:root{--bg: #f9fafb;--sidebar-bg: #ffffff;--card: #ffffff;--border: #e5e7eb;--text: #111827;--muted: #6b7280;--accent: #1e40af;--accent-hover: #1d3fa0;--chip-bg: #eff6ff;--chip-text: #1e40af;--input-bg: #ffffff;--source-bg: #f3f4f6;--shadow-sm: 0 1px 3px rgba(0,0,0,.07);--shadow-md: 0 4px 12px rgba(0,0,0,.09);--nav-hover: #f3f4f6;--history-active: #eff6ff}.dark{--bg: #0f172a;--sidebar-bg: #1e293b;--card: #1e293b;--border: #334155;--text: #f1f5f9;--muted: #94a3b8;--accent: #3b82f6;--accent-hover: #2563eb;--chip-bg: #1e3a5f;--chip-text: #93c5fd;--input-bg: #1e293b;--source-bg: #0f172a;--shadow-sm: 0 1px 3px rgba(0,0,0,.3);--shadow-md: 0 4px 12px rgba(0,0,0,.4);--nav-hover: #334155;--history-active: #1e3a5f}*{box-sizing:border-box;margin:0;padding:0}body{background:var(--bg)}.app{display:flex;height:100vh;background-color:var(--bg);font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;color:var(--text);overflow:hidden}.sidebar{width:248px;flex-shrink:0;display:flex;flex-direction:column;background-color:var(--sidebar-bg);border-right:1px solid var(--border);transition:transform .22s ease;overflow:hidden}.sidebar-logo{display:flex;align-items:center;gap:10px;padding:20px 16px 16px;border-bottom:1px solid var(--border);flex-shrink:0}.logo-icon{width:34px;height:34px;border-radius:9px;background-color:var(--accent);display:flex;align-items:center;justify-content:center;color:#fff;font-weight:700;font-size:16px;flex-shrink:0}.logo-text{font-weight:700;font-size:13px;color:var(--text);line-height:1.35}.sidebar-nav{display:flex;flex-direction:column;gap:2px;padding:12px 10px 0;flex-shrink:0}.nav-item{display:flex;align-items:center;gap:9px;padding:8px 10px;border-radius:7px;border:none;background:none;font-size:13.5px;font-weight:500;cursor:pointer;text-align:left;width:100%;color:var(--muted);transition:background-color .12s,color .12s}.nav-item:hover{background-color:var(--nav-hover);color:var(--text)}.nav-item.active{background-color:var(--history-active);color:var(--accent);font-weight:600}.nav-icon{font-size:15px;width:18px;text-align:center}.history-section{flex:1;display:flex;flex-direction:column;padding:16px 10px 8px;min-height:0}.history-header{display:flex;align-items:center;gap:6px;font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.07em;color:var(--muted);padding:0 4px 8px;flex-shrink:0}.history-list{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:1px}.history-empty{font-size:12px;color:var(--muted);padding:4px 6px;font-style:italic}.history-item{display:block;width:100%;padding:7px 10px;border-radius:7px;border:none;background:none;color:var(--muted);font-size:13px;text-align:left;cursor:pointer;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;transition:background-color .12s,color .12s}.history-item:hover{background-color:var(--nav-hover);color:var(--text)}.history-item.active{background-color:var(--history-active);color:var(--accent);font-weight:500}.sidebar-bottom{flex-shrink:0;padding:10px 10px 16px;border-top:1px solid var(--border);display:flex;flex-direction:column;gap:6px}.theme-toggle{display:flex;align-items:center;gap:8px;background:none;border:1px solid var(--border);border-radius:7px;padding:7px 10px;font-size:12px;cursor:pointer;color:var(--muted);width:100%;transition:border-color .12s,color .12s}.theme-toggle:hover{border-color:var(--accent);color:var(--text)}.version{font-size:11px;color:var(--muted);padding-left:4px}.mobile-bar{display:none;align-items:center;justify-content:space-between;padding:12px 16px;background-color:var(--sidebar-bg);border-bottom:1px solid var(--border);flex-shrink:0}.hamburger{background:none;border:none;font-size:20px;cursor:pointer;color:var(--text);padding:4px;line-height:1}.mobile-title{font-weight:600;font-size:14px;color:var(--text)}.mobile-overlay{display:none;position:fixed;top:0;right:0;bottom:0;left:0;background-color:#00000073;z-index:15}.main{flex:1;display:flex;flex-direction:column;overflow:hidden;min-width:0}.chat-area{flex:1;overflow-y:auto;padding:0 