*{box-sizing:border-box}html{scroll-behavior:smooth}body{overflow-wrap:anywhere}button,a,input,select,summary{-webkit-tap-highlight-color:transparent}button,a.button{font-size:14px;font-weight:650}button,.button{border:1px solid var(--msp-line);border-radius:10px;background:var(--msp-surface);color:var(--msp-text);padding:10px 16px;cursor:pointer;min-height:44px;text-decoration:none;display:inline-flex;align-items:center;justify-content:center;gap:8px}button:hover:not(:disabled),.button:hover{border-color:var(--msp-accent-text);background:var(--msp-accent-soft)}button:disabled{opacity:.58}.primary{background:var(--msp-accent);border-color:var(--msp-accent);color:var(--msp-on-accent)}a{color:var(--msp-accent-text)}p{margin:8px 0 16px}h1,h2,h3{line-height:1.3;margin:0}h2{font-size:23px}h3{font-size:17px}small,.muted{color:var(--msp-muted)}.site-header{min-height:80px;border-bottom:1px solid var(--msp-line);background:var(--msp-surface);display:flex;align-items:center;justify-content:space-between;gap:20px;padding:14px max(24px,calc((100vw - 1400px)/2));flex-wrap:wrap}.brandmark{display:flex;align-items:center;gap:11px;color:var(--msp-text);text-decoration:none;font-weight:800;font-size:21px}.brandmark small{font-size:12px;font-weight:500;margin-left:8px}.brand-icon{display:grid;place-items:center;width:42px;height:44px;border-radius:11px;background:var(--msp-accent);color:var(--msp-on-accent);font-family:var(--gewu-font-display)}.site-header nav{display:flex;gap:22px;align-items:center;flex-wrap:wrap}.site-header nav a{display:flex;align-items:center;min-height:44px;font-size:14px;color:var(--msp-muted);text-decoration:none}.site-header nav a[aria-current]{color:var(--msp-accent-text);font-weight:750}.page{max-width:1400px;margin:auto;padding:32px 28px 20px}.intro{display:grid;grid-template-columns:1.2fr 1fr;gap:24px;min-height:284px;padding:22px 12px 34px;align-items:center}.eyebrow{font-size:11px;letter-spacing:2px;color:var(--msp-accent-text);font-family:var(--gewu-font-mono);font-weight:650}.intro h1{font-family:var(--gewu-font-display);font-weight:400;font-size:clamp(34px,3.6vw,54px);letter-spacing:1px}.intro h1 span{color:var(--msp-accent-text)}.intro-copy>p:not(.eyebrow){color:var(--msp-muted);margin:18px 0;line-height:1.9}.intro-tags{display:flex;gap:14px;flex-wrap:wrap;font-size:12px}.intro-tags span:before{content:'';display:inline-block;width:5px;height:5px;border-radius:50%;background:var(--msp-accent);vertical-align:middle;margin-right:7px}.intro-art{position:relative;height:240px;overflow:hidden;border:1px solid var(--msp-line);border-radius:22px;background:radial-gradient(circle at 68% 42%,var(--msp-accent-soft),transparent 60%),var(--msp-surface)}.intro-art:before{content:'';position:absolute;inset:0;background-image:linear-gradient(var(--msp-line) 1px,transparent 1px),linear-gradient(90deg,var(--msp-line) 1px,transparent 1px);background-size:26px 26px;opacity:.35}.orbit{position:absolute;border:1px solid var(--msp-edge);border-radius:50%;left:12%;top:17%;width:76%;height:60%;transform:rotate(-22deg)}.orbit-two{transform:rotate(23deg);border-color:var(--msp-accent)}.art-equation{position:absolute;inset:65px 0 auto;text-align:center;font:italic 64px Georgia,serif;letter-spacing:6px}.art-equation span{color:var(--msp-accent-text)}.art-label,.art-caption{position:absolute;font-size:11px;color:var(--msp-muted);left:22px;bottom:17px;letter-spacing:2px}.art-label{top:17px;bottom:auto;font-family:var(--gewu-font-mono)}.art-point{position:absolute;width:13px;height:13px;background:var(--msp-accent);border:3px solid var(--msp-surface);border-radius:50%;right:19%;top:28%}.account-strip{display:flex;align-items:center;justify-content:space-between;gap:18px;padding:14px 18px;border:1px solid var(--msp-line);background:var(--msp-surface);border-radius:13px;margin-bottom:20px;font-size:13px}.actions{display:flex;flex-wrap:wrap;gap:8px;align-items:center}.status:empty{display:none}.status{margin:12px 0;padding:12px 16px;border-left:3px solid var(--msp-accent);background:var(--msp-accent-soft);font-size:14px;white-space:pre-line}.status p{margin:0 0 10px}.status.error{border-color:var(--msp-science-red)}.layout{display:grid;grid-template-columns:288px minmax(0,1fr);gap:26px;align-items:start}.catalogue{position:sticky;top:18px;min-width:0}.section-heading{display:flex;justify-content:space-between;gap:12px;align-items:center;margin:7px 0 16px}.section-heading h2{font-size:18px}.count,.chip{font:12px var(--gewu-font-mono);border:1px solid var(--msp-line);padding:4px 8px;border-radius:6px;white-space:nowrap;color:var(--msp-muted)}.search-label{display:block;font-size:12px;color:var(--msp-muted);margin:10px 0 6px}input[type=search],select{width:100%;border:1px solid var(--msp-line);border-radius:10px;background:var(--msp-surface);padding:11px 13px;font:14px inherit;color:var(--msp-text)}.msp-theme-control select{width:auto}.season{padding:12px 0;border-bottom:1px solid var(--msp-line);margin-bottom:10px;font-size:12px}.season p{margin:6px 0;color:var(--msp-muted)}.season button{font-size:12px;padding:8px 12px}.formula-list{max-height:650px;overflow:auto;overscroll-behavior:contain;padding:3px}.formula-item{display:flex;width:100%;text-align:left;justify-content:flex-start;gap:11px;border:1px solid