/* Neo-Brutalism. Local fonts, flat ink, paper, yellow and blue only. */
:root{--paper:#FBF3E4;--grid:#EADFCB;--ink:#111111;--yellow:#FFD84D;--blue:#8EC5FF;--stroke:2.5px solid var(--ink);--radius:12px;--shadow:6px 6px 0 var(--ink);--snap:cubic-bezier(.34,1.56,.64,1)}
*{box-sizing:border-box}
[hidden]{display:none!important}
html{scroll-behavior:auto}
body{margin:0;color:var(--ink);background-color:var(--paper);background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);background-size:24px 24px;font-family:"Noto Sans CJK SC","Microsoft YaHei","PingFang SC",system-ui,sans-serif;font-size:16px;line-height:1.7;-webkit-font-smoothing:antialiased}
button,a{-webkit-tap-highlight-color:transparent}
button{font:inherit;color:inherit;cursor:pointer;touch-action:manipulation}
a{color:inherit;text-underline-offset:4px}
button:focus-visible,a:focus-visible{outline:3px solid var(--ink);outline-offset:5px}
button:disabled{cursor:default;box-shadow:none!important;transform:none!important;opacity:.45}
h1,h2,h3,p{margin-top:0}
h1,h2,h3{font-weight:900;line-height:1.35}
.site-header{max-width:1232px;margin:auto;padding:25px 36px;display:flex;align-items:center;justify-content:space-between;gap:20px;border-bottom:var(--stroke)}
.brand{display:flex;align-items:center;gap:12px;color:var(--ink);text-decoration:none}
.brand-mark{width:38px;height:38px;display:grid;place-items:center;background:var(--yellow);border:var(--stroke);border-radius:8px;box-shadow:3px 3px 0 var(--ink)}
.brand-mark svg{width:22px;height:22px}
.brand-name{font-size:20px;font-weight:900;letter-spacing:-.03em}
.source-link{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:8px 16px;min-height:44px;border:var(--stroke);border-radius:var(--radius);background:var(--paper);box-shadow:4px 4px 0 var(--ink);font-size:13px;font-weight:800;text-decoration:none}
.shell{width:min(1160px,calc(100% - 72px));margin:auto}
.intro{display:flex;align-items:center;gap:32px;padding:34px 0 30px}
.hero-number{font-size:142px;font-weight:900;line-height:1;letter-spacing:-.09em;font-variant-numeric:tabular-nums;flex-shrink:0;position:relative;isolation:isolate;padding-right:6px}
.hero-number::after{content:"";position:absolute;bottom:9px;left:0;right:0;height:32px;background:var(--yellow);z-index:-1;transform:rotate(-3deg)}
.intro-title{min-width:0}
.eyebrow{font-size:12px;font-weight:900;letter-spacing:.12em;margin-bottom:10px;text-transform:uppercase}
h1{font-size:clamp(29px,3.2vw,44px);letter-spacing:-.05em;margin-bottom:12px}
.intro-copy{font-size:15px;font-weight:500;line-height:1.8;margin-bottom:0;max-width:760px}
.topic-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:23px}
.topic-card{position:relative;display:flex;flex-direction:column;align-items:flex-start;min-width:0;min-height:215px;padding:21px 23px 17px;text-align:left;border:var(--stroke);border-radius:var(--radius);background:var(--paper);box-shadow:var(--shadow)}
.card-index{position:absolute;right:20px;top:16px;font-size:17px;font-weight:900;line-height:1.4;font-variant-numeric:tabular-nums}
.card-icon{width:42px;height:42px;display:grid;place-items:center;background:var(--yellow);border:var(--stroke);border-radius:8px;margin-bottom:12px}
.card-icon svg{width:24px;height:24px;display:block;stroke-width:2}
.topic-card h2{font-size:23px;letter-spacing:-.035em;margin-bottom:5px}
.card-summary{font-size:14px;line-height:1.65;margin-bottom:17px;font-weight:500}
