:root{--ink:#171717;--muted:#777;--line:#ececec;--soft:#f5f5f5;--panel:#fafafa;--radius:18px}
    *{box-sizing:border-box}
    html,body{margin:0;height:100%;font-family:Inter,"SF Pro Display","PingFang SC","Microsoft YaHei",Arial,sans-serif;color:var(--ink);background:#fff}
    button{font:inherit;color:inherit}
    .app{height:100vh;min-height:650px;display:grid;grid-template-columns:295px minmax(650px,1fr) 306px;overflow:hidden}
    .left,.progress{height:100vh;background:#fff;position:relative;z-index:2}
    .left{border-right:1px solid var(--line);padding:17px 10px 88px}
    .brand-row,.chat-head,.progress-head{height:34px;display:flex;align-items:center}
    .brand-row{padding:0 10px;justify-content:space-between}
    .brand{font-size:21px;font-weight:650;letter-spacing:-.5px}
    .brand span{color:#8d8d8d;font-weight:520}
    .icons{display:flex;gap:18px;align-items:center;color:#8a8a8a}
    .icon-btn{border:0;background:transparent;padding:3px;cursor:pointer;line-height:0;border-radius:8px}
    .icon-btn:hover{background:#eee}
    .new-chat{margin-top:28px;height:45px;padding:0 10px;display:flex;align-items:center;gap:12px;border-radius:10px;font-size:15px}
    .new-chat .shortcut{margin-left:auto;color:#777;letter-spacing:.2px}
    .day{margin:20px 10px 9px;color:#858585;font-size:13px}
    .history-list{overflow:auto;max-height:calc(100vh - 190px);scrollbar-width:none}.history{height:40px;border-radius:10px;padding:0 12px;display:flex;align-items:center;font-size:14px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;cursor:pointer}.history:hover,.history.active{background:#f0f0f0}
    .history strong{font-weight:520}
    .history .more{margin-left:auto;font-weight:bold;letter-spacing:2px}
    .account{position:absolute;left:0;right:0;bottom:0;height:77px;border-top:1px solid #f3f3f3;display:flex;align-items:center;padding:0 18px;gap:13px;background:#fff}
    .avatar{width:28px;height:28px;border-radius:50%;background:#3ca6dc;color:#fff;display:grid;place-items:center;font-size:11px}
    .account-name{font-size:19px;font-weight:650;line-height:1.15}.account-name small{font-size:13px;color:#7d7d7d;font-weight:400}
    .bag{margin-left:auto;color:#777}
    .main{height:100vh;position:relative;background:#fff;overflow:hidden}
    .chat-head{height:60px;padding:0 22px;justify-content:space-between}
    .model{font-weight:600;font-size:16px;color:#444;display:flex;gap:7px;align-items:center}
    .head-actions{display:flex;gap:20px;align-items:center}
    .conversation{height:calc(100vh - 60px);overflow-y:auto;padding:20px 34px 116px;scrollbar-width:none}
    .conversation::-webkit-scrollbar{display:none}
    .content{max-width:684px;margin:0 auto}
    .user-row{display:flex;justify-content:flex-end;margin-bottom:34px}
    .user-msg{background:#f3f3f3;padding:14px 17px;border-radius:19px;font-size:15px;line-height:1.4;max-width:520px}
    .answer{font-size:16px;line-height:1.7;margin-bottom:19px}.answer code{background:#f3f3f3;border-radius:5px;padding:2px 5px;font:13px Consolas,monospace}.analysis-note{margin:0 0 32px;padding:14px 16px;border-left:3px solid #1d1d1d;background:#f7f7f7;border-radius:0 12px 12px 0;display:flex;flex-direction:column;gap:4px;font-size:13px}.analysis-note span{color:#777}.result-strip{display:flex;gap:8px;margin:-3px 0 32px;flex-wrap:wrap}.result-strip span{padding:7px 10px;border:1px solid #e8e8e8;border-radius:9px;color:#666;font-size:12px}.conversation-divider{display:flex;align-items:center;gap:12px;margin:38px 0;color:#999;font-size:11px}.conversation-divider:before,.conversation-divider:after{content:"";height:1px;background:#eee;flex:1}
    .codebox{background:linear-gradient(180deg,#fbfbfb,#f5f5f5);border-radius:20px;padding:16px 21px 25px;min-height:522px;position:relative}
    .code-head{height:21px;display:flex;justify-content:space-between;align-items:center;font-size:12px}
    .copy{border:0;background:transparent;color:#535353;font-size:12px;cursor:pointer;display:flex;align-items:center;gap:5px}
    pre{margin:21px 0 0;white-space:pre-wrap;font:13px/1.46 "SFMono-Regular",Consolas,"Liberation Mono",monospace;color:#111}
    .jump{position:absolute;left:50%;bottom:-14px;transform:translateX(-50%);width:34px;height:34px;border-radius:50%;border:1px solid #ddd;background:#fff;box-shadow:0 2px 7px #0002;display:grid;place-items:center;cursor:pointer}
    .composer{position:absolute;z-index:5;left:50%;bottom:29px;transform:translateX(-50%);width:min(684px,calc(100% - 70px));height:54px;border:1px solid #e6e6e6;border-radius:28px;background:#fff;box-shadow:0 4px 18px #0000000c;display:flex;align-items:center;padding:0 10px 0 17px;gap:16px}
    .plus{font-size:27px;font-weight:300}.prompt-input{flex:1;min-width:0;max-height:48px;resize:none;border:0;outline:0;background:transparent;color:#222;font:16px/1.4 inherit;padding:5px 0}.prompt-input::placeholder{color:#989898}.composer:focus-within{border-color:#cacaca;box-shadow:0 5px 22px #00000013}.mic{line-height:0}
    .voice{width:38px;height:38px;border-radius:50%;background:#080808;display:flex;align-items:center;justify-content:center;gap:2px}
    .voice i{display:block;width:2px;border-radius:2px;background:#fff}.voice i:nth-child(1){height:8px}.voice i:nth-child(2){height:15px}.voice i:nth-child(3){height:20px}.voice i:nth-child(4){height:13px}.voice i:nth-child(5){height:7px}
    .progress{border-left:1px solid var(--line);padding:14px 20px 24px;overflow-y:auto}
    .progress-head{height:34px;justify-content:space-between}.progress h1{font-size:20px;margin:0;font-weight:650}.progress-actions{display:flex;gap:19px;color:#6f6f6f}
    .project{border-bottom:1px solid #eee;padding:35px 0 15px}.project-title{font-size:15px;font-weight:600}.updated{font-size:12px;color:#8c8c8c;margin-top:5px}
    .section{margin-top:14px}.section-title{font-size:13px;font-weight:650;margin-bottom:10px}
    .check-row{height:28px;display:flex;align-items:center;gap:9px;font-size:14px;cursor:pointer;border-radius:7px}.check-row:hover{background:#f5f5f5}
    .check{width:14px;height:14px;border:1px solid #c7c7c7;border-radius:50%;display:grid;place-items:center;flex:none;background:#fff;color:#666}.check.completed:after{content:"";width:5px;height:3px;border-left:1.4px solid currentColor;border-bottom:1.4px solid currentColor;transform:translateY(-1px) rotate(-45deg)}
    .card{background:#f6f6f6;border-radius:10px;padding:11px 12px;color:#5d5d5d;font-size:12px;line-height:1.8}
    .card ul{padding-left:15px;margin:0}.card li::marker{color:#aaa}.todo{padding:6px 10px 10px}.todo-toggle{width:100%;border:0;background:transparent;padding:5px 0;display:flex;gap:8px;align-items:center;text-align:left;cursor:pointer}.todo-title{flex:1}.chevron{font-size:16px;transition:transform .2s}.todo.expanded .chevron{transform:rotate(180deg)}.todo-body{display:none}.todo.expanded .todo-body{display:block}.ring{width:9px;height:9px;border:2px solid #969696;border-radius:50%;flex:none}
    .why{padding-left:17px;color:#777}.todo-actions{display:flex;gap:6px;margin:5px 0 0 17px}.tag{background:#fff;border:0;border-radius:8px;padding:4px 8px;font-size:10px;cursor:pointer}.tag:hover{background:#eaeaea}.details{display:none;margin:10px 0 0 17px;padding-top:8px;border-top:1px solid #e2e2e2;line-height:1.55}.details.open{display:block}.details ol{margin:0;padding-left:16px}.details p{margin:6px 0 0}.edit-area{display:none;margin:9px 0 0 17px}.edit-area.open{display:block}.edit-area input{width:100%;border:1px solid #d8d8d8;border-radius:8px;padding:7px 8px;background:#fff;font:12px inherit;outline:0}.edit-area input:focus{border-color:#888}.edit-area div{display:flex;gap:6px;margin-top:7px}.mini-primary,.mini-ghost{border:0;border-radius:7px;padding:4px 9px;font-size:10px;cursor:pointer}.mini-primary{background:#222;color:#fff}.mini-ghost{background:#e9e9e9}.located{display:none;margin:-2px 0 8px;background:#222;color:#fff;border-radius:7px;padding:4px 8px;font-size:10px}.located.show{display:inline-block}
    .next-line{display:flex;align-items:center;gap:8px;line-height:2.15}.continue{margin-top:17px;width:100%;height:38px;border:0;border-radius:10px;background:#1f1f1f;color:#fff;font-size:13px;cursor:pointer}.continue:hover{background:#000}
    .disclaimer{font-size:11px;color:#999;display:flex;align-items:flex-end;margin-top:22px}.disclaimer span{flex:1;line-height:1.4}.feedback{display:flex;gap:18px;font-size:17px;color:#777}
    .progress-tab{display:none;position:absolute;right:16px;top:70px;z-index:8;border:1px solid #e4e4e4;background:#fff;border-radius:18px;padding:8px 13px;box-shadow:0 3px 12px #0001;font-size:12px;cursor:pointer}.app.progress-closed{grid-template-columns:295px minmax(650px,1fr) 0}.app.progress-closed .progress{transform:translateX(100%);opacity:0}.app.progress-closed .progress-tab{display:block}.progress{transition:transform .25s ease,opacity .2s ease}.overlay{display:none}.continue.loading{opacity:.72;pointer-events:none}
    .toast{position:fixed;left:50%;top:20px;transform:translate(-50%,-20px);background:#222;color:#fff;padding:9px 15px;border-radius:9px;font-size:13px;opacity:0;pointer-events:none;transition:.25s;z-index:30}.toast.show{opacity:1;transform:translate(-50%,0)}
    svg{display:block}
    @media(max-width:1120px){.app,.app.progress-closed{grid-template-columns:245px minmax(0,1fr)}.progress{position:fixed;z-index:20;top:0;right:0;width:306px;box-shadow:-12px 0 36px #0001}.app.progress-closed .progress{transform:translateX(100%)}.progress-tab,.app.progress-closed .progress-tab{display:block}.overlay.show{display:block;position:fixed;z-index:19;inset:0;background:#0002}.app.left-closed{grid-template-columns:0 1fr}}
    @media(max-width:820px){.app,.app.progress-closed{display:block}.left{display:none}.main{width:100%}.conversation{padding-left:18px;padding-right:18px}.chat-head{border-bottom:1px solid #eee}.composer{width:calc(100% - 24px)}.codebox{min-height:auto}.content{max-width:100%}.progress{display:block;width:min(340px,92vw)}}
    @media(prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important;scroll-behavior:auto!important}}

