:root{--paper:#f3e9d2;--ink:#39382e;--faint:#786f5c;--rust:#854733;--blue:#3d6572;--line:#c6b89b;--hand:'Reenie Beanie','Segoe Print','Bradley Hand',cursive;--body:'Courier Prime','Courier New',monospace}*{box-sizing:border-box}body{margin:0;color:var(--ink);background:#38372f;font-family:var(--body);font-size:18px;line-height:1.5}button,input,summary{font:inherit}button,a,input,summary{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{cursor:default}a{color:var(--blue);text-underline-offset:4px}button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible{outline:2px solid var(--blue);outline-offset:5px}.masthead{max-width:1380px;margin:auto;padding:24px 34px 18px;display:flex;justify-content:space-between;align-items:center;color:var(--paper)}.wordmark{font-family:var(--hand);font-size:35px;line-height:1.05;color:inherit;text-decoration:none}.wordmark 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var(--hand);color:var(--rust);min-width:58px}.electrode-note h3{font:500 27px/1 var(--hand);margin:0 0 7px}.electrode-note p{font-size:16px;line-height:1.35;margin:0}.key-note{display:flex;justify-content:space-around;gap:8px;font:22px var(--hand);color:var(--rust);margin-top:17px}.right-page>.hand-note{text-align:center;margin-top:22px;font-size:24px}.notebook-footer{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:18px 6px;color:var(--paper);font-size:14px}.next-note{font:23px/1.1 var(--hand);opacity:.85}.notebook-footer button{border:0;background:transparent;color:var(--paper);font:25px var(--hand);opacity:.5;text-align:right}.notebook-footer button span{display:block;font:12px var(--body)}@media(min-width:1400px){.map-wrap{margin-top:24px}}@media(max-width:950px){main{padding:0 18px 24px}.masthead{padding:22px 24px}.page{padding-left:28px;padding-right:28px}.chapter{padding:10px 16px;font-size:22px}.page-meta 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p{font-size:17px}.source-notes{margin-top:20px}.orientation.left{left:0}.orientation.right{right:0}.key-note{font-size:23px}}@media(prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important}}

/* Clear reading text; handwriting kept for headings and personal notes. */
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/* Typewritten pages with restrained folds and handwritten bench notes. */
body{font-size:16px;line-height:1.5}.page{background-color:#eee0c0;background-image:linear-gradient(126deg,transparent 18%,#78603d09 18.5%,#fff8 18.8%,transparent 19.4%),linear-gradient(38deg,transparent 63%,#7f674a0b 64%,#fff4 64.4%,transparent 65%),repeating-linear-gradient(3deg,#6b513504 0px,#6b513504 1px,transparent 1px,transparent 4px),radial-gradient(ellipse at 0% 100%,#9a733325,transparent 65%)}h1,h2,.map-title,.wordmark,.chapter,.layout-picker button{font-family:var(--body);font-weight:400;transform:none;letter-spacing:-.7px}h1{font-size:34px;line-height:1.18}h2{font-size:22px;line-height:1.3}.map-title{font-size:25px}.wordmark{font-size:26px}.chapter{font-size:18px}.layout-picker button{font-size:23px}.layout-picker small{letter-spacing:0}.page strong,.page b{font-weight:700}.layout-reason h3{font-weight:700}.hand-note{font-size:20px}.map-tools{flex-wrap:wrap;font-size:13px}.map-tools [hidden]{display:none}.find-electrode{display:flex;align-items:center;gap:12px;margin:12px 0 5px;font-size:14px}.find-electrode input{width:165px;max-width:55%;padding:7px 8px;border:0;border-bottom:1px solid