:root{--bg:#1a1a1a;--bg-surface:#2a2a2a;--bg-elevated:#333;--text:#e0e0e0;--text-muted:#888;--accent:#6a8caf;--accent-bright:#8ab4cf;--error:#e57373;--radius:8px;--shadow:0 2px 8px #0000004d}@media (prefers-color-scheme:light){:root{--bg:#f5f5f5;--bg-surface:#fff;--bg-elevated:#eee;--text:#222;--text-muted:#666;--accent:#4a6a8f;--accent-bright:#6a8ab0;--shadow:0 2px 8px #0000001a}}*{box-sizing:border-box;margin:0;padding:0}body{background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}.app{flex-direction:column;max-width:800px;min-height:100vh;margin:0 auto;display:flex}.app-header{text-align:center;border-bottom:1px solid var(--bg-elevated);padding:1rem}.app-header h1{font-size:1.5rem;font-weight:500}.app-main{flex-direction:column;flex:1;gap:1rem;padding:1rem;display:flex}.dropzone{border:2px dashed var(--bg-elevated);border-radius:var(--radius);text-align:center;padding:3rem 2rem;transition:border-color .2s}.dropzone.active{border-color:var(--accent);background:#6a8caf1a}.dropzone-label{cursor:pointer;color:var(--text-muted);font-size:1.1rem;display:block}.error{color:var(--error);margin-top:.5rem}.library{flex-direction:column;gap:.5rem;display:flex}.library-empty{color:var(--text-muted);text-align:center;padding:2rem}.book-card{background:var(--bg-surface);border-radius:var(--radius);box-shadow:var(--shadow);justify-content:space-between;align-items:center;padding:1rem;display:flex}.book-info h3{margin-bottom:.25rem;font-size:1rem}.book-info p{color:var(--text-muted);font-size:.875rem}.badge{background:var(--bg-elevated);border-radius:4px;margin-top:.25rem;margin-right:.25rem;padding:.125rem .5rem;font-size:.75rem;display:inline-block}.btn-remove{color:var(--error);cursor:pointer;background:0 0;border:none;padding:.25rem .5rem;font-size:1.2rem}.reader-view{flex-direction:column;height:100%;display:flex}.reader-header{justify-content:space-between;align-items:center;margin-bottom:1rem;display:flex}.reader-header h2{font-size:1.1rem}.progress{color:var(--text-muted);font-size:.875rem}.reader-content{background:var(--bg-surface);border-radius:var(--radius);box-shadow:var(--shadow);flex:1;padding:1rem;font-size:1.125rem;line-height:1.8;overflow-y:auto}.karaoke-text{font-size:1.25rem;line-height:2}.word{border-radius:2px;transition:background-color .1s}.word-highlight{background:var(--accent-bright);color:var(--bg);border-radius:2px;transition:background-color 50ms}.player-bar{background:var(--bg-surface);border-radius:var(--radius);box-shadow:var(--shadow);justify-content:space-between;align-items:center;gap:1rem;padding:.75rem 1rem;display:flex;position:sticky;bottom:0}.player-controls{gap:.5rem;display:flex}.player-controls button{background:var(--bg-elevated);color:var(--text);cursor:pointer;border:none;border-radius:50%;justify-content:center;align-items:center;width:44px;height:44px;font-size:1.2rem;transition:background .2s;display:flex}.player-controls button:hover:not(:disabled){background:var(--accent)}.player-controls button:disabled{opacity:.5;cursor:not-allowed}.player-options{align-items:center;gap:.5rem;display:flex}.voice-selector{background:var(--bg-elevated);color:var(--text);border-radius:var(--radius);cursor:pointer;border:none;padding:.5rem}.speed-control{gap:.125rem;display:flex}.speed-control button{background:var(--bg-elevated);color:var(--text-muted);cursor:pointer;border:none;border-radius:4px;padding:.25rem .5rem;font-size:.75rem}.speed-control button.active{background:var(--accent);color:var(--bg)}