:root{font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;color:#242831;background:#fff;font-synthesis:none;--blue:#4d6bfe;--line:#e9edf4;--muted:#929aa8;--soft:#f6f8fc;color-scheme:light}*{box-sizing:border-box}body{margin:0}a{color:inherit;text-decoration:none}button,input,textarea{font:inherit}button{cursor:pointer}button:disabled{cursor:default}button,a,textarea{ -webkit-tap-highlight-color:transparent}button:focus-visible,a:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid #b1bfff;outline-offset:4px}[hidden]{display:none!important}::selection{background:#dce5ff}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}.skip{position:fixed;top:-90px;left:20px;padding:12px 20px;background:var(--blue);color:#fff;z-index:50}.skip:focus{top:10px}#chat-app{min-height:100svh;display:grid;grid-template-columns:238px minmax(0,1fr)}.rail{position:sticky;top:0;height:100svh;background:#f8faff;border-right:1px solid #f0f2f8;padding:30px 19px 18px;display:flex;flex-direction:column;z-index:15}.brand{display:flex;align-items:center;gap:10px;margin:0 12px 30px;font-size:24px;font-weight:650;letter-spacing:1px}.brand-ai{color:var(--blue);font-size:19px;letter-spacing:0}.brand img{border-radius:12px}.new-chat{width:100%;display:flex;align-items:center;gap:10px;padding:11px 13px;min-height:46px;background:#eef2ff;border:1px solid #dce4ff;color:#4764e8;border-radius:12px;font-size:13px;text-align:left}.new-chat>span:first-child{font-size:23px;line-height:1;font-weight:300}.new-icon{margin-left:auto;opacity:.6}.rail-section{font-size:10px;color:#a0a7b6;margin:32px 13px 12px;letter-spacing:.5px}.rail-link{display:flex;align-items:center;gap:12px;padding:12px 14px;font-size:13px;margin-bottom:5px;border-radius:10px;color:#616b7c}.rail-link>span:first-child{font-size:18px;line-height:1;width:19px;text-align:center;color:#8190a7}.rail-link.selected{background:#eaf0ff;color:#4261e4;font-weight:550}.rail-link.selected>span:first-child{color:#4d6bfe}.rail-link:hover{background:#edf2fc}.tiny-badge{font-size:9px;margin-left:auto;padding:2px 7px;border:1px solid #e2e7f2;border-radius:5px;color:#8d98ac}.rail-space{flex:1;min-height:40px}.rail-tip{margin:0 5px 28px;padding:16px 12px;color:#6d7790;border-top:1px solid #e9eef7}.rail-tip-icon{font-size:26px;color:#7990ec;display:block;margin-bottom:9px}.rail-tip strong{font-size:12px;font-weight:500}.rail-tip p{font-size:11px;line-height:1.9;margin:7px 0 0;color:#98a2b4}.rail-login{display:flex;gap:10px;align-items:center;padding:13px 5px 0;border-top:1px solid #e9edf5;font-size:12px;color:#5c667a}.rail-login small{display:block;font-size:9px;margin-top:3px;color:#a1a9b7}.rail-login>span:last-child{margin-left:auto;color:#8b98b2}.avatar{width:32px;height:32px;border-radius:50%;background:#edf1f8;display:grid;place-items:center;font-size:22px;color:#96a2b8}.chat-layout{min-width:0;display:flex;flex-direction:column;min-height:100svh}.chat-header{height:82px;padding:0 38px;display:flex;align-items:center;justify-content:space-between;gap:20px}.header-model{font-size:13px;color:#6c7484;display:flex;gap:10px;align-items:center}.header-model>span{color:#a1a8b5}.chat-header nav{display:flex;align-items:center;gap:27px;font-size:12px;color:#8790a0}.login-button{border:1px solid #dde5fc;color:#4d6bfe;border-radius:9px;padding:9px 15px;background:#f8faff;font-size:12px}.login-button span{margin-left:8px}.mobile-only,.mobile-brand{display:none}.chat-main{width:100%;max-width:890px;margin:auto;display:flex;flex-direction:column;align-items:center;padding:45px 45px 40px;flex:1;justify-content:center}.welcome{text-align:center;margin-top:-10px;margin-bottom:35px}.welcome-symbol{display:flex;justify-content:center;margin-bottom:19px}.welcome-symbol img{background:transparent;border-radius:19px}.welcome