:root {
  --font-body: 'Lora', Georgia, serif;
  --font-ui: 'Outfit', -apple-system, sans-serif;
  --font-size: 19px;
  --line-height: 1.7;
}

/* Dark mode by default */
[data-theme="dark"] {
  --bg-color: #0b0d12;
  --text-color: #d1d5db;
  --nav-bg: rgba(11, 13, 18, 0.85);
  --nav-border: rgba(255, 255, 255, 0.08);
  --accent-color: #66b0ff;
  --drawer-bg: #12141a;
  --btn-hover: rgba(255, 255, 255, 0.08);
  --btn-active-bg: rgba(102, 176, 255, 0.15);
  --btn-active-color: #66b0ff;
}

/* Sepia mode */
[data-theme="sepia"] {
  --bg-color: #f4ecd8;
  --text-color: #4a3826;
  --nav-bg: rgba(244, 236, 216, 0.9);
  --nav-border: rgba(91, 70, 54, 0.15);
  --accent-color: #d35400;
  --drawer-bg: #efe6cf;
  --btn-hover: rgba(91, 70, 54, 0.05);
  --btn-active-bg: rgba(211, 84, 0, 0.1);
  --btn-active-color: #d35400;
}

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

body {
  font-family: var(--font-body);
  background-color: var(--bg-color);
  color: var(--text-color);
  font-size: var(--font-size);
  line-height: var(--line-height);
  transition: background-color 0.4s ease, color 0.4s ease;
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

/* Navbar */
.navbar {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background-color: var(--nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--nav-border);
  font-family: var(--font-ui);
  z-index: 10;
}

.nav-brand {
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.02em;
}

.nav-controls {
  display: flex;
  align-items: center;
  gap: 20px;
}

/* Settings panel */
.settings-panel {
  display: flex;
  gap: 16px;
  align-items: center;
}
.theme-switch {
  display: flex;
  background: rgba(128,128,128,0.1);
  border-radius: 8px;
  padding: 3px;
}

button {
  background: transparent;
  border: none;
  color: var(--text-color);
  padding: 6px 14px;
  border-radius: 6px;
  cursor: pointer;
  font-family: var(--font-ui);
  font-size: 0.95rem;
  font-weight: 500;
  transition: all 0.2s ease;
}
button:hover { background: var(--btn-hover); }
button.active { 
  background: var(--btn-active-bg); 
  color: var(--btn-active-color); 
}
button:focus-visible { outline: 2px solid var(--accent-color); outline-offset: 2px; }

/* Transport (Bottom Bar) */
.transport {
  flex: 0 0 auto;
  background-color: var(--nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-top: 1px solid var(--nav-border);
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-ui);
  z-index: 10;
}

.transport button {
  border: 1px solid var(--nav-border);
}
.transport button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  border-color: transparent;
}

.audio-control { display: flex; align-items: center; gap: 16px; }
.audio-control button {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: 999px;
}

/* Reading Pane */
.reading-container {
  flex: 1 1 auto;
  overflow-y: auto;
  padding: 60px 24px 100px;
  scroll-behavior: smooth;
}

.reader-content {
  max-width: 680px;
  margin: 0 auto;
}

.reader-content h1 {
  font-family: var(--font-ui);
  font-size: 2.5em;
  margin-bottom: 0.3em;
  font-weight: 700;
  line-height: 1.1;
}

.reader-content h2.chapter-title {
  font-family: var(--font-ui);
  font-size: 1.6em;
  margin-top: 2em;
  margin-bottom: 1.2em;
  font-weight: 600;
  opacity: 0.9;
}

.reader-content p {
  margin-bottom: 1.4em;
  text-indent: 1.5em;
  text-align: justify;
}
.reader-content p.no-indent { text-indent: 0; }
.reader-content p:first-of-type { text-indent: 0; }

.reader-content hr { 
  border: none; 
  border-bottom: 1px solid var(--nav-border); 
  margin: 2.5em auto; 
  width: 50%; 
}

.scene-break { 
  text-align: center; 
  margin: 2.5em 0; 
  letter-spacing: 0.8em; 
  opacity: 0.4; 
  font-size: 1.2em;
}

/* Drawer for TOC */
.drawer {
  position: fixed;
  inset: 0 0 0 auto;
  width: min(380px, 90vw);
  background-color: var(--drawer-bg);
  border-left: 1px solid var(--nav-border);
  transform: translateX(100%);
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  z-index: 50;
  display: flex;
  flex-direction: column;
  box-shadow: -8px 0 30px rgba(0,0,0,0.15);
  font-family: var(--font-ui);
}
.drawer.open { transform: translateX(0); }

.drawer-header {
  padding: 24px;
  border-bottom: 1px solid var(--nav-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.drawer-header h2 { font-size: 1.2rem; font-weight: 600; }

.drawer-content {
  flex: 1;
  overflow-y: auto;
  padding: 12px 0;
}

.toc-item {
  width: 100%;
  text-align: left;
  border-radius: 0;
  padding: 14px 24px;
  display: block;
  font-size: 1rem;
  border-bottom: 1px solid var(--nav-border);
}
.toc-item:hover { background: var(--btn-hover); }
.toc-item.active { 
  border-left: 4px solid var(--accent-color); 
  font-weight: 600; 
  padding-left: 20px; 
  background: var(--btn-active-bg);
  color: var(--btn-active-color);
}

/* Utility */
.text-center { text-align: center; }
.mb-2 { margin-bottom: 2em; }
.mt-4 { margin-top: 4em; }