*{box-sizing:border-box}body{margin:0;min-width:320px;font-family:Inter,"Segoe UI","Microsoft YaHei",system-ui,sans-serif;font-size:16px;line-height:1.6}button,input,textarea,select{font:inherit}button,a,input,select,textarea{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.45}a{color:var(--teal)}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:3px solid var(--teal);outline-offset:3px}[hidden]{display:none!important}h1,h2,h3,p{margin:0}button{border:0}input,textarea,select{width:100%;min-width:0;color:var(--ink);background:var(--surface);border:1px solid var(--line);border-radius:8px;padding:10px 12px}input::placeholder,textarea::placeholder{color:var(--muted);opacity:1}label{display:block;font-size:.875rem;font-weight:600}label input,label select{margin-top:6px;font-weight:400}.topbar{max-width:1440px;margin:auto;padding:20px 32px;display:flex;justify-content:space-between;align-items:center;gap:16px;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:18px;text-decoration:none;color:var(--ink);font-weight:750;letter-spacing:.06em}.brand img{width:105px;height:42px;object-fit:contain}.brand>span{border-left:1px solid var(--line);padding-left:18px}.brand small{display:block;font-size:.75rem;font-weight:500;letter-spacing:.02em;color:var(--muted)}nav{display:flex;align-items:center;gap:24px}.back-link{font-size:.875rem;text-decoration:none}.workspace{max-width:1440px;margin:auto;padding:32px}.page-heading{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-bottom:28px}.eyebrow{font-size:.75rem;color:var(--teal);font-weight:700;letter-spacing:.13em;margin-bottom:8px}h1{font-size:clamp(1.65rem,2.7vw,2.4rem);font-family:Georgia,"Noto Serif SC",serif;font-weight:500;line-height:1.4}.subtitle{color:var(--muted);margin-top:8px}.work-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.05fr);gap:24px;align-items:start}.panel{border:1px solid var(--line);border-radius:18px;background:var(--surface);min-width:0;overflow:hidden}.panel-heading{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:18px 22px;border-bottom:1px solid var(--line)}h2{font-size:1rem;font-weight:650}.step{font-size:.75rem;font-weight:500;color:var(--muted);margin-right:8px;font-variant-numeric:tabular-nums}.text-button{font-size:.875rem;color:var(--teal);background:none;padding:6px 0}.image-stage{margin:18px 18px 0;min-height:340px;aspect-ratio:1.45;background:#081917;border:1px dashed #46625a;border-radius:12px;color:#eff8f3;display:flex;align-items:center;justify-content:center;overflow:hidden}.image-stage.dragging{border:2px solid var(--lime);background:#123b32}.upload-empty{text-align:center;padding:24px}.upload-icon{width:54px;height:54px;color:#9eb8ad;margin-bottom:12px}.upload-empty h3{font-size:1.125rem;font-weight:550}.upload-empty p{font-size:.875rem;color:#a5bcb3;margin:8px 0 20px}.upload-empty .file-hint{font-size:.75rem;margin:18px 0 0}.primary,.secondary{padding:11px 18px;border-radius:8px;font-size:.875rem;font-weight:650}.primary{background:var(--lime);color:#15362b}.primary:hover:not(:disabled){filter:brightness(.95)}.secondary{background:var(--surface-soft);color:var(--ink);border:1px solid var(--line)}.image-caption{display:flex;justify-content:space-between;gap:16px;padding:12px 20px;color:var(--muted);font-size:.75rem}.image-caption span:first-child{overflow-wrap:anywhere}.image-caption span:last-child{flex-shrink:0}.sample-fields{margin:8px 20px 20px;padding:16px 0 0;border:0;border-top:1px solid var(--line);min-width:0}.sample-fields legend{padding:0 10px 0 0;font-size:.875rem;font-weight:650}.scale-heading{display:flex;justify-content:space-between;gap:12px;margin:18px 0 8px;font-size:.875rem}.scale-heading small{color:var(--muted);font-weight:400;margin-left:4px}.muted{color:var(--muted);font-size:.75rem}.scale-row{display:grid;grid-template-columns:minmax(0,1fr) auto minmax(0,1fr) 74px;gap:10px}.equals{align-self:end;padding-bottom:11px;color:var(--muted)}.unit-label select{padding-inline:8px}.field-note{font-size:.75rem;color:var(--muted);line-height:1.65;margin-top:10px}.chat-panel{display:flex;flex-direction:column;min-height:740px}.messages{flex:1;min-height:230px;max-height:650px;overflow-y:auto;overscroll-behavior:contain;padding:24px 22px;scrollbar-gutter:stable}.chat-empty h3{font-size:1.125rem;font-weight:550;margin:12px 0 7px}.chat-empty>p{font-size:.875rem;color:var(--muted);max-width:360px}.assistant-mark{display:inline-grid;width:36px;height:36px;place-items:center;border-radius:10px;background:var(--deep);color:var(--lime);font-family:Georgia,serif;font-size:1.3rem}.question-chips{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin-top:22px}.question-chips button{text-align:left;display:flex;flex-direction:column;gap:7px;border:1px solid var(--line);border-radius:10px;background:var(--surface);color:var(--ink);padding:12px}.question-chips button:hover{border-color:var(--teal);background:var(--surface-soft)}.question-chips strong{font-size:.875rem;font-weight:600}.question-chips