:root{color-scheme:light;--ink:#182c3e;--muted:#64717b;--gold:#af8544;--canvas:#eae9e4;--paper:#fffefb;--line:#deded5;--text-size:14px}*{box-sizing:border-box}body{margin:0;background:var(--canvas);color:var(--ink);font-family:Arial,'Apple SD Gothic Neo','Malgun Gothic',sans-serif}a{color:inherit}button,select{font:inherit;color:inherit}button,a,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer;border:1px solid var(--line);border-radius:6px;background:var(--paper);padding:10px 14px;min-height:42px}button:hover,a.preview:hover{border-color:var(--gold);color:var(--gold)}button:disabled{opacity:.4;cursor:default}:focus-visible{outline:3px solid #c39650;outline-offset:4px}.reader-header{height:78px;background:#142c40;color:#fff;display:flex;align-items:center;gap:32px;padding:0 36px;border-bottom:3px solid var(--gold)}.brand{text-decoration:none;font-size:23px;letter-spacing:2px;font-weight:800;white-space:nowrap}.brand span{color:#dfb777}.edition{font-size:10px;letter-spacing:2px;color:#c4d1dc}.edition b{display:block;font-size:14px;letter-spacing:1px;margin-top:5px;color:white}.back{margin-left:auto;font-size:13px;text-decoration:none}.reader-layout{display:grid;grid-template-columns:285px minmax(0,1fr);max-width:1600px;margin:auto}aside{height:calc(100dvh - 78px);position:sticky;top:0;overflow:auto;background:var(--paper);border-right:1px solid var(--line);padding:30px 22px}.toc-head{display:flex;align-items:center;justify-content:space-between;color:var(--muted);font-size:11px;letter-spacing:2px;margin-bottom:24px}.toc-head b{display:block;font-size:22px;letter-spacing:0;margin-top:6px;color:var(--ink)}#close-toc{display:none}nav a{display:block;text-decoration:none;line-height:1.7;padding:9px 10px;font-size:13px;border-radius:5px}nav a[aria-current=page]{background:#ede7da;color:#5e431d;font-weight:700}nav a span{display:block;color:var(--muted);font-size:11px}nav details{border-top:1px solid var(--line);margin-top:12px;padding-top:12px}nav summary{cursor:pointer;font-size:14px;font-weight:700;padding:10px 0;line-height:1.5}nav summary small{color:var(--gold);font-size:10px;margin-right:8px}nav .locked{color:var(--muted)}.toc-note{font-size:11px;line-height:1.8;color:var(--muted);margin-top:32px}main{min-width:0;padding:22px 5% 24px}.reading-tools{display:flex;align-items:center;gap:14px;max-width:870px;margin:0 auto 20px;font-size:12px}.preferences{margin-left:auto;display:flex;align-items:center;gap:6px}.preferences button{padding:7px 10px}.preferences span{min-width:20px;text-align:center;color:var(--muted)}#open-toc{display:none}#access-label{color:var(--muted)}#status{max-width:870px;margin:auto;color:var(--muted);font-size:13px}#status:not(:empty){padding:0 0 15px}#paper{max-width:870px;margin:auto;background:var(--paper);min-height:690px;padding:58px 64px 54px;box-shadow:0 12px 36px #152a3a0c,3px 3px 0 var(--line);border:1px solid var(--line);border-radius:2px;overflow-wrap:anywhere;animation:turn .23s ease-out;transform-origin:left center}#paper:focus{outline:none}@keyframes turn{from{opacity:.5;transform:perspective(1500px) rotateY(2deg) translateX(7px)}to{opacity:1;transform:none}}.eyebrow{font-size:11px;font-weight:700;letter-spacing:2px;color:var(--gold);margin:0 0 20px}.book-title{font-family:Georgia,'Batang',serif;font-size:clamp(38px,5vw,60px);line-height:1.25;letter-spacing:-2px;margin:0 0 20px}.book-title