:root{--bg: #f4f5f8;--surface: #ffffff;--border: #e3e6ec;--text: #1c2430;--text-muted: #6b7684;--accent: #4f46e5;--accent-strong: #4338ca;--accent-soft: #eef0fe;--user-bubble: linear-gradient(135deg, #4f46e5, #6366f1);--danger: #b3261e;--danger-soft: #fdecea;--danger-border: #f2c6c3;--warn: #92400e;--warn-soft: #fdf3d7;--radius-lg: 16px;--radius-md: 12px;--radius-sm: 8px;--shadow-sm: 0 1px 2px rgb(16 24 40 / .06);--shadow-md: 0 6px 20px rgb(16 24 40 / .08)}*{box-sizing:border-box}html,body,#root{height:100%}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased}button{font:inherit}.app-shell{display:flex;height:100%;overflow:hidden}.chat-pane{flex:1;display:flex;flex-direction:column;min-width:0;height:100%}.chat-header{display:flex;align-items:baseline;justify-content:space-between;gap:12px;padding:14px 22px;background:var(--surface);border-bottom:1px solid var(--border)}.chat-header__title{margin:0;font-size:17px;font-weight:700}.chat-header__status{font-size:12px;color:var(--text-muted)}.chat-header__status.is-busy{color:var(--accent-strong);font-weight:600}.sidebar{width:280px;flex-shrink:0;display:flex;flex-direction:column;background:var(--surface);border-right:1px solid var(--border)}.sidebar__brand{display:flex;align-items:center;gap:10px;padding:18px 18px 12px}.sidebar__logo{display:inline-flex;align-items:center;justify-content:center;width:34px;height:34px;border-radius:10px;background:var(--user-bubble);color:#fff;font-size:15px;flex-shrink:0}.sidebar__name{font-weight:700;font-size:15px}.sidebar__tagline{font-size:11px;color:var(--text-muted)}.sidebar__new{margin:6px 14px;padding:10px 12px;border:1px dashed var(--border);border-radius:var(--radius-md);background:transparent;color:var(--accent-strong);font-weight:600;cursor:pointer;transition:background .15s,border-color .15s}.sidebar__new:hover{background:var(--accent-soft);border-style:solid;border-color:var(--accent)}.sidebar__list{flex:1;overflow-y:auto;padding:6px;display:flex;flex-direction:column;gap:2px}.conversation-item{display:flex;flex-direction:column;gap:3px;width:100%;padding:10px 12px;text-align:left;border:none;background:transparent;border-radius:var(--radius-md);cursor:pointer}.conversation-item:hover{background:var(--bg)}.conversation-item.is-active{background:var(--accent-soft)}.conversation-item__preview{font-size:14px;color:var(--text);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.conversation-item.is-active .conversation-item__preview{font-weight:600}.conversation-item__time{font-size:11px;color:var(--text-muted)}.sidebar__footer{display:flex;align-items:center;justify-content:space-between;gap:8px;padding:12px 16px;border-top:1px solid var(--border)}.sidebar__user{font-size:13px;font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.sidebar__logout{border:none;background:transparent;color:var(--text-muted);font-size:13px;padding:6px 10px;border-radius:var(--radius-sm);cursor:pointer;flex-shrink:0}.sidebar__logout:hover{background:var(--bg);color:var(--danger)}.message-list{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:12px;padding:22px}.message-list--empty{align-items:center;justify-content:center}.empty-chat{text-align:center;color:var(--text-muted)}.empty-chat h2{margin:0 0 6px;font-size:18px;color:var(--text)}.empty-chat p{margin:0;font-size:14px}.msg{display:flex}.msg--user{justify-content:flex-end}.msg--assistant{justify-content:flex-start}.msg--system{justify-content:center}.msg__bubble{max-width:min(72%,560px);padding:10px 14px;border-radius:var(--radius-lg);background:var(--surface);box-shadow:var(--shadow-sm)}.msg--user .msg__bubble{background:var(--user-bubble);color:#fff;border-bottom-right-radius:4px}.msg--assistant .msg__bubble{border:1px solid var(--border);border-bottom-left-radius:4px}.msg--system .msg__bubble{background:transparent;box-shadow:none;color:var(--text-muted);font-size:13px;font-style:italic;padding:2px 