@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@400;500;600;700&family=Noto+Serif+JP:wght@500;700&display=swap');
body.buku-active #app>.page{animation:none}.bk-app{--bk-purple:#6651ad;--bk-soft:#f0ebf8;--bk-mint:#e7f2ec;--bk-muted:#66756d;--bk-paper:#fffdf5;--bk-page-ink:#293e35;--bk-n5:#2563eb;--bk-n4:#3b963f;--bk-n3:#eab308;--bk-n2:#ea7b12;--bk-n1:#dc2626;color:var(--ink);font:17px/1.75 'DM Sans','Noto Sans JP',system-ui,sans-serif;max-width:1100px;margin:auto}.bk-app *{box-sizing:border-box}.bk-app button,.bk-app summary,.bk-app h2,.bk-app h3{font-family:'DM Sans','Noto Sans JP',system-ui,sans-serif}.bk-app button{font-size:16px;min-height:44px;transition:none!important;transform:none!important;animation:none!important;cursor:pointer}.bk-app button:disabled{opacity:.45;cursor:default}.bk-app button:focus-visible,.bk-app summary:focus-visible,.bk-app a:focus-visible{outline:3px solid #c5842e;outline-offset:4px}.bk-app [hidden]{display:none!important}.bk-app [lang=ja]{font-family:'Noto Sans JP',sans-serif;word-break:normal;overflow-wrap:anywhere}.bk-kicker{font-size:12px;color:var(--bk-purple);letter-spacing:1.8px}.bk-welcome{padding:30px;background:linear-gradient(120deg,#e8f1e9,#f3ecf8);border:1px solid #d9e5dc;border-radius:12px;position:relative;overflow:hidden;margin-bottom:32px}.bk-welcome h2{font-size:34px;line-height:1.4;margin:12px 0}.bk-welcome p{color:var(--bk-muted);font-size:16px}.bk-welcome-symbol{position:absolute;right:44px;top:48px;display:grid;place-items:center;width:125px;height:140px;border:3px solid #baa6d2;background:#fffcf4;box-shadow:8px 7px 0 #d6c8e7;transform:rotate(7deg);color:#8a70ad;font:70px 'Noto Serif JP',serif;border-radius:5px}.bk-welcome-symbol span{position:absolute;top:-25px;right:-27px;font-size:35px;color:#c39646}.bk-section-title{display:flex;justify-content:space-between;align-items:center;gap:15px;margin:20px 0}.bk-section-title h2{font-size:26px;line-height:1.4}.bk-section-title p{color:var(--bk-muted);font-size:14px;margin-top:5px}.bk-section-title button,.bk-link{background:none;color:var(--bk-purple);padding:9px 0;white-space:nowrap}.bk-shelf-section{margin-bottom:30px}.bk-shelf{display:flex;gap:23px;overflow-x:auto;scroll-snap-type:x mandatory;padding:5px 6px 21px;scrollbar-width:thin}.bk-book{flex:0 0 182px;background:none;text-align:left;padding:0;scroll-snap-align:start;min-width:0}.bk-cover{position:relative;width:100%;aspect-ratio:2/3;background:#e7ecdf;border-radius:4px 9px 9px 4px;box-shadow:4px 5px 0 #c9c8bb55,8px 9px 18px #26352d15;overflow:hidden;border-left:5px solid #ffffff45}.bk-cover:after{content:'';position:absolute;left:0;top:0;bottom:0;width:9px;background:linear-gradient(90deg,#0002,transparent)}.bk-cover img{width:100%;height:100%;object-fit:cover;display:block}.bk-cover-fallback{display:grid;place-items:center;width:100%;height:100%;font-size:60px;color:#6d8662;background:linear-gradient(135deg,#e6edd8,#e9dcf5)}.bk-cover-title{writing-mode:vertical-rl;position:absolute;right:12px;top:13px;max-height:80%;font:600 23px/1.7 'Noto Serif JP',serif!important;letter-spacing:3px;background:#fffcf2dc;padding:10px 