span{display:block;font-size:.4em;letter-spacing:0;font-family:Arial,sans-serif;margin-bottom:16px}.deck{color:var(--muted);font-size:17px;line-height:1.9}.rule{height:1px;background:var(--gold);width:65px;margin:30px 0}.metrics{display:flex;gap:35px;padding:20px 0 28px;border-bottom:1px solid var(--line);margin-bottom:32px}.metrics b{display:block;font-family:Georgia,serif;font-size:28px}.metrics span{font-size:11px;color:var(--muted)}.prose{font-size:var(--text-size);line-height:1.95;word-break:keep-all;overflow-wrap:anywhere}.prose p{margin:0 0 1.2em}.prose h2{font-size:1.15em;margin:1.8em 0 .8em}.previews{display:grid;gap:9px;margin-top:28px}.preview{display:flex;align-items:center;justify-content:space-between;text-decoration:none;border:1px solid var(--line);border-radius:6px;padding:15px 18px;font-size:14px;gap:14px}.preview small{color:var(--muted);font-size:11px}.unit-title{font-size:25px;line-height:1.5;margin:0 0 8px;letter-spacing:-.8px}.unit-meta{font-size:12px;color:var(--muted);line-height:1.7;margin-bottom:28px}.mode{display:flex;border-bottom:1px solid var(--line);gap:24px;margin:24px 0 35px}.mode button{background:transparent;border:0;border-radius:0;border-bottom:2px solid transparent;padding:12px 0;font-size:14px;color:var(--muted)}.mode button[aria-pressed=true]{color:var(--ink);border-color:var(--gold);font-weight:bold}.question-number{font-family:Georgia,serif;font-size:38px;color:var(--gold);margin-bottom:20px}.question-text{font-size:calc(var(--text-size) + 2px);line-height:1.8;font-weight:600;word-break:keep-all}.options{list-style:none;margin:32px 0;padding:0;display:grid;gap:10px;font-size:var(--text-size);line-height:1.8}.options li{padding:15px 18px;background:color-mix(in srgb,var(--canvas) 40%,var(--paper));border-radius:4px}.answer-heading{font-size:calc(var(--text-size) + 2px);line-height:1.8;padding:18px 22px;border-left:3px solid var(--gold);background:color-mix(in srgb,var(--gold) 9%,var(--paper));margin-bottom:20px}.answer-meta{font-size:12px;color:var(--muted);line-height:1.8;margin-bottom:28px}.answer-body p{padding-bottom:18px;border-bottom:1px solid var(--line)}.paper-bottom{margin-top:48px;display:flex;justify-content:space-between;border-top:1px solid var(--line);padding-top:18px;font-size:10px;letter-spacing:1px;color:var(--muted)}.page-nav{display:flex;align-items:center;justify-content:space-between;gap:12px;max-width:870px;margin:22px auto 0;font-size:13px}.page-nav[hidden]{display:none}.page-nav select{padding:8px;border:1px solid var(--line);border-radius:5px;background:var(--paper)}.reader-note{text-align:center;font-size:10px;color:var(--muted);letter-spacing:2px;margin:25px 0 0}.notice{font-size:14px;line-height:1.8;color:var(--muted);padding:18px;border:1px solid var(--line);margin:26px 0}.primary-link{display:inline-block;background:#18354b;color:white;border-radius:5px;padding:14px 20px;text-decoration:none;font-size:14px}.night{color-scheme:dark;--ink:#e1e4e7;--muted:#a5b1bb;--canvas:#101c26;--paper:#1d2d3a;--line:#3a4a57;--gold:#d3ae71}.night nav a[aria-current=page]{background:#3b403f;color:#f1d6aa}@media(min-width:1400px){main{padding-top:28px}}@media(max-width:1000px){.reader-layout{grid-template-columns:245px minmax(0,1fr)}#paper{padding:38px 32px}main{padding:20px 24px}.reader-header{padding:0 24px}}@media(max-width:760px){.reader-header{height:66px;padding:0 18px;gap:17px}.brand{font-size:19px}.edition{font-size:8px}.edition b{font-size:12px}.back{font-size:11px}.reader-layout{display:block}aside{display:none;position:fixed;top:66px;bottom:0;left:0;width:min(90vw,340px);height:calc(100dvh - 66px);z-index:10;box-shadow:15px 0 40px #0005}aside.open{display:block}#close-toc,#open-toc{display:block}main{padding:14px 12px}.reading-tools{gap:8px;margin-bottom:14px}.preferences{gap:3px}.preferences button{padding:7px 9px}#access-label{font-size:10px}#paper{padding:34px 24px;min-height:580px}.unit-title{font-size:22px}.metrics{gap:30px}.question-text{font-size:var(--text-size)}.page-nav{margin-top:18px}.book-title{font-size:44px}}@media(prefers-reduced-motion:reduce){#paper{animation:none}}
/* Shared visual language with the theory book viewer. */
body{background:radial-gradient(ellipse at 50% 25%,#233a4b 0,#102231 50%,#08131d 100%);background-attachment:fixed;font-family:system-ui,-apple-system,'Malgun Gothic',sans-serif}.reader-header{height:auto;min-height:74px;padding:15px 28px;background:#0b1722bb;border-bottom:1px solid #ffffff14;justify-content:space-between;gap:20px}.reader-identity{display:flex;align-items:center;gap:18px}.brand{font-family:Georgia,serif;font-size:23px;letter-spacing:0;font-weight:700}.brand span{color:#d7b774}.edition{font-size:17px;color:#f5f6f7;letter-spacing:0;border-left:1px solid #ffffff24;padding-left:18px}.header-actions{display:flex;gap:8px;align-items:center}.header-actions button,.header-actions a,#part-tabs a{font-size:14px;min-height:42px;border:1px solid #ffffff29;border-radius:6px;background:#ffffff06;color:#f5f6f7;padding:9px 16px;text-decoration:none;line-height:1.5}.header-actions a{margin:0}.header-actions button:hover,.header-actions a:hover,#part-tabs a:hover{background:#ffffff15;border-color:#d7b774}#open-toc{display:block}#part-tabs{display:flex;gap:8px;padding:8px 20px;background:#102231;border-bottom:1px solid #ffffff14;overflow-x:auto}#part-tabs a{white-space:nowrap;flex-shrink:0;padding:12px 15px}#part-tabs a[aria-current=page]{background:#d7b774;border-color:#d7b774;color:#142331;font-weight:650}#preview-notice{padding:8px 20px;font-size:14px;line-height:1.7;color:#f5f6f7;background:#102231}.reader-layout{display:block;max-width:none}.reader-layout main{padding:20px 28px 0}.reader-layout aside{position:fixed;top:0;left:0;bottom:0;height:100dvh;width:286px;z-index:20;box-shadow:15px 0 40px #0007;background:#0b1925;color:#f5f6f7;border-right:1px solid #ffffff1a;padding:22px 16px}.reader-layout aside[hidden]{display:none}.reader-layout aside.open{display:block}.toc-head b{color:#f5f6f7}.toc-head,.toc-note,aside nav a span{color:#aebac6}aside nav details{border-color:#ffffff1a}aside nav a[aria-current=page]{background:#d7b774;color:#142331}aside nav a[aria-current=page] span{color:#344451}aside nav .locked{color:#aebac6}#close-toc{display:block;background:#ffffff06;color:white;border-color:#ffffff29}.reading-tools{max-width:870px;color:#aebac6}#access-label,#status{color:#d7b774}.preferences span{color:#aebac6}.preferences button{background:#ffffff06;border-color:#ffffff29;color:#f5f6f7}#paper{box-shadow:0 18px 25px #0007;border:0;border-radius:3px;min-height:690px}.page-nav{max-width:none;justify-content:center;background:#0b1722bb;border-top:1px solid #ffffff14;margin:24px -28px 0;padding:12px 20px 16px;color:#f5f6f7;gap:18px}.page-nav button{background:#d7b774;border-color:#d7b774;color:#142331;font-weight:650;min-width:74px}.page-nav select{background:#ffffff0b;border-color:#ffffff30;color:white}.page-nav option{background:#102231;color:white}.reader-note{color:#aebac6;padding-bottom:20px}.expanded #paper,.expanded .reading-tools{max-width:1180px}.expanded #paper{padding:48px 7%}.night #paper{--paper:#1d2d3a;--ink:#e1e4e7}.header-actions a:focus-visible,#part-tabs a:focus-visible{outline:3px solid #d7b774;outline-offset:2px}@media(max-width:760px){.reader-header{padding:12px 14px;gap:12px;flex-wrap:wrap}.reader-identity{gap:12px}.edition{font-size:15px;padding-left:12px}.header-actions{gap:5px;flex-wrap:wrap}.header-actions button,.header-actions a{font-size:12px;padding:8px 10px}#part-tabs{padding:8px 12px}#part-tabs a{font-size:13px;padding:10px 12px}#preview-notice{font-size:12px;padding:7px 12px}.reader-layout main{padding:14px 12px 0}.page-nav{margin-left:-12px;margin-right:-12px}.reading-tools{margin-bottom:14px}#paper{min-height:580px}.expanded #paper{padding:30px 18px}}

#paper{animation:none;touch-action:pan-y;backface-visibility:hidden;will-change:auto}.page-turn-layer{position:absolute;z-index:12;pointer-events:none;overflow:hidden;backface-visibility:hidden;box-shadow:0 18px 35px #0007;border-radius:3px;transform-style:preserve-3d}.turn-paper{overflow-wrap:anywhere;box-sizing:border-box;box-shadow:inset 9px 0 24px #00000010;min-height:100%}@media(prefers-reduced-motion:reduce){.page-turn-layer{display:none}}
/* Bound-book spread: one moving leaf, two faces, and a stationary opposite page. */
#paper.book-spread{position:relative;display:grid;grid-template-columns:1fr 1fr;max-width:1120px;padding:0;min-height:0;height:min(790px,calc(100dvh - 260px));min-height:570px;background:var(--paper);perspective:2600px;overflow:visible;box-shadow:0 22px 45px #0008,0 3px 0 #d1cbbd,0 6px 0 #eee9dc;border-radius:3px}.book-leaf{min-width:0;position:relative;display:flex;flex-direction:column;padding:32px 42px 25px;background:#fffdf7;color:#283037;height:100%;overflow:hidden;font-family:Georgia,'Batang','바탕',serif}.left-leaf{border-radius:3px 0 0 3px;background:linear-gradient(90deg,#fffdf7 92%,#e8e3d8 100%)}.right-leaf{border-radius:0 3px 3px 0;background:linear-gradient(90deg,#e8e3d8 0%,#fffdf7 8%)}.book-binding{position:absolute;left:50%;top:0;bottom:0;width:2px;background:#504a3938;box-shadow:0 0 16px 4px #51483918;z-index:3;pointer-events:none}.running-head{display:flex;justify-content:space-between;gap:16px;font-family:system-ui,sans-serif;color:#7d786d;font-size:10px;line-height:1.5;padding-bottom:18px;margin-bottom:18px;border-bottom:1px solid #cfc7b950;flex-shrink:0}.running-head span:last-child{text-align:right}.leaf-body{flex:1;min-height:0;overflow-y:auto;scrollbar-width:thin;scrollbar-color:#cbbfa5 transparent;padding-right:5px}.folio{text-align:center;font-size:12px;color:#6f685c;padding-top:20px;flex-shrink:0}.book-spread .eyebrow{font-size:10px;letter-spacing:1px;margin-bottom:14px;color:#967641;font-family:system-ui,sans-serif}.book-spread .unit-title{font-size:22px;line-height:1.6;font-weight:600;margin-bottom:30px;font-family:Georgia,'Batang','바탕',serif}.book-spread .question-number{font-size:32px;margin-bottom:16px;font-family:Georgia,serif;color:#9d7e47}.book-spread .question-text{font-size:var(--text-size);font-weight:600;line-height:1.95;margin:0 0 24px}.book-spread .options{font-size:var(--text-size);gap:16px;margin:24px 0;line-height:1.85}.book-spread .options li{background:none;border-radius:0;padding:0}.book-spread .answer-heading{border:0;background:none;padding:0 0 17px;border-bottom:1px solid #ba9b6366;font-size:var(--text-size);margin:0 0 15px}.book-spread .answer-meta{font-family:system-ui,sans-serif;font-size:10px;color:#847e73;margin-bottom:22px}.book-spread .prose{font-size:calc(var(--text-size) - 2px);line-height:1.95}.book-spread .answer-body p{border:0;padding:0;margin:0 0 1.2em}.leaf-action{margin-top:32px}.leaf-action button,.reflection button{font-family:system-ui,sans-serif;background:transparent;color:#7c6337;border:1px solid #bda774;font-size:12px;padding:10px 15px}.source-id{font-family:system-ui,sans-serif;font-size:9px;color:#928a7c;margin-top:24px}.reflection{display:flex;min-height:90%;flex-direction:column;align-items:center;justify-content:center;text-align:center}.reflection h2{font-size:23px;line-height:1.8;font-weight:500}.reflection p:not(.eyebrow){font-size:16px;color:#82796a;line-height:2}.reflection .rule{margin:20px 0}.reflection button{margin-top:24px}.turning-leaf{position:absolute;top:0;width:50%;height:100%;z-index:8;transform-style:preserve-3d;pointer-events:none}.turning-leaf.forward{left:50%;transform-origin:left center}.turning-leaf.backward{left:0;transform-origin:right center}.turn-face{position:absolute;inset:0;width:100%;height:100%;backface-visibility:hidden;border-radius:2px;box-shadow:0 0 25px #0003}.turn-face.front{transform:rotateY(0deg);background:linear-gradient(90deg,#e9e3d8,#fffdf7 10%,#fffdf7 90%,#eee9dd)}.turn-face.back{transform:rotateY(180deg);background:linear-gradient(90deg,#fffdf7 85%,#ddd6c8)}.stationary-leaf{position:absolute;top:0;width:50%;height:100%;z-index:4;pointer-events:none}.stationary-leaf.left-leaf{left:0}.stationary-leaf.right-leaf{left:50%}.expanded #paper.book-spread{max-width:1400px;height:1000px}.night .book-leaf{background:#263542;color:#e3e0d7}.night .reflection p:not(.eyebrow),.night .running-head,.night .folio{color:#b6b0a4}.night .turn-face{background:#263542}@media(max-width:1000px){.book-leaf{padding:25px 27px 20px}.book-spread .unit-title{font-size:20px}}@media(max-width:760px){#paper.book-spread{display:block;height:calc(100dvh - 275px);min-height:520px;max-width:580px;perspective:none}.book-spread .right-leaf{display:none}.book-spread.show-answer .left-leaf{display:none}.book-spread.show-answer .right-leaf{display:flex}.book-leaf{padding:25px 28px 20px;background:#fffdf7;border-radius:3px}.book-binding{display:none}.book-spread .question-text,.book-spread .options{font-size:var(--text-size)}.expanded #paper.book-spread{height:85dvh;padding:0}.turn-paper.book-spread{display:block!important;padding:0!important}.turn-paper .book-leaf{height:100%}.turn-paper .right-leaf{display:none}.turn-paper.show-answer .left-leaf{display:none}.turn-paper.show-answer .right-leaf{display:flex}.turn-paper .book-binding{display:none}}

/* Adult-reader typography: restrained default, adjustable for comfortable reading. */
.book-spread .unit-title{font-size:19px;line-height:1.6;letter-spacing:-.3px;margin-bottom:25px}.book-spread .question-number{font-size:26px;margin-bottom:14px}.book-spread .question-text{font-size:var(--text-size);line-height:1.85;font-weight:600}.book-spread .options{font-size:var(--text-size);line-height:1.85;gap:14px}.book-spread .prose{font-size:var(--text-size);line-height:1.9}.book-spread .answer-heading{font-size:calc(var(--text-size) + 1px);line-height:1.7}.reflection h2{font-size:20px;line-height:1.8}.reflection p:not(.eyebrow){font-size:16px;line-height:1.9}.book-title{font-size:44px;letter-spacing:-1px}.deck{font-size:16px}.metrics b{font-size:25px}@media(max-width:760px){.book-title{font-size:36px}.book-spread .unit-title{font-size:19px}.reflection h2{font-size:19px}}

