:root{--bg:#f7f8fa;--panel:#fff;--text:#171a21;--muted:#6f7582;--line:#e6e8ec;--soft:#f1f3f6;--primary:#315efb;--primary-dark:#2449d8;--danger:#d14343;--shadow:0 18px 50px rgba(26,31,44,.10);font-family:Inter,"PingFang SC","Microsoft YaHei",system-ui,-apple-system,sans-serif;color:var(--text);background:var(--bg)}*{box-sizing:border-box}html,body{margin:0;min-height:100%;background:var(--bg)}body{overflow:hidden}button,input,textarea,select{font:inherit}.hidden{display:none!important}.mobile-only{display:none}.toast{position:fixed;left:50%;top:24px;z-index:1000;transform:translate(-50%,-12px);padding:11px 16px;border:1px solid var(--line);border-radius:12px;background:#fff;box-shadow:var(--shadow);opacity:0;pointer-events:none;transition:.2s;font-size:14px}.toast.show{opacity:1;transform:translate(-50%,0)}.toast.error{color:#b42318;border-color:#f1c7c3}.wordmark{display:inline-flex;align-items:center;gap:11px;color:var(--text);text-decoration:none}.wordmark>span{display:grid;place-items:center;width:34px;height:34px;border-radius:11px;background:var(--text);color:#fff;font-weight:750}.wordmark strong{font-size:17px;letter-spacing:-.02em}.wordmark.compact>span{width:31px;height:31px;border-radius:10px;font-size:13px}.wordmark.compact strong{font-size:15px}.auth-view{min-height:100vh;overflow:auto;background:#fff}.auth-shell{min-height:100vh;display:grid;grid-template-columns:minmax(0,1.1fr) minmax(430px,.9fr)}.auth-intro{padding:48px 64px;display:flex;flex-direction:column;background:linear-gradient(145deg,#f5f7fb 0%,#eef2fb 100%);border-right:1px solid var(--line)}.intro-copy{margin:auto 0;max-width:690px}.kicker,.welcome-kicker{display:inline-block;color:var(--primary);font-size:12px;font-weight:750;letter-spacing:.14em}.intro-copy h1{font-size:clamp(44px,5vw,72px);line-height:1.08;letter-spacing:-.055em;margin:22px 0 20px}.intro-copy p{font-size:18px;line-height:1.8;color:var(--muted);max-width:560px}.intro-points{display:flex;gap:24px;flex-wrap:wrap;color:#4d5564;font-size:13px}.intro-points span:before{content:"";display:inline-block;width:6px;height:6px;border-radius:50%;background:var(--primary);margin-right:8px;vertical-align:2px}.auth-panel{display:grid;place-items:center;padding:48px;background:#fff}.auth-box{width:min(100%,420px)}.auth-head h2{font-size:30px;letter-spacing:-.04em;margin:0 0 8px}.auth-head p{margin:0;color:var(--muted)}.auth-tabs{display:flex;background:var(--soft);padding:4px;border-radius:12px;margin:32px 0 24px}.auth-tabs button{flex:1;border:0;background:transparent;border-radius:9px;padding:10px;cursor:pointer;color:var(--muted)}.auth-tabs button.active{background:#fff;color:var(--text);box-shadow:0 2px 8px rgba(20,26,40,.07)}form label,.stack-form label{display:block;margin-bottom:16px}form label span,.stack-form label span{display:block;font-size:13px;font-weight:650;margin-bottom:8px}input,textarea,select{width:100%;border:1px solid var(--line);background:#fff;border-radius:12px;color:var(--text);outline:none;transition:.18s}input,select{height:46px;padding:0 13px}textarea{padding:13px;resize:vertical}input:focus,textarea:focus,select:focus{border-color:#94a9ff;box-shadow:0 0 0 4px rgba(49,94,251,.08)}.btn{border:0;border-radius:11px;padding:11px 15px;font-weight:680;cursor:pointer;transition:.18s}.btn:disabled{opacity:.45;cursor:not-allowed}.btn.primary{background:var(--primary);color:#fff}.btn.primary:hover{background:var(--primary-dark)}.btn.ghost{background:#fff;color:var(--text);border:1px solid var(--line)}.btn.danger{background:#fff3f2;color:var(--danger)}.btn.wide{width:100%}.auth-note{margin:18px 0 0;text-align:center;color:#9499a3;font-size:12px;line-height:1.7}.app{height:100vh;display:grid;grid-template-columns:280px