:root{--bg: #0f172a;--surface: #1e293b;--border: #334155;--text: #f8fafc;--muted: #94a3b8;--accent: #3b82f6;--accent-hover: #2563eb;--user-msg: #2563eb;--bot-msg: #334155;--radius: 14px}*{box-sizing:border-box;margin:0;padding:0}body{font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--text);line-height:1.5;min-height:100vh}.app{max-width:900px;margin:0 auto;padding:1rem}button{font:inherit;cursor:pointer;border:none;border-radius:8px;transition:background .2s}.topnav{display:flex;justify-content:space-between;align-items:center;padding:1rem 0}.logo{font-size:1.5rem;font-weight:700;letter-spacing:-.02em;background:linear-gradient(135deg,#60a5fa,#a78bfa);-webkit-background-clip:text;-webkit-text-fill-color:transparent}.nav-links{display:flex;gap:.75rem}.nav-links button{background:var(--surface);color:var(--text);padding:.5rem 1rem;border:1px solid var(--border)}.nav-links button:hover{background:var(--border)}.hero{text-align:center;padding:4rem 1rem}.hero h1{font-size:clamp(2.5rem,8vw,4rem);letter-spacing:-.03em;margin-bottom:1rem}.tagline{color:var(--muted);font-size:1.2rem;margin-bottom:2rem}.cta{background:var(--accent);color:#fff;padding:.9rem 2rem;font-size:1.1rem;border-radius:999px}.cta:hover{background:var(--accent-hover)}.features{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:1rem;margin-top:2rem}.feature{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.5rem}.feature h3{margin-bottom:.5rem}.feature p{color:var(--muted)}.page-header{margin:2rem 0 1.5rem}.page-header h2{font-size:2rem;letter-spacing:-.02em}.subtitle{color:var(--muted)}.chat-page{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1rem;display:flex;flex-direction:column;height:70vh}.chat-window{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:.75rem;padding:1rem 0}.msg{max-width:80%;padding:.75rem 1rem;border-radius:12px}.msg.user{align-self:flex-end;background:var(--user-msg)}.msg.bot{align-self:flex-start;background:var(--bot-msg)}.msg-label{display:block;font-size:.75rem;color:#cbd5e1;margin-bottom:.25rem}.chat-input{display:flex;gap:.5rem}.chat-input input{flex:1;padding:.75rem 1rem;border-radius:8px;border:1px solid var(--border);background:var(--bg);color:var(--text)}.chat-input button{background:var(--accent);color:#fff;padding:.75rem 1.5rem}.chat-input button:hover{background:var(--accent-hover)}.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1rem}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.5rem}.card h3{font-size:1rem;color:var(--muted);margin-bottom:.5rem}.card p{font-size:1.5rem;font-weight:600}.back{background:transparent;color:var(--accent);padding:.5rem 0;margin-top:1rem}.back:hover{color:#93c5fd}@media(max-width:640px){.hero{padding:2rem 1rem}.chat-page{height:75vh}.msg{max-width:90%}}