.card-bottom{display:flex;align-items:center;justify-content:space-between;gap:12px;width:100%;margin-top:auto;font-size:12px;font-weight:700}
.arrow{display:grid;place-items:center;width:29px;height:29px;border:2px solid var(--ink);border-radius:7px;background:var(--paper);font-size:19px;font-weight:900;line-height:1}
.arrow svg{width:17px;height:17px;stroke-width:2.5}
.topic-card:first-child{background:var(--yellow)}
.topic-card:first-child .card-icon{background:var(--paper)}
.topic-card,.source-link,.back-button,.subtopic-button,.prev-next,.dialog-close{transition:transform 180ms var(--snap),box-shadow 180ms var(--snap),background-color 120ms linear}
@media(hover:hover){.topic-card:hover,.source-link:hover,.back-button:hover,.subtopic-button:hover,.prev-next:hover:not(:disabled),.dialog-close:hover{transform:translate(-2px,-2px);box-shadow:8px 8px 0 var(--ink)}.topic-card:hover .arrow{background:var(--yellow)}}
.topic-card:active,.source-link:active,.back-button:active,.subtopic-button:active,.prev-next:active:not(:disabled),.dialog-close:active{transform:translate(5px,5px);box-shadow:1px 1px 0 var(--ink);transition-duration:120ms}
.overview-footer{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:10px;margin:26px 0 0;font-size:13px;font-weight:600}
.overview-footer p{margin:0}
.back-button{display:inline-flex;align-items:center;gap:9px;min-height:44px;margin:26px 0 25px;padding:8px 15px;border:var(--stroke);border-radius:var(--radius);box-shadow:4px 4px 0 var(--ink);background:var(--paper);font-size:14px;font-weight:800}
.back-button svg{width:18px;height:18px}
.detail-heading{max-width:880px;padding-bottom:26px}
.detail-heading h1{margin-bottom:10px}
.detail-heading .eyebrow{display:inline-block;background:var(--yellow);border:2px solid var(--ink);padding:3px 8px;transform:rotate(-1deg)}
.detail-intro{font-size:16px;line-height:1.8;margin-bottom:0}
.detail-layout{display:grid;grid-template-columns:296px minmax(0,1fr);gap:27px;align-items:start}
.subtopic-list{display:grid;gap:17px;position:sticky;top:25px}
.subtopic-button{position:relative;min-height:109px;padding:20px 16px 18px 54px;text-align:left;background:var(--paper);border:var(--stroke);border-radius:var(--radius);box-shadow:4px 4px 0 var(--ink)}
.subtopic-button .step{position:absolute;left:15px;top:21px;width:25px;height:25px;display:grid;place-items:center;border:2px solid var(--ink);border-radius:6px;font-size:12px;font-weight:900;line-height:1;background:var(--paper)}
.subtopic-button h2{font-size:17px;margin:0 0 5px;line-height:1.5}
.subtopic-button p{font-size:13px;line-height:1.65;margin:0}
.subtopic-button[aria-pressed="true"]{background:var(--yellow);transform:translate(3px,3px);box-shadow:1px 1px 0 var(--ink)}
.subtopic-button[aria-pressed="true"] .step{color:var(--paper);background:var(--ink)}
.lesson-panel{min-width:0;padding:30px 33px 24px;border:var(--stroke);border-radius:var(--radius);box-shadow:var(--shadow);background:var(--paper)}
.lesson-label{display:inline-block;background:var(--yellow);border:2px solid var(--ink);padding:3px 9px;font-size:12px;font-weight:900;letter-spacing:.08em;margin-bottom:14px}
.lesson-title{font-size:clamp(24px,2.3vw,31px);line-height:1.45;letter-spacing:-.04em;margin-bottom:12px}
.lesson-summary{font-size:17px;line-height:1.8;font-weight:600;margin-bottom:24px}
.lesson-section{margin-top:24px}
.lesson-section h3{font-size:15px;margin:0 0 10px;line-height:1.5;display:flex;align-items:center;gap:9px}