/* Native ChatGPT Web geometry, calibrated against the supplied desktop reference. */
:root{--ink:#0d0d0d;--muted:#676767;--line:#e5e5e5;--soft:#f7f7f8;--panel:#fff}
html,body{font-family:ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",Arial,sans-serif;-webkit-font-smoothing:antialiased}
.app{grid-template-columns:322px minmax(720px,1fr) 330px}
.left{padding:18px 12px 82px}
.brand{font-size:22px;font-weight:650;letter-spacing:-.55px}
.new-chat{margin-top:24px;height:48px;padding:0 10px;border-bottom:1px solid #ececec;border-radius:0;font-size:16px}
.day{margin:14px 10px 6px;font-size:12px}
.history-list{max-height:calc(100vh - 170px);scrollbar-width:thin;scrollbar-color:#d4d4d4 transparent}
.history{height:45px;padding:0 10px;font-size:16px}
.account{height:82px;padding:0 20px}
.avatar{width:30px;height:30px}
.account-name{font-size:16px;font-weight:600;line-height:1.25}
.chat-head{height:64px;padding:0 28px}
.conversation{height:calc(100vh - 64px);padding:24px 38px 132px;scrollbar-width:thin;scrollbar-color:#8b8b8b transparent}
.content{max-width:960px}
.user-row{margin-bottom:48px}
.user-msg{padding:14px 20px;border-radius:24px;font-size:16px;line-height:1.55;max-width:620px}
.answer{font-size:16px;line-height:1.78;margin-bottom:24px}
.codebox{background:#f7f7f8;border-radius:18px;padding:18px 22px 28px;min-height:500px}
pre{margin-top:22px;font-size:13px;line-height:1.55}
.composer{bottom:28px;width:min(960px,calc(100% - 76px));height:66px;border-radius:33px;padding:0 10px 0 22px;gap:18px;box-shadow:0 2px 12px #00000014}
.plus{font-size:31px;line-height:1}
.voice{width:48px;height:48px}
.progress{padding:16px 22px 24px}
.progress-head{height:36px}
.project{padding:28px 0 16px}
.card{background:#f7f7f8;border-radius:12px;padding:12px 13px}
.progress-tab{right:18px;top:72px}
@media(min-width:1501px){.content{width:930px;max-width:none;margin-left:208px;margin-right:0}.composer{left:246px;transform:none;width:930px}.app.progress-closed{grid-template-columns:322px minmax(720px,1fr) 0}.app.progress-closed .content{width:960px}.app.progress-closed .composer{width:960px}}
@media(max-width:1500px) and (min-width:1121px){.app,.app.progress-closed{grid-template-columns:260px minmax(0,1fr)}.progress{position:fixed;z-index:20;top:0;right:0;width:330px;box-shadow:-12px 0 36px #0001}.app.progress-closed .progress{transform:translateX(100%)}.progress-tab,.app.progress-closed .progress-tab{display:block}.overlay.show{display:block;position:fixed;z-index:19;inset:0;background:#0002}.app.left-closed{grid-template-columns:0 1fr}}
@media(max-width:1280px){.app,.app.progress-closed{grid-template-columns:260px minmax(0,1fr)}.progress{position:fixed;z-index:20;top:0;right:0;width:330px;box-shadow:-12px 0 36px #0001}.app.progress-closed .progress{transform:translateX(100%)}.progress-tab,.app.progress-closed .progress-tab{display:block}.overlay.show{display:block;position:fixed;z-index:19;inset:0;background:#0002}.app.left-closed{grid-template-columns:0 1fr}}
@media(max-width:820px){.conversation{padding-left:18px;padding-right:18px}.composer{width:calc(100% - 24px);height:58px}.voice{width:42px;height:42px}}

