:root{--bg:#f5f4ef;--paper:#fffefa;--ink:#243b34;--muted:#7b827a;--green:#254b40;--line:#e5e7de;--accent:#dce8be;--red:#a04436}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:Inter,"PingFang SC","Microsoft YaHei",sans-serif;font-size:15px;line-height:1.65}[hidden]{display:none!important}button,input,textarea{font:inherit}button,.file-button{touch-action:manipulation}button,a,label.file-button{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{opacity:.45;cursor:not-allowed}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible{outline:3px solid #98ad68;outline-offset:3px}.topbar{height:84px;padding:0 max(28px,calc((100vw - 1380px)/2));display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);background:var(--paper)}.brand{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--ink);font-size:23px;font-weight:700;letter-spacing:-.7px}.brand-icon{display:flex;align-items:center;justify-content:center;width:37px;height:37px;background:var(--green);color:white;border-radius:11px;font-family:Georgia,serif;font-size:29px}.brand-icon span{color:var(--accent)}.brand-label{font-size:12px;font-weight:400;letter-spacing:2px;border-left:1px solid #d6dace;padding-left:15px;margin-left:6px;color:var(--muted)}main{max-width:1380px;margin:auto;padding:34px 28px 18px}.intro{display:flex;align-items:center;justify-content:space-between;margin-bottom:28px;gap:16px}.eyebrow{font-size:11px;letter-spacing:2px;font-weight:600;color:#788364}h1{font-size:32px;letter-spacing:-1px;margin:9px 0 7px;font-weight:600}p{margin:8px 0}.intro p{color:var(--muted);font-size:14px}.subject-chip{font-size:12px;padding:7px 14px;border:1px solid #d7ddcc;border-radius:30px;white-space:nowrap;background:#eff1e8}.workspace-grid{display:grid;grid-template-columns:minmax(320px,.82fr) minmax(0,1.4fr);gap:24px;align-items:start}.input-column{display:grid;gap:20px}.card{background:var(--paper);border:1px solid var(--line);border-radius:20px;box-shadow:0 4px 20px #283d2a03}.upload-card,.history-card{padding:24px}.section-title{display:flex;align-items:center;justify-content:space-between;gap:8px;margin-bottom:18px}h2{font-size:17px;font-weight:600;margin:0}h3{font-size:15px;font-weight:500;margin:12px 0 3px}.step-number{font-family:Georgia,serif;font-size:13px;color:#8c9b75;margin-right:10px}.muted{color:var(--muted);font-size:12px}.dropzone{border:1px dashed #ccd6c0;border-radius:13px;background:#f5f7ef;padding:26px 12px 21px;text-align:center}.dropzone.dragging{background:#e6eecf;border-color:var(--green)}.camera-icon{font-size:32px;line-height:1.1;color:#7f936a}.dropzone p{font-size:12px;color:var(--muted);margin-bottom:19px}.upload-actions{display:flex;gap:9px;justify-content:center}.primary,.secondary{border:0;border-radius:10px;min-height:45px;padding:10px 20px;font-size:14px;font-weight:500;display:inline-flex;align-items:center;justify-content:center;gap:15px}.primary{background:var(--green);color:white}.primary:hover{background:#386151}.secondary{background:#fffefa;border:1px solid #d8dfcd;color:var(--green)}.secondary:hover{background:#f1f3e9}.file-button{cursor:pointer}.dropzone small{display:block;margin-top:18px;color:#919587;font-size:10px}.field-label{display:flex;justify-content:space-between;font-size:13px;margin:21px 0 9px}.field-label span{color:var(--muted);font-size:11px}textarea,input{width:100%;border:1px solid var(--line);border-radius:10px;background:#fffefa;padding:12px;color:var(--ink)}textarea{resize:vertical;font-size:13px;line-height:1.8}textarea::placeholder{color:#9a9f93}.submit-button{display:flex;justify-content:space-between;width:100%;margin-top:17px}.helper{font-size:11px;color:var(--muted);margin:13px 0 