/* 延续第一讲纸色、墨黑、黄。不同教学任务用结构图、线框、同内容对照、状态和时间线。 */
.l2c-scene { display:flex; flex-direction:column; gap:24px; max-width:1440px; width:100%; margin:0 auto; }
.l2c-page .head { max-width:1120px; }
.l2c-page .t { font-size:clamp(2rem,3.35vw,3.65rem); line-height:1.2; }
.l2c-page .lede { max-width:60em; }
.l2c-note { font-size:.94rem; line-height:1.7; color:var(--text-2); max-width:75em; }
.t-ink .l2c-note { color:var(--on-ink-2); }
.l2c-teacher { margin-top:auto; font-size:.92rem; max-width:75em; border-top:1px solid var(--line-2); padding-top:10px; }
.t-ink .l2c-teacher { border-color:var(--line-ink-2); }
.l2c-teacher summary { cursor:pointer; color:var(--muted); }
.t-ink .l2c-teacher summary { color:var(--on-ink-2); }
.l2c-teacher p { padding-top:10px; }
.l2c-split { display:grid; grid-template-columns:minmax(0,1fr) minmax(0,1fr); gap:clamp(24px,4vw,64px); align-items:start; }
.l2c-split>* { min-width:0; }
.l2c-choices { display:flex; flex-wrap:wrap; gap:8px; }
.l2c-choices button { border:1px solid var(--line-2); padding:8px 16px; font-size:1rem; border-radius:4px; line-height:1.4; min-height:44px; }
.t-ink .l2c-choices button { border-color:var(--line-ink-2); }
.l2c-choices button[aria-pressed="true"] { background:var(--mark); color:var(--ink); border-color:var(--mark); font-weight:600; }
.l2c-explain { font-size:1.2rem; line-height:1.8; padding-top:14px; min-height:4em; max-width:50em; }
.l2c-links { display:flex; flex-wrap:wrap; align-items:center; gap:12px; }
.l2c-rows { display:grid; gap:16px; }
.l2c-rows li { padding-top:14px; border-top:1px solid var(--line-2); }
.t-ink .l2c-rows li { border-color:var(--line-ink-2); }
.l2c-rows b { font-size:1.18rem; }
.l2c-rows p { margin-top:4px; font-size:1.06rem; line-height:1.75; }
.l2c-cover .t { font-size:clamp(2.6rem,5vw,6rem); max-width:17em; letter-spacing:-.035em; line-height:1.15; }
.l2c-cover .lede { font-size:1.25rem; }
.l2c-cover-bottom { margin-top:20px; display:grid; grid-template-columns:1fr 1fr; align-items:end; gap:40px; }
.l2c-cover-question { font-size:1.5rem; line-height:1.65; }
.l2c-cover-bottom .btn { margin-top:18px; }
.l2c-route { display:grid; grid-template-columns:repeat(8,1fr); border-top:1px solid var(--line-ink-2); padding-top:18px; margin-top:24px; gap:12px; }
.l2c-route li { font-size:.98rem; }
.l2c-route span { display:block; color:var(--mark); font:1rem var(--mono); margin-bottom:10px; }
.l2c-compare { display:grid; grid-template-columns:1fr 1fr; gap:24px; }
.l2c-event { border:1px solid var(--line-2); background:var(--white); color:var(--text); padding:26px; }
.l2c-event header { display:flex; gap:16px; padding-bottom:18px; border-bottom:1px solid var(--line-2); margin-bottom:18px; }
.l2c-event header span { font-family:var(--mono); }
.l2c-event h2,.l2c-style-sample h2,.l2c-layer-card h2 { font-size:2rem; line-height:1.35; margin:12px 0; }
.l2c-event-type { font-size:.86rem; color:#57534b; }
.l2c-event-meta { font-size:1.05rem; font-weight:600; margin:12px 0; }
.l2c-event>p,.l2c-style-sample>p { line-height:1.7; }
.l2c-action { display:block; background:var(--ink); color:var(--white); padding:12px 22px; font-size:1rem; font-weight:600; margin-top:24px; min-height:46px; border-radius:4px; }
.l2c-action:disabled { opacity:.65; }
.l2c-feedback { font-size:1rem; line-height:1.75; min-height:3.5em; padding-top:14px; }