h1{font-size:32px;line-height:1.5;font-weight:580;letter-spacing:-.6px;margin:0;color:#2c3341}.welcome h1 span{color:#4d6bfe;margin-left:6px}.welcome>p{font-size:14px;color:#949caa;letter-spacing:.5px;margin:12px 0 0}.composer-area{width:100%}.composer{border:1px solid #e4e8f0;border-radius:23px;background:#fff;box-shadow:0 5px 28px #263d7410;transition:border-color .2s,box-shadow .2s;padding:19px 19px 14px}.composer:focus-within{border-color:#b1c1ff;box-shadow:0 5px 28px #4d6bfe13}.composer textarea{display:block;resize:none;width:100%;min-height:74px;max-height:240px;padding:1px 2px 7px;border:0;background:transparent;color:#293245;outline:none;font-size:15px;line-height:1.7;overflow-y:auto}.composer textarea:focus-visible{outline:0}.composer textarea::placeholder{color:#a2a9b7}.composer-toolbar{display:flex;align-items:center;justify-content:space-between;gap:15px;margin-top:8px}.model-tools{display:flex;align-items:center;gap:11px;min-width:0}.current-model{display:flex;align-items:center;gap:7px;border-radius:8px;padding:6px 10px;font-size:11px;color:#61739b;background:#f4f7fd;white-space:nowrap}.model-dot{width:5px;height:5px;background:#7796eb;border-radius:50%}.more-models{font-size:11px;color:#8b96ab;white-space:nowrap;padding:5px 1px}.more-models span{margin-left:5px}.send-button,.stop-button{width:36px;height:36px;border:0;border-radius:11px;background:var(--blue);color:white;display:grid;place-items:center;flex-shrink:0;transition:background .2s}.send-button:disabled{background:#e9edf6;color:#adb8cc}.send-button svg{width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}.stop-button{font-size:12px}.suggestions{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap;margin-top:20px}.suggestions button{display:flex;align-items:center;gap:8px;border:1px solid #e8ecf3;background:#fff;color:#7a8497;font-size:11px;padding:9px 13px;border-radius:9px;transition:background .2s,color .2s,border-color .2s}.suggestions button:hover{background:#f4f7ff;color:#4d6bfe;border-color:#ced9ff}.suggestions button span{font-size:14px;color:#92a1bd}.guest-note{font-size:10px;text-align:center;color:#a0a8b7;margin:20px 0 0;line-height:1.9}.guest-note span{color:#909bad}.guest-note a{color:#788fe3}.chat-footer{display:flex;align-items:center;justify-content:space-between;gap:15px;padding:22px 34px;font-size:9px;color:#a2aab8}.chat-footer>div{display:flex;gap:12px;white-space:nowrap}.chat-footer a:hover{color:#4d6bfe}.message-status{font-size:12px;color:#7d8baa;min-height:0;margin:0}.message-status:not(:empty){margin-top:13px;line-height:1.8}.message-status.error{color:#ad5d5d}.messages{width:100%;display:flex;flex-direction:column;gap:25px;min-width:0}.chat-main.has-messages{justify-content:flex-start;padding-top:18px;padding-bottom:10px}.has-messages .welcome,.has-messages .suggestions{display:none}.has-messages .composer-area{position:sticky;bottom:0;background:linear-gradient(0deg,#fff 90%,#fff0);padding-top:24px;margin-top:auto;padding-bottom:16px;z-index:3}.has-messages .guest-note{margin-top:9px}.message{display:flex;gap:13px;line-height:1.85;font-size:14px;min-width:0}.message.user{align-self:flex-end;max-width:88%;display:block;white-space:pre-wrap;overflow-wrap:anywhere;background:#eef3ff;color:#3d4e78;padding:12px 18px;border-radius:18px 18px 4px 18px}.assistant-avatar{width:29px;height:29px;flex-shrink:0}.assistant-body{flex:1;min-width:0;padding-top:1px}.answer-text{white-space:pre-wrap;overflow-wrap:anywhere}.answer-text:empty::after{content:'正在思考…';color:#8e9bb2;font-size:13px}.message.complete .answer-text:empty::after{content:''}.answer-text pre{white-space:pre;overflow:auto;background:#f6f8fc;border:1px solid #e5eaf3;padding:16px;border-radius:10px;font:12px/1.8 ui-monospace,Consolas,monospace;margin:15px 0}.answer-text code{font-family:ui-monospace,Consolas,monospace}.answer-text :not(pre)>code{background:#f0f4fb;padding:2px 5px;border-radius:4px;font-size:12px}.thinking{font-size:12px;color:#8995aa;border-left:2px solid #e0e7f9;padding-left:12px;margin-bottom:13px}.thinking summary{cursor:pointer}.thinking p{white-space:pre-wrap;max-height:220px;overflow:auto;font-size:11px;line-height:1.9;overflow-wrap:anywhere}.answer-actions{display:flex;gap:15px;margin-top:12px}.answer-actions button{border:0;background:none;padding:3px 0;color:#9aa6b9;font-size:11px}.answer-actions button:hover{color:#4d6bfe}.rail-backdrop{position:fixed;inset:0;z-index:10;border:0;background:#1b31524d}.no-js{position:fixed;bottom:20px;left:50%;transform:translateX(-50%);background:#eef3ff;padding:15px 25px;font-size:13px;color:#4d6bfe;z-index:30}.icon-button{border:0;background:transparent;color:#7b89a6;width:32px;height:36px}
@media(min-width:1500px){.chat-main{max-width:940px;padding-left:55px;padding-right:55px}.welcome{margin-bottom:40px}.welcome h1{font-size:35px}.rail{padding-top:36px}#chat-app{grid-template-columns:256px minmax(0,1fr)}}
@media(max-width:1050px){#chat-app{grid-template-columns:210px minmax(0,1fr)}.rail{padding:25px 14px 17px}.brand{margin-left:10px}.chat-main{padding-left:30px;padding-right:30px}.chat-header{padding:0 28px}.chat-footer{padding:20px 26px}.rail-section{font-size:9px}.rail-tip{padding-left:8px}}
@media(max-width:760px){#chat-app{display:block}.rail{position:fixed;left:0;width:258px;transform:translateX(-100%);transition:transform .2s;height:100dvh;box-shadow:10px 0 40px #30427318}body.menu-open .rail{transform:translateX(0)}.mobile-only{display:block}.mobile-brand{display:block;margin-right:auto;font-size:18px;color:#4d6bfe;font-weight:600;white-space:nowrap}.header-model{display:none}.chat-header{height:70px;padding:0 16px;gap:10px}.chat-header nav{gap:10px}.chat-header nav>a:first-child{display:none}.login-button{font-size:11px;padding:8px 11px}.login-button span{margin-left:4px}.chat-main{padding:26px 20px 45px;max-width:640px}.welcome{margin-top:-15px;margin-bottom:31px}.welcome-symbol{margin-bottom:20px}.welcome-symbol img{width:53px;height:53px}.welcome h1{font-size:27px}.welcome>p{font-size:13px;margin-top:10px}.composer{padding:16px 14px 13px;border-radius:20px}.composer textarea{font-size:14px;min-height:98px}.model-tools{gap:9px}.current-model{font-size:10px;padding:6px 8px;gap:6px}.more-models{font-size:10px}.more-models span{margin-left:2px}.suggestions{gap:8px;margin-top:18px}.suggestions button{padding:8px 10px;font-size:10px;gap:5px}.suggestions button span{font-size:12px}.guest-note{font-size:9px;margin-top:17px}.chat-footer{padding:16px 20px;display:block;text-align:center;font-size:9px;line-height:1.8}.chat-footer>div{justify-content:center;margin-top:6px;gap:10px}.message{font-size:13px;gap:10px}.message.user{max-width:90%;padding:11px 15px}.assistant-avatar{width:26px;height:26px}.has-messages .composer-area{padding-top:20px}.chat-main.has-messages{padding:12px 16px 0}.has-messages .composer textarea{min-height:58px}.has-messages .composer{border-radius:17px}.has-messages .guest-note{font-size:8px}.chat-layout{min-height:100dvh}}
@media(max-width:370px){.chat-main{padding-left:14px;padding-right:14px}.suggestions{gap:6px}.suggestions button{padding:8px;font-size:9px}.welcome h1{font-size:25px}.more-models{font-size:9px}.current-model{font-size:9px}.guest-note{font-size:8px}.composer{padding-left:12px;padding-right:12px}}
@media(prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important;scroll-behavior:auto!important}}
.embedded #chat-app{display:block}.embedded .rail,.embedded .chat-header{display:none}.embedded .chat-layout{min-height:100svh}
/* Match body readability across chat, touch screens, and enlarged text. */
.guest-note,.chat-footer,.rail-section,.message-status{font-size:.8125rem;color:#6c7890}
