:root{--background:#f8f9fa;--foreground:#202124;--primary:#1a73e8;--primary-hover:#1557b0;--surface:#fff;--border:#dadce0;--chord:#d97706;--muted:#5f6368;--nav-height:60px}[data-theme=dark]{--background:#202124;--foreground:#e8eaed;--primary:#8ab4f8;--primary-hover:#aecbfa;--surface:#303134;--border:#5f6368;--chord:#f59e0b;--muted:#9aa0a6}*{box-sizing:border-box;margin:0;padding:0}html{scroll-behavior:smooth}html,body{height:100%}body{background-color:var(--background);color:var(--foreground);padding-bottom:var(--nav-height);flex-direction:column;min-height:100vh;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif;transition:background-color .3s,color .3s;display:flex}a{color:inherit;text-decoration:none}button{cursor:pointer;background:0 0;border:none;font-family:inherit}.container{flex-direction:column;flex:1;width:100%;max-width:800px;min-height:calc(100vh + 120px);margin:0 auto;padding:1rem;display:flex}.mobile-nav{height:var(--nav-height);background-color:var(--surface);border-top:1px solid var(--border);z-index:50;justify-content:space-around;align-items:center;display:flex;position:fixed;bottom:0;left:0;right:0;box-shadow:0 -2px 10px #0000001f}.nav-item{color:var(--foreground);opacity:.7;flex-direction:column;align-items:center;padding:.5rem;font-size:.75rem;display:flex}.nav-item.active{color:var(--primary);opacity:1}.nav-icon{margin-bottom:2px;font-size:1.5rem}.app-header{background-color:var(--surface);border-bottom:1px solid var(--border);z-index:40;justify-content:space-between;align-items:center;padding:1rem;display:flex;position:sticky;top:0}.logo{color:var(--primary);font-size:1.25rem;font-weight:700}.card{background-color:var(--surface);border:1px solid var(--border);border-radius:8px;margin-bottom:1rem;padding:1rem;box-shadow:0 1px 3px #0000000d}.card-title{margin-bottom:.5rem;font-size:1.1rem;font-weight:600}.input{border:1px solid var(--border);background-color:var(--background);width:100%;color:var(--foreground);border-radius:8px;margin-bottom:1rem;padding:.75rem;font-size:1rem}.btn{background-color:var(--primary);color:#fff;text-align:center;border-radius:8px;width:100%;padding:.75rem 1.5rem;font-weight:600;transition:background-color .2s;display:block}.btn:hover{background-color:var(--primary-hover)}.btn-secondary{color:var(--foreground);border:1px solid var(--border);background-color:#0000}.btn-secondary:hover{background-color:var(--border)}.alphabet-index{flex-wrap:wrap;justify-content:center;gap:.5rem;margin:1rem 0;display:flex}.alpha-btn{background-color:var(--surface);border:1px solid var(--border);width:32px;height:32px;color:var(--foreground);border-radius:4px;justify-content:center;align-items:center;font-weight:700;display:flex}.alpha-btn:hover{background-color:var(--border)}.song-list-item{border-bottom:1px solid var(--border);justify-content:space-between;align-items:center;gap:1rem;padding:1rem;display:flex}.song-list-item:last-child{border-bottom:none}.song-list-item a{min-width:0}.song-title{word-wrap:break-word;overflow-wrap:break-word;word-break:break-word;font-size:1.1rem;font-weight:500}.song-key{color:var(--primary);white-space:nowrap;background-color:#1a73e81a;border:1px solid #1a73e84d;border-radius:4px;flex-shrink:0;padding:.2rem .5rem;font-size:.8rem;font-weight:600}[data-theme=dark] .song-key{color:var(--primary);background-color:#8ab4f81a;border-color:#8ab4f84d}.chord{color:var(--chord);letter-spacing:.02em;font-family:Courier New,monospace;font-size:.95em;font-weight:700;line-height:1.4}.lyric-line{white-space:pre-wrap;margin-bottom:.2rem;font-family:inherit}.controls-bar{background-color:var(--surface);border-radius:8px;justify-content:space-between;align-items:center;gap:1rem;margin-bottom:1rem;padding:1rem;display:flex}.control-group{align-items:center;gap:.5rem;display:flex}.control-btn{height:36px;color:var(--primary);cursor:pointer;background-color:#1a73e80d;border:1px solid #1a73e840;border-radius:8px;flex:1;justify-content:center;align-items:center;min-width:36px;font-size:1.25rem;font-weight:700;transition:all .2s;display:flex}.control-btn:hover{background-color:var(--primary);color:#fff;border-color:var(--primary)}[data-theme=dark] .control-btn{color:var(--primary);background-color:#8ab4f814;border:1px solid #8ab4f859}[data-theme=dark] .control-btn:hover{background-color:var(--primary);color:#202124;border-color:var(--primary)}.control-value{text-align:center;min-width:2rem;font-weight:600}.language-grid{grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:1rem;margin-top:1rem;display:grid}.language-card{background-color:var(--surface);border:1px solid var(--border);cursor:pointer;border-radius:12px;flex-direction:column;height:120px;transition:transform .2s,box-shadow .2s,border-color .2s;display:flex;overflow:hidden}.language-card:hover{border-color:var(--primary);transform:translateY(-2px);box-shadow:0 4px 12px #00000014}.card-indicator{width:100%;height:6px}.card-content{flex-direction:column;flex:1;justify-content:space-between;padding:1rem;display:flex}.lang-title{color:var(--foreground);font-size:1rem;font-weight:600}.lang-count{color:var(--muted);font-size:.8rem}.suggestion-item:hover{background-color:var(--background)!important}