:root{--font-sans:"Plus Jakarta Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;--font-mono:"Fira Code", monospace;--bg-dark:#0b0f19;--bg-card:#151d30;--bg-card-hover:#1c263e;--primary:#2563eb;--primary-hover:#1d4ed8;--accent:#10b981;--accent-hover:#059669;--text-primary:#f3f4f6;--text-secondary:#9ca3af;--text-muted:#6b7280;--border-color:#24324f;--glass-bg:#151d30b3;--glass-border:#24324f99;--shadow-sm:0 1px 2px 0 #0000000d;--shadow-md:0 4px 6px -1px #0000001a, 0 2px 4px -1px #0000000f;--shadow-lg:0 10px 15px -3px #0000001a, 0 4px 6px -2px #0000000d;--shadow-xl:0 20px 25px -5px #0003, 0 10px 10px -5px #0000000a}*{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-sans);background-color:var(--bg-dark);color:var(--text-primary);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;line-height:1.6}a{color:inherit;text-decoration:none;transition:all .2s}button,input,textarea{font-family:inherit}.container{width:100%;max-width:1200px;margin:0 auto;padding:0 2rem}header{background-color:var(--glass-bg);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);border-bottom:1px solid var(--glass-border);z-index:50;position:sticky;top:0}.header-container{justify-content:space-between;align-items:center;height:70px;display:flex}.logo-wrapper{color:#fff;letter-spacing:-.025em;align-items:center;gap:.75rem;font-size:1.5rem;font-weight:800;display:flex}.logo-wrapper span{background:linear-gradient(135deg,#60a5fa 0%,#2563eb 100%);-webkit-text-fill-color:transparent;-webkit-background-clip:text}.nav-links{align-items:center;gap:2rem;display:flex}.nav-link{color:var(--text-secondary);font-size:.95rem;font-weight:500}.nav-link:hover,.nav-link.active{color:#fff}.hero-section{background:radial-gradient(circle at 100% 0,#2563eb26,#0000 45%),radial-gradient(circle at 0 100%,#10b98114,#0000 45%);padding:5rem 0 6rem;position:relative;overflow:hidden}.hero-content{text-align:center;max-width:800px;margin:0 auto}.badge{color:#60a5fa;background-color:#2563eb26;border:1px solid #2563eb40;border-radius:9999px;align-items:center;margin-bottom:1.5rem;padding:.35rem .85rem;font-size:.8rem;font-weight:600;display:inline-flex}.hero-title{letter-spacing:-.04em;background:linear-gradient(90deg,#fff,#9ca3af);-webkit-text-fill-color:transparent;-webkit-background-clip:text;margin-bottom:1.5rem;font-size:3.5rem;font-weight:800;line-height:1.15}.hero-subtitle{color:var(--text-secondary);max-width:600px;margin-bottom:2.5rem;margin-left:auto;margin-right:auto;font-size:1.25rem}.btn{cursor:pointer;border:none;border-radius:8px;justify-content:center;align-items:center;gap:.5rem;padding:.75rem 1.5rem;font-size:.95rem;font-weight:600;transition:all .2s;display:inline-flex}.btn-primary{background-color:var(--primary);color:#fff}.btn-primary:hover{background-color:var(--primary-hover);transform:translateY(-2px);box-shadow:0 4px 12px #2563eb59}.btn-secondary{background-color:var(--bg-card);color:var(--text-primary);border:1px solid var(--border-color)}.btn-secondary:hover{background-color:var(--bg-card-hover);border-color:var(--text-secondary);transform:translateY(-2px)}.btn-accent{background-color:var(--accent);color:#fff}.btn-accent:hover{background-color:var(--accent-hover);transform:translateY(-2px);box-shadow:0 4px 12px #10b98159}.book-grid{grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:2.5rem;padding:3rem 0;display:grid}.book-card{background-color:var(--bg-card);border:1px solid var(--border-color);box-shadow:var(--shadow-md);border-radius:16px;flex-direction:column;height:100%;transition:all .3s cubic-bezier(.4,0,.2,1);display:flex;overflow:hidden}.book-card:hover{border-color:#3b82f6;transform:translateY(-6px);box-shadow:0 12px 30px #0000004d,0 0 20px #2563eb26}.book-cover-container{background-color:#101524;justify-content:center;align-items:center;min-height:280px;padding:2.5rem 1.5rem;display:flex;position:relative;overflow:hidden}.book-cover-container:after{content:"";background:linear-gradient(#0000,#0009);height:40px;position:absolute;bottom:0;left:0;right:0}.css-book{width:150px;height:210px;transform-style:preserve-3d;perspective:1000px;border-radius:4px 12px 12px 4px;flex-direction:column;justify-content:space-between;padding:1.25rem 1rem;transition:transform .3s;display:flex;position:relative;box-shadow:8px 12px 24px #00000080}.css-book:before{content:"";z-index:5;background:linear-gradient(90deg,#00000059 0%,#ffffff1a 40%,#0000000d 60%,#00000040 100%);border-radius:4px 0 0 4px;width:8px;position:absolute;top:0;bottom:0;left:0}.book-card:hover .css-book{transform:rotateY(-10deg)scale(1.03)}.css-book-title{color:#fff;letter-spacing:-.01em;text-transform:uppercase;margin-top:1rem;font-size:.9rem;font-weight:700;line-height:1.3}.css-book-subtitle{color:#ffffffb3;margin-top:.4rem;font-size:.55rem;line-height:1.3}.css-book-author{color:#ffffffd9;text-transform:uppercase;letter-spacing:.05em;font-size:.55rem;font-weight:600}.css-book-badge{color:#10b981;background:#0000004d;border:1px solid #10b9814d;border-radius:4px;padding:.15rem .4rem;font-size:.5rem;font-weight:800;position:absolute;top:10px;right:10px}.book-card-body{flex-direction:column;flex-grow:1;padding:1.5rem;display:flex}.book-card-title{color:#fff;margin-bottom:.5rem;font-size:1.25rem;font-weight:700;line-height:1.3}.book-card-description{color:var(--text-secondary);-webkit-line-clamp:3;-webkit-box-orient:vertical;flex-grow:1;margin-bottom:1.5rem;font-size:.88rem;display:-webkit-box;overflow:hidden}.book-card-footer{border-top:1px solid var(--border-color);justify-content:space-between;align-items:center;margin-top:auto;padding-top:1.25rem;display:flex}.book-price-wrapper{flex-direction:column;display:flex}.original-price{color:var(--text-muted);font-size:.75rem;text-decoration:line-through}.current-price{color:#fff;font-size:1.35rem;font-weight:800}footer{border-top:1px solid var(--border-color);color:var(--text-secondary);background-color:#070a12;margin-top:6rem;padding:4rem 0;font-size:.9rem}.footer-content{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:2rem;display:flex}.footer-logo{color:#fff;font-size:1.25rem;font-weight:800}.footer-links{gap:1.5rem;display:flex}.back-btn{color:var(--text-secondary);align-items:center;gap:.5rem;margin-top:2rem;margin-bottom:2rem;font-weight:500;display:inline-flex}.back-btn:hover{color:#fff}.book-detail-grid{grid-template-columns:350px 1fr;gap:3.5rem;margin-bottom:5rem;display:grid}.book-detail-sidebar{position:sticky;top:100px}.book-large-cover{width:100%;max-width:320px;height:440px;transform-style:preserve-3d;border-radius:6px 16px 16px 6px;flex-direction:column;justify-content:space-between;margin-bottom:2rem;padding:2.5rem 2rem;display:flex;position:relative;box-shadow:15px 20px 40px #0009}.book-large-cover:before{content:"";z-index:5;background:linear-gradient(90deg,#00000059 0%,#ffffff1a 40%,#0000000d 60%,#00000040 100%);border-radius:6px 0 0 6px;width:14px;position:absolute;top:0;bottom:0;left:0}.book-large-cover-title{color:#fff;text-transform:uppercase;letter-spacing:-.02em;font-size:1.8rem;font-weight:800;line-height:1.25}.book-large-cover-subtitle{color:#ffffffbf;margin-top:1rem;font-size:.85rem}.book-large-cover-author{color:#ffffffe6;text-transform:uppercase;letter-spacing:.07em;font-size:.8rem;font-weight:700}.metadata-box{background-color:var(--bg-card);border:1px solid var(--border-color);border-radius:12px;margin-top:2rem;padding:1.5rem}.metadata-title{color:#fff;border-bottom:1px solid