transparent;background:transparent;border-radius:11px;padding:12px 10px;margin:3px 0;min-height:66px}.formula-item[aria-current=true]{background:var(--msp-surface);border-color:var(--msp-accent-text);box-shadow:inset 3px 0 var(--msp-accent)}.formula-item .item-number{font:11px var(--gewu-font-mono);color:var(--msp-muted);align-self:flex-start;padding-top:5px}.formula-item .item-copy{flex:1;min-width:0}.formula-item strong{font-size:13px;display:block}.formula-item small{font-size:11px;font-weight:400}.formula-item .level{font:11px var(--gewu-font-mono);padding:3px 5px;background:var(--msp-raised);border-radius:5px}.workspace{min-width:0}.view-nav{display:flex;gap:5px;padding:5px;background:var(--msp-raised);border:1px solid var(--msp-line);border-radius:12px;margin-bottom:18px;flex-wrap:wrap}.view-nav button{flex:1;padding:10px 8px;background:transparent;border-color:transparent;white-space:nowrap;font-size:13px}.view-nav button[aria-pressed=true]{background:var(--msp-surface);color:var(--msp-accent-text);border-color:var(--msp-line);box-shadow:0 2px 5px #00000008}.panel{border:1px solid var(--msp-line);border-radius:16px;padding:24px;background:var(--msp-surface);margin-bottom:18px;min-width:0}.panel>p{color:var(--msp-muted);font-size:14px}.detail-top{display:flex;justify-content:space-between;gap:18px}.detail-top h2{margin:8px 0 12px;font-size:28px}.pet{width:80px;height:80px;object-fit:contain}.pet-caption{font-size:11px;text-align:center;color:var(--msp-muted)}.theme-emblem{height:70px;width:70px;display:grid;place-items:center;border:1px solid var(--msp-accent-text);border-radius:20px;transform:rotate(8deg);font:32px var(--gewu-font-display);color:var(--msp-accent-text);background:var(--msp-accent-soft)}.math{max-width:100%;min-width:0;overflow-x:auto;overflow-y:hidden;padding:8px 2px}.formula-main{font-size:25px;background:var(--msp-bg);border:1px solid var(--msp-line);padding:28px 18px;border-radius:12px;margin:14px 0 20px;text-align:center}.katex-display{margin:.3em 0}.formula-main .katex{font-size:1.25em}.formula-main:focus-visible{outline-offset:0!important}.symbol-row{display:flex;flex-wrap:wrap;gap:8px}.symbol-row button{min-width:54px;padding:8px 13px;background:var(--msp-bg)}.symbol-row button[aria-pressed=true]{border-color:var(--msp-accent-text);background:var(--msp-accent-soft)}.symbol-detail{padding:14px 16px;background:var(--msp-bg);border-radius:10px;margin-top:12px;font-size:14px;min-height:85px}.symbol-detail strong{display:block;margin-bottom:4px}.two-col{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:20px}.teaching-block{padding:18px;border-radius:11px;border:1px solid var(--msp-line);font-size:14px}.teaching-block h3{color:var(--msp-science-green);font-size:15px}.teaching-block.caution h3{color:var(--msp-accent-text)}ul,ol{padding-left:21px}li{margin:8px 0}.intuition{border-left:3px solid var(--msp-accent);padding:8px 15px;margin:18px 0;font-size:15px}.variant{padding:12px 0;border-bottom:1px solid var(--msp-line)}.variant:last-child{border:0}.variant p{font-size:12px;color:var(--msp-muted);margin:4px 0}.subheading{margin:20px 0 12px}.fineprint{font-size:12px!important;color:var(--msp-muted);line-height:1.8}.question{min-width:0;border:1px solid var(--msp-line);border-radius:12px;margin:16px 0;padding:18px}.question legend{font-size:15px;font-weight:650;padding:0 8px;line-height:1.8}.option{display:flex;align-items:flex-start;gap:11px;min-height:48px;padding:12px;border:1px solid var(--msp-line);border-radius:9px;margin:9px 0;font-size:14px;cursor:pointer;background:var(--msp-bg)}.option:has(input:checked){border-color:var(--msp-accent-text);background:var(--msp-accent-soft)}.option:has(input:focus-visible){outline:2px solid var(--msp-accent-text);outline-offset:2px}.option input{width:18px;height:18px;flex:none;margin:3px 0;accent-color:var(--msp-accent-text)}.question .actions{margin-top:14px}.question-result{font-size:14px;white-space:pre-line;margin-top:12px}.question-result.good{border-left:3px solid var(--msp-science-green);padding:12px;background:var(--msp-bg)}.question-result.bad{border-left:3px solid var(--msp-science-red);padding:12px;background:var(--msp-bg)}.skill-tabs{display:flex;gap:7px;flex-wrap:wrap;margin-top:16px}.skill-tabs button{font-size:12px}.skill-tabs button[aria-pressed=true]{border-color:var(--msp-accent-text);color:var(--msp-accent-text)}.step-path{display:flex;gap:10px;margin:18px 0}.step-path button{flex:1;font-size:13px}.step-path button[aria-current=step]{background:var(--msp-accent-soft);border-color:var(--msp-accent-text)}.step-path .passed{color:var(--msp-science-green)}.history-item{border-left:2px solid var(--msp-science-green);padding:12px 16px;background:var(--msp-bg);margin:10px 0;font-size:13px}.history-item summary{min-height:44px;cursor:pointer;font-weight:650}.recall-cover{min-height:190px;display:flex;flex-direction:column;align-items:center;justify-content:center;border:1px dashed var(--msp-edge);border-radius:12px;background:var(--msp-bg);text-align:center;padding:20px;margin:20px 0}.recall-cover .recall-mark{font:54px Georgia,serif;color:var(--msp-accent-text)}.ratings{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px}.ratings button{display:flex;flex-direction:column;font-size:13px;padding:12px 8px}.ratings small{font-size:11px;font-weight:400}.queue-list{display:grid;gap:8px}.queue-list