.book-spread .unit-title{font-size:calc(var(--text-size) + 2px)}.book-spread .question-number{font-size:calc(var(--text-size) + 6px)}.book-spread .answer-heading{font-size:var(--text-size)}
/* Preserve an A4 leaf ratio regardless of text length or viewport height. */
#paper.book-spread{width:min(100%,1120px);max-width:1120px;height:auto;min-height:0;aspect-ratio:420 / 297;grid-template-rows:minmax(0,1fr)}.book-spread .book-leaf{min-height:0}.expanded #paper.book-spread{width:min(100%,1400px);max-width:1400px;height:auto;min-height:0;aspect-ratio:420 / 297}@media(max-width:760px){#paper.book-spread,.expanded #paper.book-spread{width:min(100%,580px);max-width:580px;height:auto;min-height:0;aspect-ratio:210 / 297}.book-spread .book-leaf{height:100%}}

#reading-progress{font-size:12px;color:#aebac6}.page-nav{flex-wrap:wrap}@media(max-width:760px){#reading-progress{flex-basis:100%;text-align:center}}

/* Desktop reading viewport: reserve controls before fitting the A4 spread. */
#book-stage{min-width:0}#theme{white-space:nowrap}.night #paper{background:#263542;color:#e3e0d7}.night .book-leaf,.night .turn-face{background:#263542;color:#e3e0d7}.night .book-spread .question-text,.night .book-spread .options,.night .book-spread .prose,.night .book-spread .unit-title,.night .book-spread .answer-heading{color:#e3e0d7}.night .leaf-action button,.night .reflection button{color:#e4c48e;border-color:#aa946d}
@media(min-width:761px){body{height:100dvh;overflow:hidden;display:flex;flex-direction:column}.reader-header,#part-tabs,#preview-notice{flex-shrink:0}.reader-header{min-height:64px;padding-top:10px;padding-bottom:10px}#part-tabs{padding-top:6px;padding-bottom:6px}#part-tabs a{padding-top:9px;padding-bottom:9px}#preview-notice{padding-top:5px;padding-bottom:5px;font-size:12px}.reader-layout{flex:1;min-height:0;width:100%;display:flex}.reader-layout main{width:100%;height:100%;min-height:0;display:flex;flex-direction:column;padding:10px 20px 0}.reading-tools{width:100%;max-width:1120px;margin:0 auto 8px;flex-shrink:0}#status{flex-shrink:0}#book-stage{flex:1;min-height:0;overflow:hidden;display:flex;align-items:flex-start;justify-content:center;padding:4px 7px 10px}#paper{max-height:100%;overflow-y:auto;min-height:0;width:min(100%,870px)}#paper.book-spread{flex-shrink:0;max-height:none;max-width:none;overflow:visible;margin:0;min-height:0}.expanded #book-stage{overflow:auto;justify-content:flex-start}.expanded #paper.book-spread{max-width:none;margin:0 auto}.page-nav{flex-shrink:0;width:calc(100% + 40px);margin:0 -20px;padding:9px 16px;gap:12px}.reader-note{display:none}.book-leaf{padding:clamp(14px,2vh,30px) clamp(18px,2.4vw,40px) 15px}.running-head{padding-bottom:10px;margin-bottom:12px}.folio{padding-top:12px}.book-spread .unit-title{margin-bottom:18px}.leaf-action{margin-top:20px}}

#question-select{width:auto;min-width:140px;max-width:230px}@media(max-width:600px){#question-select{min-width:110px;max-width:160px}}

.speech-tools{display:flex;align-items:center;gap:8px;flex-wrap:wrap;padding:0 0 10px;font-size:12px;flex-shrink:0}.speech-tools button,.speech-tools select{font:inherit;min-height:34px;padding:5px 10px}.speech-tools label{display:flex;align-items:center;gap:5px}#speech-status{font-size:12px;color:var(--gold,#d9b96b)}@media(max-width:600px){.speech-tools{gap:5px;padding:0 8px 6px}.speech-tools button{padding:4px 7px}#speech-status:empty{display:none}}