/* 第三版：阅读优先的白色编辑排版。 */
:root{--ink:#252525;--muted:#686868;--line:#e3e3e3;--mint:#414141;font-family:'Songti SC','STSong',serif}
body{font-family:inherit}button,input{font-family:inherit}
.page-bar{height:72px;padding-inline:40px;background:#fffffff5;--bar:72px}.brand-group .edition-brand{font-size:21px;letter-spacing:-.025em}.edition-brand span{letter-spacing:0;font-size:12px}
:root{--bar:72px}.exhibition-inner{max-width:1440px;padding-inline:68px}.cover-stage{min-height:660px;align-items:center}.cover-copy{padding:54px 0 60px;max-width:520px}.cover-copy h1{font-family:'Songti SC','STSong',serif;font-weight:550;font-size:clamp(58px,5.6vw,84px);line-height:1.22;letter-spacing:-.035em;margin-bottom:30px;text-wrap:balance}.cover-description{font-size:17px;line-height:1.95;max-width:26ch}.cover-actions{margin-top:32px;gap:30px}.cover-actions .primary-action{border-radius:3px;min-height:54px;padding:16px 24px;gap:38px}.primary-action img{transition:transform .22s cubic-bezier(.16,1,.3,1)}.primary-action:hover img{transform:translateX(4px)}.cover-actions .text-action{border-bottom:1px solid #aaaaaa;border-radius:0;padding:10px 0}.cover-actions .text-action:hover{text-decoration:none;border-color:#414141}
.cover-art{width:64%;right:-42px;height:86%;top:7%;object-fit:contain;mask-image:linear-gradient(90deg,transparent,#000000 12%,#000000 96%,transparent);pointer-events:none}.cover-stage::after{background:linear-gradient(90deg,#ffffff 8%,#fffffff0 22%,#ffffff00 52%)}
.chapter-entry{padding:48px 0 54px;grid-template-columns:.75fr 1.25fr;gap:70px}.chapter-intro h2{font-family:'Songti SC','STSong',serif;font-size:29px;font-weight:500;line-height:1.4;letter-spacing:-.02em}.chapter-intro p{margin-top:19px;font-size:14px;max-width:26ch}.chapter-link{grid-template-columns:66px 1fr 24px;min-height:108px;padding:22px 12px 22px 0;transition:color .22s}.chapter-link:hover{color:#414141}.chapter-link .chapter-label,.chapter-link>img{transition:transform .22s cubic-bezier(.16,1,.3,1)}.chapter-link:hover .chapter-label,.chapter-link:hover>img{transform:translateX(4px)}.chapter-number{font-size:13px;color:#747474}.chapter-label strong{font-family:'Songti SC','STSong',serif;font-size:23px;font-weight:500;letter-spacing:-.015em}.chapter-label span{font-size:12px}.cover-footer{padding:24px 0 32px}
.outline{background:#fbfbfb;padding:24px 20px}.outline-heading{margin-bottom:20px}.outline-heading h2{font-family:'Songti SC','STSong',serif;font-size:15px}.outline-chapter>button:first-child>span{font-size:11px}.outline-chapter>.outline-node{min-height:44px}.outline-chapter>.outline-node.active{background:#ededed;color:#3f3f3f}.outline-parent{color:#484848!important}
.node-dialog #detail,.node-dialog #detail:has(.development-art),.node-dialog #detail:has(.llm-compact){max-width:1150px;padding:42px 54px 110px}.reading-heading{padding-bottom:25px;margin-bottom:32px}.reading-heading>p{display:none}.node-dialog .reading-heading h2{font-family:'Songti SC','STSong',serif;font-size:clamp(25px,2.3vw,34px);font-weight:550;letter-spacing:-.02em;line-height:1.5;padding-right:90px}.reading-heading>span{font-size:12px;bottom:35px}.node-dialog #points{max-width:70ch;font-size:17px;line-height:1.95;margin:30px auto}.node-dialog #points li+li{margin-top:13px}.node-dialog .image-stack{gap:28px}.resource-links