/* Final native-scale pass: reference screenshot is captured at ~125% Windows scale. */
.app{grid-template-columns:260px minmax(620px,1fr) 264px}
.left{padding:14px 8px 66px}
.brand-row{padding:0 10px;height:32px}
.brand{font-size:20px;letter-spacing:-.4px}
.icons{gap:16px}
.new-chat{margin-top:19px;height:39px;padding:0 10px;gap:10px;font-size:15px}
.new-chat .shortcut{font-size:14px}
.day{margin:12px 10px 5px;font-size:12px}
.history-list{max-height:calc(100vh - 136px)}
.history{height:36px;padding:0 10px;border-radius:8px;font-size:15px}
.account{height:66px;padding:0 16px;gap:10px}
.avatar{width:26px;height:26px;font-size:10px}
.account-name{font-size:15px}.account-name small{font-size:12px}
.chat-head{height:52px;padding:0 22px}
.model{font-size:15px}
.conversation{height:calc(100vh - 52px);padding:19px 30px 105px}
.content{max-width:768px;margin:0 auto}
.user-row{margin-bottom:38px}
.user-msg{padding:11px 16px;border-radius:20px;font-size:16px;line-height:1.5;max-width:500px}
.answer{font-size:16px;line-height:1.75;margin-bottom:19px}
.analysis-note{margin-bottom:26px;padding:11px 13px;font-size:13px}
.result-strip{margin-bottom:26px}
.conversation-divider{margin:30px 0}
.codebox{padding:14px 18px 23px;min-height:400px;border-radius:16px}
.code-head{font-size:12px}
pre{margin-top:18px;font-size:13px;line-height:1.5}
.composer{bottom:23px;width:min(768px,calc(100% - 56px));height:54px;border-radius:27px;padding:0 8px 0 17px;gap:14px}
.plus{font-size:27px}.prompt-input{font-size:16px}.voice{width:40px;height:40px}
.progress{padding:13px 17px 19px}
.progress-head{height:29px}.progress h1{font-size:18px}
.project{padding:22px 0 13px}.project-title{font-size:14px}.updated{font-size:11px}
.section{margin-top:12px}.section-title{font-size:12px;margin-bottom:8px}
.check-row{height:24px;font-size:13px}
.card{padding:9px 10px;border-radius:10px;font-size:11px}
.continue{height:34px;margin-top:14px}
.disclaimer{margin-top:17px;font-size:10px}
@media(min-width:1201px){.progress{position:relative;top:auto;right:auto;width:auto;box-shadow:none}.progress-tab{display:none}.app.progress-closed .progress-tab{display:block}.overlay,.overlay.show{display:none}.content{width:calc(100% - 194px);max-width:768px;margin-left:164px;margin-right:0}.composer{left:194px;transform:none;width:calc(100% - 194px);max-width:768px}.app.progress-closed{grid-template-columns:260px minmax(620px,1fr) 0}.app.progress-closed .content{width:768px}.app.progress-closed .composer{width:768px}}
@media(max-width:1200px) and (min-width:821px){.app,.app.progress-closed{grid-template-columns:220px minmax(0,1fr)}.progress{position:fixed;z-index:20;top:0;right:0;width:264px;box-shadow:-10px 0 30px #0001}.app.progress-closed .progress{transform:translateX(100%)}.progress-tab,.app.progress-closed .progress-tab{display:block}.overlay.show{display:block;position:fixed;z-index:19;inset:0;background:#0002}.content{max-width:768px;margin:0 auto}.composer{left:50%;transform:translateX(-50%);width:min(768px,calc(100% - 56px))}}
@media(max-width:820px){.composer{height:54px}.voice{width:40px;height:40px}}

