/* AI foundations: use the original paper, stone, serif and editorial rhythm. */
.course-slide{background:var(--paper);color:var(--ink);padding-top:18px;font-family:var(--sans)}
.course-ribbon{border:0;border-bottom:1px solid var(--line);margin-bottom:24px;gap:16px;padding:0 0 12px}
.course-ribbon button{display:flex;align-items:center;gap:7px;min-width:0;padding:4px 0;border:0;background:none;flex:1;color:#777269}
.course-ribbon button[aria-current=true]{background:none;color:var(--ink)}.course-ribbon button[aria-current=true] b{border-bottom:1px solid var(--ink);padding-bottom:4px}
.course-ribbon span{font:400 15px/1 var(--serif);letter-spacing:0;color:#8d7b68}.course-ribbon b{font-size:11px;font-weight:400;line-height:1.6;margin:0;white-space:nowrap}
.course-slide .course-heading{margin-bottom:26px!important}.course-heading .kicker{font-size:11px;letter-spacing:.13em;margin:0 0 12px}.course-heading .kicker span{margin-left:18px;letter-spacing:.06em}
.course-slide .course-heading h1{font-family:var(--serif);font-size:clamp(34px,3.6vw,64px);font-weight:500;line-height:1.28;letter-spacing:-.055em;max-width:none}.course-slide .course-heading h1 em{display:inline;color:#8d7b68;font-style:normal}
.course-slide .course-heading .course-lead{font-size:clamp(16px,1.35vw,22px)!important;line-height:1.7!important;margin-top:14px;color:#68635a;max-width:65ch}
.course-editorial{display:grid;grid-template-columns:1fr 1.22fr;gap:clamp(30px,4vw,72px);align-items:start}
.course-concepts{display:flex;flex-direction:column;gap:0;margin:0!important}.course-concepts article{display:grid;grid-template-columns:36px 1fr;gap:16px;padding:18px 0;border:0;border-top:1px solid var(--line);background:none;min-width:0}.course-concepts article:first-child{padding-top:16px}
.course-point-number{font:400 27px/1.35 var(--serif);color:#a19585}.course-concepts h2{font:500 clamp(21px,1.9vw,30px)/1.45 var(--serif);margin:0 0 8px;letter-spacing:-.03em}.course-concepts p{font-size:clamp(16px,1.35vw,22px);line-height:1.75;color:#5c5952;margin:0}
.course-sample{min-width:0;border-top:1px solid var(--line);padding-top:16px}.course-sample:not(.has-photos){background:#e2ddd4;border:0;padding:clamp(24px,2.4vw,40px);min-height:300px;display:flex;align-items:center}.course-sample .collection-label{display:block;font-size:10px;letter-spacing:.12em;color:#83725f;margin-bottom:15px}.course-sample-copy>p{font-size:clamp(18px,1.6vw,26px);line-height:1.9;white-space:pre-line;text-wrap:pretty}.course-sample.has-photos .course-sample-copy{padding-top:15px}.course-sample.has-photos .collection-label{display:none}.course-sample.has-photos .course-sample-copy>p{font-size:clamp(15px,1.2vw,20px);line-height:1.75;color:#625a50}
.course-photo-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.course-photo-grid[data-count="1"]{grid-template-columns:1fr}.course-photo-grid[data-count="2"]{grid-template-columns:repeat(2,minmax(0,1fr))}.course-photo-grid figure{min-width:0}.course-photo-grid img{width:100%;height:clamp(190px,25vh,310px);object-fit:contain;background:#ded8cf}.course-photo-grid figcaption{font-size:11px;line-height:1.6;color:#776b5c;padding-top:8px}.course-photo-grid[data-count="1"] img{object-fit:contain}
.course-attention{display:flex;align-items:baseline;gap:18px;border-top:1px solid var(--line);margin:22px 0 8px;padding:14px 0;font-size:clamp(14px,1.15vw,18px);line-height:1.7;color:#62594d}.course-attention span{font-size:11px;color:#8d7b68;white-space:nowrap;letter-spacing:.08em}
