:root{--ink:#1c3032;--muted:#6a7372;--paper:#f6f3ec;--card:#fffdf8;--line:#ddd8cc;--teal:#58b9b2;--teal-dark:#173a3d;--red:#db5a4d;--orange:#ef9b43;--shadow:0 12px 35px rgba(28,48,50,.09)}
*{box-sizing:border-box}html{background:var(--paper);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif}body{margin:0;min-height:100vh}.loading{padding:35vh 24px;text-align:center;color:var(--muted)}button,select,input{font:inherit}.shell{max-width:920px;margin:auto;padding:0 18px 110px}.topbar{position:sticky;top:0;z-index:20;padding:calc(12px + env(safe-area-inset-top)) 0 12px;background:linear-gradient(var(--paper) 78%,transparent)}.brand{display:flex;align-items:center;justify-content:space-between}.brand h1{font-size:21px;margin:0}.brand small{color:var(--muted)}.pill{border:1px solid var(--line);border-radius:99px;background:var(--card);padding:8px 12px;color:var(--ink)}.hero{background:var(--teal-dark);color:white;border-radius:28px;padding:24px;box-shadow:var(--shadow);overflow:hidden;position:relative}.hero:after{content:"";position:absolute;width:180px;height:180px;border:35px solid rgba(255,255,255,.07);border-radius:50%;right:-75px;top:-65px}.eyebrow{font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:#b8e3df}.hero h2{font-size:29px;line-height:1.2;margin:8px 0}.hero p{margin:0 0 18px;color:#d2e6e3}.primary{border:0;border-radius:14px;background:var(--orange);color:#20383a;font-weight:800;padding:13px 18px;box-shadow:0 5px 0 #bc702b}.primary:active{transform:translateY(3px);box-shadow:0 2px 0 #bc702b}.summary-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:18px 0}.metric{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:15px}.metric strong{font-size:25px;display:block}.metric span{font-size:12px;color:var(--muted)}.section-title{display:flex;align-items:end;justify-content:space-between;margin:27px 2px 12px}.section-title h3{margin:0;font-size:19px}.section-title span{font-size:12px;color:var(--muted)}.chapter-list{display:grid;gap:10px}.chapter{border:1px solid 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button.active{background:#d9eeeb;color:var(--teal-dark);font-weight:800}.practice{min-height:100vh;padding-bottom:40px}.practice-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px}.progress{height:7px;border-radius:99px;background:#dfddd6;overflow:hidden}.progress i{display:block;height:100%;background:var(--teal);width:0}.question-card{background:var(--card);border:1px solid var(--line);border-radius:24px;padding:20px;margin-top:16px}.tags{display:flex;gap:6px;flex-wrap:wrap}.tag{font-size:11px;border-radius:99px;padding:5px 8px;background:#e6f2f0;color:var(--teal-dark)}.question-card h2{font-size:21px;line-height:1.55;margin:14px 0}.options{display:grid;gap:10px}.option{border:1px solid #cfd7d6;border-radius:14px;background:#fff;padding:13px 14px;text-align:left;color:var(--ink);line-height:1.5}.option.selected{border-color:var(--teal);background:#e9f6f4}.option.correct{background:var(--teal);border-color:var(--teal);color:white}.option.wrong{background:var(--red);border-color:var(--red);color:white}.answer-actions{display:flex;gap:10px;margin-top:16px}.answer-actions button{flex:1}.ghost{border:1px solid var(--line);background:var(--card);border-radius:14px;padding:12px}.explanation{margin-top:18px;border-top:1px dashed var(--line);padding-top:16px}.answer-line{font-size:20px;font-weight:900;margin-bottom:12px}.answer-line .ok{color:var(--teal)}.answer-line .bad{color:var(--red)}.explanation h4{margin:12px 0 6px}.analysis{line-height:1.75;background:#eff7f3;border-left:5px solid var(--teal);padding:14px;border-radius:4px 14px 14px 4px;white-space:pre-line}.source{font-size:12px;color:var(--muted);margin-top:10px}.stats-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}.bar-row{margin:14px 0}.bar-label{display:flex;justify-content:space-between;font-size:13px;margin-bottom:6px}.bar{height:9px;background:#e3e0d9;border-radius:99px;overflow:hidden}.bar i{display:block;height:100%;background:var(--teal)}.panel{background:var(--card);border:1px solid var(--line);border-radius:22px;padding:18px;margin-top:12px}.panel h3{margin-top:0}.panel input[type=file]{width:100%;padding:14px;border:1px dashed var(--line);border-radius:12px}.notice{font-size:13px;color:var(--muted);line-height:1.6}.empty{text-align:center;padding:55px 18px;color:var(--muted)}