/* Native sidebar utilities and composer details from the second reference. */
.primary-nav{margin-top:18px;padding-bottom:8px;border-bottom:1px solid #ececec}
.primary-nav .new-chat{margin-top:0;border:0}
.nav-row{height:36px;padding:0 10px;display:flex;align-items:center;gap:10px;border-radius:8px;font-size:15px;cursor:pointer}
.nav-row:hover{background:#f2f2f2}
.nav-symbol{width:18px;font-size:18px;display:inline-flex;align-items:center;justify-content:center}
.more-symbol{font-size:13px;letter-spacing:1px}.clock-symbol{font-size:21px}
.folder-symbol{height:14px;border:1.7px solid #111;border-radius:3px;position:relative}
.folder-symbol:before{content:"";position:absolute;left:1px;top:-4px;width:7px;height:4px;border:1.7px solid #111;border-bottom:0;border-radius:2px 2px 0 0}
.day{font-size:0;margin-top:11px}.day:after{content:"最近";font-size:12px}
.history-list{max-height:calc(100vh - 330px)}
.speed{font-size:14px;color:#888;white-space:nowrap}
.accuracy-note{position:absolute;z-index:5;bottom:80px;left:50%;transform:translateX(-50%);font-size:11px;color:#aaa;white-space:nowrap}
.progress-tab{width:36px;height:94px;padding:10px 7px;border-radius:0;top:50%;right:14px;transform:translateY(-50%);flex-direction:column;justify-content:center;gap:5px;font-size:0}
.progress-tab i{display:block;width:20px;height:2px;background:#b5b5b5}.progress-tab i:last-child{background:#333}
@media(min-width:1201px){.app.progress-closed .progress-tab{display:flex}.accuracy-note{left:calc(194px + min(384px,(100% - 194px)/2));transform:translateX(-50%)}}

/* Native per-message actions. */
.user-row{flex-direction:column;align-items:flex-end}
.message-actions{display:flex;align-items:center;gap:2px;height:30px;margin-top:5px;color:#6b6b6b}
.assistant-actions{margin:4px 0 30px -4px}
.user-actions{margin-right:5px;opacity:0;transition:opacity .15s}
.user-row:hover .user-actions,.user-actions:focus-within{opacity:1}
.message-action{width:30px;height:30px;border:0;border-radius:7px;background:transparent;display:grid;place-items:center;padding:5px;cursor:pointer;color:inherit}
.message-action:hover,.message-action.active{background:#f2f2f2;color:#111}
.message-action svg{width:18px;height:18px;stroke-width:1.7}
.message-action.more-action{font-size:18px;line-height:1;padding-bottom:10px}
@media(max-width:820px){.user-actions{opacity:1}.assistant-actions{margin-bottom:24px}}

/* Native collapsed sidebar rail. */
.collapsed-left{display:none;height:100vh;border-right:1px solid #e5e5e5;background:#fff;position:relative;z-index:3;padding-top:10px;flex-direction:column;align-items:center;gap:9px}
.rail-btn{width:36px;height:36px;border:0;background:transparent;border-radius:8px;display:grid;place-items:center;cursor:pointer;color:#111;padding:7px}
.rail-btn:hover{background:#f2f2f2}.rail-btn svg{width:21px;height:21px;stroke-width:1.8}.rail-logo{margin-bottom:8px}.rail-logo svg{width:23px;height:23px}
.rail-avatar{position:absolute;bottom:13px;width:26px;height:26px;border-radius:50%;display:grid;place-items:center;background:#31a4dd;color:#fff;font-size:10px}
.app.left-closed{grid-template-columns:52px minmax(620px,1fr) 264px}
.app.left-closed .left{display:none;transform:none!important}.app.left-closed .collapsed-left{display:flex}.app.left-closed .main{grid-column:2}.app.left-closed .progress{grid-column:3}
@media(min-width:1201px){.app.left-closed.progress-closed{grid-template-columns:52px minmax(620px,1fr) 0}.app.left-closed .content{width:768px;max-width:768px;margin-left:auto;margin-right:auto}.app.left-closed .composer{left:50%;transform:translateX(-50%);width:768px}.app.left-closed .accuracy-note{left:50%;transform:translateX(-50%)}}
@media(max-width:1200px) and (min-width:821px){.app.left-closed,.app.left-closed.progress-closed{grid-template-columns:52px minmax(0,1fr)}.app.left-closed .progress{grid-column:auto}}
@media(max-width:820px){.collapsed-left{display:none!important}}

/* Typography lock — matches the native ChatGPT scale and rhythm. */
:root{--font-ui:ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",Arial,sans-serif;--font-mono:"SFMono-Regular",Consolas,"Liberation Mono",monospace}
html,body,button,textarea,input{font-family:var(--font-ui);font-kerning:normal;font-variant-ligatures:common-ligatures}
html,body{overflow:hidden}
body{font-size:16px;line-height:1.5;letter-spacing:0}
.brand{font-size:20px;line-height:26px;font-weight:650;letter-spacing:-.4px}.brand span{font-weight:500}
.new-chat,.nav-row{font-size:15px;line-height:20px;font-weight:400;letter-spacing:0}
.new-chat .shortcut{font-size:14px;line-height:20px;letter-spacing:.05px}
.day{line-height:18px;font-weight:400;letter-spacing:0}.day:after{font-size:12px}
.history{font-size:15px;line-height:20px;font-weight:400;letter-spacing:0}.history strong{font-weight:600}
.account-name{font-size:15px;line-height:19px;font-weight:600;letter-spacing:0}.account-name small{font-size:12px;line-height:16px}
.model{font-size:15px;line-height:20px;font-weight:600;letter-spacing:-.1px}
.user-msg{font-size:16px;line-height:24px;font-weight:400;letter-spacing:0}
.answer{font-size:16px;line-height:28px;font-weight:400;letter-spacing:0}
.analysis-note{font-size:13px;line-height:19px;letter-spacing:0}.result-strip{font-size:12px;line-height:18px}
.conversation-divider{font-size:11px;line-height:16px;letter-spacing:.05px}
.code-head,.copy{font-size:12px;line-height:18px;letter-spacing:0}
pre{font-family:var(--font-mono);font-size:13px;line-height:19.5px;letter-spacing:0;font-variant-ligatures:none}
.prompt-input{font-size:16px;line-height:22px;font-weight:400;letter-spacing:0}.speed{font-size:14px;line-height:20px;letter-spacing:0}
.accuracy-note{font-size:11px;line-height:16px;letter-spacing:0}
.progress h1{font-size:18px;line-height:24px;font-weight:650;letter-spacing:-.2px}
.project-title{font-size:14px;line-height:20px;font-weight:600;letter-spacing:0}.updated{font-size:11px;line-height:16px}
.section-title{font-size:12px;line-height:18px;font-weight:650;letter-spacing:0}.check-row{font-size:13px;line-height:20px;letter-spacing:0}
.card{font-size:11px;line-height:18px;letter-spacing:0}.continue{font-size:12px;line-height:18px;font-weight:600;letter-spacing:0}
.message-action{line-height:18px}