var(--faint);background:#fff3;color:var(--ink);font:inherit;border-radius:0}.map-help{font-size:13px;line-height:1.45;color:var(--faint);margin:8px 0 20px}.name-guide{margin:22px 0 0;padding-top:12px;border-top:1px dashed #9b886b}.name-guide h3{font:22px var(--hand);color:var(--blue);margin:0 0 6px}.name-guide p{font-size:14px;line-height:1.6;margin:6px 0}.bench-note{margin-top:22px;padding:13px 17px;border:1px solid #a38b6266;background:#d6c39d25;transform:rotate(-.5deg)}.bench-note h3{font:24px var(--hand);color:var(--rust);margin:0}.bench-note p{font-size:14px;line-height:1.5;margin:7px 0}.bench-note .scribble{font:20px/1.35 var(--hand);color:var(--blue);margin-top:12px}.electrode text{font-family:var(--body);font-size:16px}.electrode-note{min-height:140px}.source-notes p{font-size:13px}.layout-reason{min-height:160px}.edition{font-size:17px}.page-meta{font-size:11px}@media(max-width:740px){h1{font-size:30px}.map-title{font-size:23px}.chapter{font-size:15px}.wordmark{font-size:22px}.layout-reason{min-height:0}.layout-picker button small{font-size:12px}.key-note{font-size:18px}}

/* Keep long electrode names clear of their accompanying explanation. */
.electrode-note{display:grid;grid-template-columns:82px minmax(0,1fr);column-gap:24px;align-items:start;padding:21px 20px}.chosen-label{min-width:0;font-size:29px;line-height:1.4;overflow-wrap:anywhere;font-weight:400}.electrode-note h3{line-height:1.4;margin:0 0 10px;font-weight:400}.electrode-note>div:last-child{min-width:0}.find-electrode[hidden]{display:none}.anatomy-key{margin:12px 0 16px;font-size:14px;line-height:1.55}.anatomy-key>div{display:grid;grid-template-columns:32px minmax(0,1fr);gap:10px;margin:9px 0}.anatomy-key dt{font-weight:700}.anatomy-key dd{margin:0}.hand-note,.margin-note p,.bench-note .scribble{line-height:1.5}.bench-note .scribble{font-size:22px}@media(max-width:950px){.electrode-note{grid-template-columns:70px minmax(0,1fr);column-gap:20px;padding:18px 15px}.chosen-label{font-size:26px}}@media(max-width:420px){.electrode-note{grid-template-columns:1fr;row-gap:8px}.chosen-label{font-size:28px}}

@font-face{font-family:'Reenie Beanie';src:url('fonts/ReenieBeanie.ttf') format('truetype');font-weight:400;font-style:normal;font-display:swap}.hand-note,.margin-note p,.bench-note .scribble{font-size:28px;line-height:1.2}.bench-note h3,.name-guide h3{font-size:29px}.page-meta span:last-child{font-size:23px;line-height:1.1;letter-spacing:0}.electrode-note h3{font-size:29px}.chosen-label{font-family:var(--body);font-size:25px}.orientation{font-size:24px}.key-note{font-size:27px;flex-wrap:wrap}.source-notes summary{font-size:25px}.next-note{font-size:27px}.edition{font-size:26px;line-height:1.1}.edition span{font-size:24px}@media(max-width:950px){.chosen-label{font-size:23px}.key-note{font-size:24px}}@media(max-width:740px){.page-meta span:last-child{font-size:21px}.hand-note,.margin-note p,.bench-note .scribble{font-size:27px}}

/* The desk stays in view while each paper page can be read at its own pace. */
html,body{height:100%;overflow:hidden}
body{height:100dvh;display:flex;flex-direction:column}
.masthead{width:100%;flex:0 0 auto;padding-top:14px;padding-bottom:12px}
main{width:100%;flex:1;min-height:0;display:flex;flex-direction:column;padding-bottom:0}
.chapter-tabs{flex:0 0 auto}
.notebook{flex:1;min-height:0;grid-template-rows:minmax(0,1fr)}
.page{height:100%;min-height:0;overflow-y:auto;overscroll-behavior:contain;scrollbar-width:thin;scrollbar-color:#9b886b transparent;scrollbar-gutter:stable;padding-top:22px;padding-bottom:24px}