span{font-size:.75rem;color:var(--muted)}.message{margin-bottom:22px;overflow-wrap:anywhere}.message:last-child{margin-bottom:0}.message-role{font-size:.75rem;color:var(--muted);margin-bottom:7px;display:flex;align-items:center;justify-content:space-between}.message-body{white-space:pre-wrap;line-height:1.85;font-size:1rem}.message.user .message-body{border-radius:12px;background:var(--surface-soft);padding:12px 16px}.copy-answer{color:var(--teal);background:none;padding:4px 8px;font-size:.875rem}.message.pending .message-body{color:var(--muted)}.composer-wrap{padding:0 22px 20px}.composer-wrap form{border:1px solid var(--line);border-radius:12px;padding:12px;background:var(--surface)}textarea{display:block;border:0;padding:2px;resize:vertical;min-height:86px;max-height:240px;font-size:1rem;line-height:1.65}.composer-actions{display:flex;align-items:center;justify-content:flex-end;gap:10px;margin-top:8px}#sendHint{margin-right:auto;color:var(--muted);font-size:.75rem}.disclosure{margin-top:12px;font-size:.75rem;line-height:1.75;color:var(--muted)}.feedback{font-size:.875rem;padding:10px 12px;margin-bottom:12px;border-left:3px solid var(--amber);background:var(--surface-soft);overflow-wrap:anywhere}.feedback[data-error="true"]{border-color:var(--coral)}footer{display:flex;justify-content:space-between;gap:16px;padding:24px 0 0;font-size:.75rem;color:var(--muted);letter-spacing:.04em}.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}@media(min-width:1450px){.messages{max-height:730px}.image-stage{min-height:390px}}@media(max-width:1000px){.workspace{padding:24px}.work-grid{gap:16px}.panel-heading,.messages{padding-left:16px;padding-right:16px}.composer-wrap{padding:0 16px 16px}.question-chips{grid-template-columns:1fr}.question-chips button{flex-direction:row;justify-content:space-between;gap:10px}.image-stage{min-height:280px}.scale-row{gap:7px}.chat-panel{min-height:0}}@media(max-width:760px){.topbar{padding:14px 18px}.brand{gap:12px}.brand img{width:85px}.brand>span{padding-left:12px;font-size:.875rem}.back-link{font-size:.75rem}nav{gap:12px}.workspace{padding:24px 16px}.page-heading{align-items:start;flex-direction:column;gap:14px}.work-grid{grid-template-columns:1fr;gap:20px}.image-stage{aspect-ratio:1.4;min-height:260px}.question-chips{grid-template-columns:repeat(3,minmax(0,1fr))}.question-chips button{flex-direction:column}.messages{max-height:560px}.image-caption{flex-wrap:wrap;gap:4px}.scale-row{grid-template-columns:minmax(0,1fr) auto minmax(0,1fr) 70px}footer{font-size:.75rem}}@media(max-width:400px){.brand small{display:none}.back-link{max-width:60px}.question-chips{grid-template-columns:1fr}.question-chips button{flex-direction:row}#sendHint{max-width:100px}.scale-row{gap:5px}.scale-row input{padding-inline:8px}}@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}
/* Image, endpoints and measurements share one canvas coordinate transform. */
#dropZone.image-stage{position:relative}
#imageCanvas{position:absolute;inset:0;width:100%;height:100%;touch-action:none;user-select:none;outline-offset:-4px}
#dropZone.picking-scale{border-color:var(--lime)}
.scale-picker-actions{display:flex;align-items:center;gap:14px;flex-wrap:wrap}
.scale-picker-actions button[aria-pressed="true"]{border-color:var(--teal);color:var(--teal)}
.scale-picker-note{min-height:2.8em;margin-bottom:12px;font-size:.875rem}
.viewer-toolbar{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:14px 18px 0;flex-wrap:wrap}
.zoom-controls{display:flex;align-items:center;gap:6px}
.zoom-controls button{min-width:34px;min-height:36px;border:1px solid var(--line);border-radius:6px;background:var(--surface-soft);color:var(--ink);font-size:.875rem}
.zoom-controls output{min-width:54px;text-align:center;font-size:.875rem;font-variant-numeric:tabular-nums}
.enhance-control{display:flex;align-items:center;gap:6px;white-space:nowrap}
.enhance-control input{width:16px;height:16px;margin:0;accent-color:var(--teal)}
.viewer-status{position:absolute;top:8px;left:8px;max-width:calc(100% - 16px);padding:5px 10px;background:rgba(7,20,18,.88);color:#edf7f3;border:1px solid #587064;border-radius:6px;font-size:.75rem;pointer-events:none}
.viewer-hint{font-size:.75rem;line-height:1.7;margin:0 20px 18px;color:var(--muted)}
.scale-state{padding:2px 9px;border:1px solid var(--line);border-radius:20px;color:var(--muted);font-size:.75rem}
.scale-state[data-state="draft"]{color:var(--coral);border-color:var(--coral)}
.scale-state[data-state="applied"]{color:var(--teal);border-color:var(--teal)}
.calibration-result{padding:14px;margin-top:16px;background:var(--surface-soft);border:1px solid var(--line);border-radius:10px;overflow-wrap:anywhere}
.calibration-result strong{font-size:1.125rem;font-variant-numeric:tabular-nums;color:var(--teal)}
.calibration-result p{margin-top:6px;font-size:.875rem;color:var(--muted)}
.apply-scale{width:100%;margin-top:12px}
@media(min-width:761px){#dropZone.image-stage{min-height:420px;aspect-ratio:1.25}}