var(--border-color);margin-bottom:1rem;padding-bottom:.5rem;font-size:1rem;font-weight:700}.metadata-item{justify-content:space-between;margin-bottom:.75rem;font-size:.85rem;display:flex}.metadata-label{color:var(--text-secondary)}.metadata-value{color:#fff;font-weight:600}.book-info-main{flex-direction:column;display:flex}.book-detail-title{margin-bottom:1rem;font-size:2.75rem;font-weight:800;line-height:1.2}.book-detail-subtitle{color:var(--text-secondary);margin-bottom:1.5rem;font-size:1.35rem;font-weight:400}.book-detail-author{color:var(--accent);margin-bottom:2.5rem;font-weight:600}.purchase-action-container{border:1px solid var(--border-color);background:linear-gradient(135deg,#2563eb1a 0%,#10b9810d 100%);border-radius:16px;justify-content:space-between;align-items:center;gap:2rem;margin-bottom:3rem;padding:2rem;display:flex}.purchase-price-section{flex-direction:column;display:flex}.purchase-price-promo{color:var(--text-muted);font-size:.85rem;text-decoration:line-through}.purchase-price{color:#fff;font-size:2.25rem;font-weight:800}.purchase-buttons{gap:1rem;display:flex}.sections-nav{border-bottom:1px solid var(--border-color);gap:2.5rem;margin-bottom:2.5rem;display:flex}.section-tab-btn{color:var(--text-secondary);cursor:pointer;background:0 0;border:none;padding:1rem 0;font-size:1.1rem;font-weight:600;position:relative}.section-tab-btn:hover{color:#fff}.section-tab-btn.active{color:var(--primary)}.section-tab-btn.active:after{content:"";background-color:var(--primary);height:2px;position:absolute;bottom:-1px;left:0;right:0}.book-summary-content{color:var(--text-secondary);white-space:pre-line;font-size:1.1rem;line-height:1.75}.toc-list{flex-direction:column;gap:1rem;display:flex}.toc-item{background-color:var(--bg-card);border:1px solid var(--border-color);border-radius:12px;transition:border-color .2s;overflow:hidden}.toc-item:hover{border-color:var(--text-secondary)}.toc-header{cursor:pointer;-webkit-user-select:none;user-select:none;justify-content:space-between;align-items:center;padding:1.25rem 1.5rem;display:flex}.toc-header-left{align-items:center;gap:1rem;display:flex}.toc-chapter-title{color:#fff;font-weight:700}.toc-chapter-pages{color:var(--text-muted);background-color:#ffffff0d;border-radius:4px;padding:.15rem .5rem;font-size:.85rem;font-weight:500}.toc-body{color:var(--text-secondary);border-top:1px solid #ffffff08;padding:1rem 1.5rem 1.5rem 3rem;font-size:.95rem;animation:.2s ease-out slideDown}.preview-box{border:1px solid var(--border-color);background-color:#070a12;border-radius:12px;padding:2.5rem;overflow-x:auto}.preview-title{color:#fff;border-bottom:1px solid var(--border-color);align-items:center;gap:.5rem;margin-bottom:1.5rem;padding-bottom:.75rem;font-size:1.25rem;font-weight:700;display:flex}.preview-content{font-family:var(--font-sans);color:var(--text-secondary);white-space:pre-line;font-size:1rem;line-height:1.7}.preview-content code{font-family:var(--font-mono);color:#ef4444;background-color:#121824;border-radius:4px;padding:.15rem .35rem;font-size:.9rem}.preview-content pre{font-family:var(--font-mono);border:1px solid var(--border-color);color:#e5e7eb;background-color:#121824;border-radius:8px;margin:1.5rem 0;padding:1.5rem;font-size:.9rem;overflow-x:auto}@keyframes slideDown{0%{opacity:0;transform:translateY(-5px)}to{opacity:1;transform:translateY(0)}}@media (width<=900px){.book-detail-grid{grid-template-columns:1fr}.book-detail-sidebar{flex-direction:column;align-items:center;display:flex;position:static}.purchase-action-container{text-align:center;flex-direction:column;align-items:stretch}.purchase-buttons{justify-content:center}.hero-title{font-size:2.5rem}}@media (width<=600px){.header-container{flex-direction:column;gap:1rem;height:auto;padding:1rem 0}.nav-links{gap:1rem}}