.random-panel{margin-top:18px}.section-title.compact{margin:0 0 8px}.wide{width:100%;margin-top:14px}.count-picker{display:flex;gap:8px;align-items:center;flex-wrap:wrap}.count-chip{border:1px solid var(--line);background:var(--card);border-radius:12px;padding:9px 12px;color:var(--ink)}.count-chip.active{background:var(--teal-dark);color:#fff;border-color:var(--teal-dark)}.count-picker label{display:flex;align-items:center;gap:7px;color:var(--muted);font-size:13px}.count-picker input{width:72px;border:1px solid var(--line);background:#fff;border-radius:10px;padding:9px;color:var(--ink)}.subject-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}.subject-card{border:1px solid var(--line);background:var(--card);border-radius:18px;padding:16px;text-align:left;color:var(--ink);display:flex;flex-direction:column;gap:5px}.subject-card span{color:var(--teal-dark);font-weight:800}.subject-card b{font-size:23px}.subject-card small{color:var(--muted)}.subject-section{margin:0 0 28px;scroll-margin-top:70px}.subject-heading{display:flex;align-items:center;justify-content:space-between;margin:20px 2px 10px}.subject-heading h2{margin:0;color:var(--teal-dark);font-size:23px}.stage-hero{margin-bottom:18px}.stage-hero h2{font-size:27px}.stage-grid{display:grid;gap:12px}.stage-card{display:flex;align-items:center;justify-content:space-between;gap:12px;background:var(--card);border:1px solid var(--line);border-radius:20px;padding:17px}.stage-card h3{margin:8px 0 3px}.stage-card p{margin:0;color:var(--muted);font-size:13px}.stage-card .primary{padding:11px 13px;white-space:nowrap}.tag.orange{background:#fff0df;color:#a65c1c}.stat-split{display:grid;grid-template-columns:1fr 1fr;gap:10px}.stat-split div{background:#f6f3ec;border-radius:14px;padding:14px;display:flex;flex-direction:column;gap:4px}.stat-split b{font-size:24px}.stat-split span{font-size:12px;color:var(--muted)}.complete{padding-top:25vh}.finish-mark{display:inline-grid;place-items:center;width:72px;height:72px;border-radius:50%;background:var(--teal);color:#fff;font-size:38px}.bottom-nav button{padding-left:13px;padding-right:13px}
.net-badge{font-size:12px;font-weight:800;border-radius:99px;padding:7px 10px}.net-badge.online{background:#d9eeeb;color:var(--teal-dark)}.net-badge.offline{background:#fff0df;color:#9b571d}.offline-strip{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:14px 0;padding:13px 14px;border:1px solid #c9dfdb;background:#eaf5f3;border-radius:18px}.offline-strip div{display:flex;flex-direction:column;gap:3px}.offline-strip b{font-size:14px}.offline-strip span{font-size:12px;color:var(--muted)}.install-panel ol{padding-left:20px;line-height:1.8}.update-message{padding:11px 12px;border-radius:12px;background:#eef5f1;color:var(--teal-dark);font-size:13px;line-height:1.6}.file-button{position:relative;overflow:hidden;display:grid;place-items:center;flex:1;border:1px solid var(--line);background:var(--card);border-radius:14px;padding:12px;text-align:center}.file-button input{position:absolute;inset:0;opacity:0;cursor:pointer}.top-gap{margin-top:12px}
@media(min-width:720px){.shell{padding-left:28px;padding-right:28px}.chapter-list{grid-template-columns:1fr 1fr}.subject-grid{grid-template-columns:repeat(5,1fr)}.stage-grid{grid-template-columns:1fr 1fr}.hero{padding:34px}.hero h2{font-size:38px}.bottom-nav{width:570px;left:50%;right:auto;transform:translateX(-50%);bottom:16px;border:1px solid var(--line);border-radius:20px;padding:7px;box-shadow:var(--shadow)}}
@media(max-width:430px){.offline-strip{align-items:flex-start;flex-direction:column}.offline-strip .pill{width:100%}.brand{gap:8px}.net-badge{white-space:nowrap}.answer-actions{flex-wrap:wrap}.answer-actions>*{min-width:130px}}