.lesson-section h3::before{content:"";width:8px;height:8px;background:var(--ink);display:inline-block;flex-shrink:0}
.lesson-section p{font-size:16px;line-height:1.9;margin-bottom:0;overflow-wrap:anywhere}
.case-box{background:var(--blue);border:var(--stroke);border-radius:var(--radius);padding:18px 20px;box-shadow:3px 3px 0 var(--ink)}
.lesson-section:last-of-type:not(.case-box){border-top:2px solid var(--ink);padding-top:19px}
.lesson-nav{display:flex;justify-content:space-between;gap:14px;border-top:2px solid var(--ink);padding-top:19px;margin-top:28px}
.prev-next{min-height:44px;padding:8px 14px;background:var(--yellow);border:var(--stroke);border-radius:10px;box-shadow:3px 3px 0 var(--ink);font-size:13px;font-weight:800}
.detail-footer{font-size:13px;padding-top:23px}
.page-footer{max-width:1160px;margin:35px auto 0;padding:19px 0 25px;border-top:var(--stroke);font-size:12px;font-weight:600}
dialog{width:min(570px,calc(100% - 36px));max-height:calc(100vh - 48px);padding:35px;background:var(--paper);color:var(--ink);border:var(--stroke);border-radius:var(--radius);box-shadow:8px 8px 0 var(--ink)}
dialog::backdrop{background:#11111180}
dialog h2{font-size:26px;margin:15px 0}
dialog p{font-size:15px;line-height:1.85}
dialog a{overflow-wrap:anywhere}
.dialog-close{position:absolute;top:12px;right:14px;min-width:44px;min-height:44px;display:grid;place-items:center;border:var(--stroke);border-radius:9px;box-shadow:3px 3px 0 var(--ink);background:var(--yellow);font-size:22px;font-weight:900}
@media(max-width:1000px){.shell{width:calc(100% - 48px)}.site-header{padding:22px 24px}.intro{gap:25px}.hero-number{font-size:128px}.topic-grid{gap:19px}.topic-card{padding:19px;min-height:221px}.card-index{right:17px}.topic-card h2{font-size:21px}.detail-layout{grid-template-columns:245px minmax(0,1fr);gap:23px}.lesson-panel{padding:25px}.page-footer{margin-left:24px;margin-right:24px}}
@media(max-width:760px){.topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.intro{padding:29px 0;gap:20px}.hero-number{font-size:120px}h1{font-size:30px}.intro-copy{font-size:14px}.detail-layout{grid-template-columns:1fr}.subtopic-list{position:static;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.subtopic-button{padding:13px 10px;min-height:110px}.subtopic-button .step{position:static;margin-bottom:9px}.subtopic-button h2{font-size:14px;margin-bottom:0}.subtopic-button p{display:none}.detail-heading{padding-bottom:22px}}
@media(max-width:480px){.shell{width:calc(100% - 36px)}.site-header{padding:16px 18px;gap:10px}.brand{gap:9px}.brand-name{font-size:17px}.brand-mark{width:31px;height:31px}.source-link{font-size:11px;padding:6px 10px}.intro{position:relative;display:block;padding:25px 0 24px}.hero-number{display:block;font-size:120px;margin-bottom:16px;width:max-content}.intro-title h1{font-size:30px}.intro-copy{font-size:14px}.eyebrow{font-size:11px}.topic-grid{grid-template-columns:1fr;gap:18px}.topic-card{min-height:148px;padding:19px 18px 15px 77px}.card-icon{position:absolute;left:18px;top:23px;width:40px;height:40px}.card-index{font-size:12px;top:15px;right:15px}.topic-card h2{padding-right:19px;font-size:21px}.card-summary{font-size:13px;margin-bottom:11px}.card-bottom{font-size:11px}.arrow{width:26px;height:26px}.detail-intro{font-size:15px}.lesson-panel{padding:22px 18px}.lesson-summary{font-size:16px}.lesson-section p{font-size:15px}.case-box{padding:16px}.lesson-nav{gap:10px}.prev-next{padding:8px 10px;font-size:12px}.page-footer{margin-left:18px;margin-right:18px}.subtopic-list{gap:10px}.subtopic-button{padding:12px 9px}.subtopic-button h2{font-size:13px}dialog{padding:30px 22px}}