0}.error{color:var(--red);font-size:13px;white-space:pre-wrap}.error:empty{display:none}.previews{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:12px}.preview{position:relative}.preview img{width:100%;height:82px;object-fit:cover;border:1px solid var(--line);border-radius:8px}.remove{position:absolute;right:2px;top:2px;width:30px;height:30px;border-radius:50%;border:0;background:#244335e8;color:white}.image-number{font-size:10px;color:var(--muted)}.text-button{border:0;background:transparent;color:#6b7b62;font-size:12px;padding:10px}.empty-small{font-size:12px;color:var(--muted)}.history-item{width:100%;text-align:left;border:0;border-top:1px solid #eceee5;background:transparent;padding:14px 7px;display:flex;justify-content:space-between;gap:10px;color:var(--ink);align-items:center}.history-item.active{background:#f1f4e9;border-radius:8px}.history-item strong{display:block;font-size:13px;font-weight:500;overflow:hidden;text-overflow:ellipsis;max-width:210px;white-space:nowrap}.history-item small{font-size:10px;color:var(--muted)}.badge{font-size:10px;background:#edf1e5;color:#6c8054;padding:3px 8px;border-radius:20px;white-space:nowrap}.badge.warning{background:#fbf0da;color:#9b7831}.badge.error-badge{background:#f8e8e3;color:var(--red)}.result-card{min-height:660px;overflow:hidden}.welcome{min-height:660px;display:flex;align-items:center;justify-content:center;flex-direction:column;text-align:center;padding:36px}.math-decoration{font-family:Georgia,serif;font-size:56px;font-style:italic;color:#aeb9a0;letter-spacing:5px;margin-bottom:40px}.welcome h2{font-size:29px;line-height:1.65;letter-spacing:1px;margin:14px 0 12px}.welcome p{color:var(--muted);font-size:13px;line-height:2}.welcome-tags{display:flex;gap:9px;margin-top:35px}.welcome-tags span{font-size:10px;color:#8a937b;border:1px solid #e5e9dc;padding:5px 12px;border-radius:30px}#job-view{padding:28px}.result-header{display:flex;align-items:start;justify-content:space-between;gap:15px;padding-bottom:20px;border-bottom:1px solid var(--line)}.result-header h2{font-size:21px;line-height:1.5;margin-bottom:6px}.result-header small{color:var(--muted);font-size:11px}.originals{display:flex;gap:10px;margin:18px 0;overflow:auto}.originals img{height:95px;width:100px;object-fit:contain;background:#f2f3ed;border:1px solid var(--line);border-radius:8px}.originals a{flex-shrink:0}.solution-section{padding:19px 0;border-top:1px solid var(--line)}.solution-section h3{font-size:14px;font-weight:600;margin:0 0 12px;color:#71845b}.math-text{white-space:pre-wrap;overflow-wrap:anywhere;line-height:1.95;font-size:14px}.math-text .katex{white-space:normal}.katex-display{overflow-x:auto;overflow-y:hidden;padding:8px 0}.solution-section li{margin:10px 0;padding-left:6px}.solution-section ol,.solution-section ul{padding-left:22px;margin:0}.answer-box{background:#f0f4e5;border:1px solid #e0e7d1;border-radius:12px;padding:20px;margin:15px 0}.answer-box h3{margin-top:0;color:#60774b}.status-box{padding:35px 15px;text-align:center;color:var(--muted)}.status-box h3{font-size:17px;color:var(--ink)}.spinner{display:block;width:28px;height:28px;border:2px solid #e4e8dc;border-top-color:var(--green);border-radius:50%;animation:spin 1s linear infinite;margin:10px auto 20px}@keyframes spin{to{transform:rotate(360deg)}}.notice{background:#fcf5e6;border:1px solid #eee0b9;border-radius:12px;padding:18px;margin:16px 0;font-size:14px}.retry-box{border-top:1px solid var(--line);margin-top:24px;padding-top:20px}.retry-box label{font-size:12px;color:var(--muted)}.retry-box textarea{margin:8px 0}.retry-box .secondary{font-size:12px}footer{font-size:10px;color:#93998c;text-align:center;padding:26px 12px 6px}.login-card{max-width:430px;margin:7vh auto;background:var(--paper);border:1px solid