minmax(0,1fr);background:#fff}.sidebar{display:flex;flex-direction:column;min-width:0;background:#fafbfc;border-right:1px solid var(--line);padding:18px 14px}.side-top{height:44px;display:flex;align-items:center;justify-content:space-between;padding:0 6px}.new-chat{display:flex;align-items:center;justify-content:center;gap:8px;width:100%;margin:18px 0 20px;border:1px solid #dfe3e9;background:#fff;border-radius:12px;padding:11px;color:var(--text);font-weight:680;cursor:pointer}.new-chat:hover{border-color:#bcc5d2}.side-label{display:flex;justify-content:space-between;align-items:center;padding:0 8px 8px;color:#858b97;font-size:12px}.text-btn{border:0;background:transparent;color:var(--primary);cursor:pointer;padding:4px}.conversation-list{flex:1;overflow:auto;min-height:0}.conversation-item{display:flex;align-items:center;gap:8px;border-radius:10px;padding:10px 9px;margin:2px 0;color:#515763;font-size:13px;cursor:pointer}.conversation-item:hover,.conversation-item.active{background:#edf0f4;color:var(--text)}.conversation-item>span{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.conversation-item button{opacity:0;border:0;background:transparent;color:#969ba5;cursor:pointer}.conversation-item:hover button{opacity:1}.side-bottom{display:grid;gap:8px;padding-top:12px;border-top:1px solid var(--line)}.balance-card,.user-card,.side-link{display:flex;align-items:center;width:100%;border:0;border-radius:12px;background:#fff;padding:11px;text-decoration:none;color:var(--text);cursor:pointer;text-align:left}.balance-card{border:1px solid #dfe5ff}.balance-card>span,.user-card>span:nth-child(2){flex:1}.balance-card small,.user-card small{display:block;color:var(--muted);font-size:11px;margin-bottom:3px}.balance-card strong{font-size:17px}.balance-card b{color:var(--primary);font-size:12px}.side-link{justify-content:space-between;border:1px solid var(--line);font-size:13px}.user-card{background:transparent}.avatar{display:grid!important;place-items:center;flex:0 0 34px!important;width:34px;height:34px;margin-right:10px;border-radius:50%;background:#e8ecf4;font-size:13px;font-weight:750}.user-card strong{display:block;font-size:13px}.workspace{min-width:0;display:flex;flex-direction:column;background:#fff}.topbar{height:68px;display:flex;align-items:center;justify-content:space-between;padding:0 24px;border-bottom:1px solid var(--line)}.model-picker{display:flex;align-items:center;gap:10px;border:0;background:transparent;padding:5px 8px;border-radius:10px;cursor:pointer;text-align:left}.model-picker:hover{background:var(--soft)}.model-picker>span:nth-child(2){min-width:0}.model-picker small{display:block;color:var(--muted);font-size:10px}.model-picker strong{display:block;font-size:14px;max-width:240px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.model-icon{display:grid!important;place-items:center;width:34px;height:34px;border-radius:11px;background:#e9eeff;color:#244bc3;font-size:12px;font-weight:800}.top-actions{display:flex;align-items:center;gap:10px}.soft-tag{padding:7px 10px;border-radius:999px;background:#eef2ff;color:#3857bd;font-size:12px;font-weight:700}.announcement{margin:12px 24px 0;padding:10px 14px;border:1px solid #dfe5ff;background:#f5f7ff;border-radius:10px;color:#4f5f91;font-size:13px}.chat-scroller{flex:1;overflow:auto;min-height:0}.welcome{width:min(920px,calc(100% - 40px));margin:0 auto;padding:10vh 0 150px;text-align:center}.welcome h2{font-size:clamp(36px,5vw,60px);letter-spacing:-.055em;margin:16px 0 12px}.welcome>p{color:var(--muted);font-size:16px}.model-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:42px 0 16px;text-align:left}.model-card{position:relative;border:1px solid var(--line);background:#fff;border-radius:16px;padding:16px;min-height:150px;cursor:pointer;text-align:left;transition:.18s}.model-card:hover,.model-card.active{border-color:#aebdfb;box-shadow:0 