/* Keep every actual control on the reference's 12px / 6px system. */
.source-link,.back-button,.subtopic-button,.prev-next,.dialog-close{border:var(--stroke);border-radius:var(--radius);box-shadow:var(--shadow)}
.case-box{box-shadow:var(--shadow)}
.subtopic-button[aria-pressed="true"]{transform:none;box-shadow:var(--shadow)}
.detail-footer,.page-footer{display:flex;flex-wrap:wrap;justify-content:space-between;gap:12px}
#lesson-boundary summary{cursor:pointer;font-size:14px;font-weight:800}
#source-dialog>a{display:block;margin-top:14px}
.intro-text{min-width:0}
@media(hover:hover){.source-link:hover,.back-button:hover,.subtopic-button:hover,.prev-next:hover:not(:disabled),.dialog-close:hover{transform:translate(-2px,-2px);box-shadow:8px 8px 0 var(--ink)}}
.topic-card:active,.source-link:active,.back-button:active,.subtopic-button:active,.prev-next:active:not(:disabled),.dialog-close:active{transform:translate(6px,6px);box-shadow:0 0 0 var(--ink)}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important}html{scroll-behavior:auto}.topic-card:hover,.source-link:hover,.back-button:hover,.subtopic-button:hover,.prev-next:hover,.dialog-close:hover,.topic-card:active,.source-link:active,.back-button:active,.subtopic-button:active,.prev-next:active,.dialog-close:active{transform:none}}

/* Full-text reader: additive styles; source wording stays in HTML/JS. */
.collection-nav{display:flex;flex-wrap:wrap;align-items:center;gap:18px;margin:0 0 29px;padding:0 6px 6px 0}
.collection-button{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:48px;max-width:100%;padding:10px 18px;border:var(--stroke);border-radius:12px;background:var(--yellow);box-shadow:6px 6px 0 var(--ink);color:var(--ink);font-weight:900;font-size:14px;line-height:1.5;text-align:left;overflow-wrap:anywhere;transition:transform 180ms var(--snap),box-shadow 180ms var(--snap),background-color 120ms linear}
.collection-count{display:inline-grid;place-items:center;min-width:26px;min-height:26px;padding:1px 6px;border:2px solid var(--ink);border-radius:6px;background:var(--paper);font-size:12px;line-height:1.3;font-weight:900;font-variant-numeric:tabular-nums}
.rich-article.article-content,.source-article{min-width:0;max-width:100%;color:var(--ink);font-size:17px;line-height:1.9;overflow-wrap:anywhere;word-break:normal}
.rich-article.article-content h2,.source-article h2{font-size:26px;line-height:1.5;margin:35px 0 17px;letter-spacing:-.025em}
.rich-article.article-content h3,.source-article h3{font-size:21px;line-height:1.6;margin:27px 0 12px}
.rich-article.article-content h4,.source-article h4{font-size:18px;line-height:1.65;margin:23px 0 10px}
.rich-article.article-content p,.source-article p{font-size:inherit;line-height:inherit;margin:0 0 17px}
.rich-article.article-content>:first-child,.source-article>:first-child{margin-top:0}
.rich-article.article-content ul,.rich-article.article-content ol,.source-article ul,.source-article ol{padding-left:1.55em;margin:12px 0 22px}
.rich-article.article-content li,.source-article li{padding-left:.15em;margin-bottom:9px}
.rich-article.article-content li>p,.source-article li>p{margin-bottom:9px}
.rich-article.article-content strong,.source-article strong{font-weight:900}