.page:focus-visible{outline:2px solid var(--blue);outline-offset:-5px}
.folio{position:static;display:block;text-align:center;margin-top:24px}
.notebook-footer{flex:0 0 auto;padding:10px 6px}
.layout-reason{min-height:0}
@media(max-width:740px){
 .masthead{padding:10px 18px}.wordmark span{font-size:11px;margin-top:4px}
 main{padding:0 12px}.chapter-tabs{overflow-x:auto}.chapter{flex-shrink:0;min-height:42px;padding:9px 10px}
 .notebook{display:block;overflow-y:auto;overscroll-behavior:contain;scrollbar-width:thin;scrollbar-color:#9b886b transparent}
 .page{height:auto;overflow:visible;scrollbar-gutter:auto;padding:22px 23px 28px}
 .notebook-footer{padding:7px 4px}.notebook-footer button{font-size:19px}
}
@media(max-height:600px) and (min-width:741px){.masthead{padding-top:7px;padding-bottom:7px}.wordmark{font-size:21px}.wordmark span{font-size:11px;margin-top:3px}.edition{font-size:21px}.chapter{min-height:43px;padding:7px 15px}.chapter small{display:none}.notebook-footer{padding:5px}.next-note{font-size:22px}}
.chapter{text-decoration:none;display:block}.turn-page{color:var(--paper);text-decoration:none;font-size:16px}.method-card{padding:4px 0 5px 14px;border-left:2px solid #b3a181;margin:16px 0}.method-card h3{font-size:16px;margin:0}.method-card p{margin:7px 0}.demo-controls{display:flex;flex-wrap:wrap;gap:14px;margin:18px 0}.demo-controls label{display:flex;align-items:center;gap:7px;font-size:14px}.demo-controls input{accent-color:var(--rust);width:18px;height:18px}.trace-figure{margin:18px 0;background:#fff3;padding:10px;border:1px solid #b9a58180}.trace-figure svg{display:block;width:100%;height:auto}.trace-figure figcaption{font-size:12px;line-height:1.65;margin-top:9px}.legend-blue{color:var(--blue)}.legend-rust{color:var(--rust)}.demo-answer{border-left:2px solid var(--rust);padding-left:12px;font-size:15px;min-height:70px}.slider-label{display:flex;justify-content:space-between;gap:15px;font-size:13px}.smooth-slider{width:100%;accent-color:var(--rust);margin:16px 0}.reset-demo{background:transparent;border:1px solid var(--faint);padding:8px 12px;color:var(--ink);margin-top:18px}sup{font-size:11px}sup a{text-decoration:none}
.lesson-detail{margin:15px 0;border-bottom:1px dashed #b4a381;padding-bottom:12px}.lesson-detail summary{cursor:pointer;color:var(--blue);font-size:15px;line-height:1.5}.lesson-detail p{font-size:14px;line-height:1.6}.trace-figure svg{overflow:visible}
.artifact-picker{display:flex;gap:7px;flex-wrap:wrap;margin:17px 0 0}.artifact-picker button{background:transparent;border:1px solid #b9a581;padding:8px;color:var(--ink);font-size:13px;border-radius:3px}.artifact-picker button[aria-pressed=true]{background:#85473313;border-color:var(--rust);color:var(--rust)}.reference-demo{padding:16px;background:#fff3;border:1px solid #b9a58180;margin:15px 0}.reference-equation{display:flex;align-items:center;justify-content:space-between;gap:8px;margin:18px 0 25px}.reference-equation span{text-align:center;flex:1;min-width:0}.reference-equation b{display:block;font-size:30px;font-weight:400;color:var(--rust)}.reference-equation small{font-size:11px;display:block}.reference-equation i{font-style:normal;font-size:24px}.mini-caption{font-size:11px!important;color:var(--faint);line-height:1.5}.reference-demo>p{font-size:14px}.visual-method{padding:12px;background:#fff2}.visual-method summary{display:flex;align-items:center;gap:14px;cursor:pointer;list-style:none}.visual-method summary::-webkit-details-marker{display:none}.method-sketch{width:45%;flex-shrink:0}.visual-method summary span{font-size:15px}.visual-method small{display:block;font-size:11px;color:var(--faint);margin-top:5px}.visual-method[open] small{display:none}.visual-method p{font-size:14px}.inspect-hit{cursor:pointer}.inspect-hit:focus-visible{outline:none;stroke:var(--blue);stroke-width:2}.demo-controls{font-size:13px}