.rail-link,.suggestions button,.current-model,.more-models{font-size:.875rem}
textarea{font-size:1rem}
@media(max-width:760px){.chat-footer{font-size:.75rem}.composer-area{padding-bottom:env(safe-area-inset-bottom)}.model-tools{flex-wrap:wrap}.guest-note{font-size:.75rem;line-height:1.8}}
/* ===== Model Selector & Multi-modal (20260919) ===== */
.model-dropdown{position:fixed;background:#fff;border:1px solid #e8ecf3;border-radius:16px;box-shadow:0 12px 48px #1a2c5a1f;padding:10px;z-index:9999;max-height:70vh;overflow-y:auto;min-width:240px;max-width:340px}
.model-group{margin-bottom:6px}.model-group:last-of-type{margin-bottom:0}
.model-group-title{font-size:10px;color:#9aa3b4;padding:6px 10px 4px;letter-spacing:.3px}
.model-item{width:100%;display:flex;align-items:center;gap:12px;padding:11px 12px;border:0;background:transparent;border-radius:12px;text-align:left;transition:background .15s}
.model-item:hover{background:#f5f8ff}.model-item.selected{background:#eef2ff}
.model-badge{font-size:10px;font-weight:600;padding:3px 8px;border-radius:6px;flex-shrink:0;letter-spacing:.3px}
.model-badge.claude{background:#d97757;color:#fff}.model-badge.gpt{background:#10a37f;color:#fff}
.model-name{font-size:14px;font-weight:550;color:#2c3341;flex-shrink:0}
.model-desc{font-size:11px;color:#9aa3b4;margin-left:auto}
.model-hint{font-size:10px;color:#b0b7c3;text-align:center;margin:10px 4px 4px;line-height:1.6}
.model-selector{display:flex;align-items:center;gap:7px;border:1px solid #e8ecf3;background:#fff;border-radius:10px;padding:7px 12px;font-size:12px;color:#4a5568;transition:border-color .15s,background .15s}
.model-selector:hover{border-color:#c5d0ff;background:#f8faff}
.model-selector .chev{font-size:11px;color:#9aa3b4}
.model-selector[aria-expanded="true"]{border-color:#4d6bfe;background:#f3f6ff}
.composer-area{position:relative}.composer{position:relative}
.composer-previews{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:10px}
.preview-item{position:relative;width:84px;height:84px;border-radius:12px;overflow:hidden;background:#f0f3f9;border:1px solid #e4e8f0}
.preview-item img{width:100%;height:100%;object-fit:cover}
.preview-item .remove-preview{position:absolute;top:3px;right:3px;width:20px;height:20px;border-radius:50%;background:rgba(0,0,0,.55);color:#fff;border:0;font-size:13px;line-height:1;display:grid;place-items:center;padding:0}
.preview-file{display:flex;align-items:center;gap:8px;padding:8px 12px;background:#f5f8ff;border:1px solid #dde5f7;border-radius:10px;font-size:12px;color:#4a5568}
.preview-file .file-icon{font-size:16px}.preview-file .file-name{max-width:160px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.preview-file .remove-preview{border:0;background:none;color:#9aa3b4;font-size:15px;line-height:1;padding:0 2px}
.composer-tools{display:flex;align-items:center;gap:8px}
.composer-actions{display:flex;align-items:center;gap:8px}
.tool-btn{width:36px;height:36px;border:1px solid #e8ecf3;background:#fff;border-radius:11px;color:#6b7689;display:grid;place-items:center;transition:background .15s,border-color .15s,color .15s}
.tool-btn:hover{background:#f5f8ff;border-color:#c5d0ff;color:#4d6bfe}
.message.user .user-images{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:8px}
.message.user .user-images img{max-width:200px;max-height:160px;border-radius:10px;display:block}
.message.user .user-files{margin-bottom:6px;font-size:12px;opacity:.8}
.send-button:not(:disabled){animation:pulse-ready .4s ease}
@keyframes pulse-ready{0%{transform:scale(.85)}60%{transform:scale(1.08)}100%{transform:scale(1)}}
@media(max-width:760px){.model-dropdown{max-width:calc(100vw - 24px)}.model-item{padding:10px}.model-desc{display:none}.model-name{font-size:13px}.tool-btn{width:34px;height:34px}.preview-item{width:70px;height:70px}}