:root{--primary:#4285f4;--primary-hover:#1a73e8;--primary-pressed:#1557b0;--primary-ink:#4285f41a;--bg:#fff;--bg-soft:#f8f9fa;--text:#202124;--text-dim:#5f6368;--text-muted:#80868b;--border:#e0e3e7;--error:#d93025;--warn:#f9ab00;--ok:#1e8e3e;--shadow-1:0 1px 2px #3c40431a, 0 1px 3px 1px #3c40430d;--shadow-2:0 1px 3px #3c404326, 0 4px 8px #3c40431a;--radius:8px;--radius-lg:16px}*{box-sizing:border-box}html,body,#root{height:100%;margin:0;padding:0}body{background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased;-webkit-tap-highlight-color:transparent;overscroll-behavior-y:none;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif;font-size:16px;line-height:1.45}button{font-family:inherit}input,select{font-family:inherit;font-size:16px}code{font-family:ui-monospace,SF Mono,Menlo,Consolas,monospace}.app{min-height:100%;padding-top:env(safe-area-inset-top);padding-bottom:env(safe-area-inset-bottom);padding-left:env(safe-area-inset-left);padding-right:env(safe-area-inset-right)}.screen{flex-direction:column;min-height:100dvh;display:flex}.topbar{border-bottom:1px solid var(--border);background:var(--bg);top:env(safe-area-inset-top);z-index:10;justify-content:space-between;align-items:center;padding:14px 18px;display:flex;position:sticky}.brand{color:var(--text);letter-spacing:-.2px;font-size:18px;font-weight:500}.topbar-actions{gap:4px;display:flex}.icon-btn{cursor:pointer;color:var(--text-dim);background:0 0;border:0;border-radius:50%;min-width:44px;min-height:44px;padding:10px 12px;font-size:20px;line-height:1}.icon-btn:hover{background:var(--bg-soft);color:var(--text)}.icon-btn:active{background:var(--border)}.icon-btn.back{font-size:28px}.spacer{width:44px;display:inline-block}.lang-switcher{border-bottom:1px solid var(--border);gap:8px;padding:12px 16px;display:flex}.pair-btn{background:var(--bg-soft);border:1px solid var(--border);color:var(--text);cursor:pointer;border-radius:24px;flex:1;min-height:40px;padding:10px 14px;font-size:14px;font-weight:500;transition:all .12s}.pair-btn:hover:not(:disabled){border-color:var(--primary)}.pair-btn.active{background:var(--primary-ink);border-color:var(--primary);color:var(--primary)}.pair-btn:disabled{opacity:.5;cursor:not-allowed}.direction-badge{color:var(--primary);background:var(--primary-ink);border-bottom:1px solid var(--border);padding:10px 16px;font-size:13px}.chat-placeholder{text-align:center;flex:1;justify-content:center;align-items:center;min-height:120px;padding:32px;display:flex}.chat-feed{flex-direction:column;flex:1;gap:16px;padding:16px;display:flex;overflow-y:auto}.utterance{background:var(--bg-soft);border-radius:var(--radius-lg);box-shadow:var(--shadow-1);flex-direction:column;gap:10px;padding:14px 16px;display:flex}.utterance-source,.utterance-target{align-items:flex-start;gap:10px;display:flex}.lang-chip{background:var(--border);min-width:32px;height:22px;color:var(--text-dim);letter-spacing:.4px;border-radius:11px;flex-shrink:0;justify-content:center;align-items:center;padding:0 8px;font-size:11px;font-weight:600;display:inline-flex}.lang-chip.target{background:var(--primary);color:#fff}.utterance-source-text{color:var(--text-dim);flex:1;font-size:14px;line-height:1.45}.utterance-target-text{color:var(--text);letter-spacing:-.1px;flex:1;font-size:18px;font-weight:500;line-height:1.4}.session-bar{border-top:1px solid var(--border);background:var(--bg);flex-direction:column;gap:10px;padding:16px;display:flex;position:sticky;bottom:0}.session-btn{background:var(--primary);color:#fff;border-radius:var(--radius-lg);cursor:pointer;width:100%;min-height:64px;box-shadow:var(--shadow-2);border:0;justify-content:center;align-items:center;gap:12px;font-size:17px;font-weight:500;transition:background .12s,transform 80ms;display:flex}.session-btn:hover:not(:disabled){background:var(--primary-hover)}.session-btn:active:not(:disabled){background:var(--primary-pressed);transform:scale(.98)}.session-btn:disabled{cursor:not-allowed;opacity:.7;background:#aac9f5}.session-btn.active{background:var(--error)}.session-btn.active:hover:not(:disabled){background:#b3261e}.session-btn.connecting{background:var(--text-dim);cursor:progress}.session-btn-icon{font-size:22px;line-height:1}.dim{color:var(--text-dim);font-size:14px}.ok{color:var(--ok);margin:0;font-size:13px}.warn{color:var(--warn);margin:0;font-size:13px}.err{color:var(--error);word-break:break-word;margin:0;font-size:13px}.placeholder,.settings-list{flex:1;padding:24px 16px 32px}.setting-row{flex-direction:column;gap:8px;margin-bottom:24px;display:flex}.setting-row>label{color:var(--text-dim);text-transform:uppercase;letter-spacing:.6px;font-size:12px;font-weight:600}.setting-row input,.setting-row select{border:1px solid var(--border);border-radius:var(--radius);background:var(--bg);width:100%;color:var(--text);appearance:none;padding:12px 14px;font-size:16px}.setting-row input:focus,.setting-row select:focus{border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-ink);outline:none}.setting-hint{color:var(--text-muted);margin:0;font-size:12px}.primary-btn{background:var(--primary);color:#fff;border-radius:var(--radius);cursor:pointer;border:0;align-self:flex-start;min-height:44px;padding:12px 20px;font-size:15px;font-weight:500}.primary-btn:hover{background:var(--primary-hover)}.primary-btn:active{background:var(--primary-pressed)}.primary-btn:disabled{cursor:progress;background:#aac9f5}.primary-btn.secondary{background:var(--bg);color:var(--primary);border:1px solid var(--primary)}.primary-btn.secondary:hover{background:var(--primary-ink)}.primary-btn.secondary:active{background:#4285f42e}.history-list,.history-detail{flex:1;padding:16px;overflow-y:auto}.history-stats{padding:0 4px 12px;font-size:13px}.history-row{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius);cursor:pointer;text-align:left;flex-direction:column;align-items:flex-start;gap:4px;width:100%;margin-bottom:8px;padding:14px 16px;transition:background .12s;display:flex}.history-row:hover{background:var(--bg-soft)}.history-row:active{background:var(--border)}.history-row-pair{color:var(--primary);font-size:15px;font-weight:500}.history-row-date{color:var(--text-dim);font-size:13px}.segmented{border:1px solid var(--border);background:var(--bg-soft);border-radius:24px;display:inline-flex;overflow:hidden}.segmented button{cursor:pointer;color:var(--text-dim);background:0 0;border:0;min-height:40px;padding:10px 18px;font-size:14px;font-weight:500}.segmented button.active{background:var(--primary);color:#fff}