button{justify-content:space-between;text-align:left;gap:12px}.queue-list span{font-size:12px;font-weight:400;color:var(--msp-muted)}.metric-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:18px 0}.metric{border:1px solid var(--msp-line);border-radius:11px;padding:18px;background:var(--msp-bg)}.metric strong{font:28px var(--gewu-font-mono);display:block;margin-bottom:6px}.metric span{font-size:12px;color:var(--msp-muted)}.badge-track{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:7px;margin:20px 0}.badge-stage{text-align:center;border:1px solid var(--msp-line);border-radius:10px;padding:13px 3px;font-size:11px;color:var(--msp-muted)}.badge-stage b{font:18px var(--gewu-font-mono);display:block;margin-bottom:5px}.badge-stage.active{border-color:var(--msp-accent-text);background:var(--msp-accent-soft);color:var(--msp-accent-text)}.evidence-list{font-size:14px}.challenge-clock{font:26px var(--gewu-font-mono);color:var(--msp-accent-text);padding:10px 0}.challenge-result{font:36px var(--gewu-font-mono);margin:16px 0}.empty{padding:32px 20px;text-align:center;color:var(--msp-muted);font-size:14px}.page-footer{border-top:1px solid var(--msp-line);margin:36px 0 0;padding:24px 0;display:flex;gap:18px;align-items:center;flex-wrap:wrap;font-size:12px;color:var(--msp-muted)}.page-footer p{flex:1;min-width:180px;margin:0}.page-footer summary{min-height:44px;display:flex;align-items:center;cursor:pointer}dialog{width:min(1280px,96vw);max-width:96vw;height:92vh;max-height:92vh;padding:18px;background:var(--msp-surface);color:var(--msp-text);border:1px solid var(--msp-line);border-radius:16px}dialog::backdrop{background:var(--msp-overlay)}.dialog-top{display:flex;justify-content:space-between;align-items:center;gap:12px}.dialog-top h2{font-size:19px}#experiment-status{font-size:13px;white-space:pre-line}#experiment-frame{height:calc(100% - 150px);min-height:280px}#experiment-frame iframe{width:100%;height:100%;border:1px solid var(--msp-line);border-radius:10px}.params{display:flex;gap:6px;flex-wrap:wrap}.params code{padding:5px 8px;border-radius:6px;background:var(--msp-bg);font:12px var(--gewu-font-mono)}.preview-card{max-width:100%;width:100%;border:1px solid var(--msp-line);border-radius:12px;margin:16px 0}.preview-card svg{display:block;width:100%;height:auto}.preview-card[hidden]{display:none}.theme-emblem-wrap{max-width:105px;flex:none}.notice-title{color:var(--msp-accent-text)}
.application-steps{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin:12px 0 20px}.application-step{min-width:0;border:1px solid var(--msp-line);border-radius:10px;padding:14px;background:var(--msp-bg)}.application-step h3{font-size:14px;color:var(--msp-accent-text)}.application-step p{font-size:13px;margin:8px 0 0;white-space:pre-line}.application-step .math{font-size:14px}.question>button{margin-top:12px}.question>p[role=status]{white-space:pre-line}@media(max-width:768px){.application-steps{grid-template-columns:1fr}}
@media(min-width:1450px){.formula-list{max-height:720px}}
@media(max-width:1000px){.site-header{gap:12px;padding:12px 22px}.site-header nav{gap:15px}.layout{grid-template-columns:236px minmax(0,1fr);gap:18px}.page{padding:22px 20px}.intro h1{font-size:38px}.panel{padding:20px}.two-col{grid-template-columns:1fr}.formula-main{font-size:21px}.ratings{grid-template-columns:repeat(2,1fr)}}
@media(max-width:720px){.site-header{padding:12px 16px}.brandmark{font-size:19px}.site-header nav{order:3;width:100%;justify-content:space-between;gap:6px}.site-header .msp-theme-control>span{display:none}.msp-theme-control select{max-width:150px}.page{padding:18px 14px}.intro{display:block;padding:5px 0 24px;min-height:0}.intro h1{font-size:36px}.eyebrow{font-size:9px;letter-spacing:1.4px}.intro-art{height:auto;border:0;padding:16px 18px}
.intro-art .cta-kicker{flex:0 0 auto}
.intro-art .cta-title{font-size:20px}
.intro-art .cta-desc{font-size:13px}
.intro-art .cta-go{align-self:center}.intro-tags{gap:10px;font-size:11px}.intro-copy>p:not(.eyebrow){font-size:14px}.account-strip{align-items:flex-start;flex-direction:column;padding:13px;gap:10px}.layout{display:block}.catalogue{position:static;margin-bottom:20px;padding:14px;background:var(--msp-surface);border:1px solid var(--msp-line);border-radius:14px}.catalogue .section-heading{margin-top:0}.formula-list{max-height:210px;margin-top:10px;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px}.formula-item{padding:9px 7px;gap:6px;min-height:70px;height:100%;margin:0}.formula-item strong{font-size:12px}.formula-item .item-number{display:none}.formula-item .level{font-size:10px}.season{padding:8px 0}.view-nav{gap:3px}.view-nav button{flex:1 1 28%;font-size:12px}.panel{padding:17px 14px;border-radius:13px}.detail-top h2{font-size:23px}.detail-top{gap:10px}.pet{width:62px;height:62px}.theme-emblem{width:52px;height:52px;font-size:25px}.pet-caption{font-size:10px}.formula-main{font-size:19px;padding:22px 9px}.question{padding:12px 9px}.question legend{font-size:14px}.option{padding:11px 9px;font-size:13px}.metric-grid{gap:7px}.metric{padding:13px 9px}.metric strong{font-size:24px}.badge-track{grid-template-columns:repeat(3,1fr)}.step-path{gap:5px}.step-path button{font-size:12px;padding:9px 6px}.queue-list button{align-items:flex-start;flex-direction:column}.page-footer{gap:10px}.page-footer p{flex-basis:100%}dialog{padding:10px}.dialog-top h2{font-size:16px}.dialog-top button{padding:8px;font-size:12px}}