/* Screenshot-derived native icons. */
.primary-nav .nav-row{position:relative}.primary-nav .nav-row>svg,.primary-nav .nav-symbol{visibility:hidden}
.primary-nav .nav-row:before{content:"";position:absolute;left:6px;width:26px;height:26px;background-position:center;background-repeat:no-repeat;background-size:26px 26px}
.primary-nav .nav-row:nth-child(1):before{background-image:url("assets/native-icons/new_chat.png")}.primary-nav .nav-row:nth-child(2):before{background-image:url("assets/native-icons/library.png")}.primary-nav .nav-row:nth-child(3):before{background-image:url("assets/native-icons/project.png")}.primary-nav .nav-row:nth-child(4):before{background-image:url("assets/native-icons/scheduled.png")}.primary-nav .nav-row:nth-child(5):before{background-image:url("assets/native-icons/plugins.png")}.primary-nav .nav-row:nth-child(6):before{background-image:url("assets/native-icons/more.png")}
.collapsed-left .rail-btn svg{visibility:hidden}.collapsed-left .rail-btn{background-position:center;background-repeat:no-repeat;background-size:26px 26px}.collapsed-left .rail-btn:nth-child(1){background-image:url("assets/native-icons/logo.png")}.collapsed-left .rail-btn:nth-child(2){background-image:url("assets/native-icons/rail_new.png")}.collapsed-left .rail-btn:nth-child(3){background-image:url("assets/native-icons/search.png")}.collapsed-left .rail-btn:nth-child(4){background-image:url("assets/native-icons/chat.png")}

/* Synchronized native sidebar/content slide. */
.app{transition:grid-template-columns .24s cubic-bezier(.4,0,.2,1)}
.left{grid-column:1;grid-row:1;opacity:1;transform:translateX(0);visibility:visible;transition:opacity .18s ease,transform .24s cubic-bezier(.4,0,.2,1),visibility 0s linear}
.collapsed-left{grid-column:1;grid-row:1;display:flex;opacity:0;pointer-events:none;transform:translateX(-12px);visibility:hidden;transition:opacity .18s ease,transform .24s cubic-bezier(.4,0,.2,1),visibility 0s linear .24s}
.main{transition:width .24s cubic-bezier(.4,0,.2,1)}
.content,.composer,.accuracy-note{transition:margin .24s cubic-bezier(.4,0,.2,1),left .24s cubic-bezier(.4,0,.2,1),width .24s cubic-bezier(.4,0,.2,1),transform .24s cubic-bezier(.4,0,.2,1)}
.app.left-closed .left{display:block;opacity:0;pointer-events:none;transform:translateX(-18px);visibility:hidden;transition:opacity .16s ease,transform .24s cubic-bezier(.4,0,.2,1),visibility 0s linear .24s}
.app.left-closed .collapsed-left{display:flex;opacity:1;pointer-events:auto;transform:translateX(0);visibility:visible;transition-delay:0s}
.nav-row,.history{font-size:16px;line-height:20px}.account-name{font-size:16px;line-height:20px}
@media(prefers-reduced-motion:reduce){.app,.left,.collapsed-left,.main,.content,.composer,.accuracy-note{transition:none!important}}

/* Remaining screenshot-derived icon assets. */
.brand-row .icon-btn,.head-actions .icon-btn,.head-actions>span,.message-action,.plus,.mic,.voice,.avatar,.bag{background-position:center;background-repeat:no-repeat}
.brand-row .icon-btn svg,.head-actions .icon-btn svg,.message-action svg,.mic svg,.bag svg{visibility:hidden}
.brand-row .icon-btn:first-child{background-image:url("assets/native-icons/top_search.png");background-size:27px}.brand-row .icon-btn:last-child{background-image:url("assets/native-icons/collapse.png");background-size:27px}
.head-actions .icon-btn{width:32px;height:32px;background-image:url("assets/native-icons/top_share.png");background-size:27px}.head-actions>span{width:32px;height:32px;font-size:0;background-image:url("assets/native-icons/top_more.png");background-size:27px}
.message-action{background-size:27px 27px}.message-action.action-copy{background-image:url("assets/native-icons/action_copy.png")}.message-action.action-up{background-image:url("assets/native-icons/action_up.png")}.message-action.action-down{display:none}.message-action.action-share{background-image:url("assets/native-icons/action_share.png")}.message-action.action-retry{background-image:url("assets/native-icons/action_retry.png")}.message-action.action-more{background-image:url("assets/native-icons/action_more.png");font-size:0}.message-action.action-edit{background-image:url("assets/native-icons/action_edit.png")}
.plus{width:30px;height:30px;font-size:0;background-image:url("assets/native-icons/composer_plus.png");background-size:30px}.mic{width:30px;height:30px;background-image:url("assets/native-icons/composer_mic.png");background-size:30px}.voice{background-image:url("assets/native-icons/composer_voice.png");background-size:46px 46px;background-color:transparent}.voice i{visibility:hidden}.voice.send-ready{background-image:none;background-color:#080808}
.avatar{background-image:url("assets/native-icons/account_avatar.png");background-size:29px;font-size:0;background-color:transparent}.bag{width:30px;height:30px;background-image:url("assets/native-icons/account_store.png");background-size:29px}

