@font-face{font-family:"Source Han Serif CN";src:url("/assets/fonts/SourceHanSerifCN-Regular-Common.woff2") format("woff2");font-display:swap;font-weight:400}
@font-face{font-family:"Great Vibes";src:url("/assets/fonts/GreatVibes-Latin.woff2") format("woff2");font-display:swap}
:root{--paper:#fdfefb;--paper-deep:#f3f3ee;--paper-strong:#e7e6df;--ink:#24231f;--ink-strong:#141312;--muted:#5c5a55;--soft:#787670;--border:rgba(36,35,31,.12);--border-strong:rgba(36,35,31,.22);--accent:#83c8ef;--accent-soft:color-mix(in srgb,var(--accent) 12%,transparent);--accent-strong:#356580;--shadow:0 16px 50px rgba(33,30,25,.055);--serif:"Source Han Serif CN","Noto Serif CJK SC","Songti SC",SimSun,serif;--mono:"Cascadia Code",Consolas,monospace;color-scheme:light}
html[data-theme=dark]{--paper:#1c1c1e;--paper-deep:#252527;--paper-strong:#323236;--ink:#e3e1dc;--ink-strong:#f5f3ee;--muted:#aaa8a3;--soft:#aaa7a1;--border:rgba(239,236,229,.11);--border-strong:rgba(239,236,229,.2);--accent-soft:color-mix(in srgb,var(--accent) 17%,transparent);--accent-strong:#a5d8f5;--shadow:0 18px 60px rgba(0,0,0,.15);color-scheme:dark}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.7 var(--serif);letter-spacing:.012em;-webkit-font-smoothing:antialiased}button,input,textarea,select{font:inherit;color:inherit}button,a,input,textarea,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer;background:none;border:0}button:disabled{cursor:default;opacity:.45}a{color:inherit;text-decoration:none}button,a{touch-action:manipulation}svg{width:20px;height:20px;display:block;fill:none;stroke:currentColor;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round}button>span[data-icon]{display:inline-flex}::selection{background:color-mix(in srgb,var(--accent) 28%,transparent)}:focus-visible{outline:2px solid var(--accent-strong);outline-offset:3px}[hidden]{display:none!important}.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}.skip-link{position:fixed;top:-100px;z-index:100;padding:10px;background:var(--paper)}.skip-link:focus{top:10px}
.app{display:flex;height:100dvh;min-height:440px;overflow:hidden}.sidebar{width:264px;flex-shrink:0;display:flex;flex-direction:column;padding:28px 19px 18px;border-right:1px solid var(--border);background:color-mix(in srgb,var(--paper-deep) 54%,var(--paper));transition:margin .22s ease;z-index:30}.sidebar-brand{display:flex;align-items:center;padding:0 9px 26px;gap:10px}.signature{font:42px/1.1 "Great Vibes",var(--serif);letter-spacing:0}.brand-tag{font:12px/1.5 var(--mono);border:1px solid var(--border-strong);padding:0 5px;border-radius:4px;color:var(--muted)}.sidebar-close{margin-left:auto;display:none!important}.icon-btn{display:inline-flex;align-items:center;justify-content:center;width:36px;height:36px;border-radius:5px;color:var(--muted);flex-shrink:0}.icon-btn:hover{background:var(--paper-strong);color:var(--ink-strong)}.new-chat{display:flex;align-items:center;gap:10px;border:1px solid var(--border-strong);border-radius:6px;background:var(--paper);padding:10px 12px;text-align:left;font-size:14px;box-shadow:0 3px 8px #00000003}.new-chat:hover{border-color:var(--accent);background:var(--accent-soft)}.shortcut{margin-left:auto;font-family:var(--mono);font-size:12px;color:var(--soft)}.search-wrap{display:flex;align-items:center;gap:9px;margin:20px 9px 24px;color:var(--soft)}.search-wrap svg{width:16px;height:16px}.search-wrap input{width:100%;min-width:0;background:transparent;border:0;outline-offset:6px;font-size:14px}.search-wrap