@media(max-width:350px){.brandmark small{display:none}.intro h1{font-size:31px}.intro-tags{gap:8px}.formula-list{grid-template-columns:1fr}.formula-item{min-height:58px}.detail-top h2{font-size:21px}.ratings{grid-template-columns:1fr 1fr}.metric-grid{grid-template-columns:1fr}.metric{display:flex;gap:14px;align-items:center}.metric strong{margin:0}.view-nav button{font-size:11px}.formula-main{font-size:17px}}
/* 研习所精修：装饰限定在 hero，正文保持稳定。下一阶段氛围仅插入 #formula-hero。 */
.page{padding:32px 32px 24px}.site-header{gap:24px;padding-top:16px;padding-bottom:16px}.brandmark{gap:12px}.brand-icon{border-radius:12px}.site-header nav{gap:24px}
.intro{position:relative;isolation:isolate;gap:32px;padding:32px;margin-bottom:24px;border-radius:24px;background:var(--msp-surface);box-shadow:0 12px 40px #17171A08;overflow:hidden}
.intro-copy{position:relative;z-index:1;min-width:0}.intro h1{font-size:clamp(36px,3.8vw,56px);line-height:1.25;letter-spacing:0}.intro-copy>p:not(.eyebrow){margin:24px 0;font-size:16px}.eyebrow{font-size:12px;letter-spacing:.12em;font-weight:400}.intro-tags{gap:8px 16px}.intro-tags span:before{width:4px;height:4px;margin-right:8px}
.intro-art{position:relative;display:flex;height:256px;flex-direction:column;justify-content:center;gap:10px;padding:26px 30px;border:1px solid var(--msp-accent-soft);border-radius:16px;font-family:inherit;text-align:left;cursor:pointer;background:radial-gradient(ellipse at 88% 20%,var(--msp-accent-soft),transparent 68%),var(--msp-bg)}
.intro-art:before{background-size:32px 32px;opacity:.32}
.intro-art:hover{transform:translateY(-2px);box-shadow:0 14px 34px #17171A14}
.intro-art:active{transform:translateY(0);box-shadow:none}
.cta-kicker{align-self:flex-start;padding:5px 12px;border-radius:999px;background:var(--msp-accent-soft);color:var(--msp-accent-text);font-size:12px;font-weight:800;letter-spacing:.06em}
.cta-title{font-size:clamp(23px,2.3vw,30px);font-weight:800;line-height:1.2;letter-spacing:-.01em}
.cta-desc{color:var(--msp-muted);font-size:14px;line-height:1.7;max-width:26em}
.cta-go{align-self:flex-end;font-size:22px;font-weight:800;line-height:1;color:var(--msp-accent-text)}
.account-strip{gap:16px;padding:16px 20px;border-radius:12px;margin-bottom:24px}.layout{grid-template-columns:272px minmax(0,1fr);gap:24px}.catalogue{padding:8px 8px 8px 0}.section-heading{margin:0 0 16px}.search-label{margin:12px 0 8px}.season{padding:16px 0;margin-bottom:8px}.formula-item{gap:8px;margin:4px 0;padding:12px 8px;border-radius:8px}.formula-item[aria-current=true]{border-color:transparent;background:var(--msp-accent-soft);box-shadow:inset 3px 0 var(--msp-accent)}.formula-item .item-number{padding-top:4px}.formula-item .level{padding:4px}.formula-item strong{font-weight:650}.formula-item small{font-size:12px}.formula-list{scrollbar-width:thin;scrollbar-color:var(--msp-edge) transparent}
.view-nav{gap:4px;padding:4px;border:0;margin-bottom:24px}.view-nav button{padding:12px 8px;border-radius:8px}.panel{padding:32px;margin-bottom:24px;border:0;border-radius:20px;box-shadow:0 1px 0 var(--msp-line),0 8px 28px #17171A06}.panel>h2{font-size:24px}.panel>p{font-size:15px}.detail-top{gap:24px;align-items:flex-start}.detail-top>div:first-child{min-width:0}.detail-top h2{font-size:30px;line-height:1.4;margin:8px 0 12px}.detail-top .muted{line-height:1.8}.theme-emblem-wrap{padding:8px;max-width:120px;background:var(--msp-bg);border-radius:16px;text-align:center}.pet{display:block;margin:auto}.pet-caption{font-size:11px;line-height:1.6;margin-top:8px}.theme-emblem{transform:none;border:0;margin:auto;font-weight:400}
.lesson-route{display:flex;gap:16px;flex-wrap:wrap;margin:24px 0;color:var(--msp-muted);font-size:13px}.lesson-route>span{display:flex;align-items:center;gap:8px}.lesson-route b{font:12px var(--gewu-font-mono);color:var(--msp-accent-text);border-bottom:2px solid var(--msp-accent);padding:4px 0}
.formula-main{position:relative;margin:24px 0;padding:32px 16px;border:0;border-radius:12px;background:linear-gradient(90deg,var(--msp-bg),var(--msp-surface),var(--msp-bg));box-shadow:inset 0 1px var(--msp-line),inset 0 -1px var(--msp-line);font-size:26px}.symbol-row{margin-top:16px}.symbol-row button{padding:8px 16px}.symbol-detail{padding:16px;border-radius:8px;min-height:88px;font-size:15px}.intuition{margin:24px 0;padding:8px 16px;font-size:16px}.two-col{gap:16px;margin-top:24px}.teaching-block{padding:20px;border:0;border-radius:12px;background:var(--msp-bg);font-size:15px;line-height:1.9;box-shadow:inset 0 3px var(--msp-science-green)}.teaching-block.caution{box-shadow:inset 0 3px var(--msp-accent)}.teaching-block h3{font-size:16px;color:var(--msp-text)}.block-kicker{display:block;font:11px var(--gewu-font-mono);letter-spacing:.08em;color:var(--msp-muted);margin-bottom:12px}.teaching-block ul{margin-bottom:0;padding-left:20px}.subheading{margin:24px 0 16px}.variant{display:grid;grid-template-columns:minmax(0,1fr) minmax(120px,1fr);align-items:center;gap:16px;padding:16px 0}.variant p{font-size:13px}
/* 表达式分层：主公式 / 等价变形 / 特例 / 实验式 */
.form-layers{display:grid;gap:2px;margin-bottom:8px}
.form-layers .variant{position:relative;padding:16px 18px;border-radius:10px;background:var(--msp-bg);grid-template-columns:minmax(0,1.1fr) minmax(140px,1fr)}