6px;color:#344738;border-radius:3px;text-shadow:0 1px #fff}.bk-badge{display:inline-block;background:var(--bk-soft);color:var(--bk-purple);padding:3px 9px;font-size:12px;border-radius:4px;margin:13px 0 7px}.bk-book h3{font-size:21px;line-height:1.45;margin:0 0 3px}.bk-book-copy p{font-size:14px;color:var(--bk-muted)}.bk-sources{border-top:1px solid var(--line);padding:20px 0;color:var(--bk-muted);font-size:14px;margin-top:20px}.bk-sources summary{cursor:pointer;color:var(--bk-purple);min-height:44px;display:list-item}.bk-sources p{font-family:system-ui,sans-serif;line-height:1.8}.bk-sources a{color:var(--bk-purple)}.bk-back{padding:10px 15px;border:1px solid var(--line);border-radius:6px;background:var(--paper);color:var(--ink)}.bk-list{display:grid;gap:20px}.bk-book-list{display:flex;gap:20px;align-items:center;padding:17px;background:var(--paper);border:1px solid var(--line);border-radius:9px;width:100%}.bk-book-list .bk-cover{width:100px;flex-shrink:0}.bk-book-list .bk-cover-title{font-size:15px!important;right:6px;top:8px;letter-spacing:1px;padding:5px 3px}.bk-detail{display:grid;grid-template-columns:250px minmax(0,1fr);gap:45px;margin:28px auto 30px;max-width:800px}.bk-detail h2{font-size:34px;margin:10px 0 5px;line-height:1.5}.bk-subtitle{color:var(--bk-muted);font-size:18px}.bk-detail h3{margin:24px 0 9px;font-size:18px}.bk-description{font-family:system-ui,sans-serif;font-size:16px;line-height:1.9;color:var(--bk-muted)}.bk-primary{display:inline-flex;align-items:center;justify-content:center;background:var(--bk-purple);color:white;border:2px solid var(--bk-purple);padding:12px 22px;border-radius:6px;box-shadow:0 3px 0 #423671;gap:12px}.bk-detail .bk-primary{width:100%;margin-top:23px}.bk-chapter-list{max-width:800px;margin:25px auto}.bk-chapter-list h3{font-size:22px;margin-bottom:16px}.bk-chapter-list>button{display:flex;align-items:center;gap:17px;width:100%;background:var(--paper);border:1px solid var(--line);padding:18px;border-radius:8px;text-align:left;margin:12px 0}.bk-chapter-number{background:var(--bk-soft);color:var(--bk-purple);padding:8px 12px}.bk-chapter-list small{display:block;font-size:13px;color:var(--bk-muted);margin-top:4px}.bk-chapter-list>button>span:last-child{margin-left:auto}
.bk-reader-tools{display:flex;flex-wrap:wrap;align-items:center;gap:7px;position:sticky;top:0;z-index:12;background:var(--paper);padding:12px;border:1px solid var(--line);border-radius:9px;margin:0 0 26px;box-shadow:0 5px 20px #00000006}.bk-reader-tools>button,.bk-chapter-menu summary{background:var(--paper);border:1px solid var(--line);border-radius:5px;padding:7px 10px;min-height:44px;font-size:14px;color:var(--ink)}.bk-reader-tools>button[aria-pressed=true]{background:var(--bk-soft);color:var(--bk-purple);border-color:#bea9d6}.bk-chapter-menu{position:relative;margin-left:auto;font-size:14px}.bk-chapter-menu summary{cursor:pointer;list-style:none}.bk-chapter-menu[open]{z-index:15}.bk-chapter-menu button{display:block;background:var(--paper);border:1px solid var(--line);width:100%;min-width:180px;text-align:left;padding:13px}.bk-chapter-menu[open] button{position:relative}.bk-reading-title{margin-bottom:22px}.bk-reading-title