*{box-sizing:border-box;margin:0;padding:0}:root{--primary-color:#2196f3;--success-color:#4caf50;--error-color:#f44336;--text-primary:#333;--text-secondary:#666;--bg-primary:#f5f5f5;--bg-secondary:#fff;--border-color:#ddd}body{background:var(--bg-primary);color:var(--text-primary);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;min-height:100vh;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}.converter-app{align-items:center;display:flex;flex-direction:column;justify-content:center;min-height:100vh;padding:20px}h1{color:#111;font-size:clamp(1.8rem,5vw,2.2rem);font-weight:600;margin-bottom:8px}.subtitle,h1{text-align:center}.subtitle{color:var(--text-secondary);font-size:clamp(.9rem,2.5vw,1rem);line-height:1.5;margin-bottom:24px;max-width:600px}.container{background:var(--bg-secondary);border-radius:16px;box-shadow:0 4px 24px #0000000f;display:flex;flex-direction:column;max-height:calc(100vh - 200px);max-width:700px;padding:32px;width:100%}.drop-zone{background:#fafafa;border:2px dashed var(--border-color);border-radius:12px;cursor:pointer;padding:48px 20px;text-align:center;transition:all .2s ease}.drop-zone:hover{background:#f0f7ff;border-color:var(--primary-color)}.drop-zone.drag-over{background:#e3f2fd;border-color:#1976d2;transform:scale(1.01)}.drop-zone-text{color:#555;font-size:1.1rem;margin-bottom:16px}.drop-zone-icon{font-size:3rem;margin-bottom:16px;opacity:.3}.browse-btn{background:var(--primary-color);border:none;border-radius:24px;color:#fff;cursor:pointer;font-size:.95rem;font-weight:500;padding:11px 28px;transition:all .2s}.browse-btn:hover{background:#1976d2;box-shadow:0 4px 12px #2196f333;transform:translateY(-1px)}.browse-btn:active{transform:translateY(0)}.action-buttons{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;margin-top:24px}.add-files-btn{align-items:center;background:var(--bg-secondary);border:2px solid var(--primary-color);border-radius:24px;color:var(--primary-color);cursor:pointer;display:flex;font-size:.95rem;font-weight:500;gap:6px;padding:10px 24px;transition:all .2s}.add-files-btn:hover{background:var(--primary-color);box-shadow:0 4px 12px #2196f333;color:#fff;transform:translateY(-1px)}.convert-all-btn{background:var(--success-color);border:none;border-radius:24px;box-shadow:0 2px 8px #4caf5033;color:#fff;cursor:pointer;font-size:.95rem;font-weight:600;overflow:hidden;padding:12px 32px;position:relative;transition:all .3s}.convert-all-btn:before{background:#fff3;border-radius:50%;content:"";height:0;left:50%;position:absolute;top:50%;transform:translate(-50%,-50%);transition:width .6s,height .6s;width:0}.convert-all-btn:hover:before{height:300px;width:300px}.convert-all-btn:hover{background:#388e3c;box-shadow:0 6px 16px #4caf504d;transform:translateY(-1px)}.convert-all-btn:disabled{background:#ccc;box-shadow:none;cursor:not-allowed;transform:none}.add-files-btn:disabled{cursor:not-allowed;opacity:.5;pointer-events:none}.convert-all-btn.not-ready{background:#ccc;cursor:not-allowed}.convert-all-btn.not-ready:after{animation:rotate 2s linear infinite;content:"⏳";position:absolute;right:12px}@keyframes rotate{0%{transform:rotate(0)}to{transform:rotate(1turn)}}.restart-btn{align-items:center;background:var(--bg-secondary);border:2px solid var(--error-color);border-radius:24px;color:var(--error-color);cursor:pointer;display:flex;font-size:.95rem;font-weight:500;gap:6px;padding:10px 24px;transition:all .2s}.restart-btn:hover{background:var(--error-color);box-shadow:0 4px 12px #f4433633;color:#fff;transform:translateY(-1px)}@keyframes fadeIn{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}.container{animation:fadeIn .5s ease-out}@media (max-width:600px){.converter-app{padding:16px}.container{max-height:calc(100vh - 160px);padding:24px}.drop-zone{padding:40px 16px}.action-buttons{flex-direction:column}.add-files-btn,.convert-all-btn,.restart-btn{justify-content:center;width:100%}}@media (prefers-color-scheme:dark){:root{--text-primary:#f5f5f5;--text-secondary:#ccc;--bg-primary:#121212;--bg-secondary:#1e1e1e;--border-color:#333}.drop-zone{background:#252525}.drop-zone:hover{background:#1a237e}.drop-zone.drag-over{background:#283593}.file-item{background:#252525}.format-select{background:#333;border-color:#444;color:#f5f5f5}.status.ready{background:#1b5e20;color:#a5d6a7}.status.processing{background:#e65100;color:#ffcc80}.status.completed{background:#0d47a1;color:#90caf9}.status.error{background:#b71c1c;color:#ef9a9a}}@media print{.converter-app{display:none}}