.rich-article.article-content blockquote,.source-article blockquote{margin:21px 0;padding:13px 18px;border-left:4px solid var(--ink);background:var(--yellow)}
.rich-article.article-content blockquote p:last-child,.source-article blockquote p:last-child{margin-bottom:0}
.rich-article.article-content hr,.source-article hr{border:0;border-top:2px solid var(--ink);margin:29px 0}
.rich-article.article-content a,.source-article a{text-decoration-thickness:1.5px;overflow-wrap:anywhere}
.rich-article.article-content pre,.source-article pre{white-space:pre-wrap;overflow-wrap:anywhere;max-width:100%;font-size:.9em}
.article-block{min-width:0;padding:25px 0;border-bottom:2px solid var(--ink)}
.article-block:first-child{padding-top:0}
.article-block:last-child{border-bottom:0;padding-bottom:0}
.table-wrap{display:block;width:100%;max-width:100%;min-width:0;overflow-x:auto;overscroll-behavior-x:contain;margin:20px 0 25px;padding-bottom:5px;-webkit-overflow-scrolling:touch}
.rich-article table,.source-article table{width:100%;min-width:0;max-width:100%;table-layout:fixed;border-collapse:collapse;border:2px solid var(--ink);font-size:15px;line-height:1.75;margin:20px 0}
.table-wrap table{margin:0}
.rich-article th,.rich-article td,.source-article th,.source-article td{min-width:0;border:1.5px solid var(--ink);padding:11px 12px;text-align:left;vertical-align:top;white-space:normal;overflow-wrap:anywhere;word-break:normal}
.rich-article th:first-child:nth-last-child(2){width:26%}
.rich-article th,.source-article th{background:var(--yellow);font-weight:900}
.rich-article td,.source-article td{background:var(--paper)}
.source-pair{min-width:0;margin:23px 0;padding:19px 21px;border:var(--stroke);border-radius:12px;background:var(--blue)}
.source-label{display:inline-block;max-width:100%;padding:3px 8px;margin:0 0 11px;background:var(--yellow);border:2px solid var(--ink);border-radius:5px;font-size:12px;font-weight:900;line-height:1.6;letter-spacing:.04em}
.source-pair p:last-child{margin-bottom:0}
.reading-note{max-width:100%;font-size:13px!important;line-height:1.8!important;margin:14px 0 22px;padding-left:12px;border-left:3px solid var(--ink);overflow-wrap:anywhere}
dialog#archive-dialog.archive-drawer{width:min(1120px,calc(100% - 36px));max-width:calc(100% - 36px);height:auto;max-height:calc(100vh - 32px);max-height:calc(100dvh - 32px);margin:auto;padding:0;border:var(--stroke);border-radius:12px;box-shadow:8px 8px 0 var(--ink);overflow-x:hidden;overflow-y:auto;background:var(--paper);scrollbar-gutter:stable;overscroll-behavior:contain}
.archive-header{position:sticky;top:0;z-index:3;display:flex;align-items:center;justify-content:space-between;gap:18px;padding:20px 27px;border-bottom:var(--stroke);background:var(--yellow)}
.archive-header h2{min-width:0;margin:0;font-size:25px;line-height:1.5;overflow-wrap:anywhere}
.archive-header p{margin:4px 0 0;font-size:13px;line-height:1.6}
.archive-header .dialog-close{position:static;flex-shrink:0;background:var(--paper)}
.reading-layout{display:grid;grid-template-columns:220px minmax(0,1fr);align-items:start;gap:30px;min-width:0;padding:28px}
.archive-nav{position:sticky;top:109px;display:flex;flex-direction:column;gap:13px;min-width:0;padding:0 5px 5px 0;max-height:calc(100dvh - 165px);overflow-y:auto}
