/* ═══════════════════════════════════════════════════════
   ePUB 閱讀器 — reader.css
   ═══════════════════════════════════════════════════════ */

/* ── Design Tokens ─────────────────────────────────────── */
:root {
  --font-serif:   'Noto Serif TC', '標楷體', Georgia, serif;
  --font-sans:    'Noto Sans TC', '微軟正黑體', system-ui, sans-serif;
  --font-size:    18px;
  --line-height:  1.8;

  --topbar-h:     52px;
  --sidebar-w:    300px;

  /* Day theme (default) */
  --bg-page:      #f5f2ee;
  --bg-content:   #ffffff;
  --bg-topbar:    #2d5a27;
  --bg-sidebar:   #f0ece5;
  --text-main:    #2c2c2c;
  --text-muted:   #666;
  --border:       #ddd5c8;
  --accent:       #4a7c40;
  --link:         #4a8fa8;
  --btn-hover:    rgba(255,255,255,0.15);
}

body.theme-sepia {
  --bg-page:    #f0e6d0;
  --bg-content: #faf3e4;
  --bg-topbar:  #6b4c2a;
  --bg-sidebar: #e8d8bc;
  --text-main:  #3b2a14;
  --text-muted: #7a6040;
  --border:     #c8b090;
  --accent:     #8b6030;
  --link:       #7a5a28;
}

body.theme-night {
  --bg-page:    #1a1a1e;
  --bg-content: #242428;
  --bg-topbar:  #111114;
  --bg-sidebar: #1e1e22;
  --text-main:  #d8d2c8;
  --text-muted: #888;
  --border:     #333;
  --accent:     #6aaa60;
  --link:       #6aabcc;
  --btn-hover:  rgba(255,255,255,0.1);
}

/* ── Reset ─────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
[hidden] { display: none !important; }
html, body { height: 100%; overflow: hidden; }
body {
  font-family: var(--font-sans);
  background: var(--bg-page);
  color: var(--text-main);
  transition: background 0.2s, color 0.2s;
}
button { cursor: pointer; font-family: inherit; }
button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* ── Drop Zone ─────────────────────────────────────────── */
#drop-zone {
  position: fixed; inset: 0; z-index: 500;
  display: flex; align-items: center; justify-content: center;
  background: var(--bg-page);
  transition: background 0.15s;
}
#drop-zone.drag-over {
  background: #e4f0e4;
  outline: 4px dashed var(--accent);
  outline-offset: -16px;
}
body.theme-night #drop-zone.drag-over { background: #1e2e1e; }

#drop-inner {
  display: flex; flex-direction: column; align-items: center;
  gap: 0.6rem; text-align: center;
  padding: 2rem;
}
.drop-title  { font-family: var(--font-serif); font-size: 1.6rem; color: var(--text-main); }
.drop-sub    { color: var(--text-muted); font-size: 1rem; }
.drop-hint   { color: var(--text-muted); font-size: 0.8rem; margin-top: 0.3rem; }

#btn-open {
  padding: 0.55em 1.6em;
  background: var(--accent); color: #fff;
  border: none; border-radius: 6px;
  font-size: 1rem; font-family: var(--font-sans);
  transition: filter 0.15s;
  margin-top: 0.3rem;
}
#btn-open:hover { filter: brightness(1.12); }

/* ── Top Bar ───────────────────────────────────────────── */
#top-bar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 300;
  height: var(--topbar-h);
  display: flex; align-items: center; gap: 0.4rem;
  padding: 0 0.75rem;
  background: var(--bg-topbar);
  box-shadow: 0 2px 8px rgba(0,0,0,0.25);
  color: #fff;
}

#book-title-display {
  flex: 1; min-width: 0;
  font-size: 0.88rem; font-family: var(--font-serif);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
  color: rgba(255,255,255,0.9);
  padding: 0 0.4rem;
}

/* Icon button (toc toggle, close) */
.icon-btn {
  background: transparent; color: #fff; border: none;
  padding: 6px; border-radius: 4px; display: flex; align-items: center;
  transition: background 0.15s;
  flex-shrink: 0;
}
.icon-btn:hover { background: var(--btn-hover); }

/* Chapter nav */
#chapter-nav {
  display: flex; align-items: center; gap: 0.2rem;
  flex-shrink: 0;
}
.nav-btn {
  background: transparent; color: #fff;
  border: 1px solid rgba(255,255,255,0.35);
  border-radius: 4px; padding: 3px 10px;
  font-size: 1.2rem; line-height: 1;
  transition: background 0.15s;
}
.nav-btn:hover:not(:disabled) { background: var(--btn-hover); }
.nav-btn:disabled { opacity: 0.35; cursor: default; }
#progress-label {
  font-size: 0.8rem; white-space: nowrap; padding: 0 0.35rem;
  color: rgba(255,255,255,0.85);
}

