:root{color-scheme:light;--bg:#f7f6f0;--surface:#fffefb;--ink:#233f34;--muted:#647368;--line:#dce3d7;--green:#245143;--button:#fffefb;font:16px/1.65 system-ui,-apple-system,"Microsoft YaHei",sans-serif;background:var(--bg);color:var(--ink)}
:root[data-appearance=dark]{color-scheme:dark;--bg:#16241d;--surface:#213027;--ink:#e6eddf;--muted:#b3c2b1;--line:#405247;--green:#c6d7b4;--button:#16241d}
*{box-sizing:border-box}body{margin:0}header{max-width:1120px;margin:auto;display:flex;align-items:center;justify-content:space-between;padding:24px 32px;gap:20px}.identity{display:flex;align-items:center;gap:12px}.identity>span{font:600 24px Georgia,"Songti SC",serif}.identity small{font-size:11px;letter-spacing:.12em;text-transform:uppercase;border:1px solid var(--line);border-radius:20px;padding:2px 9px}a{color:var(--ink);text-underline-offset:5px}#exit{padding:10px;font-size:14px}main{max-width:790px;margin:7vh auto 0;padding:0 24px 24px}#welcome{text-align:center;padding:18px 0 30px}.eyebrow{font-size:11px;letter-spacing:.18em;color:var(--muted);margin:0 0 18px}h1{font:400 clamp(30px,4.3vw,46px)/1.18 Georgia,"Songti SC",serif;margin:0 0 18px}#intro{color:var(--muted);font-size:15px;max-width:560px;margin:auto}form{border:1px solid var(--line);border-radius:22px;background:var(--surface);padding:18px;box-shadow:0 12px 35px #13271b08}textarea{display:block;width:100%;font:inherit;line-height:1.6;color:var(--ink);background:transparent;border:0;resize:vertical;min-height:96px;max-height:280px;outline:none;padding:2px 5px}textarea::placeholder{color:var(--muted)}form:focus-within{outline:2px solid var(--green);outline-offset:3px}.actions{display:flex;justify-content:flex-end;align-items:center;gap:10px;margin-top:12px}button{font:inherit;font-size:14px;min-height:44px;padding:9px 19px;border-radius:24px;border:1px solid var(--line);background:transparent;color:var(--ink);cursor:pointer}#send{background:var(--green);color:var(--button);border-color:var(--green);font-weight:600}#send span{margin-left:14px}#fresh{margin-right:auto}button:disabled{opacity:.55;cursor:wait}:focus-visible{outline:2px solid var(--green);outline-offset:4px}#status{min-height:26px;margin:12px 5px;color:var(--muted);font-size:14px}#status.error{color:var(--ink);font-size:16px;line-height:1.8;margin:0 0 24px;padding:0}#status:empty{display:none}#conversation{padding-bottom:28px}#question-view{font:500 25px/1.4 Georgia,"Songti SC",serif;white-space:pre-wrap;overflow-wrap:anywhere;border-bottom:1px solid var(--line);padding-bottom:20px;margin:0 0 26px}#answer{overflow-wrap:anywhere;line-height:1.8}#answer p{white-space:pre-wrap;margin:0 0 16px}#answer h2{font:600 20px/1.4 Georgia,serif;margin:25px 0 10px}#answer ul,#answer ol{padding-left:25px}#answer li{margin:7px 0}footer{font-size:11px;line-height:1.6;color:var(--muted);text-align:center;max-width:660px;margin:8px auto}footer p{margin:5px 0}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}[hidden]{display:none!important}@media(max-width:600px){header{padding:14px 16px}.identity>span{font-size:21px}.identity{gap:8px}main{margin:4vh auto 0;padding:0 17px 20px}#welcome{padding-bottom:24px}h1{font-size:34px}#intro{font-size:14px}form{border-radius:18px;padding:14px}#question-view{font-size:23px}.actions{gap:6px}button{padding:9px 14px}}

#error-details{margin:-8px 0 24px;color:var(--muted);font-size:13px}#error-details summary{cursor:pointer;padding:8px 0;width:max-content}#error-details p{margin:5px 0}#error-details code{overflow-wrap:anywhere}

/* Same approved identity as sign-in; no sample answers or workspace access. */
.identity{text-decoration:none;min-width:0;gap:10px}.brand-icon{width:38px;height:38px;flex:none}.brand-wordmark{width:210px;max-width:40vw;height:auto}
:root[data-appearance=dark] .brand-wordmark{filter:brightness(0) invert(1)}
header{border-bottom:1px solid var(--line)}#exit{min-height:44px;display:flex;align-items:center;text-align:right;flex-shrink:0}
main{margin-top:5vh}#suggestions{display:flex;justify-content:center;align-items:center;gap:8px;flex-wrap:wrap;margin:18px 0 26px}
#suggestions>span{width:100%;text-align:center;font-size:12px;color:var(--muted)}#suggestions button{font-size:13px;background:var(--surface)}
body:has(#conversation:not([hidden])) #suggestions{display:none}
@media(max-width:600px){header{gap:8px;padding:12px}.brand-icon{width:30px;height:30px}.brand-wordmark{width:160px;max-width:37vw}.identity{gap:6px}#exit{font-size:12px;padding:8px}main{margin-top:24px}#suggestions{gap:6px}#suggestions button{padding:8px 12px}}

#question-limit{display:flex;justify-content:space-between;gap:10px;font-size:12px;color:var(--muted);margin:12px 5px 0}#question-count{font-variant-numeric:tabular-nums;white-space:nowrap}#question-limit.over-limit,#question-error{color:#a13928}:root[data-appearance=dark] #question-limit.over-limit,:root[data-appearance=dark] #question-error{color:#f4b4a5}#question-error{font-size:13px;margin:8px 5px;line-height:1.5}#send:disabled{cursor:not-allowed}@media(max-width:360px){#question-limit{font-size:11px;gap:6px}}

#answer-tools{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin:20px 0 0;border-top:1px solid var(--line);padding-top:14px}#answer-tools a{font-size:14px;padding:10px 14px;min-height:44px}#answer-tools p,#answer-tools small{width:100%;margin:0;font-size:12px;color:var(--muted)}#answer-tools p:empty{display:none}#answer-tools button[aria-pressed=true]{background:var(--green);color:var(--button)}

/* Match the authenticated reading card, without changing answer content. */
#answer:not(:empty){background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:22px 24px;min-width:0;box-shadow:0 12px 36px #253e3506}
#answer>:last-child{margin-bottom:0}
#answer a{overflow-wrap:anywhere}
#answer-tools button,#answer-tools a{border-radius:10px;min-height:44px}
#answer-tools{padding-top:16px;margin-top:16px}
#question-view{border-bottom:0;padding-bottom:0;margin-bottom:24px}
@media(max-width:600px){#answer:not(:empty){padding:17px 16px}#answer-tools{gap:8px}#question-view{margin-bottom:20px}}

/* Public home and explicit authentication remain separate actions. */
header{flex-wrap:wrap}header .sign-in{padding:10px;min-height:44px;display:flex;align-items:center;white-space:nowrap}#exit{white-space:nowrap}@media(max-width:600px){header .identity{margin-right:auto}header #exit,header .sign-in{font-size:12px;padding:8px}}