28px 24px}.empty-state{display:flex;flex-direction:column;align-items:center;text-align:center;padding-top:56px;max-width:620px;margin:0 auto}.product-icon{width:68px;height:68px;border-radius:18px;background-color:var(--accent);display:flex;align-items:center;justify-content:center;font-size:30px;margin-bottom:20px;box-shadow:var(--shadow-md)}.empty-title{font-size:22px;font-weight:700;color:var(--text);letter-spacing:-.02em;margin-bottom:8px}.empty-subtitle{font-size:14px;color:var(--muted);line-height:1.65;max-width:440px;margin-bottom:24px}.chips{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin-bottom:36px}.chip{padding:5px 13px;border-radius:999px;font-size:12px;font-weight:500;background-color:var(--chip-bg);color:var(--chip-text);border:1px solid var(--border)}.card-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;width:100%}.prompt-card{display:flex;flex-direction:column;align-items:flex-start;gap:6px;padding:18px 16px;border-radius:12px;border:1px solid var(--border);background-color:var(--card);cursor:pointer;text-align:left;box-shadow:var(--shadow-sm);transition:box-shadow .15s,transform .12s}.prompt-card:hover:not(:disabled){box-shadow:var(--shadow-md);transform:translateY(-2px)}.prompt-card:disabled{opacity:.5;cursor:not-allowed}.card-icon{font-size:20px}.card-title{font-size:13px;font-weight:600;color:var(--text)}.card-desc{font-size:12px;color:var(--muted);line-height:1.55}.messages{max-width:760px;margin:0 auto;padding-top:28px;display:flex;flex-direction:column;gap:16px}.user-bubble{align-self:flex-end;background-color:var(--accent);color:#fff;border-radius:16px 16px 4px;padding:12px 16px;max-width:75%}.assistant-bubble{align-self:flex-start;background-color:var(--card);border:1px solid var(--border);border-radius:16px 16px 16px 4px;padding:12px 16px;max-width:85%;box-shadow:var(--shadow-sm)}.role-label{font-size:10px;font-weight:700;margin-bottom:5px;text-transform:uppercase;letter-spacing:.07em;opacity:.6}.message-text{margin:0;line-height:1.7;white-space:pre-wrap;font-size:14px}.thinking{margin:0;font-style:italic;opacity:.5;font-size:14px}.sources-summary{display:inline-block;font-size:12px;cursor:pointer;color:var(--muted);margin-top:10px}.source-item{margin-top:8px;padding:9px 11px;border-radius:8px;background-color:var(--source-bg);border:1px solid var(--border)}.source-title{font-size:13px;font-weight:600;color:var(--text)}.source-snippet{margin:3px 0 0;font-size:12px;color:var(--muted);line-height:1.5}.error-msg{color:#dc2626;font-size:14px;text-align:center}.input-bar{padding:14px 28px 18px;border-top:1px solid var(--border);background-color:var(--bg);flex-shrink:0}.input-form{max-width:760px;margin:0 auto;display:flex;gap:10px}.input-field{flex:1;padding:11px 18px;border-radius:999px;border:1px solid var(--border);background-color:var(--input-bg);color:var(--text);font-size:14px;outline:none;min-width:0;transition:border-color .15s}.input-field::placeholder{color:var(--muted)}.input-field:focus{border-color:var(--accent)}.send-button{padding:11px 22px;background-color:var(--accent);color:#fff;border:none;border-radius:999px;font-size:14px;font-weight:600;cursor:pointer;flex-shrink:0;transition:background-color .15s,opacity .15s}.send-button:hover:not(:disabled){background-color:var(--accent-hover)}.send-button:disabled{opacity:.45;cursor:not-allowed}@media (max-width: 767px){.sidebar{position:fixed;left:0;top:0;bottom:0;z-index:20;transform:translate(-100%)}.sidebar.open{transform:translate(0)}.mobile-bar{display:flex}.mobile-overlay{display:block}.card-grid{grid-template-columns:1fr}.empty-state{padding-top:24px}.chat-area{padding:0 16px 16px}.input-bar{padding:12px 16px 16px}.user-bubble{max-width:88%}.assistant-bubble{max-width:95%}}