.form-layers .variant.form-primary{box-shadow:inset 3px 0 var(--msp-accent)}
.form-layers .variant.form-special{box-shadow:inset 3px 0 var(--msp-science-green)}
.form-layers .variant.form-experiment{box-shadow:inset 3px 0 var(--msp-muted)}
.form-kind{display:inline-block;margin-bottom:8px;padding:3px 9px;border-radius:999px;background:var(--msp-accent-soft);color:var(--msp-accent-text);font:600 11px var(--gewu-font-mono);letter-spacing:.06em;justify-self:start}
.form-special .form-kind{background:var(--msp-accent-soft)}
.form-experiment .form-kind{background:var(--msp-bg);color:var(--msp-muted);border:1px solid var(--msp-line)}
.teaching-block.basis{box-shadow:inset 0 3px var(--msp-line);margin-top:20px}
.basis-note{font-size:14px;line-height:1.9;margin:0}
@media(max-width:720px){.form-layers .variant{grid-template-columns:minmax(0,1fr);gap:8px}}.fineprint{font-size:13px!important}.lesson-panel>.fineprint{padding-top:16px;margin-bottom:0;border-top:1px dashed var(--msp-line)}
.derivation-panel>.math{margin:24px 0;padding:24px 16px;text-align:center;font-size:24px;background:var(--msp-bg);border-radius:12px}.experiment-panel{background:linear-gradient(135deg,var(--msp-surface),var(--msp-bg));box-shadow:inset 3px 0 var(--msp-science-blue),0 1px 0 var(--msp-line)}.experiment-panel .params{gap:8px;margin:16px 0}.experiment-panel .params code{padding:8px 12px;background:var(--msp-surface);border-radius:8px}.practice-panel{position:relative}.skill-tabs{gap:8px;margin:24px 0}.skill-tabs button{font-size:13px}.skill-tabs button[aria-pressed=true]{background:var(--msp-accent-soft)}.question{padding:24px 20px;margin:24px 0;border-radius:12px}.question legend{font-size:16px;font-weight:700}.option{gap:12px;padding:16px;margin:8px 0;border-radius:8px;font-size:15px;line-height:1.8;background:var(--msp-surface)}.option input{margin-top:4px}.option:has(input:checked){box-shadow:inset 3px 0 var(--msp-accent);background:var(--msp-accent-soft)}.question .actions{margin-top:24px}.question-result{font-size:14px;line-height:1.9}.question-result.good,.question-result.bad{padding:16px}.question-result:empty{display:none}.application-steps{gap:0;margin:16px 0 24px;border-radius:12px;overflow:hidden;background:var(--msp-bg)}.application-step{padding:16px;border:0;border-radius:0;background:transparent}.application-step p{font-size:14px;line-height:1.8}.step-path{gap:8px;margin:24px 0;flex-wrap:wrap}.step-path button{padding:12px 8px;border-radius:8px}.step-path button[aria-current=step]{box-shadow:inset 0 -3px var(--msp-accent)}.history-item{padding:16px;margin:16px 0;border-radius:0 8px 8px 0}
.honor-levels{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:24px 0}.current-evidence,.earned-honor{padding:24px;border-radius:12px;background:var(--msp-bg);min-width:0}.current-evidence{background:var(--msp-accent-soft)}.evidence-value{display:block;font:48px var(--gewu-font-mono);font-variant-numeric:tabular-nums;color:var(--msp-text);line-height:1.2}.current-evidence .evidence-value{color:var(--msp-accent-text)}.honor-levels p{font-size:14px;line-height:1.8;margin:12px 0 0}.badge-track{gap:8px;margin:24px 0}.badge-stage{border-radius:8px;padding:16px 4px}.badge-stage.unavailable{border-style:dashed}.evidence-list{padding-left:20px;line-height:1.9}.evidence-list li{margin:16px 0}.metric-grid{gap:16px;margin:24px 0}.metric{padding:20px;border:0;border-radius:12px}.metric span{font-size:13px}.count,.level,.metric strong,.challenge-clock,.badge-stage b{font-variant-numeric:tabular-nums}.page-footer{gap:16px;padding:24px 0;margin-top:40px}.ratings{gap:8px}.preview-card{border-radius:16px;overflow:hidden}
@media(max-width:1100px){.layout{grid-template-columns:240px minmax(0,1fr)}.panel{padding:24px}.intro{padding:24px;gap:24px}.two-col{grid-template-columns:1fr}.honor-levels{gap:12px}.current-evidence,.earned-honor{padding:16px}.detail-top h2{font-size:26px}}
@media(max-width:720px){.page{padding:16px}.site-header{padding:12px 16px;gap:12px}.intro{padding:24px 20px;margin-bottom:16px}.intro-copy>p:not(.eyebrow){font-size:15px;margin:16px 0}.intro h1{font-size:36px}.intro-art{height:auto;border:0;padding:16px 18px}
.intro-art .cta-kicker{flex:0 0 auto}
.intro-art .cta-title{font-size:20px}
.intro-art .cta-desc{font-size:13px}
.intro-art .cta-go{align-self:center}.intro-tags{font-size:12px;gap:8px 12px}.layout{display:block}.account-strip{padding:16px;margin-bottom:16px}.account-strip .actions{width:100%}.catalogue{padding:16px;margin-bottom:24px}.formula-item{padding:12px 8px;flex-wrap:wrap}.formula-item .item-copy{flex-basis:calc(100% - 4px)}.formula-item .level{font-size:11px}.formula-list{gap:8px;max-height:232px}.view-nav{margin-bottom:16px}.panel{padding:24px 16px;margin-bottom:16px;border-radius:16px}.detail-top{gap:12px}.detail-top h2{font-size:24px}.theme-emblem-wrap{max-width:88px;padding:8px}.pet-caption{font-size:10px}.lesson-route{gap:8px 12px;font-size:12px}.formula-main{padding:24px 8px;font-size:21px}.teaching-block{padding:16px}.question{padding:16px 12px}.option{padding:12px;font-size:15px}.application-step{padding:16px}.variant{grid-template-columns:1fr;gap:0}.honor-levels{grid-template-columns:1fr}.current-evidence,.earned-honor{padding:20px}.metric-grid{gap:8px}.metric{padding:16px 8px}.step-path button{flex-basis:28%;font-size:12px}.badge-track{grid-template-columns:repeat(3,minmax(0,1fr))}.block-kicker{font-size:10px}.page-footer{margin-top:24px}}
