*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}:root{--bg: #09090B;--surface: #111113;--surface-2: #18181B;--border: rgba(255, 255, 255, .07);--border-hover: rgba(255, 255, 255, .14);--text-primary: #FAFAFA;--text-secondary: #A1A1AA;--text-muted: #52525B;--accent: #E8C468;--accent-dim: rgba(232, 196, 104, .12);--accent-border: rgba(232, 196, 104, .25);--success: #22C55E;--radius: 10px;--radius-sm: 6px;--radius-lg: 16px}html{font-size:16px}body{background:var(--bg);color:var(--text-primary);font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;line-height:1.6}input,button,select,textarea{font-family:inherit}a{color:inherit;text-decoration:none}img{display:block;max-width:100%}::selection{background:#e8c46840}::-webkit-scrollbar{width:5px}::-webkit-scrollbar-track{background:var(--bg)}::-webkit-scrollbar-thumb{background:#27272a;border-radius:99px}.container{max-width:1160px;margin:0 auto;padding:0 1.5rem}.hide-mobile{display:flex}.show-mobile{display:none}@media(max-width:768px){.hide-mobile{display:none!important}.show-mobile{display:flex!important}}.hero-section{border-bottom:1px solid var(--border);padding:5rem 0 4rem}@media(max-width:640px){.hero-section{padding:2rem 0 1.75rem}.hero-title{font-size:1.75rem!important}}.category-bar{padding:2.5rem 0;border-bottom:1px solid var(--border)}@media(max-width:640px){.category-bar{padding:1.75rem 0}}.ebook-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:1rem}@media(max-width:640px){.ebook-grid{grid-template-columns:repeat(2,1fr);gap:.75rem}}.section-header{display:flex;justify-content:space-between;align-items:baseline;margin-bottom:1.25rem}.section-label{color:var(--text-muted);font-size:.72rem;font-weight:600;text-transform:uppercase;letter-spacing:.09em}.catalog-layout{display:flex;gap:2rem;align-items:flex-start}.catalog-sidebar{width:210px;flex-shrink:0;position:sticky;top:76px}@media(max-width:768px){.catalog-layout{flex-direction:column;gap:1.25rem}.catalog-sidebar{width:100%;position:static;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1rem}}.ebook-detail-grid{display:grid;grid-template-columns:220px 1fr;gap:3rem;align-items:start}@media(max-width:640px){.ebook-detail-grid{grid-template-columns:1fr;gap:1.5rem}.ebook-cover-sticky{position:static!important;width:160px!important;height:210px!important;margin:0 auto}}.checkout-grid{display:grid;grid-template-columns:1fr 320px;gap:1.5rem;align-items:start}@media(max-width:768px){.checkout-grid{grid-template-columns:1fr}}.buy-box{display:flex;align-items:center;justify-content:space-between;gap:1.5rem;flex-wrap:wrap}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:3rem;margin-bottom:2.5rem}@media(max-width:640px){.footer-grid{grid-template-columns:1fr 1fr;gap:2rem}.footer-brand{grid-column:1 / -1}}.auth-wrapper{min-height:calc(100vh - 61px);display:flex;align-items:center;justify-content:center;padding:2rem 1.5rem}@media(max-width:480px){.auth-wrapper{align-items:flex-start;padding-top:2rem}}.cta-section{padding:5rem 0;text-align:center}.cta-inner{max-width:540px;margin:0 auto}@media(max-width:640px){.cta-section{padding:3rem 0}}.ebook-section{padding:3.5rem 0;border-bottom:1px solid var(--border)}@media(max-width:640px){.ebook-section{padding:2.25rem 0}}@media(max-width:480px){.card-cover{height:150px!important}}.cta-buttons{display:flex;gap:.75rem;flex-wrap:wrap}@media(max-width:480px){.cta-buttons{flex-direction:column}.cta-buttons a,.cta-buttons button{width:100%;text-align:center;justify-content:center}}.specs-row{display:flex;gap:.5rem;flex-wrap:wrap;margin-bottom:1.5rem}.filter-toggle{display:none;width:100%;padding:.6rem .9rem;background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text-secondary);font-size:.85rem;cursor:pointer;align-items:center;gap:.5rem;justify-content:space-between;margin-bottom:.75rem}@media(max-width:768px){.filter-toggle{display:flex}}@keyframes fadeUp{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}.fade-up{animation:fadeUp .3s ease both}