h2{font-size:27px;line-height:1.5;margin:10px 0}.bk-progress{display:flex;gap:16px;align-items:center;margin:13px 0;font-size:13px;color:var(--bk-muted)}.bk-progress>div{height:5px;background:var(--line);border-radius:20px;flex:1;max-width:240px;overflow:hidden}.bk-progress i{display:block;background:#7a9c79;height:100%;border-radius:20px}.bk-audio-status{font-family:system-ui,sans-serif;font-size:13px;color:var(--bk-muted);min-height:20px;margin:8px 0}.bk-prose{max-width:780px;margin:auto}.bk-sentence{padding:22px 0;border-bottom:1px solid var(--line)}.bk-jp{font-size:var(--bk-font,22px);line-height:2.8!important;color:inherit;font-weight:400;letter-spacing:.03em}.bk-token{padding:0 1px}.bk-token ruby{ruby-align:center}.bk-token rt{font-size:.46em;line-height:1.2;letter-spacing:0}.bk-no-furi rt{visibility:hidden}.bk-color .bk-lv-5{border-bottom:2px solid var(--bk-n5)}.bk-color .bk-lv-4{border-bottom:2px solid var(--bk-n4)}.bk-color .bk-lv-3{border-bottom:2px solid var(--bk-n3)}.bk-color .bk-lv-2{border-bottom:2px solid var(--bk-n2)}.bk-color .bk-lv-1{border-bottom:2px solid var(--bk-n1)}.bk-sentence-actions{display:flex;gap:8px;margin:13px 0 2px;flex-wrap:wrap}.bk-sentence-actions button{font-size:13px;padding:7px 12px;background:var(--paper);border:1px solid var(--line);border-radius:5px;color:var(--bk-purple)}.bk-sentence-actions button:last-child{min-width:44px;margin-left:auto}.bk-translation{font:16px/1.85 system-ui,sans-serif;margin:15px 0 4px;color:var(--bk-muted)}.bk-explanation{background:#29382f;color:#edf4e9;border-radius:7px;padding:19px;margin:16px 0;font:15px/1.8 system-ui,sans-serif}.bk-explanation>div+div{margin-top:17px;padding-top:15px;border-top:1px solid #ffffff25}.bk-explanation strong{display:block;color:#d8c5ff;font-size:18px}.bk-explanation b{display:block;margin:6px 0;color:#e2eccc}.bk-explanation p{margin:0}.bk-spread{background:var(--bk-paper);color:var(--bk-page-ink);display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);border:1px solid #dcd5c3;border-radius:9px;overflow:hidden;box-shadow:0 13px 35px #382b1c10,4px 4px 0 #eee9dc;align-items:stretch}.bk-spread figure{margin:0;padding:22px;background:#f5f1e3;display:flex;flex-direction:column;justify-content:center;border-right:1px solid #dcd5c3}.bk-spread img{width:100%;height:auto;display:block;object-fit:contain;border-radius:4px}.bk-spread figcaption{font-size:12px;text-align:center;letter-spacing:1px;margin-top:18px;color:#7d7b6e}.bk-paper{padding:12px 25px 18px;background:linear-gradient(90deg,#e8e0d44d,transparent 18px)}.bk-paper .bk-sentence{border-color:#e2ded0}.bk-paper .bk-sentence:last-child{border-bottom:0}.bk-paper .bk-translation{color:#5e6b61}.bk-paper .bk-sentence-actions button{background:#fffdf6;border-color:#e0dccf;color:#67528e}.bk-page-controls{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:25px 0}.bk-page-controls button{background:var(--paper);border:1px solid var(--line);padding:10px 15px;border-radius:6px;color:var(--ink)}.bk-page-controls>span{font-size:14px;color:var(--bk-muted)}.bk-levels{margin:27px 