8px}.msg__badges{display:flex;gap:6px;margin-bottom:6px}.badge{display:inline-block;font-size:11px;font-weight:600;padding:2px 9px;border-radius:999px;letter-spacing:.01em}.badge--exercise{background:var(--warn-soft);color:var(--warn)}.msg--user .badge--exercise{background:#ffffff38;color:#fff}.badge--failed{background:var(--danger-soft);color:var(--danger)}.msg__text{white-space:pre-wrap;word-break:break-word;line-height:1.55;font-size:15px}.msg__time{display:block;margin-top:5px;font-size:10.5px;color:var(--text-muted);text-align:right}.msg--user .msg__time{color:#ffffffbf}.typing{display:inline-flex;gap:4px;padding:4px 0}.typing span{width:6px;height:6px;border-radius:50%;background:var(--text-muted);animation:typing-blink 1.2s infinite}.typing span:nth-child(2){animation-delay:.2s}.typing span:nth-child(3){animation-delay:.4s}@keyframes typing-blink{0%,80%,to{opacity:.25}40%{opacity:1}}.meta-card{margin-top:10px;padding:10px 12px;background:#f8f9fc;border:1px solid var(--border);border-radius:var(--radius-sm);font-size:13px}.meta-card__title{margin:0 0 6px;font-size:10.5px;font-weight:700;text-transform:uppercase;letter-spacing:.07em;color:var(--text-muted)}.meta-card__row{display:grid;grid-template-columns:150px 1fr;gap:6px;padding:2px 0}.meta-card__label{color:var(--text-muted)}.meta-card__row ul{margin:0;padding-left:18px}.meta-card__escalation{margin:8px 0 0;padding:8px 10px;border-radius:var(--radius-sm);background:var(--danger-soft);color:var(--danger);font-weight:600;font-size:12.5px}.error-banner{display:flex;align-items:center;justify-content:space-between;gap:10px;margin:0 18px 10px;padding:10px 14px;background:var(--danger-soft);color:var(--danger);border:1px solid var(--danger-border);border-radius:var(--radius-md);font-size:14px}.error-banner__message{overflow-wrap:anywhere}.error-banner__dismiss{border:none;background:transparent;color:inherit;font-size:18px;line-height:1;padding:2px 6px;border-radius:var(--radius-sm);cursor:pointer;flex-shrink:0}.error-banner__dismiss:hover{background:#b3261e1a}.composer{display:flex;align-items:flex-end;gap:10px;padding:14px 18px;background:var(--surface);border-top:1px solid var(--border)}.exercise-toggle{display:inline-flex;align-items:center;gap:6px;padding:9px 12px;border:1px solid var(--border);border-radius:999px;font-size:13px;color:var(--text-muted);white-space:nowrap;cursor:pointer;user-select:none}.exercise-toggle input{accent-color:var(--accent);margin:0}.exercise-toggle:has(input:checked){background:var(--warn-soft);border-color:#eccf8f;color:var(--warn)}.composer__textarea{flex:1;resize:none;border:1px solid var(--border);border-radius:var(--radius-md);padding:11px 14px;font:inherit;font-size:15px;line-height:1.4;max-height:160px;min-height:44px;outline:none;background:var(--surface);color:var(--text);transition:border-color .15s,box-shadow .15s}.composer__textarea:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-soft)}.composer__textarea:disabled{background:var(--bg);cursor:not-allowed}.composer__send{border:none;background:var(--accent);color:#fff;font-weight:600;font-size:14px;padding:11px 18px;border-radius:var(--radius-md);cursor:pointer;transition:background .15s}.composer__send:hover:not(:disabled){background:var(--accent-strong)}.composer__send:disabled{opacity:.45;cursor:not-allowed}.splash{height:100%;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:14px;color:var(--text-muted);font-size:15px;padding:20px;text-align:center}.splash--error{color:var(--danger)}.splash__link{color:var(--accent-strong)}.spinner{width:28px;height:28px;border-radius:50%;border:3px solid var(--border);border-top-color:var(--accent);animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}@media(max-width:720px){.sidebar{width:210px}.sidebar__tagline{display:none}.msg__bubble{max-width:88%}.meta-card__row{grid-template-columns:1fr;gap:2px}}