/* Toolbar controls */
#toolbar-controls {
  display: flex; align-items: center; gap: 0.35rem; flex-shrink: 0;
}
.ctrl-group {
  display: flex; align-items: center; gap: 2px;
  border: 1px solid rgba(255,255,255,0.25);
  border-radius: 5px; overflow: hidden; padding: 0 2px;
}
.ctrl-btn {
  background: transparent; color: #fff;
  border: none; padding: 4px 7px;
  font-size: 0.78rem; font-family: var(--font-sans);
  transition: background 0.15s; white-space: nowrap;
}
.ctrl-btn:hover { background: var(--btn-hover); }
#font-size-display {
  font-size: 0.75rem; color: rgba(255,255,255,0.8);
  min-width: 2.2em; text-align: center;
}

/* Theme buttons */
.theme-group { gap: 0; }
.theme-btn {
  background: transparent; color: rgba(255,255,255,0.75);
  border: none; padding: 4px 8px; font-size: 0.78rem;
  transition: background 0.15s, color 0.15s;
}
.theme-btn:hover     { background: var(--btn-hover); color: #fff; }
.theme-btn.active    { background: rgba(255,255,255,0.22); color: #fff; font-weight: 600; }

/* Open button */
.open-btn {
  border: 1px solid rgba(255,255,255,0.4) !important;
  border-radius: 4px !important;
  margin-left: 0.2rem;
}

/* ── TOC Sidebar ───────────────────────────────────────── */
#toc-sidebar {
  position: fixed;
  top: var(--topbar-h); left: 0; bottom: 0;
  z-index: 250; width: var(--sidebar-w);
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  transform: translateX(-100%);
  transition: transform 0.25s ease, background 0.2s;
  overflow: hidden;
}
#toc-sidebar.is-open { transform: translateX(0); }

#toc-header {
  display: flex; justify-content: space-between; align-items: center;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border);
  font-weight: 600; font-family: var(--font-serif);
  font-size: 0.95rem; color: var(--text-main);
  flex-shrink: 0;
}
#btn-toc-close {
  background: transparent; border: none;
  color: var(--text-muted); font-size: 1rem; padding: 2px 6px;
  border-radius: 4px; transition: background 0.15s;
  cursor: pointer;
}
#btn-toc-close:hover { background: var(--border); }

#toc-list {
  overflow-y: auto; flex: 1; padding: 0.4rem 0;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}
#toc-list a {
  display: block;
  padding: 0.4rem 1rem;
  font-size: 0.88rem; line-height: 1.55;
  color: var(--text-main);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: background 0.12s;
  word-break: break-all;
}
#toc-list a:hover   { background: var(--border); text-decoration: none; }
#toc-list a.active  {
  border-left-color: var(--accent);
  background: rgba(74,124,64,0.1);
  font-weight: 600;
  color: var(--accent);
}
body.theme-night #toc-list a.active { background: rgba(106,170,96,0.1); }
.toc-d1 { padding-left: 1.8rem !important; font-size: 0.83rem !important; }
.toc-d2 { padding-left: 2.8rem !important; font-size: 0.8rem  !important; }
.toc-d3 { padding-left: 3.6rem !important; font-size: 0.78rem !important; }

/* Sidebar backdrop */
#toc-backdrop {
  position: fixed; inset: 0; z-index: 240;
  background: rgba(0,0,0,0.38);
}

/* ── Reader Area ───────────────────────────────────────── */
#reader-area {
  position: fixed;
  top: var(--topbar-h); left: 0; right: 0; bottom: 0;
  background: var(--bg-page);
  transition: left 0.25s ease;
}
body.sidebar-pinned #reader-area { left: var(--sidebar-w); }
body.sidebar-pinned #top-bar     { padding-left: calc(var(--sidebar-w) + 0.75rem); }

#chapter-display {
  width: 100%; height: 100%;
  display: block;
  background: var(--bg-content);
  overflow: auto;
  box-sizing: border-box;
}

/* ── Loading Overlay ───────────────────────────────────── */
#loading-overlay {
  position: fixed; inset: 0; z-index: 600;
  background: rgba(0,0,0,0.55);
  display: flex; align-items: center; justify-content: center;
}
#loading-inner {
  background: var(--bg-content);
  border-radius: 12px; padding: 2rem 2.5rem;
  text-align: center; color: var(--text-main);
  min-width: 200px;
}
.spinner {
  width: 40px; height: 40px;
  border: 4px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 1rem;
}
@keyframes spin { to { transform: rotate(360deg); } }
#loading-msg { font-size: 0.9rem; color: var(--text-muted); }