@media(max-width:350px){.intro{padding:20px 16px}.intro h1{font-size:32px}.formula-list{grid-template-columns:1fr}.detail-top{flex-wrap:wrap}.theme-emblem-wrap{display:flex;max-width:none;align-items:center;gap:12px}.pet-caption{margin:0}.pet{width:48px;height:48px}.metric-grid{grid-template-columns:1fr}.formula-main{font-size:18px}}
/* 公式训练器：独立、低干扰的分类与逐题训练界面。 */
body.trainer-mode{background:var(--msp-bg)}
body.trainer-mode>.site-header,
body.trainer-mode #formula-hero,
body.trainer-mode .account-strip,
body.trainer-mode>.page>#global-status:empty,
body.trainer-mode .catalogue,
body.trainer-mode #view-nav,
body.trainer-mode .page-footer{display:none!important}
body.trainer-mode .page{max-width:920px;padding:18px 20px 96px}
body.trainer-mode .layout{display:block}
body.trainer-mode .workspace{min-width:0}
body.trainer-mode #content{min-height:calc(100vh - 132px)}
.trainer-shell{display:grid;gap:18px}
.trainer-head{min-height:72px;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:16px;padding:12px 18px;border-radius:18px;background:var(--msp-text);color:var(--msp-bg)}
.trainer-title{display:flex;align-items:center;gap:10px;font-size:20px;font-weight:800;letter-spacing:.04em}
.trainer-mark{display:grid;place-items:center;width:34px;height:34px;border-radius:10px;background:var(--msp-accent);color:var(--msp-on-accent);font:800 22px var(--gewu-font-display)}
.trainer-exit{justify-self:start;border-color:transparent;background:transparent;color:inherit;padding:8px 10px}
.trainer-exit:hover:not(:disabled){background:#ffffff18;border-color:#ffffff26}
.trainer-count{justify-self:end;font-size:12px;color:color-mix(in srgb,var(--msp-bg) 74%,transparent)}
.trainer-categories,.trainer-formula-strip,.trainer-stage{padding:22px;border:1px solid var(--msp-line);border-radius:18px;background:var(--msp-surface);box-shadow:0 8px 28px #17171a0a}
.trainer-categories>h2,.trainer-formula-strip>h2{font-size:18px}
.trainer-categories>p{margin:6px 0 16px;color:var(--msp-muted);font-size:13px}
.trainer-category-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}
.trainer-category{position:relative;display:grid;grid-template-columns:42px 1fr auto;grid-template-rows:auto auto;text-align:left;justify-content:stretch;padding:14px 12px;min-height:82px;border-radius:14px}
.trainer-category[aria-pressed=true]{background:var(--msp-accent-soft);border-color:var(--msp-accent);box-shadow:inset 3px 0 var(--msp-accent)}
.trainer-category-icon{grid-row:1/3;display:grid;place-items:center;width:34px;height:34px;margin:auto 8px auto 0;border-radius:10px;background:var(--msp-bg);font-size:20px;color:var(--msp-accent-text)}
.trainer-category strong{align-self:end;font-size:15px}
.trainer-category small{align-self:start;font-size:11px;color:var(--msp-muted)}
.trainer-check{grid-column:3;grid-row:1/3;align-self:center;display:grid;place-items:center;width:23px;height:23px;border:1.5px solid var(--msp-edge);border-radius:6px;color:var(--msp-accent-text);font-weight:900}
.trainer-formula-chips{display:flex;gap:8px;margin-top:14px;overflow-x:auto;padding-bottom:4px;scrollbar-width:thin}
.trainer-formula-chips button{flex:0 0 auto;border-radius:999px;padding:9px 14px;min-height:40px;font-size:13px}
.trainer-formula-chips button[aria-pressed=true]{background:var(--msp-accent);border-color:var(--msp-accent);color:var(--msp-on-accent)}
.trainer-stage{padding:26px}
.trainer-meta{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.trainer-meta span{font-size:12px;color:var(--msp-muted)}
.trainer-meta span:last-child{margin-left:auto}
.trainer-meta strong{font-size:18px}
.trainer-stage>.math{margin:18px 0;padding:18px;border-radius:12px;background:var(--msp-bg);font-size:22px;text-align:center}
.trainer-stage .question{margin:0;padding:0;border:0;background:transparent}
.trainer-stage .question legend{font-size:18px;line-height:1.75}
.trainer-stage .question>.fineprint{margin-bottom:14px}
.trainer-stage .option{background:var(--msp-bg);border-color:transparent}
.trainer-stage .option:has(input:checked){background:var(--msp-accent-soft);box-shadow:inset 3px 0 var(--msp-accent)}
.trainer-stage .question>.actions button:nth-child(2){display:none}
.trainer-stage .application-steps{display:none}
.trainer-stage .question-result{margin-top:14px}
.trainer-next{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-top:18px;padding:16px;border-radius:12px;background:var(--msp-accent-soft)}
.trainer-next p{margin:0;font-weight:700}
@media(max-width:720px){body.trainer-mode .page{padding:10px 10px 88px}.trainer-shell{gap:12px}.trainer-head{min-height:62px;padding:8px 10px;border-radius:14px;grid-template-columns:1fr auto 1fr}.trainer-title{font-size:17px}.trainer-mark{width:30px;height:30px;font-size:19px}.trainer-exit{font-size:0;padding:8px}.trainer-exit:before{content:'←';font-size:22px}.trainer-count{font-size:10px}.trainer-categories,.trainer-formula-strip,.trainer-stage{padding:16px;border-radius:14px}.trainer-category-grid{grid-template-columns:1fr 1fr;gap:8px}.trainer-category{min-height:72px;padding:10px 8px;grid-template-columns:34px 1fr auto}.trainer-category-icon{width:28px;height:28px;font-size:17px}.trainer-category strong{font-size:14px}.trainer-stage{padding:18px 14px}.trainer-meta strong{width:100%;order:-1}.trainer-meta span:last-child{margin-left:0}.trainer-stage>.math{font-size:19px;padding:15px 7px}.trainer-stage .question legend{font-size:16px}.trainer-next{align-items:stretch;flex-direction:column}.trainer-next button{width:100%}}