.course-teach-more{display:flex;flex-wrap:wrap;gap:0 28px;border-top:1px solid var(--line)}.course-discuss,.course-explain,.course-tool-demo,.course-workshop{font-size:14px;line-height:1.8;padding:12px 0;border:0;margin:0!important}.course-teach-more details[open]{flex-basis:100%}.course-teach-more summary{cursor:pointer;min-height:26px;color:#6f5c47;font-weight:400}.course-teach-more details>p{margin-top:12px;color:#625c52;white-space:pre-line;max-width:85ch}.course-explain>p{font-size:17px;line-height:1.9}.course-footer{border-top:1px solid var(--line);margin-top:0!important;padding:12px 0;font-size:11px;gap:16px 26px}.course-footer button{border:0;border-bottom:1px solid var(--ink);background:none;color:var(--ink);font-size:12px;padding:6px 0;margin-left:auto}
.course-tool-tabs{display:flex;gap:12px;margin:12px 0}.course-tool-tabs button{background:none;border:1px solid var(--line);padding:10px 16px;color:var(--ink);font-size:15px}.course-tool-tabs button[aria-pressed=true]{background:var(--dark);color:var(--paper)}.course-tool-demo>strong{display:block;margin-top:12px;font-size:17px;font-weight:500}.course-tool-demo>p{font-size:17px}
.course-lab{background:transparent;padding:22px 0;border-top:1px solid var(--line)}.course-lab h2{font-family:var(--serif);font-weight:500}.course-lab>p,.course-prompt-grid label,.course-output-label,.course-cost-form label{font-size:16px;color:#625c52}.course-prompt-grid textarea,#course-prompt-output{font-size:16px;line-height:1.8}.course-checks label{font-size:17px}.course-checks input{width:18px;height:18px;accent-color:#80664d;flex:none}#course-cost-result{background:#e0dbd2;color:var(--ink)}#course-cost-result>b{font-family:var(--serif);color:var(--ink)}#course-cost-result>span{font-size:16px}.course-quiz button{font-size:15px}.course-quiz button[aria-pressed=true]{background:var(--dark);color:var(--paper)}
@media(min-width:1500px){.course-slide{padding-top:23px}.course-ribbon{margin-bottom:30px}.course-concepts article{padding:22px 0}.course-photo-grid img{height:clamp(230px,29vh,340px)}}
@media(max-width:1100px){.course-ribbon{gap:14px}.course-ribbon button{flex:none;min-width:105px}.course-editorial{gap:28px;grid-template-columns:1fr 1.1fr}.course-slide .course-heading h1{font-size:38px}.course-concepts article{gap:9px;grid-template-columns:28px 1fr}.course-concepts p{font-size:16px}.course-photo-grid{gap:8px}.course-photo-grid figcaption{font-size:10px}}
@media(max-width:760px){.course-slide{padding-top:16px}.course-ribbon{margin-bottom:22px}.course-ribbon button{min-width:112px}.course-slide .course-heading h1{font-size:clamp(29px,7.7vw,42px);line-height:1.35}.course-slide .course-heading h1 em{display:block}.course-slide .course-heading .course-lead{font-size:16px!important}.course-editorial{grid-template-columns:1fr;gap:22px}.course-concepts article{position:static;padding:15px 0;grid-template-columns:30px 1fr}.course-point-number{position:static;font-size:25px}.course-concepts h2{font-size:23px}.course-concepts p{font-size:17px}.course-sample:not(.has-photos){min-height:0;padding:23px}.course-sample-copy>p{font-size:18px}.course-photo-grid img{height:220px}.course-photo-grid[data-count="3"] img{height:170px}.course-photo-grid figcaption{font-size:10px}.course-sample.has-photos .course-sample-copy>p{font-size:16px}.course-attention{display:block;font-size:15px;margin-top:22px}.course-attention span{display:block;margin-bottom:7px}.course-teach-more{display:block}.course-footer{gap:12px}.course-footer span{width:auto}.course-footer button{margin-left:auto}.course-heading .kicker{font-size:10px}.course-heading .kicker span{margin-left:10px}}
@media(prefers-reduced-motion:reduce){.course-slide{animation:none}}