10px 28px rgba(41,63,123,.08);transform:translateY(-2px)}.model-card .model-icon{margin-bottom:22px}.model-card strong{display:block;font-size:14px;margin-bottom:6px}.model-card small{display:block;color:var(--muted);font-size:12px;line-height:1.5}.model-card .badge{position:absolute;right:12px;top:12px;font-size:10px;color:#435ba8;background:#eef2ff;border-radius:999px;padding:4px 7px}.suggestions{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.suggestions button{border:1px solid var(--line);background:#fafbfc;border-radius:13px;padding:13px;text-align:left;cursor:pointer}.suggestions button:hover{background:#f3f5f8}.suggestions strong{display:block;font-size:13px}.suggestions span{display:block;color:var(--muted);font-size:11px;margin-top:5px}.messages{width:min(860px,calc(100% - 36px));margin:0 auto;padding:38px 0 150px}.message{display:grid;grid-template-columns:34px minmax(0,1fr);gap:14px;padding:22px 0;border-bottom:1px solid #f0f1f3}.message-avatar{display:grid;place-items:center;width:34px;height:34px;border-radius:10px;background:#edf0f5;font-size:12px;font-weight:750}.message.assistant .message-avatar{background:#e8edff;color:#2f4db2}.message-head{display:flex;align-items:center;gap:8px;margin-bottom:8px}.message-head strong{font-size:13px}.message-head small{color:#999ea8;font-size:10px}.message-body{font-size:15px;line-height:1.8;color:#2d323c;overflow-wrap:anywhere}.message-body p{margin:.45em 0}.message-body pre{overflow:auto;background:#111827;color:#e5e7eb;padding:14px;border-radius:12px;font-size:13px}.message-body code:not(pre code){background:#f0f2f5;padding:2px 5px;border-radius:5px}.typing{display:inline-flex;gap:5px}.typing i{width:6px;height:6px;background:#aab0bc;border-radius:50%;animation:blink 1s infinite}.typing i:nth-child(2){animation-delay:.15s}.typing i:nth-child(3){animation-delay:.3s}@keyframes blink{50%{opacity:.25}}.composer-wrap{position:fixed;bottom:0;left:280px;right:0;padding:18px 24px 12px;background:linear-gradient(180deg,rgba(255,255,255,0),#fff 24%,#fff)}.composer{width:min(860px,100%);margin:0 auto;border:1px solid #dfe2e7;background:#fff;border-radius:18px;box-shadow:0 12px 34px rgba(27,34,50,.10);padding:11px 12px 10px}.composer textarea{border:0;box-shadow:none;min-height:46px;max-height:180px;padding:9px 8px;resize:none}.composer textarea:focus{box-shadow:none}.composer-row{display:flex;align-items:center;justify-content:space-between;padding-left:8px}.composer-row>span{color:#9a9faa;font-size:11px}.send-btn{display:grid;place-items:center;width:36px;height:36px;border:0;border-radius:11px;background:var(--text);color:#fff;cursor:pointer}.send-btn:disabled{opacity:.25}.disclaimer{text-align:center;color:#a0a5ae;font-size:10px;margin:8px 0 0}.modal{position:fixed;inset:0;z-index:100;display:grid;place-items:center;padding:24px}.backdrop{position:absolute;inset:0;background:rgba(24,28,36,.32);backdrop-filter:blur(3px)}.dialog{position:relative;width:min(720px,100%);max-height:min(820px,calc(100vh - 40px));overflow:auto;background:#fff;border-radius:20px;box-shadow:var(--shadow);padding:22px}.dialog-head{display:flex;align-items:flex-start;justify-content:space-between;margin-bottom:20px}.dialog-head h3{margin:0;font-size:22px;letter-spacing:-.03em}.dialog-head p{margin:6px 0 0;color:var(--muted);font-size:13px}.icon-btn{display:grid;place-items:center;width:36px;height:36px;border:1px solid var(--line);border-radius:10px;background:#fff;cursor:pointer}.model-list{display:grid;gap:8px}.model-list button{display:flex;align-items:center;gap:12px;border:1px solid var(--line);background:#fff;border-radius:13px;padding:12px;text-align:left;cursor:pointer}.model-list button:hover,.model-list button.active{border-color:#aebdfb;background:#fafbff}.model-list .model-icon{flex:0 0 38px}.model-list strong{display:block;font-size:14px}.model-list small{display:block;color:var(--muted);font-size:11px;margin-top:4px}.model-list .billing{margin-left:auto;color:#3955ae;background:#eff2ff;padding:5px 8px;border-radius:999px;font-size:10px}.product-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.product-card{position:relative;border:1px solid var(--line);background:#fff;border-radius:14px;padding:16px;cursor:pointer;text-align:left}.product-card.active{border-color:#8ba2ff;box-shadow:0 0 0 3px rgba(49,94,251,.08)}.product-card .badge{position:absolute;right:10px;top:10px;font-size:10px;color:#fff;background:var(--primary);padding:4px 7px;border-radius:999px}.product-card strong{display:block;font-size:14px}.product-card .price{display:block;font-size:26px;font-weight:760;margin:18px 0 8px}.product-card small{color:var(--muted);font-size:11px;line-height:1.5}.pay-methods{display:flex;align-items:center;justify-content:space-between;margin:18px 0 14px;padding:12px 0;border-top:1px solid var(--line)}.pay-methods>span{font-size:13px;font-weight:650}.pay-methods button{border:1px solid var(--line);background:#fff;border-radius:9px;padding:8px 12px;margin-left:6px;cursor:pointer}.pay-methods button.active{border-color:#7e98ff;color:#3154c4;background:#f5f7ff}.dialog-section{margin-top:24px;padding-top:18px;border-top:1px solid var(--line)}.section-title{display:flex;justify-content:space-between;align-items:center;margin-bottom:10px}.section-title strong{font-size:13px}.simple-list{display:grid;gap:8px}.simple-row{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:10px 0;border-bottom:1px solid #f0f1f3;font-size:12px}.simple-row:last-child{border-bottom:0}.simple-row span:first-child{min-width:0}.simple-row strong{display:block;font-size:12px}.simple-row small{display:block;color:var(--muted);margin-top:4px}.status{font-size:10px;border-radius:999px;padding:5px 8px;background:#f0f2f5;color:#68707e}.status.paid{background:#ebf8ef;color:#24713f}.status.pending{background:#fff5df;color:#9a6612}.account-stats{display:grid;grid-template-columns:1fr 1fr;gap:10px}.account-stats>div{background:#f7f8fa;border-radius:14px;padding:16px}.account-stats small{display:block;color:var(--muted);font-size:11px}.account-stats strong{display:block;font-size:20px;margin-top:8px}.account-actions{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:14px}.small-dialog{width:min(430px,100%)}.stack-form{display:grid;gap:4px}.empty{padding:24px;text-align:center;color:var(--muted);font-size:13px;border:1px dashed var(--line);border-radius:12px}
@media(max-width:980px){.auth-shell{grid-template-columns:1fr}.auth-intro{min-height:44vh;padding:32px}.intro-copy{margin:60px 0}.auth-panel{padding:38px 24px}.app{grid-template-columns:1fr}.mobile-only{display:grid}.sidebar{position:fixed;inset:0 auto 0 0;width:min(86vw,300px);z-index:50;transform:translateX(-105%);transition:.22s;box-shadow:var(--shadow)}.sidebar.open{transform:none}.composer-wrap{left:0}.topbar{padding:0 14px}.model-grid{grid-template-columns:repeat(2,1fr)}.welcome{padding-top:7vh}.top-actions .btn{display:none}}@media(max-width:620px){.auth-intro{padding:24px}.intro-copy h1{font-size:38px}.intro-points{gap:12px}.auth-panel{padding:30px 20px}.welcome{width:calc(100% - 28px);padding-bottom:130px}.welcome h2{font-size:38px}.model-grid{grid-template-columns:1fr 1fr;gap:8px;margin-top:30px}.model-card{padding:13px;min-height:132px}.suggestions{grid-template-columns:1fr}.messages{width:calc(100% - 28px)}.composer-wrap{padding:12px 12px 8px}.composer-row>span{display:none}.dialog{padding:18px}.product-grid{grid-template-columns:1fr}.account-stats,.account-actions{grid-template-columns:1fr}.soft-tag{display:none}}