.bk{--bk-paper:#f7f5f0;--bk-ink:#141414;--bk-accent:#a8391a;--bk-rule:#c9c5ba;--bk-muted:#5f5f5b;--bk-card:#ffffff;--bk-free:#2f6b3a;background:var(--bk-paper);color:var(--bk-ink);margin-top:1.5rem;padding:0 1.25rem 2.5rem}.dark .bk{--bk-paper:#16140f;--bk-ink:#f1eee6;--bk-accent:#e58a63;--bk-rule:#3a3630;--bk-muted:#a6a196;--bk-card:#1f1c16;--bk-free:#8fd19b}@media (min-width:768px){.bk{padding:0 3rem 3.5rem}}.bk a{text-decoration:none}.bk-kicker{font-size:.8rem;letter-spacing:.14em;font-weight:600;color:var(--bk-accent)}.bk-head{padding:3rem 0 1.75rem;display:flex;flex-direction:column;gap:.75rem}.bk-h1{margin:0;font-size:clamp(2.1rem,7vw,3.75rem);line-height:1.2;font-weight:700}.bk-lead{margin:0;max-width:34rem;font-size:1.05rem;line-height:1.9;color:var(--bk-muted)}.bk-tabs{display:flex;flex-wrap:wrap;gap:.25rem 1.5rem;border-bottom:1px solid var(--bk-rule)}.bk-tab{background:none;border:0;border-bottom:2px solid transparent;margin-bottom:-1px;padding:0 0 .6rem;font:inherit;font-size:.95rem;color:var(--bk-muted);cursor:pointer}.bk-tab:hover{color:var(--bk-ink)}.bk-tab[aria-pressed=true]{color:var(--bk-ink);font-weight:700;border-bottom-color:var(--bk-accent)}.bk-row{display:flex;align-items:center;gap:1rem;padding:1.15rem 0;border-bottom:1px solid var(--bk-rule);color:inherit}.bk-row:focus-visible .bk-title,.bk-row:hover .bk-title{color:var(--bk-accent)}.bk-num{width:1.75rem;flex:none;font-size:1.05rem;color:var(--bk-accent)}.bk-thumb{width:3.5rem;height:4.75rem;flex:none;overflow:hidden;background:#141414;display:flex;align-items:center;justify-content:center;color:#f7f5f0;font-size:1.15rem;text-align:center;line-height:1.3}.bk-thumb img{width:100%;height:100%;object-fit:cover}.bk-info{flex:1;min-width:0;display:flex;flex-direction:column;gap:.2rem}.bk-title{margin:0;font-size:1.2rem;font-weight:700;line-height:1.45}.bk-sub{font-size:.9rem;color:var(--bk-muted)}.bk-price{font-size:.95rem;font-weight:700;white-space:nowrap;text-align:right}.bk-price[data-free=true]{color:var(--bk-free)}.bk-arrow{font-size:1.3rem}@media (min-width:640px){.bk-thumb{width:4.5rem;height:6rem}.bk-title{font-size:1.4rem}.bk-row{gap:1.75rem}}.bk-empty{padding:2.5rem 0;color:var(--bk-muted);line-height:1.9}.bk-back{padding:1.5rem 0 0;font-size:.95rem}.bk-back a{color:var(--bk-accent)}.bk-detail{display:grid;grid-template-columns:minmax(0,1fr);gap:2rem;padding-top:1.75rem}@media (min-width:768px){.bk-detail{grid-template-columns:minmax(0,1fr) 17rem;gap:3.5rem}}.bk-main{display:flex;flex-direction:column;gap:1.1rem;min-width:0}.bk-h1-sm{margin:0;font-size:clamp(1.9rem,6vw,3.2rem);line-height:1.3;font-weight:700}.bk-author{font-size:1.05rem;color:var(--bk-muted)}.bk-desc{font-size:1.1rem;line-height:2}.bk-rail{display:flex;flex-direction:column;gap:1rem}@media (max-width:767px){.bk-rail{order:-1}}.bk-cover{width:100%;max-width:17rem;aspect-ratio:3/4;background:#141414;color:#f7f5f0;overflow:hidden;display:flex;align-items:center;justify-content:center;flex-direction:column;gap:.6rem;text-align:center}.bk-cover img{width:100%;height:100%;object-fit:cover}.bk-buy{border-top:2px solid var(--bk-ink);padding-top:1rem;display:flex;flex-direction:column;gap:.75rem;max-width:17rem}.bk-buy-price{font-size:1.9rem;font-weight:700}.bk-btn,.bk-btn-ghost{display:block;width:100%;text-align:center;padding:.8rem 1rem;font:inherit;font-size:1rem;font-weight:700;cursor:pointer;border-radius:0}.bk-btn{background:var(--bk-accent);color:#ffffff;border:1px solid var(--bk-accent)}.dark .bk-btn{color:#16140f}.bk-btn:hover{filter:brightness(.92)}.bk-btn:disabled{opacity:.65;cursor:default}.bk-btn-ghost{background:transparent;color:var(--bk-ink);border:1px solid var(--bk-ink)}.bk-btn-ghost:hover{background:var(--bk-ink);color:var(--bk-paper)}.bk-note{font-size:.85rem;line-height:1.8;color:var(--bk-muted)}.bk-error{font-size:.9rem;color:#c0392b}.bk-toc-head{margin-top:1.5rem;padding-bottom:.6rem;border-bottom:1px solid var(--bk-ink);display:flex;align-items:baseline;justify-content:space-between;gap:1rem}.bk-toc-title{letter-spacing:.14em;font-weight:700}.bk-toc-count,.bk-toc-title{font-size:.85rem;color:var(--bk-muted)}.bk-ch-btn,.bk-ls-btn{width:100%;display:flex;align-items:baseline;gap:1rem;background:none;border:0;border-bottom:1px solid var(--bk-rule);color:inherit;font:inherit;text-align:left;cursor:pointer;padding:1rem 0}.bk-ch-btn{font-size:1.15rem;font-weight:700}.bk-ch-btn:hover,.bk-ch-no,.bk-ls-btn:hover:not(:disabled){color:var(--bk-accent)}.bk-ch-no{width:2rem;flex:none}.bk-grow{flex:1;min-width:0}.bk-ls-btn{padding:.8rem 0 .8rem 1.5rem;font-size:1rem}.bk-ls-btn:disabled{color:var(--bk-muted);cursor:default}.bk-tag{font-size:.8rem;font-weight:700;white-space:nowrap;color:var(--bk-muted)}.bk-tag[data-free=true]{color:var(--bk-free)}.bk-tag svg{vertical-align:-2px;margin-right:.25rem}.bk-lesson{padding:1.75rem 0 2.25rem;border-bottom:1px solid var(--bk-ink);max-width:40rem}@media (min-width:640px){.bk-lesson{padding-left:1.5rem}}.bk-prose{font-size:1.15rem;line-height:2.1}.bkr-overlay{position:fixed;inset:0;z-index:200;background:rgba(10,10,8,.6);display:flex;align-items:stretch;justify-content:center}.bkr{--r-paper:#f7f5f0;--r-ink:#141414;--r-muted:#5f5f5b;--r-rule:#c9c5ba;--r-accent:#a8391a;--hl:#ffe98a;position:relative;display:flex;flex-direction:column;width:100%;height:100dvh;background:var(--r-paper);color:var(--r-ink)}.bkr[data-night=true]{--r-paper:#121110;--r-ink:#e8e4da;--r-muted:#a09b90;--r-rule:#34302a;--r-accent:#e58a63;--hl:#6b5a12}@media (min-width:768px){.bkr-overlay{align-items:center}.bkr{width:min(52rem,94vw);height:92dvh;border:1px solid var(--r-rule);box-shadow:0 20px 60px