:root{--ink:#07151b;--green:#0f5448;--mint:#b9e2d6;--gold:#e4b24b;--line:#2b4147}*{box-sizing:border-box}body{margin:0;background:var(--ink);color:#f3f5f4;font:16px/1.65 system-ui,sans-serif}a{color:inherit}button,input,select{font:inherit}button,a,input,select{touch-action:manipulation}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid var(--gold);outline-offset:4px}.wrap{width:min(1180px,calc(100% - 40px));margin:auto}header{border-bottom:1px solid var(--line)}.nav{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:18px 0}.brand{display:flex;gap:15px;align-items:center;text-decoration:none;font-weight:750;font-size:14px;letter-spacing:.1em}.brand img{width:86px;height:50px;object-fit:contain}nav{display:flex;gap:25px;font-size:14px}nav a{text-decoration:none}.intro{padding:64px 0 42px}.eyebrow{color:var(--gold);font-size:14px;letter-spacing:.12em;font-weight:700}h1{font:700 clamp(2.6rem,5.6vw,5rem)/1.08 Georgia,serif;letter-spacing:-.03em;margin:20px 0}h1 em{color:var(--mint)}.lead{max-width:740px;color:#c4d5d1;font-size:18px}.launch{display:inline-block;border-left:3px solid var(--gold);padding:10px 18px;background:#12282e;color:#d3dfdc;font-size:14px;margin-top:14px}.catalogue{padding:24px 0 75px}.heading{display:flex;justify-content:space-between;align-items:center;gap:20px}h2{font:700 2.1rem/1.2 Georgia,serif}.heading p{color:#b6c8c3;font-size:14px}.filters{display:grid;grid-template-columns:2fr 1fr 1fr;gap:18px;margin-bottom:28px}label{font-size:14px;color:#c4d5d1;display:block}input,select{width:100%;padding:12px 14px;background:#10252c;color:white;border:1px solid #486067;border-radius:7px;margin-top:7px;min-height:48px}.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}.book{background:#10252c;border:1px solid var(--line);border-top:3px solid var(--green);padding:27px;display:flex;flex-direction:column;border-radius:8px;min-height:365px}.subject{font-size:14px;color:var(--gold);margin:0 0 20px}.book h3{font:700 1.6rem/1.25 Georgia,serif;margin:0 0 12px}.subtitle{color:var(--mint);margin:0 0 12px}.description{color:#bed0ca;margin:0 0 20px}.badges{display:flex;flex-wrap:wrap;gap:7px;margin-top:auto}.badge{border:1px solid #49635f;padding:3px 10px;border-radius:20px;font-size:14px}.book button,.checkout{margin-top:22px;background:var(--gold);color:var(--ink);border:0;border-radius:6px;padding:11px 17px;font-weight:700;cursor:pointer;text-decoration:none;display:inline-block}.guide{background:#0c3430;padding:55px 0}.guidegrid{display:grid;grid-template-columns:repeat(3,1fr);gap:35px}.guide h3{font-size:18px}.guide p{color:#c4d5d1}.note{font-size:14px;border-top:1px solid #41605a;padding-top:22px;margin-top:28px}footer{padding:35px 0;color:#a6bdb6;font-size:14px}dialog{background:#10252c;color:white;border:1px solid #49635f;border-radius:12px;padding:34px;width:min(680px,calc(100% - 28px));max-height:90vh;overflow:auto}dialog::backdrop{background:rgba(0,0,0,.75)}dialog h2{padding-right:25px}.close{position:absolute;right:18px;top:12px;background:none;color:white;border:0;font-size:32px;cursor:pointer}.option{border-top:1px solid var(--line);padding:18px 0}.option h3{margin:0}.option p{margin:8px 0;color:#c4d5d1}.unavailable{font-size:14px;color:var(--gold)}@media(max-width:850px){.grid{grid-template-columns:repeat(2,1fr)}.guidegrid{grid-template-columns:1fr}.filters{grid-template-columns:1fr 1fr}.filters label:first-child{grid-column:1/-1}.nav{flex-wrap:wrap}}@media(max-width:540px){.grid,.filters{grid-template-columns:1fr}.filters label:first-child{grid-column:auto}.wrap{width:calc(100% - 28px)}nav{gap:18px}.heading{align-items:start;flex-direction:column;gap:0}.intro{padding-top:36px}.book{min-height:0}h1{font-size:2.7rem}}

.release{align-self:flex-start;display:inline-block;border:1px solid #b59451;color:#f2cd7d;font-size:12px;font-weight:800;letter-spacing:.06em;border-radius:30px;padding:4px 11px;margin:-8px 0 18px}.release.free{border-color:#8bd4ac;color:#9becbd}.price-tags{margin-top:auto;display:grid;gap:5px;border-top:1px solid var(--line);padding-top:16px;font-size:14px}.price-tags span{display:flex;justify-content:space-between;gap:10px}.price-tags strong{text-align:right;color:var(--mint)}.book small{color:#a5bab2;font-size:11px;display:block;margin-top:12px}.book .meta{font-size:13px;color:var(--mint)}.pagination{display:flex;align-items:center;justify-content:center;gap:20px;margin:30px 0}.pagination button,.agreement button{background:var(--gold);border:0;border-radius:6px;padding:11px 16px;font-weight:700;cursor:pointer}button:disabled{opacity:.5;cursor:not-allowed}.agreement{margin-top:22px;border-top:1px solid var(--line);padding-top:10px}.agreement p{font-size:14px}.accept-label{display:flex;align-items:flex-start;gap:12px;margin:20px 0;font-size:15px}.accept-label input{width:22px;height:22px;min-height:22px;flex-shrink:0;margin:2px 0}.filters{grid-template-columns:2fr 1fr 1fr}.checkout:disabled{background:#72847e;color:#10201a;cursor:not-allowed}#agreement-status{color:var(--mint)}@media(max-width:540px){.filters{grid-template-columns:1fr}.price-tags span{flex-wrap:wrap}}