0;padding:22px;background:var(--paper);border:1px solid var(--line);border-radius:8px}.bk-levels h3{font-size:17px;margin-bottom:14px}.bk-level-bar{height:8px;display:flex;border-radius:10px;overflow:hidden;background:var(--line)}.bk-level-fill{height:100%;display:block}.bk-level-5{background:var(--bk-n5)}.bk-level-4{background:var(--bk-n4)}.bk-level-3{background:var(--bk-n3)}.bk-level-2{background:var(--bk-n2)}.bk-level-1{background:var(--bk-n1)}.bk-level-legend{display:flex;gap:12px;flex-wrap:wrap;margin:14px 0 8px;font-size:13px}.bk-level-legend i{display:inline-block;width:8px;height:8px;margin-right:6px;border-radius:50%}.bk-levels p{font:12px/1.7 system-ui,sans-serif;color:var(--bk-muted)}.bk-finish-chapter{width:100%;margin:5px 0 20px}.bk-note{color:var(--bk-muted);text-align:center;font-size:14px;margin:20px 0}.bk-quiz{max-width:690px;margin:30px auto}.bk-quiz h2{font:500 25px/1.9 'Noto Sans JP',sans-serif;margin:24px 0}.bk-option{display:flex;align-items:center;gap:17px;text-align:left;width:100%;padding:17px;background:var(--paper);border:2px solid var(--line);border-radius:7px;margin:13px 0;color:var(--ink)}.bk-option>span{display:grid;place-items:center;width:32px;height:34px;background:var(--bk-soft);color:var(--bk-purple);flex-shrink:0}.bk-option.bk-correct{border-color:#70a08a;background:#e6f3ea;opacity:1!important;color:#244f3a}.bk-option.bk-wrong{border-color:#c3927d;background:#faeee6;opacity:1!important;color:#704b3d}.bk-feedback{font:15px/1.7 system-ui,sans-serif;min-height:30px;margin:20px 0}.bk-quiz>.bk-primary{width:100%}.bk-done{text-align:center;padding:40px 20px;background:var(--bk-soft);border-radius:12px;max-width:700px;margin:25px auto}.bk-done-star{display:block;font-size:45px;color:#b48a3f}.bk-done h2{font-size:32px;line-height:1.5;margin:14px 0}.bk-done>strong{display:block;font-size:66px;line-height:1.5;color:var(--bk-purple);margin-top:20px}.bk-done>strong small{font-size:27px}.bk-done>div{display:flex;gap:13px;justify-content:center;flex-wrap:wrap;margin-top:27px}.bk-error{color:#9a4e3d;font-family:system-ui,sans-serif;font-size:14px}.dark .bk-app{--bk-soft:#342f48;--bk-purple:#c0abfa;--bk-mint:#2d4639;--bk-muted:#aebeaf;--bk-paper:#2b3029;--bk-page-ink:#ece9d9;--bk-n5:#60a5fa;--bk-n4:#4ade80;--bk-n3:#facc15;--bk-n2:#fb923c;--bk-n1:#f87171}.dark .bk-welcome{background:linear-gradient(120deg,#293f32,#342f45);border-color:var(--line)}.dark .bk-primary{color:#241c34}.dark .bk-spread{border-color:#4e5144;box-shadow:4px 4px 0 #171f19}.dark .bk-spread figure{background:#252d26;border-color:#4e5144}.dark .bk-paper{background:#2b3029}.dark .bk-paper .bk-sentence{border-color:#4b5044}.dark .bk-paper .bk-sentence-actions button{background:#34392f;border-color:#58604e;color:#d2c3ef}.dark .bk-paper .bk-translation{color:#c5ceb9}.dark .bk-explanation{background:#18251e}.dark .bk-error{color:#e7ae98}
@media(max-width:850px){.bk-spread{grid-template-columns:1fr}.bk-spread figure{padding:20px;border-right:0;border-bottom:1px solid #dcd5c3}.bk-spread img{max-height:430px}.bk-paper{padding:10px 23px 20px}.bk-detail{grid-template-columns:190px minmax(0,1fr);gap:28px}.bk-chapter-menu{margin-left:0}.bk-reader-tools{gap:6px;padding:9px}.bk-reader-tools>button{padding:7px 9px}}