@media(min-width:761px){.course-slide{padding-bottom:14px}.course-ribbon{margin-bottom:18px;padding-bottom:8px}.course-slide .course-heading{margin-bottom:20px!important}.course-concepts article{padding:14px 0}.course-attention{margin-top:16px;padding:12px 0}}
@media(min-width:761px) and (max-height:820px){.course-ribbon{margin-bottom:14px;padding-bottom:5px}.course-slide .course-heading h1{font-size:clamp(32px,3.3vw,46px)}.course-slide .course-heading .course-lead{font-size:16px!important;margin-top:10px}.course-heading .kicker{margin-bottom:8px}.course-concepts article{padding:10px 0}.course-concepts h2{font-size:23px;margin-bottom:5px}.course-concepts p{font-size:16px;line-height:1.65}.course-sample:not(.has-photos){min-height:240px;padding:24px}.course-sample-copy>p{font-size:20px;line-height:1.75}.course-photo-grid img{height:180px}.course-sample.has-photos .course-sample-copy>p{font-size:15px}.course-attention{font-size:14px;margin-top:12px}.course-slide .course-heading{margin-bottom:16px!important}}

/* Classroom emphasis: charcoal carries the takeaway; muted olive guides the eye. */
.course-slide{--course-charcoal:#292a28;--course-olive:#626b50;--course-olive-light:#c6ceb7;--course-olive-wash:#e0e3d7}
.course-slide .course-heading h1 em{color:var(--course-olive)}
.course-heading .kicker>span{color:var(--course-olive)}
.course-slide .course-heading .course-lead{display:flex;align-items:baseline;gap:16px;width:fit-content;max-width:100%;padding:11px 18px 11px 15px;border-left:4px solid var(--course-olive);background:var(--course-charcoal);color:#f6f3ee;line-height:1.65!important}
.course-slide .course-heading .course-lead:before{content:'本课重点';flex:none;font-size:11px;letter-spacing:.12em;color:var(--course-olive-light)}
.course-ribbon button[aria-current=true]{background:var(--course-charcoal);color:#f6f3ee;padding-inline:10px}
.course-ribbon button[aria-current=true] span{color:var(--course-olive-light)}
.course-ribbon button[aria-current=true] b{border:0;padding-bottom:0}
.course-point-number{color:var(--course-olive)}
.course-sample:not(.has-photos){background:var(--course-olive-wash);border-left:3px solid var(--course-olive)}
.course-sample .collection-label{color:var(--course-olive)}
.course-sample.has-photos .course-sample-copy{border-left:3px solid var(--course-olive);margin-top:13px;padding:0 0 0 15px}
.course-attention>span{background:var(--course-olive);color:#f6f3ee;display:inline-block;padding:4px 9px;letter-spacing:.06em}
.course-teach-more summary,.course-footer a{color:var(--course-olive)}
.course-checks input{accent-color:var(--course-olive)}
.course-slide #course-cost-result{background:var(--course-charcoal);color:#f6f3ee}
.course-slide #course-cost-result>b{color:var(--course-olive-light)}
.course-slide #course-cost-result[data-invalid=true]{background:var(--course-olive-wash);color:var(--ink)}
.course-slide .course-quiz-feedback[data-correct=true]{color:var(--course-olive)}
@media(min-width:761px) and (max-height:820px){.course-slide .course-heading .course-lead{padding-block:8px}.course-slide .course-heading{margin-bottom:14px!important}.course-ribbon{margin-bottom:12px}.course-concepts article:first-child{padding-top:10px}}
@media(max-width:760px){.course-slide .course-heading .course-lead{display:block;width:100%;padding:13px 15px}.course-slide .course-heading .course-lead:before{display:block;margin-bottom:5px;font-size:10px}.course-attention>span{width:fit-content;margin-bottom:8px}.course-ribbon button[aria-current=true]{min-width:122px}.course-sample.has-photos .course-sample-copy{padding-left:12px}}