a{font-size:12px;line-height:1.8}.resource-links a:hover{text-decoration:underline}.node-footer{margin-top:36px;padding-top:22px}.node-controls{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);width:100%;gap:20px}.node-dialog .node-controls button{min-height:72px;text-align:left;padding:14px 18px;border-radius:6px;white-space:normal;font-size:12px;font-weight:400;line-height:1.4;max-width:100%;display:flex;flex-direction:column;gap:7px;justify-content:center;background:#ffffff;color:#686868}.node-dialog .node-controls button strong{font-size:14px;font-weight:500;color:#414141;overflow-wrap:anywhere}.node-dialog .node-controls button:last-child{text-align:right;align-items:flex-end;background:#f5f5f5;border:1px solid #e1e1e1;color:#616161}.node-dialog .node-controls button:hover{border-color:#9f9f9f;background:#f2f2f2}.node-dialog .node-controls button:disabled{opacity:.45;background:#fbfbfb}.parameter-table{font-size:14px}.parameter-table td{line-height:1.8}
.read-transition .reading-heading{animation:reading-arrive .3s cubic-bezier(.16,1,.3,1)}@keyframes reading-arrive{from{opacity:.65;clip-path:inset(0 0 18%)}to{opacity:1;clip-path:inset(0 0 0)}}
@media(min-width:1600px){.exhibition-inner{max-width:1580px;padding:0 88px}.cover-stage{min-height:730px}.cover-copy h1{font-size:84px}.cover-art{width:66%;right:-42px}.chapter-entry{gap:90px}}
@media(max-width:1000px){.page-bar{padding:0 24px}.exhibition-inner{padding:0 38px}.cover-stage{min-height:620px}.cover-copy h1{font-size:62px}.cover-copy{max-width:390px}.cover-art{width:72%;right:-38px}.chapter-entry{gap:35px}.node-dialog #detail,.node-dialog #detail:has(.development-art),.node-dialog #detail:has(.llm-compact){padding:32px 30px 100px}}
@media(max-width:700px){:root{--bar:66px}.page-bar{height:66px;padding:0 16px}.brand-group .edition-brand{font-size:19px}.exhibition-inner{padding:0 24px}.cover-stage{min-height:690px;display:block}.cover-copy{padding:40px 0 0;max-width:100%}.cover-copy h1{font-size:54px;line-height:1.2;margin-bottom:21px}.cover-description{font-size:14px;line-height:1.8}.cover-actions{margin-top:25px;gap:23px}.cover-actions .primary-action{padding:14px 18px;gap:23px;min-height:50px}.cover-art{inset:auto -24px 0;width:calc(100% + 48px);height:365px;mask-image:linear-gradient(180deg,transparent,#000000 12%,#000000 90%,transparent)}.cover-stage::after{background:none}.chapter-entry{grid-template-columns:1fr;padding:35px 0;gap:19px}.chapter-intro h2{font-size:25px}.chapter-intro p{margin-top:14px}.chapter-link{grid-template-columns:50px 1fr 22px;min-height:96px;padding-block:22px}.chapter-label strong{font-size:20px}.chapter-number{font-size:12px}.node-dialog #detail,.node-dialog #detail:has(.development-art),.node-dialog #detail:has(.llm-compact){padding:28px 20px 70px}.node-dialog .reading-heading h2{font-size:24px;padding-right:0;line-height:1.5}.reading-heading>span{position:static;margin-top:13px}.node-dialog #points{font-size:15px;line-height:1.95}.node-controls{gap:12px}.node-dialog .node-controls button{padding:12px;min-width:0;min-height:80px}.node-dialog .node-controls button strong{font-size:12px}.parameter-table{font-size:12px}}
@media(prefers-reduced-motion:reduce){.read-transition .reading-heading{animation:none}.chapter-link,.primary-action img{transition:none}}

