--bg-page);
  color: var(--text-main);
  font-family: var(--reading-font);
  transition: background-color 0.25s ease, color 0.25s ease;
  overflow-x: hidden;
}

/* 进度条 */
.progress-bar-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: transparent;
  z-index: 1000;
}
.progress-bar {
  height: 100%;
  width: 0%;
  background-color: var(--progress-bg);
  transition: width 0.1s ease;
}

/* 整体布局 */
.layout {
  display: flex;
  min-height: 100vh;
}

/* 侧边栏 */
.sidebar {
  width: var(--sidebar-width);
  height: 100vh;
  position: sticky;
  top: 0;
  background-color: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  z-index: 900;
  transition: transform 0.3s ease, margin-left 0.3s ease;
  font-family: var(--font-sans);
}

.sidebar.collapsed {
  margin-left: calc(-1 * var(--sidebar-width));
}

.sidebar-header {
  padding: 18px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-color);
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
}

.novel-selector-wrap {
  padding: 14px 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  border-bottom: 1px solid var(--border-color);
}
.novel-selector-wrap label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.novel-selector-wrap select {
  padding: 8px 12px;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-main);
  font-size: 0.95rem;
  outline: none;
  cursor: pointer;
}

.book-info-card {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-sidebar);
}
.book-info-card h3 {
  font-size: 1.1rem;
  margin-bottom: 4px;
}
.book-info-card .author {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}
.book-info-card .summary {
  font-size: 0.85rem;
  color: var(--text-main);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 10px;
}
.book-info-card .tags {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}
.tag-badge {
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 12px;
  background: var(--accent-light);
  color: var(--accent);
}

.chapter-list-header {
  padding: 12px 20px;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 600;
}

.chapter-list {
  list-style: none;
  overflow-y: auto;
  flex: 1;
  padding: 0 10px 20px 10px;
}
.chapter-item {
  padding: 10px 14px;
  border-radius: 6px;
  cursor: pointer;
  margin-bottom: 4px;
  font-size: 0.92rem;
  color: var(--text-main);
  transition: background 0.15s ease;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.chapter-item:hover {
  background: var(--bg-hover);
}
.chapter-item.active {
  background: var(--accent-light);
  color: var(--accent);
  font-weight: 600;
}

/* 主内容区 */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.top-bar {
  position: sticky;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: var(--bg-page);
  border-bottom: 1px solid var(--border-color);
  z-index: 800;
  backdrop-filter: blur(8px);
  font-family: var(--font-sans);
}

.left-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  overflow: hidden;
}
.header-chapter-title {
  font-weight: 600;
  font-size: 0.95rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 320px;
}

.reading-controls {
  display: flex;
  align-items: center;
  gap: 12px;
}

.font-controls {
  display: flex;
  align-items: center;
  background: var(--bg-card);
  border-radius: 6px;
  padding: 2px;
}
.font-val {
  font-size: 0.8rem;
  min-width: 42px;
  text-align: center;
  color: var(--text-muted);
}

.icon-btn, .pill-btn {
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--text-main);
  padding: 6px 10px;
  border-radius: 6px;
  font-size: 0.88rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s;
}
.pill-btn {
  background: var(--bg-card);
  padding: 4px 10px;
}
.icon-btn:hover, .pill-btn:hover {
  background: var(--bg-hover);
}

.theme-picker {
  display: flex;
  gap: 6px;
}
.theme-btn {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
}
.theme-btn.active {
  border-color: var(--accent);
  transform: scale(1.15);
}
.theme-light { background: #fcfcfd; border: 1px solid #ccc; }
.theme-sepia { background: #fbf0d9; border: 1px solid #d8be96; }
.theme-dark { background: #1e2227; }
.theme-oled { background: #000000; border: 1px solid #444; }

/* 阅读容器 */
.reader-container {
  flex: 1;
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 48px 24px 80px 24px;
  width: 100%;
}

.reader-content {
  font-size: var(--font-size);
  line-height: var(--line-height);
  letter-spacing: 0.03em;
  word-break: break-word;
}

.reader-content h1 {
  font-size: 1.85em;
  margin-bottom: 1.6em;
  text-align: center;
  font-weight: 700;
  padding-bottom: 0.5em;
  border-bottom: 1px dashed var(--border-color);
}

.reader-content p {
  margin-bottom: var(--paragraph-spacing);
  text-indent: 2em;
  text-align: justify;
}

.reader-content blockquote {
  margin: 1.5em 0;
  padding: 12px 20px;
  border-left: 4px solid var(--accent);
  background: var(--bg-card);
  border-radius: 0 6px 6px 0;
  font-size: 0.95em;
  color: var(--text-muted);
}
.reader-content blockquote p {
  text-indent: 0;
  margin-bottom: 0.5em;
}
.reader-content blockquote p:last-child {
  margin-bottom: 0;
}

.reader-content ul, .reader-content ol {
  margin: 1em 0 1em 2em;
}

/* 翻页按钮 */
.chapter-nav {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 60px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  font-family: var(--font-sans);
}

.nav-btn {
  flex: 1;
  padding: 12px 18px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-main);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}
.nav-btn:hover:not(:disabled) {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}
.nav-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}
.nav-btn.secondary {
  flex: 0 0 auto;
}

/* 加载动画 */
.loading-state {
  text-align: center;
  padding: 60px 0;
  color: var(--text-muted);
}
.spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--border-color);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 16px auto;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}

/* 响应式适配 */
.mobile-only {
  display: none;
}
.sidebar-overlay {
  display: none;
}

@media (max-width: 860px) {
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    transform: translateX(0);
    box-shadow: 4px 0 20px rgba(0,0,0,0.15);
  }
  .sidebar.collapsed {
    transform: translateX(-100%);
    margin-left: 0;
  }
  .mobile-only {
    display: inline-flex;
  }
  .sidebar-overlay {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.4);
    z-index: 850;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
  }
  .sidebar-overlay.active {
    opacity: 1;
    pointer-events: auto;
  }
  .reader-container {
    padding: 24px 16px 60px 16px;
  }
  .header-chapter-title {
    max-width: 140px;
  }
}