.turning-spread{backface-visibility:hidden;box-shadow:10px 12px 35px #0005;will-change:transform,opacity}.turning-spread .page{scrollbar-width:none}.turning-spread .page::-webkit-scrollbar{display:none}
.band-picker{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin:18px 0}.band-picker button{font-size:16px;padding:10px 5px;background:#fff2;color:var(--ink);border:1px solid #b9a581;border-radius:3px}.band-picker small{display:block;font-size:11px;margin-top:6px}.band-picker button[aria-pressed=true]{border-color:var(--rust);background:#85473313}.chapter-tabs{overflow-x:auto;flex-shrink:0}.chapter{flex-shrink:0}@media(max-width:740px){.chapter:nth-child(3){display:block}.chapter{font-size:13px}.band-picker{grid-template-columns:repeat(2,minmax(0,1fr))}}
.book-turn-stage{position:fixed;z-index:100;pointer-events:none;perspective:1800px;isolation:isolate}.turn-still{position:absolute;top:0;height:100%!important;overflow:hidden!important}.turn-leaf{position:absolute;top:0;height:100%;transform-style:preserve-3d;will-change:transform;box-shadow:8px 0 20px #392b2520}.turn-face{position:absolute!important;inset:0;width:100%;height:100%!important;overflow:hidden!important;backface-visibility:hidden;scrollbar-width:none;box-sizing:border-box}.turn-front{transform:translateZ(.2px)}.turn-back{transform:rotateY(180deg) translateZ(.2px)}.turn-face:after{content:'';position:absolute;inset:0;pointer-events:none;background:linear-gradient(90deg,#5d452520,transparent 18%,#fff2 60%,#5d452515)}

/* Separate printed faces keep the reverse readable rather than mirrored. */
.turn-face{-webkit-backface-visibility:hidden;backface-visibility:hidden;background-color:#eee0c0}.turn-front{transform:rotateY(0deg) translateZ(1px)}.turn-back{transform:rotateY(180deg) translateZ(1px)}.turn-leaf{transform-style:preserve-3d}.turn-face:after{background:linear-gradient(90deg,#5d452512,transparent 14%,transparent 85%,#5d452518)}
/* The print stays upright while a curved paper edge reveals the next spread. */
.paper-fold-stage{position:fixed;z-index:100;pointer-events:none;overflow:hidden;border-radius:3px 9px 9px 3px}.paper-fold-old{position:absolute;inset:0;width:100%;height:100%;margin:0;box-shadow:none;will-change:clip-path}.paper-fold-old .page{scrollbar-width:none}.paper-fold-old .page::-webkit-scrollbar{display:none}.paper-curl{position:absolute;top:-2%;height:104%;width:clamp(36px,7vw,100px);opacity:0;border-radius:55% 8% 8% 55% / 4% 2% 2% 4%;background:linear-gradient(90deg,#715c3420 0%,#d6c29b 12%,#f7edda 35%,#fff8e5 47%,#ead7b0 65%,#b79b6b 83%,#46371e45 100%);box-shadow:12px 0 20px #33260f25,-8px 0 15px #33260f18;will-change:left,transform;transform:translateX(-50%)}.paper-curl.backwards{background:linear-gradient(270deg,#715c3420 0%,#d6c29b 12%,#f7edda 35%,#fff8e5 47%,#ead7b0 65%,#b79b6b 83%,#46371e45 100%)}