/* The reference shows a bare five-line handle; the red rectangle is annotation only. */
.progress-tab{width:36px;height:64px;right:26px;top:50%;padding:6px 8px;border:0!important;border-radius:0!important;background:transparent!important;box-shadow:none!important;gap:7px;align-items:center}
.progress-tab:hover{background:transparent!important}.progress-tab i{width:20px;height:2px;border-radius:2px;background:#b7b7b7}.progress-tab i:last-child{background:#333}

/* Hover preview opened from the waveform handle. */
.progress-peek{position:absolute;z-index:40;right:20px;top:50%;width:320px;transform:translateY(-50%);padding:8px;background:#fff;border:1px solid #dedede;border-radius:16px;box-shadow:0 10px 30px #00000020;opacity:0;visibility:hidden;pointer-events:none;transition:opacity .14s ease,transform .18s ease,visibility 0s linear .18s}
.progress-peek.show{opacity:1;visibility:visible;pointer-events:auto;transform:translateY(-50%) translateX(-48px);transition-delay:0s}
.peek-list{display:flex;flex-direction:column;gap:1px}.peek-item{min-height:35px;padding:7px 10px;border-radius:9px;font-size:14px;line-height:20px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;cursor:pointer}.peek-item:hover,.peek-item.active{background:#f1f1f1}
.peek-footer{height:42px;margin-top:5px;padding-top:6px;border-top:1px solid #ededed;display:flex;align-items:center;justify-content:flex-end}.peek-progress-button{height:32px;padding:0 13px;border:0;border-radius:9px;background:#111;color:#fff;font-size:13px;font-weight:600;cursor:pointer}.peek-progress-button:hover{background:#000}
@media(max-width:820px){.progress-peek{right:8px;width:min(320px,calc(100vw - 24px))}.progress-peek.show{transform:translateY(-50%) translateX(-38px)}}

/* ChatGPT-native interaction states. */
.model,.plus,.new-chat,.history,.head-actions>span,.speed,.voice{cursor:pointer}
.model,.speed{border-radius:7px;padding:5px 7px;margin-left:-7px}.model:hover,.speed:hover{background:#f2f2f2}
.voice.send-ready{gap:0}.voice.send-ready i{display:none}.voice.send-ready:after{content:"↑";color:#fff;font-size:22px;font-weight:500;line-height:1}
.ui-popover{position:fixed;z-index:80;min-width:190px;padding:6px;background:#fff;border:1px solid #e5e5e5;border-radius:12px;box-shadow:0 10px 32px #00000020}
.popover-item{width:100%;height:38px;padding:0 10px;border:0;background:transparent;border-radius:8px;display:flex;align-items:center;gap:10px;text-align:left;font-size:14px;cursor:pointer}.popover-item:hover{background:#f3f3f3}.popover-item.active:after{content:"✓";margin-left:auto}
.resource-popover{position:fixed;z-index:82;width:300px;max-height:calc(100vh - 82px);overflow:auto;padding:10px 12px 12px;background:#fff;border:1px solid #e7e7e7;border-radius:22px;box-shadow:0 12px 38px #00000018;color:#202020;font-family:var(--font-ui)}
.resource-section{padding:8px 8px 10px;border-bottom:1px solid #ededed}.resource-section:last-child{border-bottom:0;padding-bottom:4px}.resource-section h2{margin:0 0 7px;font-size:13px;line-height:20px;font-weight:400;color:#777}.resource-row{width:100%;height:34px;padding:0 2px;border:0;border-radius:7px;background:transparent;display:flex;align-items:center;gap:9px;text-align:left;font:400 13px/18px var(--font-ui);color:#333;cursor:pointer}.resource-row:hover{background:#f4f4f4}.resource-globe{width:18px;font-size:21px;line-height:18px;color:#222}.resource-file{width:18px;font-size:18px;text-align:center}.image-file{color:#ff4fa2}.doc-file{color:#1687ff}.resource-ellipsis{overflow:hidden;white-space:nowrap;text-overflow:ellipsis}.browser-preview{height:116px;border:1px solid #e7e7e7;border-radius:13px;display:grid;place-items:center;background:#fff}.browser-spinner{width:15px;height:15px;border:2px dotted #222;border-radius:50%;animation:resourceSpin 1.1s linear infinite}@keyframes resourceSpin{to{transform:rotate(360deg)}}
.resource-section-head{display:flex;align-items:baseline;justify-content:space-between}.resource-section-head span{font-size:10px;color:#999}.progress-summary{width:100%;min-height:56px;padding:9px 8px;border:0;border-radius:11px;background:#f7f7f7;display:flex;align-items:center;gap:9px;text-align:left;cursor:pointer}.progress-summary:hover{background:#f1f1f1}.summary-mark{width:9px;height:9px;border:2px solid #8b8b8b;border-radius:50%}.progress-summary>span:nth-child(2){min-width:0;display:flex;flex:1;flex-direction:column}.progress-summary strong{font-size:12px;line-height:18px;font-weight:500}.progress-summary small{font-size:10px;line-height:16px;color:#888}.progress-summary b{font-size:20px;font-weight:300;color:#777}.open-current-progress{width:100%;height:34px;margin-top:8px;border:0;border-radius:9px;background:#202020;color:#fff;font:500 12px/18px var(--font-ui);cursor:pointer}.open-current-progress:hover{background:#111}
.modal-backdrop{position:fixed;z-index:90;inset:0;background:#0006;display:grid;place-items:center;padding:20px}.native-modal{width:min(480px,calc(100vw - 32px));background:#fff;border-radius:18px;padding:20px;box-shadow:0 18px 60px #0003}.native-modal h2{margin:0 0 8px;font-size:20px;line-height:28px}.native-modal p{margin:0 0 18px;color:#666;font-size:14px;line-height:21px}.modal-actions{display:flex;justify-content:flex-end;gap:8px}.modal-actions button,.edit-buttons button{border:0;border-radius:9px;padding:8px 13px;font-size:13px;cursor:pointer}.modal-actions .primary,.edit-buttons .primary{background:#111;color:#fff}.modal-actions .secondary,.edit-buttons .secondary{background:#eee}
.inline-edit{width:min(620px,100%);background:#f4f4f4;border-radius:20px;padding:12px}.inline-edit textarea{width:100%;min-height:70px;resize:vertical;border:0;outline:0;background:transparent;font:16px/24px var(--font-ui)}.edit-buttons{display:flex;justify-content:flex-end;gap:7px;margin-top:8px}
.empty-state{min-height:calc(100vh - 210px);display:grid;place-items:center;text-align:center}.empty-state h2{font-size:28px;line-height:36px;font-weight:500;letter-spacing:-.5px}
.mock-thinking{display:flex;gap:5px;align-items:center;height:28px}.mock-thinking i{width:5px;height:5px;border-radius:50%;background:#777;animation:pulse 1s infinite}.mock-thinking i:nth-child(2){animation-delay:.16s}.mock-thinking i:nth-child(3){animation-delay:.32s}@keyframes pulse{0%,70%,100%{opacity:.25}35%{opacity:1}}
.jump{opacity:0;pointer-events:none;transition:opacity .15s}.jump.visible{opacity:1;pointer-events:auto}
.toast{max-width:min(420px,calc(100vw - 32px));text-align:center}