.l2c-event label { display:block; font-size:.95rem; margin-top:20px; }
.l2c-event input { width:100%; display:block; padding:10px; border:1px solid #a29f96; border-radius:2px; margin-top:6px; background:var(--white); }
.l2c-query { text-decoration:underline; font-size:.95rem; margin-top:8px; }
.l2c-brief { display:grid; grid-template-columns:.8fr 1.2fr; gap:56px; }
.l2c-brief blockquote { font-size:clamp(1.9rem,3vw,3rem); line-height:1.5; padding-top:10px; }
.l2c-wire-area { display:grid; grid-template-columns:1fr 1fr; gap:44px; align-items:center; }
.l2c-wire { max-width:540px; min-height:300px; border:2px solid #93918a; padding:26px; background:#e6e5df; color:#252525; font-size:1.2rem; }
.l2c-wire b { display:block; font-size:1.7rem; }
.l2c-wire-filter,.l2c-wire-row,.l2c-wire-button { padding:12px 14px; margin-top:14px; border:1px solid #b9b8b1; background:#f4f3ef; }
.l2c-wire-button { border-color:#888; max-width:260px; background:#d5d4ce; }
.l2c-flow-line { display:flex; flex-wrap:wrap; align-items:center; gap:16px; font-size:1.04rem; border-top:1px solid var(--line-2); padding-top:22px; }
.l2c-flow-line i { font-style:normal; opacity:.5; }
.l2c-architecture { display:grid; grid-template-columns:1fr 110px 1fr 110px 1fr; align-items:center; gap:10px; margin-top:16px; }
.l2c-architecture section { padding:26px 20px; border:1px solid var(--line-ink-2); min-height:210px; transition:background-color .2s,color .2s; }
.l2c-architecture section.active { background:var(--mark); color:var(--ink); border-color:var(--mark); }
.l2c-architecture h2 { font-size:2.2rem; margin:12px 0; }
.l2c-architecture section>span { font-size:.92rem; }
.l2c-architecture p { font-size:1rem; margin-bottom:14px; }
.l2c-architecture code { font-size:.85rem; }
.l2c-arrow { font-size:1rem; text-align:center; }
.l2c-arrow small { display:block; margin-top:12px; opacity:.7; font-size:.9rem; }
.l2c-request-bottom { display:grid; grid-template-columns:1fr auto; gap:20px; align-items:start; }
.l2c-request-bottom .btn { margin-top:22px; min-width:130px; }
.l2c-packet { font:1rem/1.7 var(--mono); color:var(--mark); }
.l2c-request-bottom .l2c-explain { min-height:5em; }
.l2c-code { padding:24px; background:var(--ink-2); color:var(--on-ink); border:1px solid #434348; font:1.07rem/1.9 var(--mono); white-space:pre-wrap; overflow-wrap:anywhere; margin:0; }
.l2c-layer-card { padding:28px; min-height:340px; }
.l2c-layer-card[data-layer="0"] { padding:0; font-family:serif; }
.l2c-layer-card[data-layer="0"] h2 { font-size:1.5rem; }
.l2c-layer-card[data-layer="0"] .l2c-action { background:#eee; color:#333; border:1px solid #999; padding:4px 10px; border-radius:0; min-height:0; font-weight:400; }
.l2c-layer-card:not([data-layer="0"]) { border-left:6px solid var(--mark); background:var(--white); }
.l2c-layer-card [data-card-result] { padding-top:14px; font-size:1rem; }
.l2c-tech-list { display:grid; }
.l2c-tech-list button { padding:16px 12px; border-bottom:1px solid var(--line-2); display:flex; gap:24px; text-align:left; font-size:1.16rem; }
.l2c-tech-list button b { font:1rem var(--mono); opacity:.6; }
.l2c-tech-list button[aria-pressed="true"] { background:var(--mark); }
.l2c-tech-detail { min-height:340px; padding:30px 0; }