/* ── Chapter Jump Menu ─────────────────────────────────── */
#jump-menu {
  position: fixed; z-index: 800;
  background: var(--bg-content);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.25);
  display: flex; flex-direction: column;
  overflow: hidden;
  min-width: 140px;
  animation: fadeIn 0.15s ease;
}
@keyframes fadeIn {
  from { opacity: 0; transform: scale(0.92); }
  to   { opacity: 1; transform: scale(1); }
}
#jump-menu button {
  background: transparent; border: none;
  padding: 0.75rem 1.2rem;
  font-size: 0.95rem; font-family: var(--font-sans);
  color: var(--text-main); text-align: left;
  transition: background 0.12s;
}
#jump-menu button:hover { background: var(--bg-sidebar); }
#jump-menu button:disabled { opacity: 0.35; cursor: default; }
#jump-menu button + button { border-top: 1px solid var(--border); }

/* ── Error Toast ───────────────────────────────────────── */
#error-toast {
  position: fixed; bottom: 1.5rem; left: 50%; transform: translateX(-50%);
  z-index: 700;
  background: #d32f2f; color: #fff;
  border-radius: 8px; padding: 0.75rem 1.5rem;
  font-size: 0.9rem; box-shadow: 0 4px 16px rgba(0,0,0,0.3);
  max-width: 90vw; text-align: center;
  animation: slideUp 0.25s ease;
}
@keyframes slideUp {
  from { opacity: 0; transform: translateX(-50%) translateY(12px); }
  to   { opacity: 1; transform: translateX(-50%) translateY(0);    }
}

/* ── Google Drive button ────────────────────────────────── */
.open-btns {
  display: flex; gap: 0.5rem; align-items: center;
  flex-wrap: wrap; justify-content: center;
}
#btn-gdrive {
  display: flex; align-items: center; gap: 0.45em;
  padding: 0.55em 1.3em;
  background: #fff; color: #444;
  border: 1px solid #ccc; border-radius: 6px;
  font-size: 1rem; font-family: var(--font-sans);
  text-decoration: none;
  transition: box-shadow 0.15s;
}
#btn-gdrive:hover { box-shadow: 0 1px 6px rgba(0,0,0,0.22); }
body.theme-night #btn-gdrive { background: #2a2a2e; color: #ccc; border-color: #444; }

#btn-haodoo {
  padding: 0.55em 1.3em;
  background: #fff; color: #c0392b;
  border: 1px solid #c0392b; border-radius: 6px;
  font-size: 1rem; font-family: var(--font-sans);
  text-decoration: none;
  transition: background 0.15s, color 0.15s;
}
#btn-haodoo:hover { background: #c0392b; color: #fff; }
body.theme-night #btn-haodoo { background: #2a2a2e; color: #e74c3c; border-color: #e74c3c; }
body.theme-night #btn-haodoo:hover { background: #e74c3c; color: #fff; }

#btn-gdrive-new {
  background: rgba(255,255,255,0.12); color: #fff;
  border: 1px solid rgba(255,255,255,0.4); border-radius: 4px;
  padding: 3px 10px; font-size: 0.88rem; font-family: var(--font-sans);
  transition: background 0.15s;
}
#btn-gdrive-new:hover { background: rgba(255,255,255,0.25); }


/* ── Responsive ────────────────────────────────────────── */
@media (min-width: 900px) {
  /* Pin sidebar on desktop */
  #toc-backdrop { display: none !important; }
}

@media (max-width: 700px) {
  :root { --sidebar-w: 82vw; }
  #book-title-display { display: none; }
  #toolbar-controls { gap: 0.2rem; }
  .ctrl-group { padding: 0; }
  #font-size-display { min-width: 1.8em; }
}

@media (max-width: 480px) {
  /* 兩列工具列：第一列 TOC+章節導覽，第二列其他控制鈕 */
  :root { --topbar-h: 78px; --sidebar-w: 90vw; }
  #top-bar {
    height: auto;
    flex-wrap: wrap;
    padding: 2px 0.5rem;
    align-content: center;
    row-gap: 0;
  }
  #chapter-nav { flex: 1; justify-content: flex-end; }
  #toolbar-controls {
    width: 100%; justify-content: center;
    padding: 2px 0; gap: 0.15rem;
    border-top: 1px solid rgba(255,255,255,0.2);
  }
  .ctrl-btn { padding: 3px 5px; font-size: 0.72rem; }
  .theme-btn { padding: 3px 6px; font-size: 0.72rem; }
  #btn-gdrive-new { display: none; }
}