@media(max-width:360px){.trainer-category-grid{grid-template-columns:1fr}.trainer-category{min-height:64px}.trainer-count{display:none}}
/* 全屏训练器 v2：范围多选页 → 单题满屏页。 */
body.trainer-mode>.msp-bottom-nav{display:none!important}
body.trainer-mode .page{max-width:none;width:100%;min-height:100vh;padding:0;background:var(--msp-bg)}
body.trainer-mode #content{min-height:100vh}
body.trainer-mode .trainer-shell{width:100%;min-height:100vh;display:flex;flex-direction:column;gap:0}
/* 顶部只留一点点呼吸位，不再用 margin-top:auto 把整块压到屏幕中间——
那样 900px 高的桌面屏会在标题上方空出 360px 死白。多出来的空间自然落到网格下方。 */
body.trainer-mode .trainer-categories{width:min(760px,calc(100% - 32px));margin:clamp(12px,3vh,40px) auto 0;padding:20px 28px 28px;border:0;box-shadow:none;background:transparent}
body.trainer-mode .trainer-categories>h1{text-align:center;font-size:clamp(24px,4vw,36px)}
body.trainer-mode .trainer-categories>p{text-align:center;margin:10px 0 26px;color:var(--msp-muted)}
body.trainer-mode .trainer-category-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
body.trainer-mode .trainer-category{min-height:92px;background:var(--msp-surface);border-color:var(--msp-line);box-shadow:0 8px 24px #17171a0a}
body.trainer-mode .trainer-category[aria-pressed=true]{background:var(--msp-accent-soft);border-color:var(--msp-accent);box-shadow:inset 3px 0 var(--msp-accent),0 8px 24px #17171a0a}
/* 标题贴顶后，剩余高度让「开始训练」留在屏幕底部，空白落在网格与按钮之间，
而不是堆在标题上方（sticky 只在内容超出一屏时生效，平铺时得靠 margin-top:auto 顶到底）。 */
body.trainer-mode .trainer-start-bar{position:sticky;bottom:0;width:min(760px,100%);margin:auto auto 0;padding:20px max(16px,env(safe-area-inset-left)) calc(20px + env(safe-area-inset-bottom));background:linear-gradient(180deg,transparent,var(--msp-bg) 24%)}
body.trainer-mode .trainer-start{width:100%;min-height:58px;border-radius:16px;font-size:18px}
body.trainer-question-mode{overflow:hidden}
body.trainer-question-mode .trainer-shell{justify-content:stretch}
/* 高度必须扣掉 sticky 顶栏（.rail 固定 64px）：stage 是从 y=64 才开始的一屏，
写死 100vh 会让底部 64px 连同第 4 行「下一题」按钮被 body{overflow:hidden} 直接裁掉，
用户看到的就是「没有下一题按钮」（页面根本滚不到，overflow:hidden 已禁止滚动）。 */
body.trainer-question-mode .trainer-stage{width:100%;height:calc(100vh - 64px);min-height:calc(100vh - 64px);margin:0;padding:20px clamp(16px,4vw,54px) max(20px,env(safe-area-inset-bottom));border:0;border-radius:0;box-shadow:none;background:var(--msp-bg);display:grid;grid-template-rows:auto 8px minmax(0,1fr) auto;gap:18px}
body.trainer-question-mode .trainer-question-head{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:48px}
body.trainer-question-mode .trainer-back{padding:8px 12px;background:transparent;border-color:transparent}
body.trainer-question-mode .trainer-question-head strong{font-size:17px;font-variant-numeric:tabular-nums}
body.trainer-question-mode .trainer-progress{height:8px;border-radius:999px;background:var(--msp-surface);overflow:hidden;box-shadow:inset 0 0 0 1px var(--msp-line)}
body.trainer-question-mode .trainer-progress i{display:block;height:100%;border-radius:inherit;background:var(--msp-accent);transition:width .2s}
body.trainer-question-mode .trainer-question-card{width:min(920px,100%);min-height:0;margin:0 auto;padding:0;border-radius:24px;background:transparent;box-shadow:none;overflow:auto;perspective:1400px;align-self:stretch}
body.trainer-question-mode .trainer-card-inner{display:grid;min-height:100%;transform-style:preserve-3d;transition:transform .58s cubic-bezier(.2,.72,.2,1)}
body.trainer-question-mode .trainer-question-card.is-flipped .trainer-card-inner{transform:rotateY(180deg)}
body.trainer-question-mode .trainer-card-face{grid-area:1/1;padding:clamp(22px,4vh,44px);border-radius:24px;background:var(--msp-surface);box-shadow:0 12px 38px #17171a10;backface-visibility:hidden;-webkit-backface-visibility:hidden}
body.trainer-question-mode .trainer-card-back{display:flex;min-height:100%;flex-direction:column;align-items:center;justify-content:flex-start;text-align:center;transform:rotateY(180deg)}
/* 翻面动画跑完（JS 在 620ms 后加 .is-settled）后题面已转到背面，让它退出布局高度计算。
此前正反两面共占同一网格行，卡片会被题面撑到 975px（格子只有 706px），答案被
margin:auto 顶到中间 → 卡片顶部空出 185px「一大块空白」，卡片变高还会继续往下挤。 */
body.trainer-question-mode .trainer-question-card.is-settled .trainer-card-front{position:absolute;inset:0;overflow:auto;pointer-events:none}
body.trainer-question-mode .trainer-question-card.is-settled .trainer-card-inner{min-height:0}
/* 垂直居中交给内层的 margin:auto，内容再长也只是正常滚动，不会把顶部裁掉滚不回来 */
body.trainer-question-mode .trainer-answer-inner{width:100%;max-width:920px;margin:auto;display:flex;flex-direction:column;align-items:center}
body.trainer-question-mode .trainer-question-category{display:block;text-align:center;color:var(--msp-muted);font-size:12px}
body.trainer-question-mode .trainer-card-front>h1{text-align:center;font-size:clamp(24px,4vw,36px);margin:8px 0 20px}
body.trainer-question-mode .trainer-card-front>.math{margin:0 0 24px;padding:18px;border-radius:14px;background:var(--msp-bg);font-size:clamp(20px,3vw,30px);text-align:center}