.l2c-tech-detail h2 { font-size:2.2rem; line-height:1.5; margin-bottom:20px; }
.l2c-tech-detail>p { font-size:1.15rem; line-height:1.8; }
.l2c-tech-detail .l2c-note { margin-top:20px; font-size:1rem; }
.l2c-combinations { display:grid; grid-template-columns:repeat(3,1fr); gap:30px; }
.l2c-combinations section { border-top:2px solid var(--ink); padding-top:20px; }
.l2c-combinations span { font:1rem var(--mono); color:var(--muted); }
.l2c-combinations h2 { font-size:1.6rem; line-height:1.5; margin:14px 0; }
.l2c-combinations b { font-size:1.04rem; display:block; min-height:3em; }
.l2c-combinations p { font-size:1.08rem; margin-top:14px; line-height:1.8; }
.l2c-recommend { padding:22px 0; border-top:1px solid var(--line-2); font-size:1.24rem; font-weight:500; }
.l2c-design-brief { display:grid; grid-template-columns:1.05fr 1fr; gap:48px; align-items:start; margin-top:16px; }
.l2c-big-statement { font-size:clamp(2rem,3.25vw,3.5rem); line-height:1.55; }
.l2c-style-sample { min-height:380px; padding:28px; background:var(--white); color:var(--text); border-top:4px solid var(--ink); }
.l2c-style-sample[data-style="0"] h2 { font-size:2.5rem; max-width:8em; }
.l2c-style-sample[data-style="1"] { background:var(--mark); border:none; }
.l2c-style-sample[data-style="1"] h2 { font-size:3.8rem; line-height:1.08; max-width:none; font-weight:750; letter-spacing:-.04em; }
.l2c-style-sample[data-style="1"] h2 span { display:block; }
.l2c-style-sample[data-style="1"] .l2c-event-meta { padding-top:16px; border-top:2px solid var(--ink); }
.l2c-style-sample[data-style="2"] { border:1px solid var(--line-2); }
.l2c-style-sample[data-style="2"] h2 { font-size:1.65rem; }
.l2c-style-sample[data-style="2"] .l2c-action { width:100%; }
.l2c-style-observation { padding-top:20px; }
.l2c-style-observation h2 { font-size:1.8rem; }
.l2c-style-observation>p { font-size:1.25rem; line-height:1.8; margin-top:18px; }
.l2c-style-observation .l2c-note { font-size:1.02rem; }
.l2c-design-anatomy { padding:28px; border-left:1px solid var(--line-2); background:var(--white); }
.l2c-design-anatomy h2 { font-size:3.5rem; line-height:1.25; margin:20px 0; }
.l2c-design-anatomy>div { padding:16px 0; border-top:1px solid var(--line-2); }
.l2c-design-anatomy button { background:var(--ink); color:var(--white); padding:10px 18px; margin-top:20px; font-size:1rem; }
.l2c-design-anatomy[data-inspect="0"] h2 { text-decoration:underline; text-decoration-color:var(--mark); text-underline-offset:12px; }
.l2c-design-anatomy[data-inspect="1"] { border-left:4px solid var(--mark); }
.l2c-design-anatomy[data-inspect="2"]>div { background:var(--mark); padding-left:12px; }
.l2c-design-anatomy[data-inspect="3"] button { outline:3px solid var(--mark); outline-offset:4px; }
.l2c-motion-types { display:grid; grid-template-columns:1.2fr 1fr; gap:56px; }
.l2c-motion-demo { border-left:1px solid var(--line-2); padding:28px; }
.l2c-copy-pair { display:grid; grid-template-columns:1fr 1fr; gap:40px; }
.l2c-copy-pair section { border-top:1px solid var(--line-ink-2); padding-top:18px; }
.l2c-copy-pair section>p { color:var(--on-ink-2); font-size:1rem; }
.l2c-copy-pair blockquote { font-size:clamp(1.8rem,3vw,3.4rem); line-height:1.5; margin-top:22px; min-height:4.5em; }
.l2c-copy-pair section:last-child blockquote { color:var(--mark); }
