:root{--bg:#0b1020;--panel:#111827;--panel2:#172033;--text:#f8fafc;--muted:#94a3b8;--accent:#3b82f6;--accent2:#06b6d4;--danger:#ef4444;--ok:#22c55e;--border:rgba(148,163,184,.22);--shadow:0 24px 80px rgba(0,0,0,.35);--radius:22px}
html[data-theme=light]{--bg:#f4f7fb;--panel:#ffffff;--panel2:#eef4ff;--text:#0f172a;--muted:#64748b;--accent:#2563eb;--accent2:#0891b2;--border:rgba(15,23,42,.12);--shadow:0 20px 60px rgba(15,23,42,.12)}
html[data-theme=ocean]{--bg:#061826;--panel:#082f49;--panel2:#0e7490;--text:#ecfeff;--muted:#a5f3fc;--accent:#06b6d4;--accent2:#38bdf8}
html[data-theme=purple]{--bg:#170b2e;--panel:#24113f;--panel2:#39205d;--text:#faf5ff;--muted:#c4b5fd;--accent:#a855f7;--accent2:#ec4899}
html[data-theme=emerald]{--bg:#052016;--panel:#063524;--panel2:#064e3b;--text:#ecfdf5;--muted:#a7f3d0;--accent:#10b981;--accent2:#84cc16}
html[data-theme=sunset]{--bg:#28120a;--panel:#3b1d12;--panel2:#5f2e16;--text:#fff7ed;--muted:#fed7aa;--accent:#f97316;--accent2:#facc15}
*{box-sizing:border-box}body{margin:0;background:radial-gradient(circle at top left,var(--panel2),transparent 35%),var(--bg);color:var(--text);font-family:Inter,system-ui,Segoe UI,Arial,sans-serif;min-height:100vh}a{color:var(--accent);text-decoration:none}button,input,textarea,select{font:inherit}button{cursor:pointer}.auth-page{display:grid;place-items:center;padding:20px}.auth-card,.panel{width:min(460px,100%);background:linear-gradient(180deg,rgba(255,255,255,.08),rgba(255,255,255,.03)),var(--panel);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:28px}.brand-mark{width:58px;height:58px;border-radius:18px;background:linear-gradient(135deg,var(--accent),var(--accent2));display:grid;place-items:center;font-weight:900;font-size:28px;color:white;box-shadow:0 16px 40px rgba(59,130,246,.35)}.brand-mark.small{width:38px;height:38px;border-radius:12px;font-size:18px}.muted{color:var(--muted)}.small{font-size:14px}.alert{padding:12px 14px;border-radius:14px;margin:12px 0}.error{background:rgba(239,68,68,.14);border:1px solid rgba(239,68,68,.35)}.success{background:rgba(34,197,94,.14);border:1px solid rgba(34,197,94,.35)}label{display:block;margin:14px 0 6px;color:var(--muted);font-weight:700}input,textarea,select{width:100%;border:1px solid var(--border);background:var(--panel2);color:var(--text);border-radius:14px;padding:13px 14px;outline:none}input:focus,textarea:focus,select:focus{border-color:var(--accent);box-shadow:0 0 0 4px color-mix(in srgb,var(--accent) 20%,transparent)}.primary,.send,.side-action{border:0;background:linear-gradient(135deg,var(--accent),var(--accent2));color:white;border-radius:14px;padding:13px 16px;font-weight:800;margin-top:16px}.theme-float{position:fixed;right:18px;top:18px;z-index:9;border:1px solid var(--border);background:var(--panel);color:var(--text);border-radius:999px;padding:10px 14px}.layout{display:grid;grid-template-columns:310px 1fr;height:100vh}.sidebar{border-right:1px solid var(--border);background:color-mix(in srgb,var(--panel) 88%,transparent);backdrop-filter:blur(18px);padding:16px;display:flex;flex-direction:column;gap:14px}.side-brand{display:flex;gap:10px;align-items:center}.side-action{width:100%;margin:0}.side-search{padding:11px}.chat-list{overflow:auto;display:flex;flex-direction:column;gap:8px}.chat-item{border:1px solid var(--border);background:var(--panel2);color:var(--text);border-radius:14px;padding:10px;text-align:left}.side-bottom{margin-top:auto;display:grid;gap:8px}.side-bottom a,.side-bottom button{border:1px solid var(--border);background:var(--panel2);color:var(--text);border-radius:12px;padding:10px;text-align:left}.chat-main{display:grid;grid-template-rows:auto 1fr auto;min-width:0}.topbar{display:flex;align-items:center;justify-content:space-between;padding:18px 22px;border-bottom:1px solid var(--border);background:rgba(0,0,0,.08)}.topbar h1{margin:0}.topbar p{margin:2px 0 0;color:var(--muted)}#modelSelect{width:auto;min-width:230px}.messages{overflow:auto;padding:24px;display:flex;flex-direction:column;gap:16px}.welcome{margin:auto;text-align:center;max-width:560px;display:grid;place-items:center;gap:10px}.msg{max-width:850px;padding:16px 18px;border:1px solid var(--border);border-radius:18px;line-height:1.55;white-space:pre-wrap}.msg.user{align-self:flex-end;background:linear-gradient(135deg,var(--accent),var(--accent2));color:white}.msg.assistant{align-self:flex-start;background:var(--panel)}.composer{margin:16px 22px 22px;border:1px solid var(--border);background:var(--panel);border-radius:24px;padding:10px;display:grid;grid-template-columns:auto 1fr auto auto auto;gap:8px;position:relative;box-shadow:var(--shadow)}.composer button{border:0;border-radius:14px;background:var(--panel2);color:var(--text);padding:10px 12px}.composer .send{margin:0;background:linear-gradient(135deg,var(--accent),var(--accent2));color:white}.composer textarea{border:0;background:transparent;resize:none;max-height:180px;padding:10px}.emoji-panel{position:absolute;bottom:65px;right:16px;background:var(--panel);border:1px solid var(--border);border-radius:18px;padding:12px;box-shadow:var(--shadow);max-width:260px;line-height:2;font-size:22px}.page-wrap{padding:28px}.codebar{display:flex;justify-content:flex-end}.copy-code{width:auto;border:1px solid var(--border);background:var(--panel2);color:var(--text);border-radius:10px;padding:6px 10px}@media(max-width:800px){.layout{grid-template-columns:1fr}.sidebar{position:fixed;inset:0 28% 0 0;z-index:20;transform:translateX(-100%);transition:.25s}.sidebar.open{transform:none}.topbar{padding-left:58px}.composer{margin:10px;grid-template-columns:auto 1fr auto}.composer #voiceBtn,.composer #emojiBtn{display:none}.messages{padding:14px}.auth-card{padding:22px}}