@media(max-width:520px){.bk-welcome{padding:23px 19px}.bk-welcome h2{font-size:28px;max-width:78%}.bk-welcome p{font-size:14px;position:relative;z-index:1}.bk-welcome-symbol{right:20px;top:49px;width:65px;height:82px;font-size:40px;border-width:2px;box-shadow:4px 4px 0 #d6c8e7}.bk-welcome-symbol span{font-size:24px;right:-14px;top:-16px}.bk-kicker{font-size:10px;letter-spacing:1.2px}.bk-section-title h2{font-size:25px}.bk-section-title p{font-size:13px}.bk-section-title button{font-size:14px}.bk-shelf{gap:20px}.bk-book{flex-basis:150px}.bk-book h3{font-size:19px}.bk-cover-title{font-size:20px!important}.bk-detail{grid-template-columns:1fr;gap:25px;margin-top:25px}.bk-cover-large{max-width:205px;margin:auto}.bk-detail h2{font-size:29px}.bk-detail>div+div{text-align:center}.bk-description{text-align:left;font-size:16px}.bk-detail h3{text-align:left}.bk-reader-tools>button span{display:none}.bk-reader-tools>button{font-size:13px}.bk-reader-tools>button[data-action=play-all]{flex:1}.bk-reader-tools{position:sticky;top:0;margin-left:-6px;margin-right:-6px}.bk-chapter-menu{width:100%}.bk-chapter-menu summary{font-size:13px}.bk-reading-title h2{font-size:25px}.bk-spread figure{padding:14px}.bk-spread figcaption{margin-top:11px}.bk-paper{padding:3px 17px 16px}.bk-jp{line-height:2.65!important;letter-spacing:0}.bk-sentence{padding:20px 0}.bk-sentence-actions button{font-size:12px;padding:7px 9px}.bk-translation{font-size:15px}.bk-page-controls button{font-size:13px;padding:9px 11px}.bk-levels{padding:19px}.bk-progress{font-size:12px}.bk-quiz h2{font-size:22px}.bk-option{padding:15px 13px;font-size:17px}.bk-done h2{font-size:27px}.bk-done>div{flex-direction:column}.bk-book-list .bk-cover{width:85px}.bk-book-list .bk-cover-title{font-size:14px!important}.bk-chapter-list>button{padding:15px;gap:13px}}
@media(prefers-reduced-motion:reduce){.bk-app *{animation:none!important;transition:none!important;scroll-behavior:auto!important}.bk-shelf{scroll-snap-type:none}}

/* Keep shelf covers aligned when a book title wraps. */
.bk-book:not(.bk-book-list){display:flex;flex-direction:column;align-items:stretch;justify-content:flex-start}.bk-book>.bk-cover{flex-shrink:0}

/* Serial fiction: keep the prose continuous, with optional study after the reading. */
.bk-credit{max-width:780px;margin:22px auto;color:var(--bk-muted);font:13px/1.8 'DM Sans',system-ui,sans-serif}.bk-serial-end{max-width:780px;margin:30px auto 24px;padding-top:22px;border-top:1px solid var(--line)}.bk-serial-end nav{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap}.bk-story-end{text-align:center;font-size:15px;letter-spacing:4px;margin:25px 0}.bk-optional-quiz{margin-top:26px;color:var(--bk-muted);font-size:14px}.bk-optional-quiz summary{cursor:pointer;min-height:44px;color:var(--bk-purple)}.bk-optional-quiz p{margin:10px 0}.bk-chapter-list button[aria-current=true]{border-color:var(--bk-purple);background:var(--bk-soft)}
@media(max-width:520px){.bk-serial-end nav{flex-direction:column}.bk-serial-end nav button{width:100%}.bk-credit{font-size:12px}}