body.trainer-question-mode .trainer-question-card .question{margin:0;padding:0;border:0;background:transparent}
body.trainer-question-mode .trainer-answer-kicker{color:var(--msp-accent-text);font-size:13px;font-weight:800;letter-spacing:.08em}
body.trainer-question-mode .trainer-card-back h2{margin:12px 0 18px;font-size:clamp(25px,4vw,40px)}
body.trainer-question-mode .trainer-answer-value{max-width:720px;margin:0;padding:16px 20px;border-radius:14px;background:var(--msp-accent-soft);color:var(--msp-accent-text);font-size:clamp(18px,2.7vw,25px);font-weight:800;line-height:1.6;white-space:pre-line}
body.trainer-question-mode .trainer-answer-explanation{max-width:720px;margin:22px 0 0;color:var(--msp-muted);font-size:16px;line-height:1.8;white-space:pre-line}
/* 答案面题面回放：题面与选项按左对齐读，比居中大字更适合逐条核对。
整块给出「正确答案 / 你的选择」两个标记，答错时也能看清自己选了哪条。 */
body.trainer-question-mode .trainer-answer-recap{width:100%;max-width:720px;margin:16px 0 4px;padding:16px 18px;border-radius:14px;background:var(--msp-bg);box-shadow:inset 0 0 0 1px var(--msp-line);text-align:left}
body.trainer-question-mode .trainer-answer-label{display:block;margin-bottom:8px;color:var(--msp-muted);font-size:11px;font-weight:800;letter-spacing:.1em}
body.trainer-question-mode .trainer-answer-prompt{margin:0 0 12px;font-size:16px;font-weight:700;line-height:1.7}
body.trainer-question-mode .trainer-answer-options{margin:0;padding:0;list-style:none;display:flex;flex-direction:column;gap:8px}
body.trainer-question-mode .trainer-answer-option{display:flex;align-items:baseline;gap:10px;padding:9px 12px;border-radius:10px;background:var(--msp-surface);font-size:14px;line-height:1.6}
body.trainer-question-mode .trainer-answer-option>b{flex:0 0 auto;font-weight:800;font-variant-numeric:tabular-nums}
body.trainer-question-mode .trainer-answer-option>span{flex:1 1 auto;min-width:0}
body.trainer-question-mode .trainer-answer-option.is-correct{background:var(--msp-accent-soft);color:var(--msp-accent-text);box-shadow:inset 0 0 0 1px var(--msp-accent)}
body.trainer-question-mode .trainer-answer-tag{flex:0 0 auto;padding:2px 8px;border-radius:999px;background:var(--msp-accent);color:#fff;font-size:11px;font-style:normal;font-weight:800}
body.trainer-question-mode .trainer-answer-option.is-correct .trainer-answer-tag{background:var(--msp-accent-text);color:var(--msp-accent-soft)}
body.trainer-question-mode .trainer-answer-tag.is-miss{background:transparent;color:var(--msp-muted);box-shadow:inset 0 0 0 1px var(--msp-line)}
body.trainer-question-mode .trainer-answer-miss{margin:10px 0 0;font-size:13px;line-height:1.7}
body.trainer-question-mode .trainer-answer-title{margin:18px 0 12px!important;font-size:clamp(18px,2.4vw,22px)!important}
body.trainer-question-mode .trainer-question-card .question legend{text-align:center;font-size:clamp(18px,2.5vw,24px);line-height:1.65;margin-bottom:16px}
body.trainer-question-mode .trainer-question-card .option{max-width:760px;margin:10px auto;background:var(--msp-bg);font-size:16px}
body.trainer-question-mode .trainer-question-card .actions{justify-content:center}
body.trainer-question-mode .trainer-question-card .actions button:nth-child(2){display:none}
body.trainer-question-mode .trainer-question-card .application-steps{display:none}
body.trainer-question-mode .trainer-next{width:min(920px,100%);margin:0 auto;padding:0;background:transparent;align-self:end}
body.trainer-question-mode .trainer-next button{width:100%;min-height:56px;border-radius:16px;font-size:17px}
@media(max-height:560px){body.trainer-question-mode .trainer-stage{gap:10px;padding-top:12px}body.trainer-question-mode .trainer-question-head{min-height:40px}body.trainer-question-mode .trainer-next button{min-height:48px;font-size:16px}}
@media(max-width:720px){body.trainer-mode .trainer-categories{width:100%;padding:24px 14px 12px}body.trainer-mode .trainer-category-grid{grid-template-columns:1fr 1fr;gap:8px}body.trainer-mode .trainer-category{min-height:78px}body.trainer-question-mode .trainer-stage{padding:10px 10px calc(12px + env(safe-area-inset-bottom));gap:10px}body.trainer-question-mode .trainer-card-face{padding:20px 14px;border-radius:18px}body.trainer-question-mode .trainer-card-front>.math{font-size:20px;padding:14px 6px;margin-bottom:16px}body.trainer-question-mode .trainer-question-card .question legend{font-size:17px}body.trainer-question-mode .trainer-question-card .option{padding:11px;font-size:14px;margin:7px auto}body.trainer-question-mode .trainer-question-card .actions{margin-top:14px}body.trainer-question-mode .trainer-answer-explanation{font-size:14px;line-height:1.7}body.trainer-question-mode .trainer-answer-recap{padding:12px 12px}body.trainer-question-mode .trainer-answer-prompt{font-size:15px}body.trainer-question-mode .trainer-answer-option{flex-wrap:wrap;gap:6px;font-size:13px}body.trainer-question-mode .trainer-answer-option>span{flex:1 1 100%}body.trainer-question-mode .trainer-answer-tag{margin-left:auto}}
@media(max-width:380px){body.trainer-mode .trainer-category-grid{grid-template-columns:1fr}body.trainer-mode .trainer-categories>p{margin-bottom:16px}body.trainer-mode .trainer-category{min-height:66px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation:none!important;transition:none!important}button:active:not(:disabled){transform:none!important}}