input::placeholder{color:var(--soft)}.history-label{font-size:12px;letter-spacing:.08em;color:var(--soft);margin:0 10px 12px}.history{flex:1;overflow-y:auto;scrollbar-width:thin;min-height:0}.history-empty{font-size:14px;color:var(--soft);margin:14px 10px}.history-group{font-size:12px;color:var(--soft);margin:20px 10px 8px}.history-group:first-child{margin-top:0}.history-row{display:flex;align-items:center;border-radius:5px;margin-bottom:4px;gap:0;padding-right:5px}.history-row.active{background:var(--accent-soft)}.history-row:hover{background:var(--paper-strong)}.history-open{font-size:14px;text-align:left;flex:1;min-width:0;padding:9px 10px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.history-row .icon-btn{width:27px;height:30px;opacity:0}.history-row .icon-btn svg{width:14px;height:14px}.history-row:hover .icon-btn,.history-row:focus-within .icon-btn{opacity:1}.sidebar-bottom{padding:15px 9px 0;border-top:1px solid var(--border);margin-top:14px}.sidebar-bottom p{font-size:12px;color:var(--soft);margin:0 0 14px}.sidebar-bottom>div{display:flex;align-items:center;justify-content:space-between}.sidebar-bottom a{display:flex;align-items:center;gap:8px;font-size:14px}.sidebar-bottom a svg{width:16px;height:16px}.sidebar-hidden .sidebar{margin-left:-264px}
.main{position:relative;min-width:0;flex:1;display:flex;flex-direction:column}.topbar{height:76px;flex-shrink:0;display:flex;align-items:center;justify-content:space-between;gap:15px;padding:0 34px;color:var(--muted);font-size:14px}.topbar>div{display:flex;gap:14px;align-items:center;min-width:0}.topbar-title{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:40vw}.topbar>a{white-space:nowrap;border-bottom:1px solid var(--border-strong);font-size:13px}.conversation{flex:1;min-height:0;overflow:auto;scrollbar-width:thin;overscroll-behavior:contain}.welcome{max-width:800px;margin:0 auto;padding:0 24px;text-align:center}.eyebrow{font-family:var(--mono);font-size:11px;letter-spacing:.18em;color:var(--soft)}.welcome h1{font-weight:400;font-size:clamp(28px,3.3vw,42px);letter-spacing:-.04em;line-height:1.6;margin:18px 0 12px}.welcome h1>span:first-child{color:var(--accent-strong)}.hello-dot{color:var(--accent);margin-left:3px}.welcome p{color:var(--soft);font-size:16px;margin:0}.main.empty .conversation{display:flex;align-items:flex-end;flex:0 1 auto;min-height:210px;height:calc(41dvh - 76px);overflow:visible}.main.empty .welcome{width:100%}.main.empty .composer-area{margin-top:38px;padding-bottom:0}.main.empty .messages{display:none}.main:not(.empty) .welcome{display:none}.messages{max-width:848px;margin:0 auto;padding:24px 38px 45px}.message{margin-bottom:34px;min-width:0}.message.user{display:flex;justify-content:flex-end}.user .message-content{max-width:85%;padding:12px 18px;background:var(--paper-deep);border:1px solid var(--border);border-radius:12px 12px 3px 12px;white-space:pre-wrap;overflow-wrap:anywhere}.assistant-label{display:flex;align-items:center;gap:8px;margin-bottom:14px;font-size:14px;color:var(--muted)}.assistant-label .ai-dot{width:8px;height:8px;background:var(--accent);border-radius:2px;transform:rotate(45deg)}.markdown{overflow-wrap:anywhere;line-height:1.85;font-size:16px;min-height:1.5em}.markdown>:first-child{margin-top:0}.markdown>:last-child{margin-bottom:0}.markdown p{margin:0 0 16px}.markdown h1,.markdown h2,.markdown h3{font-weight:600;margin:24px 0 