:root{--bg:#f8fafc;--card:#fff;--accent:#0b74de;--accent2:#7c4dff;--muted:#6b7280;--text:#0f172a}*{box-sizing:border-box}html,body{height:100%}body{margin:0;font-family:Poppins,Inter,system-ui,Arial;background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased}.container{max-width:1100px;margin:18px auto;padding:18px}.site-header{background:#fff;border-bottom:1px solid #eef2ff;position:sticky;top:0;z-index:60}.header-inner{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px}.logo img{height:44px}.nav{display:flex;gap:12px;align-items:center}.nav a{color:var(--muted);text-decoration:none;padding:8px 12px;border-radius:10px}.nav a.active,.nav a:hover{background:linear-gradient(90deg,var(--accent),var(--accent2));color:#fff;box-shadow:0 8px 20px rgba(11,116,222,0.12)}.card{background:var(--card);padding:20px;border-radius:12px;box-shadow:0 8px 24px rgba(2,6,23,0.04)}.grid{display:grid;grid-template-columns:1fr 340px;gap:20px;margin-top:20px}@media(max-width:900px){.grid{grid-template-columns:1fr}.logo img{height:36px}}.button{background:linear-gradient(90deg,var(--accent),var(--accent2));color:#fff;padding:10px 14px;border-radius:12px;border:none;cursor:pointer;box-shadow:0 8px 24px rgba(11,116,222,0.12)}.small{font-size:13px;color:var(--muted)}.chat-window{height:520px;overflow:auto;padding:16px;border-radius:12px;border:1px solid #eef6ff;background:#fff}.msg{display:block;max-width:80%;margin:10px 0;padding:12px;border-radius:12px;line-height:1.45}.msg.user{margin-left:auto;background:linear-gradient(90deg,#e6f2ff,#dbeefe);border-bottom-right-radius:4px}.msg.ai{background:#f8fafc;margin-right:auto;border-bottom-left-radius:4px}.input{flex:1;padding:12px;border-radius:12px;border:1px solid #eef2ff;font-size:15px}.footer-note{margin-top:12px;font-size:13px;color:var(--muted)}