:root{--bg:#0b1020;--panel:#111936;--panel2:#172348;--text:#eef3ff;--muted:#9fb0d0;--accent:#4f8cff;--accent2:#30d1a3;--danger:#ff6b6b;--border:rgba(255,255,255,.1)}*{box-sizing:border-box}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;background:radial-gradient(circle at top left,#1d2b62 0,#0b1020 44%,#050814 100%);color:var(--text);height:100vh}.app{max-width:980px;margin:0 auto;height:100vh;display:flex;flex-direction:column;padding:18px}.topbar{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:14px 16px;background:rgba(17,25,54,.78);border:1px solid var(--border);border-radius:20px;backdrop-filter:blur(12px);box-shadow:0 18px 60px rgba(0,0,0,.25)}h1{margin:0;font-size:25px;letter-spacing:.04em}.topbar p{margin:5px 0 0;color:var(--muted);font-size:14px}.ghost,.fileBtn,.send{border:1px solid var(--border);border-radius:14px;background:rgba(255,255,255,.08);color:var(--text);padding:11px 14px;font-size:15px;cursor:pointer;white-space:nowrap}.ghost:hover,.fileBtn:hover{background:rgba(255,255,255,.14)}.chat{flex:1;overflow-y:auto;padding:18px 4px 12px;display:flex;flex-direction:column;gap:14px}.msg{display:flex;gap:10px;animation:fade .2s ease}.msg.user{justify-content:flex-end}.bubble{max-width:min(760px,88%);padding:13px 15px;border-radius:18px;line-height:1.65;font-size:16px;white-space:pre-wrap;word-break:break-word}.user .bubble{background:linear-gradient(135deg,var(--accent),#7657ff);border-bottom-right-radius:6px}.ai .bubble{background:rgba(17,25,54,.92);border:1px solid var(--border);border-bottom-left-radius:6px}.meta{font-size:12px;color:var(--muted);margin-bottom:5px}.composer{background:rgba(17,25,54,.9);border:1px solid var(--border);border-radius:22px;padding:12px;box-shadow:0 -18px 60px rgba(0,0,0,.18)}textarea{width:100%;resize:none;border:1px solid var(--border);border-radius:16px;background:rgba(5,8,20,.65);color:var(--text);padding:13px 14px;font-size:16px;line-height:1.55;outline:none}textarea:focus{border-color:rgba(79,140,255,.7);box-shadow:0 0 0 4px rgba(79,140,255,.12)}.actions{display:flex;gap:8px;align-items:center;margin-top:10px;flex-wrap:wrap}.send{margin-left:auto;background:linear-gradient(135deg,var(--accent2),var(--accent));border:0;font-weight:700;padding:12px 22px}.send:disabled,.fileBtn:disabled{opacity:.55;cursor:not-allowed}.preview{margin-bottom:10px;padding:10px;border:1px dashed rgba(255,255,255,.25);border-radius:14px;color:var(--muted);display:flex;align-items:center;gap:10px}.preview img{width:72px;height:72px;object-fit:cover;border-radius:12px}.hidden{display:none}.typing{color:var(--muted)}.typing:after{content:'▋';animation:blink .9s infinite}.recording{background:rgba(255,107,107,.22)!important;border-color:rgba(255,107,107,.6)!important}.hint{color:var(--muted);font-size:14px;text-align:center;margin:auto;padding:26px}.err{color:#ffd0d0}.bubble img{max-width:260px;border-radius:12px;display:block;margin-top:8px}@keyframes fade{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:none}}@keyframes blink{50%{opacity:0}}@media(max-width:640px){.app{padding:10px}.topbar{border-radius:16px}.topbar p{font-size:12px}.bubble{max-width:94%;font-size:15px}.actions{gap:7px}.send{width:100%;margin-left:0}.fileBtn{flex:1;text-align:center;padding:10px 8px}h1{font-size:22px}}