:root{--bg: #f7f8fb;--panel: #ffffff;--border: #e5e7ed;--accent: #1f6feb;--text: #1f2430;--muted: #6b7280;--radius: 14px;--shadow: 0 8px 24px rgba(31, 47, 79, .08);font-family:SF Pro Display,Segoe UI,system-ui,-apple-system,sans-serif;color:var(--text);background:radial-gradient(circle at 20% 20%,rgba(31,111,235,.05),transparent 35%),radial-gradient(circle at 80% 10%,rgba(31,111,235,.08),transparent 30%),var(--bg)}*{box-sizing:border-box}body{margin:0;height:100vh;overflow:hidden}#app{height:100vh;overflow:hidden}.app-shell{display:grid;grid-template-columns:280px 1fr;height:100vh}.sidebar{background:#fff;border-right:1px solid var(--border);padding:18px;display:flex;flex-direction:column;gap:12px;height:100vh;overflow:hidden}.sidebar-header{display:flex;align-items:center;justify-content:space-between;gap:8px}.logo{font-weight:700;letter-spacing:.4px}button{border:1px solid var(--border);background:#fff;color:var(--text);padding:8px 12px;border-radius:10px;cursor:pointer;transition:all .15s ease;font-size:14px}button:hover{border-color:#c8d0e0;box-shadow:0 2px 10px #0000000a}button:active{transform:translateY(1px)}button.primary{background:var(--accent);color:#fff;border-color:var(--accent);box-shadow:0 6px 20px #1f6feb40}button.primary:hover{background:#195cc4}button.ghost{background:transparent;border:none;font-size:18px;padding:6px 10px}.sidebar-actions{display:flex;gap:10px}.history-header{font-size:13px;color:var(--muted);padding:4px 2px}.conversation-list{list-style:none;margin:0;padding:0;overflow-y:auto;flex:1;display:flex;flex-direction:column;gap:6px}.conversation-list li{padding:10px 12px;border:1px solid transparent;border-radius:12px;background:#f9fafc;cursor:pointer;transition:all .15s ease;color:var(--text)}.conversation-list li:hover{border-color:var(--border)}.conversation-list li.active{background:#e9f1ff;border-color:var(--accent);color:#0f2a5f}.chat-pane{display:grid;grid-template-rows:auto 1fr auto;height:100vh}.topbar{display:flex;align-items:center;justify-content:space-between;padding:18px 24px 12px}.topbar .title{font-weight:600;font-size:16px}.top-actions{display:flex;align-items:center;gap:12px}.status{color:var(--muted);font-size:13px}.account{display:inline-flex;align-items:center;gap:8px;padding:6px 10px;background:#f1f5ff;border:1px solid var(--border);border-radius:10px}.user-name{font-size:13px;color:#0f2a5f}.chat-log{padding:12px 24px 24px;overflow-y:auto;display:flex;flex-direction:column;gap:14px}.message{display:inline-block;max-width:70%;padding:12px 14px;border-radius:var(--radius);background:#fff;border:1px solid var(--border);box-shadow:var(--shadow);line-height:1.5;white-space:normal;word-break:break-word}.message.assistant{background:#f1f4fb;border-color:#dfe6f5}.message.user{background:#fff;margin-left:auto;border-color:#d7dbe5;white-space:pre-wrap}.options-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:10px;margin-top:10px}.option-btn{text-align:left;border-radius:12px;padding:10px 12px;background:#fff;border:1px solid var(--border)}.option-btn:hover{border-color:var(--accent)}.inline-actions{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-top:10px}.composer{border-top:1px solid var(--border);padding:14px 20px 16px;background:linear-gradient(180deg,rgba(255,255,255,.92),#fff);display:flex;flex-direction:column;gap:8px}.composer textarea{width:100%;resize:none;border:1px solid var(--border);border-radius:12px;padding:12px;font-size:14px;line-height:1.5;outline:none;background:#fff;transition:border .15s ease}.composer textarea:focus{border-color:var(--accent);box-shadow:0 0 0 3px #1f6feb1f}.composer-actions{display:flex;align-items:center;justify-content:space-between;gap:12px}.hint{color:var(--muted);font-size:13px}.loader-wrapper{position:relative;display:inline-flex;min-height:24px;align-items:center;gap:10px;color:#1f6feb}.letter-wrapper{display:flex;gap:1px}.loader-letter{display:inline-block;opacity:.4;animation:loader-letter-anim 2s infinite;border-radius:50ch;color:#1f6feb;font-weight:600}.loader-letter:nth-child(1){animation-delay:0s}.loader-letter:nth-child(2){animation-delay:.1s}.loader-letter:nth-child(3){animation-delay:.2s}.loader-letter:nth-child(4){animation-delay:.3s}.loader-letter:nth-child(5){animation-delay:.4s}.loader-letter:nth-child(6){animation-delay:.5s}.loader-letter:nth-child(7){animation-delay:.6s}.loader-letter:nth-child(8){animation-delay:.7s}.loader-letter:nth-child(9){animation-delay:.8s}.loader-letter:nth-child(10){animation-delay:.9s}@keyframes loader-letter-anim{0%,to{opacity:.4;transform:translateY(0)}20%{opacity:1;transform:scale(1.15)}40%{opacity:.7;transform:translateY(0)}}@media (max-width: 900px){.app-shell{grid-template-columns:1fr}.sidebar{position:fixed;inset:0 auto 0 -100%;max-width:260px;z-index:10;transition:transform .2s ease;box-shadow:var(--shadow)}.sidebar.open{transform:translate(100%)}.chat-log .message{max-width:100%}.topbar{padding-right:12px}}.login-shell{min-height:100vh;display:flex;align-items:center;justify-content:center;background:var(--bg);padding:20px}.login-card{width:360px;background:#fff;border:1px solid var(--border);border-radius:16px;box-shadow:var(--shadow);padding:24px;display:flex;flex-direction:column;gap:12px}.login-card .logo{font-weight:700;font-size:20px;letter-spacing:.4px}.login-sub{color:var(--muted);margin:0 0 8px}.login-form{display:flex;flex-direction:column;gap:10px}.login-form input{padding:10px 12px;border-radius:10px;border:1px solid var(--border);font-size:14px}.login-form input:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px #1f6feb1f}.login-form .error{color:#c2410c;background:#fff3e8;border:1px solid #f1c9a8;padding:8px 10px;border-radius:8px;font-size:13px}