12px;line-height:1.5}.markdown h1{font-size:1.5em}.markdown h2{font-size:1.3em}.markdown h3{font-size:1.1em}.markdown ul,.markdown ol{padding-left:1.6em}.markdown blockquote{border-left:3px solid var(--accent);padding:3px 16px;margin:16px 0;color:var(--muted)}.markdown a{color:var(--accent-strong);text-decoration:underline;text-underline-offset:4px}.markdown img{max-width:100%}.markdown code{font-family:var(--mono);font-size:.88em;background:var(--paper-deep);padding:2px 5px;border-radius:4px}.markdown pre{position:relative;overflow:auto;border:1px solid var(--border);border-radius:6px;padding:40px 18px 18px;background:var(--paper-deep);line-height:1.6}.markdown pre code{padding:0;background:transparent;white-space:pre;font-size:13px}.code-copy{position:absolute;top:7px;right:9px;font-size:12px;color:var(--muted);padding:2px 7px;border:1px solid var(--border);border-radius:4px}.table-wrap{max-width:100%;overflow:auto;margin:16px 0}.markdown table{border-collapse:collapse;min-width:50%;font-size:14px}.markdown th,.markdown td{border:1px solid var(--border);padding:8px 12px;white-space:normal}.markdown th{background:var(--paper-deep);font-weight:600}.markdown hr{border:0;border-top:1px solid var(--border);margin:24px 0}.katex-display{overflow:auto hidden}.reasoning{border-left:2px solid var(--border-strong);padding:0 0 0 14px;margin-bottom:18px;color:var(--soft);font-size:14px}.reasoning summary{cursor:pointer;margin-bottom:8px}.reasoning .markdown{font-size:14px}.message-actions{display:flex;align-items:center;gap:3px;margin-top:12px;color:var(--soft)}.message-actions .icon-btn{width:30px;height:30px}.message-actions svg{width:16px;height:16px}.message-actions .model-caption{font:11px var(--mono);margin-left:8px;color:var(--soft)}.typing{display:inline-flex;gap:5px;padding:7px 0}.typing i{width:5px;height:5px;border-radius:50%;background:var(--accent-strong);animation:pulse 1.2s ease infinite}.typing i:nth-child(2){animation-delay:.15s}.typing i:nth-child(3){animation-delay:.3s}@keyframes pulse{50%{opacity:.25}}.message-error{margin-top:10px;color:#a24937;font-size:14px}.hljs-keyword,.hljs-selector-tag,.hljs-literal{color:#8260a5}.hljs-string,.hljs-attr{color:#477254}.hljs-number,.hljs-title{color:#397694}.hljs-comment{color:var(--soft)}html[data-theme=dark] .hljs-keyword{color:#c5a5ed}html[data-theme=dark] .hljs-string,html[data-theme=dark] .hljs-attr{color:#a9cbaa}html[data-theme=dark] .hljs-number,html[data-theme=dark] .hljs-title{color:#8bc9ec}
.composer-area{position:relative;flex-shrink:0;width:min(100% - 76px,772px);margin:0 auto;padding-bottom:max(14px,env(safe-area-inset-bottom))}.composer{border:1px solid var(--border-strong);border-radius:12px;padding:17px 18px 12px;background:var(--paper);box-shadow:var(--shadow);transition:border-color .2s}.composer:has(#prompt:focus){border-color:color-mix(in srgb,var(--accent) 80%,var(--border-strong))}textarea{display:block;width:100%;resize:none;border:0;outline:none;background:transparent;min-height:60px;max-height:200px;line-height:1.65;padding:0 1px;font-size:16px}textarea::placeholder{color:var(--soft)}textarea:focus-visible{outline:none}.composer-tools{display:flex;justify-content:space-between;align-items:center;gap:8px;margin-top:12px}.send-controls{display:flex;align-items:center;gap:10px;margin-left:auto}.send-btn{height:34px;width:34px;border-radius:6px;display:flex;align-items:center;justify-content:center;background:var(--accent);color:#153247;flex-shrink:0}.send-btn:not(:disabled):hover{filter:brightness(.95)}.send-btn:disabled{background:var(--paper-strong);color:var(--soft);opacity:.7}.scroll-bottom{position:absolute;top:-47px;left:calc(50% - 