/* Lighter, smaller native ChatGPT typography pass. */
:root{--font-ui:"Segoe UI","Microsoft YaHei UI","Microsoft YaHei",Arial,sans-serif}
body{font-size:15px;font-weight:400;color:#171717}
.brand{font-size:19px;line-height:25px;font-weight:600;letter-spacing:-.35px}.brand span{font-weight:400}
.new-chat,.nav-row{font-size:15px;line-height:20px;font-weight:400}.new-chat .shortcut{font-size:13px;font-weight:400;color:#777}
.history{font-size:14px;line-height:19px;font-weight:400}.history strong{font-weight:500}.day:after{font-size:12px;font-weight:400}
.account-name{font-size:14px;line-height:18px;font-weight:500}.account-name small{font-size:11px;line-height:15px;font-weight:400}
.model{font-size:14px;line-height:19px;font-weight:500}
.user-msg{font-size:15px;line-height:22px;font-weight:400}.answer{font-size:15px;line-height:26px;font-weight:400}
.analysis-note{font-size:12px;line-height:18px;font-weight:400}.analysis-note strong{font-weight:600}.result-strip span{font-size:11px;line-height:17px}
.code-head,.copy{font-size:11px;line-height:17px;font-weight:400}pre{font-size:12.5px;line-height:19px;font-weight:400}
.prompt-input{font-size:15px;line-height:21px;font-weight:400}.speed{font-size:13px;line-height:19px;font-weight:400}.accuracy-note{font-size:10px;line-height:15px;font-weight:400}
.progress h1{font-size:17px;line-height:23px;font-weight:600}.project-title{font-size:13px;line-height:19px;font-weight:500}.updated{font-size:10px;line-height:15px}
.section-title{font-size:11px;line-height:17px;font-weight:600}.check-row{font-size:12px;line-height:19px;font-weight:400}.card{font-size:10.5px;line-height:17px;font-weight:400}.continue{font-size:11px;font-weight:500}
.peek-item{font-size:13px;line-height:19px;font-weight:400}.peek-progress-button{font-size:12px;font-weight:500}
.native-modal h2{font-size:18px;line-height:25px;font-weight:600}.native-modal p,.popover-item{font-size:13px;line-height:19px;font-weight:400}
.inline-edit textarea{font:15px/22px var(--font-ui)}.empty-state h2{font-size:25px;line-height:33px;font-weight:400}
.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}
.head-actions{gap:12px}.head-actions .controls-btn{background-image:url("assets/native-icons/top_controls.png");background-size:34px 29px}
.chat-head{justify-content:flex-end}

/* Native layout coordinates from the supplied reference viewport. */
@media(min-width:1201px){
  .app.progress-closed:not(.left-closed){grid-template-columns:260px minmax(620px,1fr) 0}
  .app.progress-closed:not(.left-closed) .conversation{padding-left:30px;padding-right:30px}
  .app.progress-closed:not(.left-closed) .content{width:768px;max-width:768px;margin-left:auto;margin-right:auto}
  .app.progress-closed:not(.left-closed) .composer{left:50%;transform:translateX(-50%);width:768px;max-width:768px;bottom:25px}
  .app.progress-closed:not(.left-closed) .accuracy-note{left:50%;transform:translateX(-50%);bottom:82px}
}

/* Sidebar geometry matched to the native reference. */
.left{padding-top:8px;padding-bottom:58px}
.primary-nav{margin-top:18px;padding-bottom:8px}
.nav-row{height:36px;padding-left:7px;padding-right:7px;gap:9px}
.primary-nav .nav-row:before{left:3px}
.day{margin-left:7px;margin-right:7px}
.history{padding-left:7px;padding-right:7px}
.account{height:58px;padding-left:16px;padding-right:16px}
.history-list{max-height:calc(100vh - 314px)}

/* Native sidebar alignment and compact navigation type. */
.primary-nav{border-bottom:0;margin-left:10px;margin-right:8px;padding-bottom:8px}
.primary-nav .nav-row{width:100%;padding-left:7px;padding-right:7px;font-size:14px;line-height:19px;font-weight:400}
.primary-nav .nav-row:before{left:0}
.day{margin-top:11px;margin-left:10px;margin-right:10px;line-height:17px}
.day:after{font-size:12px;line-height:17px;font-weight:400;color:#8b8b8b}
.history{padding-left:10px;padding-right:10px}

/* Native sidebar gutters: compact icon inset and icon-to-label gap. */
.brand-row{padding-left:4px}
.primary-nav{margin-left:2px;margin-right:8px}
.primary-nav .nav-row{padding-left:0;gap:8px}
.primary-nav .nav-row:before{left:0}
.day{margin-left:2px;margin-right:10px}
.history{padding-left:4px}