.l2c-copy-state { font-size:1.8rem; line-height:1.75; margin-top:28px; min-height:5em; }
.l2c-fixed-brief h2 { font-size:1.3rem; margin-bottom:10px; }
.l2c-fixed-brief>p { font-size:1.08rem; margin-bottom:24px; }
.l2c-fixed-brief .l2c-explain { border-top:1px solid var(--line-2); }
.l2c-review-preview { max-width:410px; border:1px solid var(--line-2); background:var(--white); color:var(--text); padding:24px; margin:0 auto; width:100%; }
.l2c-review-preview>p { font-size:.9rem; }
.l2c-review-preview h2 { font-size:4.2rem; line-height:1.17; padding:22px 0 72px; }
.l2c-review-preview .l2c-preview-meta { font-size:1rem; line-height:1.7; margin-bottom:20px; }
.l2c-review-preview button { padding:12px 20px; background:var(--mark); color:var(--ink); width:100%; font-size:1rem; }
.l2c-review-preview.fixed h2 { font-size:2.5rem; padding-bottom:24px; }
.l2c-review-preview.fixed .l2c-preview-meta { border-top:1px solid var(--line-2); padding-top:20px; }
.l2c-resource-rows { display:grid; }
.l2c-resource-rows section { display:grid; grid-template-columns:110px 1fr; gap:24px; border-top:1px solid var(--line-2); padding:20px 0; }
.l2c-resource-rows section>span { font-size:1rem; color:var(--muted); }
.l2c-resource-rows h2 { font-size:1.35rem; margin-bottom:6px; }
.l2c-resource-rows p { font-size:1.05rem; }
.l2c-git-map { display:grid; grid-template-columns:repeat(4,1fr); gap:20px; margin-top:12px; }
.l2c-git-map section { border-top:2px solid var(--line-ink-2); padding:22px 14px; }
.l2c-git-map section.active { border-color:var(--mark); background:var(--mark); color:var(--ink); }
.l2c-git-map span { font:1rem var(--mono); }
.l2c-git-map h2 { font-size:1.7rem; margin:18px 0 10px; }
.l2c-git-map p { font-size:1.06rem; }
.l2c-timeline { display:grid; }
.l2c-timeline li { display:grid; grid-template-columns:110px 1fr; gap:28px; padding:13px 0; border-top:1px solid var(--line-2); }
.l2c-timeline time { font:1.45rem/1.3 var(--mono); }
.l2c-timeline small { font: .82rem var(--sans); display:block; margin-top:6px; color:var(--muted); }
.l2c-timeline h2 { font-size:1.18rem; }
.l2c-timeline p { font-size:1rem; margin-top:3px; }
.l2c-remote { border:1px solid var(--line-2); padding:28px; background:var(--white); }
.l2c-remote>p { font-size:.92rem; }
.l2c-remote h2 { font:1.65rem/1.5 var(--mono); overflow-wrap:anywhere; margin:20px 0; }
.l2c-remote dl { display:grid; grid-template-columns:100px 1fr; gap:20px 10px; font-size:1.04rem; margin-bottom:24px; }
.l2c-remote dt { color:var(--muted); }
.l2c-remote a { display:inline-block; margin-top:16px; font-weight:600; }
.l2c-git-check { padding:30px; border-left:4px solid var(--mark); background:var(--white); }
.l2c-git-check h2 { font-size:1.6rem; margin-bottom:20px; }
.l2c-git-check label { display:block; padding:12px 0; font-size:1.1rem; }
.l2c-git-check input { width:20px; height:20px; vertical-align:middle; margin-right:10px; accent-color:var(--ink); }
.l2c-takeaway { display:grid; grid-template-columns:1.1fr 1fr; gap:64px; margin-top:16px; }
.l2c-takeaway>div { display:grid; align-content:start; justify-items:start; gap:24px; }
.l2c-optional-links { display:grid; grid-template-columns:1fr 1fr; gap:16px 40px; }
.l2c-optional-links button { padding:18px 0; border-bottom:1px solid var(--line-2); font-size:1.18rem; text-align:left; display:flex; justify-content:space-between; gap:20px; }