rgba(0,0,0,.4)}}.bkr-top{display:flex;align-items:center;gap:.5rem;padding:.4rem .5rem .4rem .9rem;border-bottom:1px solid var(--r-rule);flex:none}.bkr-ttl{flex:1;min-width:0;font-size:.9rem;color:var(--r-muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.bkr-tb,.bkr-x{background:none;border:1px solid transparent;color:var(--r-ink);font:inherit;cursor:pointer;min-width:44px;min-height:44px;display:inline-flex;align-items:center;justify-content:center;gap:.3rem;padding:0 .6rem;font-size:.95rem;white-space:nowrap}.bkr-x{font-size:1.3rem}.bkr-tb:hover,.bkr-x:hover{border-color:var(--r-rule)}.bkr-tools{display:flex;gap:.15rem;padding:.25rem .5rem;border-bottom:1px solid var(--r-rule);overflow-x:auto;flex:none;-webkit-overflow-scrolling:touch}.bkr-tb[data-on=true]{background:var(--r-ink);color:var(--r-paper)}.bkr-scroll{flex:1;overflow-y:auto;-webkit-overflow-scrolling:touch}.bkr-page{max-width:40rem;margin:0 auto;padding:1.75rem 1.25rem 3rem}.bkr-h{margin:0 0 1.25rem;font-size:1.5em;line-height:1.4;font-weight:700}.bkr-prose{line-height:2.1;word-break:break-word}.bkr-prose p{margin:0 0 1em}.bkr-prose h3,.bkr-prose h4{margin:1.4em 0 .5em;line-height:1.5;font-weight:700}.bkr-prose ol,.bkr-prose ul{margin:0 0 1em;padding-left:1.5em}.bkr-prose ul{list-style:disc}.bkr-prose ol{list-style:decimal}.bkr-prose blockquote{margin:1em 0;padding-left:1em;border-left:3px solid var(--r-accent);color:var(--r-muted)}.bkr-prose table{width:100%;border-collapse:collapse;margin:1em 0;display:block;overflow-x:auto}.bkr-prose td,.bkr-prose th{border:1px solid var(--r-rule);padding:.4em .6em}.bkr-prose a{color:var(--r-accent);text-decoration:underline}.bkr-prose img{max-width:100%;height:auto}.bkr[data-night=true] .bkr-h,.bkr[data-night=true] .bkr-prose *{background-color:initial!important;color:inherit!important}.bkr-prose mark.bkr-hl,mark.bkr-hl{background:var(--hl)!important;color:inherit!important;cursor:pointer;padding:.05em 0}.bkr-hint{margin-top:2rem;font-size:.82rem}.bkr-hint,.bkr-lock{color:var(--r-muted)}.bkr-lock{display:flex;flex-direction:column;gap:.9rem;align-items:flex-start;padding:1.5rem 0;line-height:1.9}.bkr-lock .bk-btn{max-width:16rem;--bk-accent:var(--r-accent)}.bkr-nav{display:flex;align-items:center;justify-content:space-between;gap:.5rem;border-top:1px solid var(--r-rule);padding:.4rem .5rem calc(.4rem + env(safe-area-inset-bottom));flex:none}.bkr-nb{background:none;border:0;color:var(--r-ink);font:inherit;font-size:.95rem;font-weight:700;min-height:44px;padding:0 .6rem;cursor:pointer}.bkr-nb:hover:not(:disabled){color:var(--r-accent)}.bkr-nb:disabled{opacity:.35;cursor:default}.bkr-count{font-size:.85rem;color:var(--r-muted)}.bk-lsmark{color:var(--bk-accent);margin-right:.35rem}.bkr-tb[aria-pressed=true]{background:var(--r-ink);color:var(--r-paper)}.bkr-tb:disabled{opacity:.35;cursor:default}