.skip:focus{z-index:80}@media(prefers-reduced-motion:reduce){.chapter-link .chapter-label,.chapter-link>img{transition:none}}

/* 黑白版：仅改变呈现，原始教学素材文件保持完整。 */
:root{--bg:#fff;--paper:#fff;--ink:#202020;--muted:#666;--line:#dedede;--mint:#202020;--accent:#333}
.cover-actions .primary-action{background:#202020;color:#fff}.cover-actions .primary-action:hover{background:#414141}.cover-art{filter:grayscale(1)}
#graph{filter:grayscale(1)}.outline-node.active{color:#202020!important}.outline-parent{color:#444!important}

.outline,.logic-map{filter:grayscale(1)}

/* 第三章正文中的横向逻辑树；窄屏仅图内横向滚动。 */
.reading-diagram{margin:28px 0 36px;min-width:0}
.reading-diagram h3{font-size:22px;line-height:1.5;margin:0 0 14px;color:#202020}
.reading-diagram-controls{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-bottom:12px}
.reading-diagram-controls button{padding:7px 12px;background:#fff;color:#222;border:1px solid #aaa;border-radius:6px;font:inherit;font-size:14px;cursor:pointer}
.reading-diagram-controls button:hover{background:#eee}
.reading-diagram-controls button:focus-visible,.reading-diagram-frame:focus-visible,.reading-diagram .node:focus-visible{outline:2px solid #222;outline-offset:3px}
.reading-diagram-controls span{font-size:14px;color:#555}
.reading-diagram-frame{max-width:100%;overflow:auto;padding:12px;background:#fafafa;scrollbar-color:#aaa #f1f1f1}
.reading-diagram-canvas{width:max-content;min-width:100%}
.reading-diagram-canvas svg{display:block}
@media(max-width:700px){.reading-diagram h3{font-size:19px}.reading-diagram-controls span{flex-basis:100%}.reading-diagram-frame{padding:8px}}

.reading-diagram-frame{max-height:680px}
.reading-diagram .flowchart-link,.reading-diagram .edgePaths path{fill:none!important;stroke:#888!important;stroke-width:1.2px!important}
.reading-diagram .marker path{fill:#888!important;stroke:#888!important}

.reading-diagram-canvas svg{margin-inline:auto}

.reading-source{margin:24px 0 30px;color:#555;font-size:15px;line-height:1.8}
.reading-source a{color:#202020;text-decoration:underline;text-underline-offset:4px;font-weight:500}
.reading-source p{margin:10px 0 0;max-width:75ch}
.reading-source a:focus-visible{outline:2px solid #202020;outline-offset:4px}

/* 阅读目录：各级文字及交互状态统一为纯黑。 */
.outline .outline-heading,.outline .outline-heading>span,.outline .outline-chapter>button,.outline .outline-chapter>button:first-child>span,.outline .outline-chapter>button strong,.outline .outline-parent,.outline .outline-node,.outline .outline-node:hover,.outline .outline-node.active{color:#000!important}

/* 底部资料引用居中弱化；前后节使用紧凑文字导航。 */
.node-dialog .resource-links{flex-direction:row;justify-content:center;align-items:center;text-align:center;gap:4px 20px;border:0;padding:0;margin:22px 0 8px}
.node-dialog .resource-links .resource-link{font-size:11px;line-height:1.7;color:#777;border:0;padding:0;text-decoration:none}
.node-dialog .resource-links .resource-link:hover{color:#000;text-decoration:underline}
.node-dialog .node-footer,.node-dialog .resource-links+.node-footer{border:0;margin-top:18px;padding-top:0}
.node-dialog .node-controls{display:flex;justify-content:space-between;align-items:flex-start;gap:24px;width:100%}
.node-dialog .node-controls button,.node-dialog .node-controls button:last-child{min-width:0;min-height:44px;max-width:46%;padding:4px 0;border:0;border-radius:0;background:transparent;box-shadow:none;gap:3px;line-height:1.5;font-size:11px;color:#777}
.node-dialog .node-controls button strong{font-size:13px;font-weight:400;color:#222}
.node-dialog .node-controls button:hover{background:transparent;border:0;color:#000;transform:none}
.node-dialog .node-controls button:hover strong{text-decoration:underline;text-underline-offset:3px}
.node-dialog .node-controls button:disabled{background:transparent;opacity:.4}