.l2c-legacy-note { margin-bottom:18px; }
.still .l2c-architecture section { transition:none; }
@media(prefers-reduced-motion:reduce) { .l2c-architecture section { transition:none; } }
@media(max-width:1000px) {
 .l2c-cover-bottom { gap:24px; }
 .l2c-route { grid-template-columns:repeat(4,1fr); gap:20px; }
 .l2c-architecture { grid-template-columns:1fr 60px 1fr 60px 1fr; gap:6px; }
 .l2c-architecture section { padding:20px 14px; }
 .l2c-arrow { font-size:.85rem; }
}
@media(max-width:760px) {
 .l2c-scene { gap:22px; }
 .l2c-page .t { font-size:2rem; }
 .l2c-cover .t { font-size:2.8rem; }
 .l2c-cover .lede { font-size:1.06rem; }
 .l2c-split,.l2c-cover-bottom,.l2c-compare,.l2c-brief,.l2c-wire-area,.l2c-design-brief,.l2c-motion-types,.l2c-copy-pair,.l2c-takeaway { grid-template-columns:1fr; gap:24px; }
 .l2c-cover-question { font-size:1.2rem; }
 .l2c-route { grid-template-columns:repeat(2,1fr); margin-top:0; }
 .l2c-route li { font-size:.96rem; }
 .l2c-route span { margin-bottom:6px; }
 .l2c-choices { gap:7px; }
 .l2c-choices button { padding:8px 12px; font-size:.94rem; }
 .l2c-event { padding:20px; }
 .l2c-event h2 { font-size:1.65rem; }
 .l2c-feedback { min-height:0; }
 .l2c-architecture { grid-template-columns:1fr; margin-top:0; gap:10px; }
 .l2c-architecture section { min-height:0; padding:18px; }
 .l2c-architecture h2 { font-size:1.8rem; margin:6px 0; }
 .l2c-arrow { padding:0 12px; font-size:1rem; text-align:left; }
 .l2c-arrow small { display:inline; margin-left:18px; }
 .l2c-request-bottom { grid-template-columns:1fr; gap:0; }
 .l2c-request-bottom .l2c-explain { min-height:0; }
 .l2c-request-bottom .btn { justify-self:start; }
 .l2c-code { padding:18px; font-size:.95rem; line-height:1.8; }
 .l2c-layer-card { min-height:0; padding:20px; }
 .l2c-tech-detail { min-height:0; padding:8px 0; }
 .l2c-tech-detail h2 { font-size:1.7rem; }
 .l2c-combinations { grid-template-columns:1fr; gap:24px; }
 .l2c-combinations b { min-height:0; }
 .l2c-big-statement { font-size:1.95rem; }
 .l2c-style-sample { min-height:0; padding:22px; }
 .l2c-style-sample[data-style="0"] h2 { font-size:2rem; }
 .l2c-style-sample[data-style="1"] h2 { font-size:3.1rem; }
 .l2c-style-observation { padding-top:0; }
 .l2c-style-observation>p { font-size:1.13rem; }
 .l2c-design-anatomy h2 { font-size:2.8rem; }
 .l2c-motion-demo { padding:18px 0; border-left:0; border-top:1px solid var(--line-2); }
 .l2c-copy-pair blockquote { font-size:1.8rem; min-height:0; margin-top:12px; }
 .l2c-copy-state { min-height:0; font-size:1.5rem; }
 .l2c-review-preview h2 { font-size:3.2rem; padding-bottom:54px; }
 .l2c-review-preview.fixed h2 { font-size:2.2rem; }
 .l2c-resource-rows section { grid-template-columns:1fr; gap:6px; padding:18px 0; }
 .l2c-resource-rows h2 { font-size:1.2rem; }
 .l2c-git-map { grid-template-columns:1fr 1fr; gap:14px; }
 .l2c-git-map h2 { font-size:1.35rem; }
 .l2c-git-map section { padding:18px 12px; }
 .l2c-timeline li { grid-template-columns:74px 1fr; gap:16px; padding:16px 0; }
 .l2c-timeline time { font-size:1.2rem; }
 .l2c-remote { padding:20px; }
 .l2c-remote dl { grid-template-columns:82px 1fr; }
 .l2c-optional-links { grid-template-columns:1fr; gap:8px; }
 .l2c-takeaway { gap:28px; }
 .l2c-page .btn { white-space:normal; }
}