.chapter{display:flex;flex-wrap:wrap;align-content:center;align-items:center;justify-content:center;text-align:center;column-gap:8px;min-height:65px}.chapter span{margin:0}.chapter small{flex-basis:100%;text-align:center}.chapter-tabs{align-items:stretch}@media(max-width:740px){.chapter{min-height:44px}}@media(max-height:600px) and (min-width:741px){.chapter{min-height:43px}}

.picture-trials{display:flex;gap:8px;flex-wrap:wrap;margin:15px 0}.picture-trials button{flex:1;min-width:44px;background:#fff3;border:1px solid var(--line);color:var(--ink);font:36px/1.1 var(--body);padding:7px}.picture-trials button small{display:block;font:14px var(--body);margin-top:6px}.picture-trials button[aria-pressed=true]{border-color:var(--rust);background:#85473315}

.record-flow{margin:18px 0;display:grid;gap:10px;border-left:2px solid var(--blue);padding-left:14px}.record-flow div{padding:7px 10px;background:#fff2}.record-flow b{display:block;font-size:16px;color:var(--blue)}.record-flow span{font-size:15px;display:block;margin-top:3px}.record-flow svg{display:block;width:100%;max-width:240px;height:55px}

/* Phone and small-tablet reading: one paper column, visible chapters and touch controls. */
.mobile-page-links{display:none}
@media(max-width:900px){
 html,body{width:100%;max-width:100%;overflow:hidden}
 body{font-size:16px;line-height:1.6;height:100dvh;min-height:0;padding-top:env(safe-area-inset-top)}
 .masthead{padding:10px max(12px,env(safe-area-inset-right)) 9px max(12px,env(safe-area-inset-left))}
 .wordmark{font-size:23px;letter-spacing:-.5px}.wordmark span{font-size:12px;letter-spacing:0;margin-top:4px}.edition{display:none}
 main{padding:0 max(8px,env(safe-area-inset-right)) 0 max(8px,env(safe-area-inset-left));min-width:0}
 .chapter-tabs{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px;padding:0;overflow:visible}
 .chapter,.chapter:nth-child(n){display:flex;min-width:0;min-height:46px;padding:9px 6px;font-size:14px;line-height:1.35;column-gap:6px;letter-spacing:-.3px;border-radius:4px;transform:none;flex-wrap:nowrap}
 .chapter span{font-size:12px;flex:0 0 auto}.chapter small{display:none}
 .mobile-page-links{display:flex;gap:8px;flex:0 0 auto;padding:6px 0}
 .mobile-page-links button{flex:1;min-height:44px;border:1px solid #b9a58160;border-radius:3px;background:transparent;color:var(--paper);font-size:14px;touch-action:manipulation}
 .notebook{display:block;min-width:0;min-height:0;overflow-y:auto;overflow-x:hidden;overscroll-behavior:contain;-webkit-overflow-scrolling:touch;scrollbar-gutter:auto;grid-template-rows:none}
 .notebook:after{display:none}.page{height:auto;min-width:0;overflow:visible;padding:20px 18px 26px;scrollbar-gutter:auto;scroll-margin-top:12px}
 .left-page{border-bottom:1px solid var(--line)}.right-page{padding-top:25px}
 .page-meta{font-size:11px;letter-spacing:.5px;flex-wrap:wrap}.page-meta span:last-child{display:none}
 h1{font-size:30px;line-height:1.2;margin:18px 0}h2,.map-title{font-size:23px;line-height:1.3}
 .page p{overflow-wrap:break-word}.source-notes p,.lesson-detail p,.bench-note p,.visual-method p,.name-guide p{font-size:15px;line-height:1.6}
 .source-notes summary{font-size:27px;min-height:44px;display:list-item;padding:7px 0}.lesson-detail summary{font-size:16px;min-height:44px;padding:8px 0}
 .band-picker{grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}.band-picker button,.artifact-picker button,.layout-picker button,.reset-demo{min-height:48px;font-size:16px;touch-action:manipulation}