.archive-tab{display:block;width:100%;min-width:0;min-height:46px;padding:11px 13px;text-align:left;white-space:normal;overflow-wrap:anywhere;border:var(--stroke);border-radius:12px;background:var(--paper);box-shadow:var(--shadow);font-size:14px;font-weight:800;line-height:1.6;transition:transform 180ms var(--snap),box-shadow 180ms var(--snap),background-color 120ms linear}
.archive-tab[aria-selected="true"],.archive-tab[aria-pressed="true"],.archive-tab.active{background:var(--yellow);transform:none;box-shadow:var(--shadow)}
#archive-content{min-width:0;max-width:100%;scroll-margin-top:115px}
#archive-content:focus{outline:none}
@media(hover:hover){.collection-button:hover,.archive-tab:hover{transform:translate(-2px,-2px);box-shadow:8px 8px 0 var(--ink)}}
.collection-button:active,.archive-tab:active{transform:translate(6px,6px);box-shadow:0 0 0 var(--ink);transition-duration:120ms}
@media(max-width:759px){.reading-layout{grid-template-columns:minmax(0,1fr);gap:23px;padding:22px}.archive-nav{position:static;display:flex;flex-direction:row;flex-wrap:wrap;gap:12px;max-height:none;overflow:visible}.archive-tab{width:auto;flex:1 1 145px}.archive-header{padding:17px 22px}.archive-header h2{font-size:21px}.rich-article.article-content h2,.source-article h2{font-size:24px}.collection-nav{gap:15px}.collection-button{font-size:13px}#subtopic-list .subtopic-button{min-height:64px;padding:10px}#subtopic-list .step{display:none}}
@media(max-width:480px){dialog#archive-dialog.archive-drawer{width:calc(100% - 24px);max-width:calc(100% - 24px);max-height:calc(100dvh - 24px);box-shadow:5px 5px 0 var(--ink)}.archive-header{padding:14px;gap:10px}.archive-header h2{font-size:19px}.reading-layout{padding:18px 14px;gap:20px}.archive-tab{flex-basis:115px;padding:9px 10px;font-size:12px}.rich-article.article-content,.source-article{font-size:17px;line-height:1.9}.rich-article.article-content h2,.source-article h2{font-size:22px}.rich-article.article-content h3,.source-article h3{font-size:20px}.rich-article th,.rich-article td,.source-article th,.source-article td{padding:8px 7px;font-size:13px}.source-pair{padding:16px 14px}.collection-button{flex:1 1 190px;justify-content:space-between}.collection-nav{margin-bottom:25px}.reading-note{font-size:12px!important}}
@media(prefers-reduced-motion:reduce){.collection-button,.archive-tab{transition:none!important}.collection-button:hover,.archive-tab:hover,.collection-button:active,.archive-tab:active{transform:none}}

/* neo-brutalist-ui: SLAM reading panel and the skill's mechanical controls. */
.lesson-panel{--panel-x:33px;--panel-y:30px}
.panel-heading{margin:calc(-1 * var(--panel-y)) calc(-1 * var(--panel-x)) 26px;padding:22px var(--panel-x) 20px;background:var(--blue);border-bottom:var(--stroke);border-radius:calc(var(--radius) - 2.5px) calc(var(--radius) - 2.5px) 0 0}
.panel-heading .reading-note{margin-bottom:0}
.topic-card:first-child,.topic-card:first-child .card-icon{background:var(--paper)}
.topic-card.is-current{background:var(--yellow)}
:is(.topic-card,.source-link,.back-button,.subtopic-button,.prev-next,.dialog-close,.collection-button,.archive-tab){border:var(--stroke);border-radius:var(--radius);box-shadow:var(--shadow);transition:transform 180ms var(--snap),box-shadow 180ms var(--snap),background-color 120ms linear}
.subtopic-button[aria-pressed="true"],.archive-tab[aria-pressed="true"]{border-width:3px;background:var(--yellow)}
dialog,dialog#archive-dialog.archive-drawer{box-shadow:var(--shadow)}
.source-pair{box-shadow:var(--shadow)}
