:root{--bg:#f4f5f7;--panel:#fff;--border:#e4e6eb;--text:#1a1d24;--muted:#6b7280;--accent:#2f6f4f;--accent-soft:#e8f2ec;--user-bubble:#2f6f4f;--coach-bubble:#f0f1f4;--danger:#c0392b;--shadow:0 1px 3px rgba(0,0,0,.06),0 8px 24px rgba(0,0,0,.05)}*{box-sizing:border-box}body,html{margin:0;padding:0;height:100%}body{background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif;-webkit-font-smoothing:antialiased}.app{max-width:720px;margin:0 auto;height:100vh;display:flex;flex-direction:column;padding:16px;gap:12px}.header{display:flex;align-items:center;justify-content:space-between;padding:14px 18px;background:var(--panel);border:1px solid var(--border);border-radius:14px;box-shadow:var(--shadow)}.brand{display:flex;flex-direction:column;gap:2px}.brand h1{font-size:18px;margin:0;letter-spacing:-.01em}.brand span{font-size:13px;color:var(--muted)}.header-right{gap:12px}.header-right,.status{display:flex;align-items:center}.status{gap:6px;font-size:12px;color:var(--muted)}.dot{width:8px;height:8px;border-radius:50%;background:#cbd0d8}.dot.online{background:#34a853}.dot.offline{background:var(--danger)}.lang-toggle{display:inline-flex;border:1px solid var(--border);border-radius:8px;overflow:hidden}.lang-toggle button{border:none;background:transparent;padding:4px 10px;font-size:12px;font-weight:600;color:var(--muted);cursor:pointer}.lang-toggle button.active{background:var(--accent-soft);color:var(--accent)}.messages{flex:1 1;overflow-y:auto;background:var(--panel);border:1px solid var(--border);border-radius:14px;box-shadow:var(--shadow);padding:18px;display:flex;flex-direction:column;gap:14px}.empty{margin:auto;max-width:440px;text-align:center;color:var(--muted);font-size:15px;line-height:1.55}.row{display:flex}.row.user{justify-content:flex-end}.row.coach{justify-content:flex-start}.bubble{max-width:78%;padding:11px 15px;border-radius:16px;font-size:15px;line-height:1.5;white-space:pre-wrap;word-wrap:break-word}.row.user .bubble{background:var(--user-bubble);color:#fff;border-bottom-right-radius:5px}.row.coach .bubble{background:var(--coach-bubble);color:var(--text);border-bottom-left-radius:5px}.bubble.error{background:#fdecea;color:var(--danger)}.typing{display:inline-flex;gap:4px;align-items:center}.typing span{width:6px;height:6px;border-radius:50%;background:var(--muted);animation:blink 1.3s ease-in-out infinite both}.typing span:nth-child(2){animation-delay:.2s}.typing span:nth-child(3){animation-delay:.4s}@keyframes blink{0%,80%,to{opacity:.2}40%{opacity:1}}.composer{display:flex;gap:10px;padding:10px;background:var(--panel);border:1px solid var(--border);border-radius:14px;box-shadow:var(--shadow)}.composer textarea{flex:1 1;resize:none;border:none;outline:none;font-family:inherit;font-size:15px;line-height:1.5;padding:8px 10px;max-height:140px;background:transparent;color:var(--text)}.composer button{align-self:flex-end;border:none;background:var(--accent);color:#fff;font-size:15px;font-weight:600;padding:10px 20px;border-radius:10px;cursor:pointer;transition:opacity .15s ease}.composer button:disabled{opacity:.5;cursor:not-allowed}.composer{flex-direction:column;align-items:stretch;gap:8px}.composer-input{display:flex;gap:10px}.composer-input textarea{flex:1 1;resize:none;border:none;outline:none;font-family:inherit;font-size:15px;line-height:1.5;padding:8px 10px;max-height:140px;background:transparent;color:var(--text)}.composer-input button{align-self:flex-end;border:none;background:var(--accent);color:#fff;font-size:15px;font-weight:600;padding:10px 20px;border-radius:10px;cursor:pointer;transition:opacity .15s ease}.composer-input button:disabled{opacity:.5;cursor:not-allowed}.ground-toggle{display:inline-flex;align-items:center;gap:8px;cursor:pointer;-webkit-user-select:none;-moz-user-select:none;user-select:none;font-size:13px;color:var(--muted);padding:2px 4px}.ground-toggle input{position:absolute;opacity:0;width:0;height:0}.ground-toggle .switch{position:relative;width:34px;height:18px;border-radius:999px;background:#cbd0d8;transition:background .15s ease;flex:none}.ground-toggle .switch:after{content:"";position:absolute;top:2px;left:2px;width:14px;height:14px;border-radius:50%;background:#fff;transition:transform .15s ease}.ground-toggle.on .switch{background:var(--accent)}.ground-toggle.on .switch:after{transform:translateX(16px)}.ground-toggle.on .ground-label{color:var(--accent);font-weight:600}.msg-wrap{display:flex;flex-direction:column;max-width:78%}.row.user .msg-wrap{align-items:flex-end}.msg-wrap .bubble{max-width:100%}.meta{display:flex;flex-wrap:wrap;align-items:center;gap:6px;margin-top:6px;padding-left:4px}.tag{font-size:11px;font-weight:600;padding:2px 8px;border-radius:999px}.tag.ok{background:var(--accent-soft);color:var(--accent)}.tag.muted{background:#eef0f3;color:var(--muted)}.tag.warn{background:#fdf0e3;color:#b26a00}.sources{display:inline-flex;flex-wrap:wrap;align-items:center;gap:5px}.sources-label{font-size:11px;color:var(--muted)}.chip{font-size:11px;background:#eef1f4;color:#3a4250;padding:2px 8px;border-radius:6px;cursor:default}.chip,.ghost-btn{border:1px solid var(--border)}.ghost-btn{background:transparent;color:var(--muted);font-size:12px;font-weight:600;padding:5px 12px;border-radius:8px;cursor:pointer}.ghost-btn:hover{color:var(--accent);border-color:var(--accent)}.ghost-btn.small{padding:3px 9px;font-size:11px}.modal-backdrop{position:fixed;inset:0;background:rgba(20,24,30,.45);display:flex;align-items:center;justify-content:center;padding:16px;z-index:50}.modal{width:100%;max-width:540px;max-height:88vh;overflow-y:auto;background:var(--panel);border-radius:16px;box-shadow:var(--shadow);padding:20px}.modal-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:4px}.modal-head h2{font-size:17px;margin:0}.modal-hint{font-size:13px;color:var(--muted);margin:6px 0 14px;line-height:1.5}.upload-form{border:1px solid var(--border);border-radius:12px;padding:14px;display:flex;flex-direction:column;gap:12px}.upload-row{display:flex;gap:10px;align-items:flex-end;flex-wrap:wrap}.field{display:flex;flex-direction:column;gap:4px;font-size:12px;color:var(--muted)}.field.grow{flex:1 1;min-width:160px}.field input,.field select{border:1px solid var(--border);border-radius:8px;padding:7px 9px;font-size:14px;font-family:inherit;color:var(--text);background:#fff}.primary-btn{border:none;background:var(--accent);color:#fff;font-size:14px;font-weight:600;padding:9px 18px;border-radius:9px;cursor:pointer}.primary-btn:disabled{opacity:.5;cursor:not-allowed}.upload-error{color:var(--danger);font-size:13px;margin:0}.doc-list{margin-top:18px}.doc-list-head{font-size:12px;font-weight:600;color:var(--muted);text-transform:uppercase;letter-spacing:.04em}.doc-item,.doc-list-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:8px}.doc-item{gap:10px;padding:10px 12px;border:1px solid var(--border);border-radius:10px}.doc-main{display:flex;flex-direction:column;gap:2px;min-width:0}.doc-title{font-size:14px;color:var(--text);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.doc-corpus{font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:.04em}.doc-status{font-size:12px;font-weight:600;padding:3px 10px;border-radius:999px;white-space:nowrap;flex:none}.doc-status.pending,.doc-status.processing{background:#fdf0e3;color:#b26a00}.doc-status.ready{background:var(--accent-soft);color:var(--accent)}.doc-status.failed{background:#fdecea;color:var(--danger)}.solve-btn{align-self:flex-start;border:1px solid var(--accent);background:transparent;color:var(--accent);border-radius:999px;padding:6px 14px;font-size:13px;font-weight:600;cursor:pointer;transition:background .15s ease,color .15s ease,opacity .15s ease}.solve-btn:hover:not(:disabled){background:var(--accent);color:#fff}.solve-btn:disabled{opacity:.5;cursor:not-allowed}.model-select{border:1px solid #cbd0d8;background:transparent;color:var(--muted);border-radius:8px;padding:4px 8px;font-size:13px;cursor:pointer}.model-select:focus{outline:2px solid var(--accent);outline-offset:1px}