.ecbr-book-rail{z-index:30;box-sizing:border-box;font-family:'ABeeZee',sans-serif;color:#5f5f5f;visibility:hidden}
.ecbr-book-rail.ecbr-ready{visibility:visible}
.ecbr-book-card{box-sizing:border-box;background:#f9faff;border-right:5px solid #5F6FB2;border-radius:8px;padding:20px;box-shadow:0 4px 18px rgba(0,0,0,.08)}
.ecbr-book-cover{display:block;text-decoration:none}
.ecbr-book-cover img{display:block;width:100%;height:auto;border-radius:6px}
.ecbr-book-title{display:block;margin:16px 4px 0;text-align:center;font-family:'ABeeZee',sans-serif;font-size:22px;line-height:1.35;color:#5F6FB2;text-decoration:none}
.ecbr-book-title:hover{text-decoration:underline}
.ecbr-book-text{margin:14px 2px 0;font-family:'ABeeZee',sans-serif;font-size:16px;line-height:1.7;color:#5f5f5f;text-align:left}
.ecbr-book-text p{margin:0 0 12px}.ecbr-book-text p:last-child{margin-bottom:0}.ecbr-book-text ul,.ecbr-book-text ol{margin:10px 0 12px 22px;padding:0}.ecbr-book-text li{margin:4px 0}.ecbr-book-text a{color:#5F6FB2;text-decoration:underline}.ecbr-book-text strong,.ecbr-book-text b{font-weight:700}
.ecbr-book-button{display:block;margin-top:18px;padding:12px 16px;border-radius:8px;background:#5F6FB2;color:#fff!important;text-align:center;text-decoration:none!important;font-family:'ABeeZee',sans-serif;font-size:17px;line-height:1.3;transition:transform .15s ease,box-shadow .15s ease}
.ecbr-book-button:hover{transform:translateY(-2px);box-shadow:0 6px 14px rgba(0,0,0,.12)}
.ecbr-book-rail.ecbr-desktop{position:absolute;box-sizing:border-box}
.ecbr-book-rail.ecbr-desktop .ecbr-book-card{position:sticky;top:var(--ecbr-sticky-top,90px)}
.ecbr-book-rail.ecbr-fallback{position:relative!important;left:auto!important;top:auto!important;height:auto!important;width:min(92%,var(--ecbr-rail-width,420px))!important;margin:34px auto!important}
.ecbr-book-rail.ecbr-fallback .ecbr-book-card{position:static}
@media (prefers-reduced-motion:reduce){.ecbr-book-button{transition:none}}

/* v1.0.16: stable fluid width; central lane detection no longer depends on Download button text. */