.source-pair summary{display:grid;grid-template-columns:24px minmax(0,1fr);align-items:center;gap:10px;min-height:44px;padding:10px 12px;list-style:none;cursor:pointer;border:var(--stroke);border-radius:var(--radius);background:var(--paper);box-shadow:var(--shadow);font-size:14px;font-weight:900;overflow-wrap:anywhere;transition:transform 180ms var(--snap),box-shadow 180ms var(--snap)}
.source-pair summary::-webkit-details-marker{display:none}
.source-pair summary::before{content:"+";font-size:24px;line-height:1;text-align:center}
.source-pair[open] summary{background:var(--yellow);margin-bottom:22px}
.source-pair[open] summary::before{content:"−"}
@media(hover:hover){:is(.topic-card,.source-link,.back-button,.subtopic-button,.prev-next,.dialog-close,.collection-button,.archive-tab):hover:not(:disabled),.source-pair summary:hover{transform:translate(-4px,-4px);box-shadow:10px 10px 0 var(--ink)}}
:is(.topic-card,.source-link,.back-button,.subtopic-button,.prev-next,.dialog-close,.collection-button,.archive-tab):active:not(:disabled),.source-pair summary:active{transform:translate(4px,4px);box-shadow:2px 2px 0 var(--ink);transition-duration:120ms}
@media(min-width:761px){.subtopic-list{max-height:calc(100dvh - 80px);overflow-y:auto;padding:4px 10px 10px 4px;scrollbar-gutter:stable}}
@media(max-width:1000px){.lesson-panel{--panel-x:25px;--panel-y:25px}}
@media(max-width:480px){.lesson-panel{--panel-x:18px;--panel-y:22px}.panel-heading{padding-top:18px;padding-bottom:16px}}
@media(prefers-reduced-motion:reduce){:is(.topic-card,.source-link,.back-button,.subtopic-button,.prev-next,.dialog-close,.collection-button,.archive-tab):hover,:is(.topic-card,.source-link,.back-button,.subtopic-button,.prev-next,.dialog-close,.collection-button,.archive-tab):active,.source-pair summary:hover,.source-pair summary:active{transform:none!important;transition:none!important}}

/* Original-video time chips: keep the article text, add a mechanical link. */
.video-time-link{display:inline-block;max-width:100%;min-height:44px;margin:3px 3px 6px;padding:5px 8px;background:var(--yellow);border:var(--stroke);border-radius:8px;box-shadow:3px 3px 0 var(--ink);font-weight:900;font-variant-numeric:tabular-nums;line-height:1.65;text-decoration:underline;text-underline-offset:3px;overflow-wrap:anywhere;vertical-align:baseline;transition:transform 180ms var(--snap),box-shadow 180ms var(--snap)}
@media(hover:hover){.video-time-link:hover{transform:translate(-2px,-2px);box-shadow:5px 5px 0 var(--ink)}}
.video-time-link:active{transform:translate(2px,2px);box-shadow:1px 1px 0 var(--ink);transition-duration:120ms}
@media(prefers-reduced-motion:reduce){.video-time-link{transition:none}.video-time-link:hover,.video-time-link:active{transform:none}}

/* STAMP: a printed circuit badge, personal reading receipt, reversible state. */
.archive-reading-main{min-width:0;max-width:100%}
@media(min-width:760px){.archive-nav{top:164px;max-height:calc(100dvh - 220px)}}
.read-pill{display:inline-block;margin-top:16px;padding:3px 9px;border:2px solid var(--ink);border-radius:6px;background:var(--paper);font-size:12px;line-height:1.6;font-weight:900}
.read-pill.is-read{background:#2FBF71}
.read-jump{min-height:44px;padding:8px 12px;border:var(--stroke);border-radius:var(--radius);box-shadow:var(--shadow);background:var(--yellow);text-align:left;transition:transform 180ms var(--snap),box-shadow 180ms var(--snap)}
.archive-header .read-pill{margin-top:8px}