 .band-picker small,.layout-picker button small{font-size:12px;line-height:1.4}.artifact-picker{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:6px}.artifact-picker button{font-size:13px;padding:7px 3px}
 .layout-picker{gap:6px}.layout-picker button{font-size:19px;padding:8px 3px}.layout-reason{min-height:0;margin-top:14px}
 .demo-controls{gap:6px 14px}.demo-controls label{min-height:44px;font-size:15px}.demo-controls input{width:22px;height:22px;flex-shrink:0}
 .slider-label{font-size:14px;gap:8px;flex-wrap:wrap}.slider-label output{white-space:nowrap}.smooth-slider{height:44px;margin:4px 0 10px;cursor:pointer}
 .smooth-slider::-webkit-slider-thumb{min-width:24px;min-height:24px}.smooth-slider::-moz-range-thumb{width:24px;height:24px}
 .trace-figure{padding:8px;margin:14px 0}.trace-figure svg{width:100%;height:auto;max-width:100%}.trace-figure svg text{font-size:20px}.trace-figure figcaption{font-size:13px;line-height:1.5}
 .demo-answer{font-size:15px;min-height:0;line-height:1.6}.mini-caption{font-size:13px!important}
 .reference-demo{padding:12px}.reference-equation{gap:5px;margin:12px 0 18px}.reference-equation b{font-size:27px}.reference-equation small{font-size:12px;line-height:1.4}
 .visual-method summary{gap:10px;min-height:44px}.method-sketch{width:42%}.visual-method summary span{font-size:16px}
 .map-wrap{margin:27px 12px 8px}.orientation{font-size:22px}.orientation.left{left:-4px}.orientation.right{right:-4px}.electrode text{font-size:21px}
 .find-electrode{flex-wrap:wrap;gap:6px}.find-electrode label{font-size:15px}.find-electrode input{width:100%;max-width:100%;min-height:44px;font-size:16px;padding:10px 8px}
 .map-help,.map-tools,.anatomy-key{font-size:14px}.electrode-note{grid-template-columns:1fr;gap:8px;min-height:0;padding:15px;transform:none}.chosen-label{font-size:25px}.electrode-note p{font-size:16px}
 .key-note{font-size:25px;justify-content:flex-start;gap:4px 16px}.bench-note{padding:12px;transform:none}.picture-trials{gap:5px}.picture-trials button{min-width:36px;min-height:60px;font-size:30px}
 .notebook-footer{display:flex;flex-wrap:wrap;gap:4px 12px;padding:4px 2px max(4px,env(safe-area-inset-bottom));font-size:12px}.notebook-footer>span{display:none}.turn-page{display:flex;align-items:center;min-height:44px;font-size:14px;line-height:1.4}
 .paper-fold-old{height:100%!important;padding:0}.paper-fold-stage{border-radius:3px}.paper-curl{width:48px}
}
@media(max-width:360px){.chapter{font-size:12px}.chapter span{font-size:11px}.page{padding-left:14px;padding-right:14px}.wordmark{font-size:21px}.trace-figure svg text{font-size:21px}.artifact-picker{grid-template-columns:1fr}.picture-trials{display:grid;grid-template-columns:repeat(3,minmax(0,1fr))}}
@media(max-width:900px) and (max-height:500px){.masthead{padding-top:5px;padding-bottom:5px}.wordmark{font-size:18px}.wordmark span{display:none}.chapter-tabs{grid-template-columns:repeat(4,minmax(0,1fr))}.chapter,.chapter:nth-child(n){font-size:12px;min-height:44px}.chapter span{display:none}.mobile-page-links{padding:3px 0}.mobile-page-links button{min-height:36px}.notebook-footer{padding-top:0;padding-bottom:env(safe-area-inset-bottom)}.turn-page{min-height:36px}}

@media(max-width:900px){.trace-figure svg text[x="470"],.trace-figure svg text[x="475"],.trace-figure svg text[x="474"],.trace-figure svg text[x="485"],.trace-figure svg text[x="428"],.trace-figure svg text[x="436"],.trace-figure svg text[x="425"]{text-anchor:end}#background-plot text[x="224"]{font-size:18px}#model-plot text[x="111"]{font-size:18px}}