.reader{font-size:13px;color:#d0dfd7;margin:0 0 14px}.topics{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:14px}.topics span{font-size:11px;padding:3px 8px;border:1px solid #426057;border-radius:20px;color:#c4d5d1}.file-status{font-size:13px;color:#b7e4c8;border-left:2px solid #6ba78a;padding-left:10px;margin-bottom:15px}

.audio-summary{border:1px solid #426057;background:#0b1e24;border-radius:8px;padding:12px;margin:0 0 20px;min-width:0}.audio-summary p{margin:0 0 8px;font-size:13px}.audio-summary p:first-child{display:flex;justify-content:space-between;gap:8px;color:var(--mint)}.audio-summary audio{display:block;width:100%;min-width:0;height:40px}.audio-summary .audio-caption{font-size:11px;color:#b7c9c1;line-height:1.5;margin:9px 0 0}.audio-error{color:#f2cd7d}.audio-summary audio:focus-visible{outline:3px solid var(--gold);outline-offset:3px}

.book-cover{display:block;width:132px;max-width:100%;height:198px;object-fit:contain;object-position:left center;margin:14px 0 20px;border-radius:5px}.guidegrid{grid-template-columns:repeat(auto-fit,minmax(210px,1fr))}
.cover-gallery{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin:4px 0 20px}.cover-gallery figure{margin:0;min-width:0}.cover-gallery a{display:block;border-radius:4px;overflow:hidden;background:#071e1b}.cover-gallery img{display:block;width:100%;height:190px;object-fit:contain}.cover-gallery figcaption{color:#bdd3c8;font-size:11px;line-height:1.45;margin-top:6px}.summary-label{color:var(--gold);font-size:12px;text-transform:uppercase;letter-spacing:.08em;margin:0 0 8px}.audio-summary .normal-speed{font-size:12px;margin:10px 0 0;padding:5px 10px;background:#183c36;color:#e2eade;border:1px solid #668c7d;border-radius:5px}.normal-speed:focus-visible{outline:3px solid var(--gold)}#detail .cover-gallery{max-width:480px;margin:22px auto}#detail .cover-gallery img{height:300px}@media(max-width:540px){.cover-gallery img{height:230px}#detail .cover-gallery img{height:230px}}

.subtitle-groups{display:flex;flex-wrap:wrap;gap:9px;margin:20px 0 28px}.subtitle-groups button{background:#12332e;color:#e1ede6;border:1px solid #64877a;border-radius:20px;padding:9px 13px;cursor:pointer;font-size:13px}.subtitle-groups button[aria-pressed="true"]{background:var(--gold);color:var(--ink)}.group-heading{grid-column:1/-1;border-bottom:1px solid #647e6f;padding:12px 0;font-size:1.75rem;margin:25px 0 0}.quote-link{display:block;padding:10px 0;color:var(--gold);font-weight:700}.price-application{border:1px solid var(--gold);padding:18px}.price-tags span{flex-wrap:wrap}

.appreciation{padding:45px 0 65px}.appreciation-grid{display:grid;grid-template-columns:1fr 1fr;gap:28px}.appreciation-grid article{border:1px solid #49685e;border-radius:12px;background:#102b29;padding:25px}.appreciation label{margin:14px 0}.appreciation textarea{width:100%;font:inherit;color:white;background:#10252c;border:1px solid #486067;border-radius:7px;padding:12px;margin-top:7px;resize:vertical}.appreciation button{background:var(--gold);color:var(--ink);border:0;padding:12px 18px;border-radius:7px;font:inherit;font-weight:700;cursor:pointer}.appreciation .release{margin:0 0 15px}@media(max-width:700px){.appreciation-grid{grid-template-columns:1fr}nav{flex-wrap:wrap}}

.engineering-application{margin:25px 0;padding:20px;border:1px solid var(--gold);border-radius:8px}.engineering-application label{margin:14px 0}.engineering-application textarea{display:block;width:100%;padding:12px;background:#10252c;color:white;font:inherit;border:1px solid #486067;border-radius:7px;margin-top:7px}.engineering-application button{background:var(--gold);border:0;border-radius:6px;padding:12px 18px;font:inherit;cursor:pointer}.application-honeypot{position:absolute;left:-10000px;width:1px;height:1px;overflow:hidden}

.application-cta{background:var(--gold);color:var(--ink);font:inherit;font-weight:700;border:0;border-radius:7px;padding:14px 20px;cursor:pointer}.application-cta:focus-visible{outline:3px solid white;outline-offset:4px}