.read-receipt{position:relative;display:grid;grid-template-columns:minmax(0,1fr) 174px;column-gap:20px;align-items:center;margin-top:32px;padding:24px;border:var(--stroke);border-radius:var(--radius);box-shadow:var(--shadow);background:var(--paper);min-width:0;scroll-margin:24px}
.read-receipt::before{content:"";position:absolute;top:-2.5px;left:20px;width:42px;height:7px;border:2px solid var(--ink);background:var(--yellow)}
.read-receipt.is-read::before{background:#2FBF71}
.receipt-copy{min-width:0}
.receipt-eyebrow{margin:0 0 10px;font-family:monospace;font-size:11px;font-weight:900;letter-spacing:.09em;line-height:1.7}
.receipt-copy h3{margin:0 0 10px;font-size:18px;line-height:1.55;overflow-wrap:anywhere}
.receipt-status{margin:0;font-size:13px;line-height:1.7;font-weight:600;overflow-wrap:anywhere}
.reading-stamp{grid-column:2;grid-row:1 / span 2;width:100%;max-width:174px;transform:rotate(-8deg);transform-origin:center;pointer-events:none}
.reading-stamp svg{display:block;width:100%;height:auto}
.receipt-actions{grid-column:1;margin-top:19px;min-width:0}
.read-action{display:inline-flex;align-items:center;justify-content:space-between;gap:16px;max-width:100%;min-height:48px;padding:10px 16px;box-shadow:var(--shadow);border:var(--stroke);border-radius:var(--radius);font-weight:900;font-size:14px;line-height:1.6;white-space:normal;text-align:left;transition:transform 180ms var(--snap),box-shadow 180ms var(--snap)}
.read-action span{font-family:monospace;font-size:21px;line-height:1}
.read-mark{background:var(--yellow)}
.read-undo{background:var(--paper)}
.receipt-storage{grid-column:1 / -1;margin:17px 0 0;font-size:11px;line-height:1.7}
.receipt-feedback{grid-column:1 / -1;font-size:13px;font-weight:700;line-height:1.7;margin:10px 0 0;overflow-wrap:anywhere}
.receipt-feedback:empty{display:none}
.topic-progress.has-progress{display:inline-block;padding:2px 6px;border:1.5px solid var(--ink);border-radius:4px;background:#2FBF71;line-height:1.5}
.group-read-state{position:absolute;right:9px;top:9px;display:grid;place-items:center;width:21px;height:21px;border:1.5px solid var(--ink);background:#2FBF71;font-size:13px;line-height:1;font-weight:900;border-radius:4px}
.subtopic-button:has(.group-read-state:not([hidden])) h2{padding-right:15px}
.archive-tab.has-read::after{content:"✓";display:inline-block;margin-left:8px;padding:0 4px;border:1.5px solid var(--ink);background:#2FBF71;line-height:1.3;font-size:12px}
@media(hover:hover){.read-action:hover,.read-jump:hover{transform:translate(-4px,-4px);box-shadow:10px 10px 0 var(--ink)}}
.read-action:active,.read-jump:active{transform:translate(4px,4px);box-shadow:2px 2px 0 var(--ink);transition-duration:120ms}
@media(max-width:480px){.read-receipt{padding:18px;grid-template-columns:minmax(0,1fr) 126px;gap:14px}.reading-stamp{grid-column:2;grid-row:2;width:126px;max-width:100%}.receipt-copy{grid-column:1 / -1}.receipt-actions{grid-column:1;grid-row:2;margin-top:0}.read-action{gap:8px;padding:9px 10px;font-size:13px}.receipt-storage{margin-top:0}.receipt-feedback{margin-top:0}.receipt-copy h3{font-size:17px}}
@media(max-width:360px){.read-receipt{grid-template-columns:minmax(0,1fr);gap:18px}.reading-stamp{grid-column:1;grid-row:2;width:156px;justify-self:center}.receipt-actions{grid-column:1;grid-row:3}.read-action{width:100%;justify-content:space-between}}
@media(prefers-reduced-motion:reduce){.read-action,.read-jump{transition:none}.read-action:hover,.read-action:active,.read-jump:hover,.read-jump:active{transform:none}}