18px);border:1px solid var(--border);background:var(--paper);box-shadow:var(--shadow);border-radius:50%}.toast{position:fixed;bottom:30px;left:50%;transform:translateX(-50%);z-index:100;background:var(--ink);color:var(--paper);font-size:14px;border-radius:6px;padding:10px 18px;max-width:90vw;width:max-content;box-shadow:var(--shadow)}dialog{border:1px solid var(--border-strong);border-radius:10px;padding:26px;background:var(--paper);color:var(--ink);width:min(420px,calc(100vw - 32px));box-shadow:var(--shadow)}dialog::backdrop{background:#0005;backdrop-filter:blur(3px)}dialog h2{font-size:20px;font-weight:400;margin:0 0 22px}dialog input{width:100%;padding:9px 12px;border:1px solid var(--border-strong);border-radius:5px;background:var(--paper)}.dialog-actions{display:flex;justify-content:flex-end;gap:10px;margin-top:24px}.dialog-actions button{padding:7px 16px;border:1px solid var(--border);border-radius:5px}.dialog-actions .primary{background:var(--accent);color:#153247;border-color:var(--accent)}
@media(min-width:1500px){.main.empty .conversation{height:calc(43dvh - 76px)}.sidebar{width:282px}.sidebar-hidden .sidebar{margin-left:-282px}}
@media(max-width:1050px){.topbar{padding:0 22px}.sidebar{width:238px}.sidebar-hidden .sidebar{margin-left:-238px}.composer-area{width:calc(100% - 44px)}.messages{padding:20px 24px 35px}}
@media(max-width:720px){.app{min-height:0}.sidebar{position:fixed;inset:0 auto 0 0;width:280px!important;max-width:85vw;margin-left:0!important;transform:translateX(-100%);transition:transform .2s}.mobile-sidebar .sidebar{transform:translateX(0)}.sidebar-close{display:flex!important}.backdrop{position:fixed;inset:0;background:#0004;z-index:25}.topbar{height:62px;padding:0 14px}.topbar>a{font-size:12px}.topbar-title{max-width:42vw}.topbar>div{gap:5px}.main.empty .conversation{height:calc(35dvh - 62px);min-height:172px}.welcome{padding:0 14px}.eyebrow{font-size:9px;letter-spacing:.14em}.welcome h1{font-size:29px;margin-top:14px}.welcome p{font-size:14px}.main.empty .composer-area{margin-top:26px}.composer-area{width:calc(100% - 28px);padding-bottom:max(10px,env(safe-area-inset-bottom))}.composer{padding:13px 13px 10px}.messages{padding:18px 18px 30px}.message{margin-bottom:28px}.user .message-content{max-width:90%}.history-row .icon-btn{opacity:1}.markdown{font-size:16px}.message-actions .model-caption{font-size:10px}.shortcut{display:none}}
@media(max-height:600px){.main.empty .conversation{min-height:130px;height:auto}.main.empty .composer-area{margin-top:16px}.welcome h1{margin:8px 0}.topbar{height:55px}.main.empty{overflow-y:auto}.main.empty .conversation{flex-shrink:0}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* Paper menus and motion share the blog's quiet, fine-lined styling. */
.model-wrap{position:relative;display:flex;align-items:center;user-select:none}
.model-trigger{display:flex;align-items:center;gap:9px;min-height:34px;padding:5px 7px;color:var(--muted);font-size:13px;line-height:1.5;border:0;border-radius:5px;background:transparent;white-space:nowrap}
.model-trigger:hover,.model-trigger:active,.model-trigger[aria-expanded=true]{background:transparent;color:var(--muted)}
.model-trigger:focus:not(:focus-visible),.model-option:focus:not(:focus-visible){outline:none}