/* Optical text alignment: keep native icons fixed, shift sidebar labels only. */
.brand,.primary-nav .nav-row>span:last-child,.account-name{transform:translateX(4px)}
.day:after{display:inline-block;transform:translate(5px,3px);font-size:14px}
.history{padding-left:8px}
.history.active strong{margin-left:1px}
.primary-nav .nav-row:before,.brand-row .icon-btn,.left .avatar,.left .bag{transform:translateX(4px)}
.brand-row .icon-btn{transform:translate(4px,4px)}
.left .account .avatar,.left .account .bag,.left .account .account-name{transform:translateX(2px)}

/* Exact native ChatGPT Plus wordmark cropped from the supplied reference. */
.brand{width:117px;height:22px;font-size:0;line-height:0;background:url("assets/native-icons/brand-title.png") left center/117px auto no-repeat}

/* Match resource and progress surfaces to the 14px history/body text scale. */
.resource-section h2,
.resource-row,
.progress-summary strong,
.open-current-progress{
  font-size:14px;
  line-height:20px;
}
.resource-section-head span,
.progress-summary small{
  font-size:12px;
  line-height:17px;
}
.progress .project-title,
.progress .section-title,
.progress .check-row,
.progress .todo-title,
.progress .next-line,
.progress .continue{
  font-size:14px;
  line-height:20px;
}
.progress .updated,
.progress .why,
.progress .details{
  font-size:12px;
  line-height:18px;
}
.progress .card{
  font-size:14px;
  line-height:20px;
}
.progress .disclaimer{
  font-size:12px;
  line-height:18px;
}
.progress .disclaimer span{white-space:nowrap}
.accuracy-note{
  font-size:12px;
  line-height:18px;
  color:#999;
}
.progress .tag,
.progress .mini-primary,
.progress .mini-ghost{
  font-size:12px;
  line-height:17px;
}
.progress-close{
  width:32px;
  height:32px;
  padding:0;
  background:transparent url("assets/native-icons/panel_close.png") center/24px 24px no-repeat;
}
.progress-close:hover{background-color:#f2f2f2}
.app:not(.progress-closed) #progressSettings{cursor:default}

/* Native resource-type icons cropped from the supplied ChatGPT reference. */
.resource-row{gap:5px}
.resource-globe,
.resource-file{
  width:24px;
  height:24px;
  flex:0 0 24px;
  display:block;
  font-size:0;
  line-height:0;
  background-position:center;
  background-repeat:no-repeat;
  background-size:24px 24px;
}
.resource-globe{background-image:url("assets/native-icons/resource_web.png")}
.resource-file.image-file{background-image:url("assets/native-icons/resource_image.png")}
.resource-file.doc-file{background-image:url("assets/native-icons/resource_doc.png")}

/* One status-marker language across completed, result, pending and next items. */
.progress .check,
.progress .ring,
.progress .card > ul > li::before{
  width:5px;
  height:5px;
  box-sizing:border-box;
  flex:0 0 5px;
  border:0;
  border-radius:50%;
  background:#a7a7a7;
}
.progress .check.completed:after{content:none}
.progress .card > ul{padding-left:0;list-style:none}
.progress .card > ul > li{display:flex;align-items:center;gap:9px;word-break:keep-all}
.progress .card > ul > li::before{content:""}
.progress{
  scrollbar-width:thin;
  scrollbar-color:#969696 transparent;
  scrollbar-gutter:stable;
}
.progress::-webkit-scrollbar{width:8px}
.progress::-webkit-scrollbar-track{background:transparent}
.progress::-webkit-scrollbar-thumb{background:#969696;border-radius:8px}

/* Native full-height sidebar scrolling with sticky brand/new-chat chrome. */
.left{overflow:hidden;padding:0 0 58px}
.left-scroll{
  height:calc(100vh - 58px);
  overflow-y:auto;
  padding:8px 8px 18px;
  scrollbar-width:thin;
  scrollbar-color:#c6c6c6 transparent;
  scrollbar-gutter:stable;
}
.left-scroll::-webkit-scrollbar{width:8px}
.left-scroll::-webkit-scrollbar-track{background:transparent}
.left-scroll::-webkit-scrollbar-thumb{background:#c6c6c6;border-radius:8px}
.left-sticky{
  position:sticky;
  top:0;
  z-index:6;
  isolation:isolate;
  margin:-8px -8px 0;
  padding:8px 8px 0;
  background:#fff;
}
.left-sticky:before{
  content:"";
  position:absolute;
  z-index:-1;
  top:-32px;
  right:0;
  bottom:0;
  left:0;
  background:#fff;
}
.left-sticky .brand-row{position:relative;top:auto;background:#fff}
.left-sticky>.sticky-new-chat{
  position:relative;
  top:auto;
  width:calc(100% - 4px);
  height:36px;
  margin:18px 0 0;
  padding:0 7px 0 0;
  gap:8px;
  border:0;
  border-radius:8px;
  background:#fff;
  font-size:14px;
  line-height:19px;
  font-weight:400;
  transform:translateX(4px);
}
.left-sticky>.sticky-new-chat:hover{background:#f2f2f2}
.left-sticky>.sticky-new-chat>span:last-child{transform:translateX(4px)}
.sticky-new-chat>svg{visibility:hidden}
.sticky-new-chat:before{content:"";position:absolute;left:0;width:26px;height:26px;transform:translateX(4px);background:url("assets/native-icons/new_chat.png") center/26px 26px no-repeat}
.primary-nav .nav-new-chat-source{display:none}
.left-scroll .primary-nav{margin-top:8px}
.left-scroll .history-list{overflow:visible;max-height:none}
.left>.account{height:58px}
.brand span{display:none}
.brand{transform:translate(6px,4px)}
.primary-nav{margin-left:4px;margin-top:18px}

/* Context navigator target feedback. */
.context-anchor{scroll-margin-block:120px}.context-anchor.context-flash{animation:contextFlash 1.25s ease}
@keyframes contextFlash{0%,100%{filter:none}20%{filter:drop-shadow(0 0 0 transparent)}35%{background-color:#ececec}70%{background-color:#f5f5f5}}
.user-row.context-flash .user-msg,.analysis-note.context-flash,.result-strip.context-flash{box-shadow:0 0 0 2px #d4d4d4;transition:box-shadow .25s}
.codebox.context-flash{box-shadow:0 0 0 2px #d4d4d4;transition:box-shadow .25s}.check-row.navigating{background:#ededed}