var(--line);border-radius:24px;padding:36px}.login-card h1{font-size:33px;line-height:1.6;margin-top:15px}.login-card p{color:var(--muted);font-size:13px}.login-card form{margin-top:28px}.login-card label{font-size:12px}.login-card input{margin:8px 0 16px}.login-card .primary{width:100%;justify-content:space-between}.login-card .error{color:var(--red)}@media(max-width:900px){main{padding:24px 20px}.topbar{padding:0 22px;height:72px}.workspace-grid{gap:16px;grid-template-columns:minmax(280px,.85fr) minmax(0,1fr)}.upload-card,.history-card{padding:18px}#job-view{padding:20px}h1{font-size:27px}.intro .subject-chip{display:none}.upload-actions{gap:6px}.file-button{padding:10px 13px}.welcome h2{font-size:24px}.welcome{padding:20px}.history-item strong{max-width:160px}}@media(max-width:700px),(max-width:1100px) and (orientation:portrait){.workspace-grid{grid-template-columns:1fr}.topbar{height:66px}.brand{font-size:21px}.brand-label{font-size:10px;padding-left:10px;margin-left:0}.intro{margin-bottom:20px}h1{font-size:25px}.intro p{font-size:12px}.result-card,.welcome{min-height:450px}.history-card{order:2}.welcome{padding:35px 20px}.math-decoration{margin-bottom:25px}.input-column{display:contents}.upload-card{order:0}.result-card{order:1}.history-card{order:2}.login-card{padding:26px;margin:3vh auto}.previews img{height:110px}.history-item strong{max-width:240px}}@media(prefers-reduced-motion:reduce){.spinner{animation:none}}@media print{.topbar,.intro,.input-column,footer,.retry-box,.originals{display:none!important}.workspace-grid{display:block}.result-card{border:none}body{background:white}main{padding:0}}
.progress-track{height:11px;width:100%;max-width:500px;margin:24px auto 8px;border-radius:99px;background:#e8eddf;overflow:hidden}.progress-fill{height:100%;width:0;background:linear-gradient(90deg,#9ab780,#254b40);border-radius:99px;transition:width .6s ease}.progress-meta{display:flex;justify-content:space-between;gap:12px;max-width:500px;margin:auto;font-size:12px}.progress-meta strong{color:var(--green);font-weight:600}.progress-tip{font-size:12px;line-height:1.7}.difficulty-note{max-width:580px;margin:12px auto;color:var(--ink);font-size:13px}@media(prefers-reduced-motion:reduce){.progress-fill{transition:none}}
.progress-complete{margin:4px 0 20px}.progress-complete .progress-track{margin:18px 0 6px;max-width:none}.progress-complete-label{text-align:right;color:var(--green);font-size:12px;font-weight:600}
.insights-card,.question-card{padding:24px}select{font:inherit;width:100%;border:1px solid var(--line);border-radius:10px;background:var(--paper);padding:12px;color:var(--ink)}select:focus-visible{outline:3px solid #98ad68;outline-offset:3px}.mastery-box{border-top:1px solid var(--line);padding-top:20px;margin-top:20px}.mastery-box p{font-size:12px;color:var(--muted)}.mastery-actions{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}.mastery-actions button{padding:8px 11px;min-height:38px;font-size:12px}.mastery-actions button.chosen{background:var(--green);color:white;border-color:var(--green)}.topic-item{border-top:1px solid var(--line);padding:11px 3px}.topic-item strong{font-size:13px;font-weight:600}.topic-item small{display:block;font-size:11px;color:var(--muted)}.question-item{width:100%;text-align:left;border:0;border-top:1px solid var(--line);background:transparent;padding:12px 4px;color:var(--ink)}.question-item strong{display:block;font-size:13px;font-weight:500}.question-item small{font-size:11px;color:var(--muted)}@media(max-width:900px){.insights-card,.question-card{padding:18px}}@media(max-width:700px),(max-width:1100px) and (orientation:portrait){.insights-card{order:3}.question-card{order:4}}@media print{.mastery-box{display:none!important}}