.model-trigger:focus-visible,.model-option:focus-visible{outline:1px solid var(--border-strong);outline-offset:2px}
.model-chevron{display:flex;transition:transform .24s cubic-bezier(.22,1,.36,1)}
.model-chevron svg{width:13px;height:13px}
.model-wrap.is-open .model-chevron{transform:rotate(180deg)}
.model-menu{position:absolute;top:calc(100% + 16px);bottom:auto;right:0;z-index:40;width:240px;max-width:calc(100vw - 72px);padding:8px;border:1px solid var(--border);border-radius:6px;background:var(--paper);box-shadow:0 8px 32px color-mix(in srgb,var(--ink-strong) 8%,transparent),0 2px 8px color-mix(in srgb,var(--ink-strong) 3%,transparent);visibility:hidden;opacity:0;pointer-events:none;transform:translateY(-6px) scale(.985);transform-origin:top right;transition:opacity .18s ease,transform .24s cubic-bezier(.22,1,.36,1),visibility 0s .24s,background-color .38s,border-color .38s,color .38s}
.model-wrap.is-open .model-menu{visibility:visible;opacity:1;pointer-events:auto;transform:translateY(0) scale(1);transition-delay:0s}
.model-option{display:flex;align-items:center;justify-content:space-between;gap:14px;width:100%;padding:11px 9px;border-radius:4px;background:transparent;color:var(--ink);font-size:14px;line-height:1.5;text-align:left}
.model-option:hover,.model-option:active,.model-option[aria-selected=true]{background:transparent}
.model-option svg{width:15px;height:15px;color:var(--soft);flex-shrink:0}
.composer-area{padding-bottom:max(24px,env(safe-area-inset-bottom))}
body,.main,.composer,.user .message-content,.history-row,.new-chat,.icon-btn,.send-btn,.markdown pre,.markdown code,.markdown th,dialog,dialog input,.toast{transition:background-color .38s ease,color .38s ease,border-color .38s ease,box-shadow .38s ease}
.sidebar{transition:margin .22s ease,transform .2s ease,background-color .38s ease,color .38s ease,border-color .38s ease}
.welcome h1>span,.welcome p,.topbar,.assistant-label,.history-label,.history-group,.sidebar-bottom,.sidebar-bottom p,.model-trigger,.model-option,.model-option svg{transition:color .38s ease,border-color .38s ease}
@keyframes paper-arrive{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:translateY(0)}}
@keyframes paper-fade{from{opacity:0}to{opacity:1}}
.is-entering .sidebar-brand,.is-entering .new-chat,.is-entering .search-wrap,.is-entering .history-label,.is-entering .history,.is-entering .sidebar-bottom{animation:paper-fade .65s ease both}
.is-entering .topbar{animation:paper-arrive .6s cubic-bezier(.22,1,.36,1) .04s both}
.is-entering .welcome .eyebrow{display:inline-block;animation:paper-arrive .7s cubic-bezier(.22,1,.36,1) .10s both}
.is-entering .welcome h1{animation:paper-arrive .7s cubic-bezier(.22,1,.36,1) .17s both}
.is-entering .welcome p{animation:paper-arrive .7s cubic-bezier(.22,1,.36,1) .24s both}
.is-entering .composer-area{animation:paper-arrive .7s cubic-bezier(.22,1,.36,1) .30s both}
@media(max-width:720px){.model-trigger{font-size:12px;gap:7px}.model-menu{width:228px}.composer-area{padding-bottom:max(16px,env(safe-area-inset-bottom))}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* Leave room below the composer while the downward menu is open. */
.composer-area{transition:padding-bottom .24s cubic-bezier(.22,1,.36,1)}
.main .composer-area:has(.model-wrap.is-open){padding-bottom:calc(76px + env(safe-area-inset-bottom))}
@media(prefers-reduced-motion:reduce){.composer-area{transition:none}}