.textbook-bar{display:flex;align-items:center;gap:10px;flex-wrap:wrap;padding:10px 14px;margin:8px 0;border:1px solid #cbdde7;border-radius:10px;background:#f5fafc;color:#23465b;font-size:13px}.textbook-bar button,.textbook-dialog button{padding:9px 13px;border:1px solid #a8c5d3;border-radius:7px;background:#fff;color:#23465b;cursor:pointer;font:inherit}.textbook-bar span{flex:1;min-width:160px}.textbook-bar [hidden]{display:none!important}.textbook-dialog{width:min(760px,92vw);max-height:88vh;box-sizing:border-box;border:1px solid #a8c5d3;border-radius:14px;padding:24px;color:#23465b;background:#fff;font:16px/1.6 system-ui,sans-serif}.textbook-dialog::backdrop{background:rgba(15,30,45,.6)}.textbook-heading{display:flex;align-items:center;justify-content:space-between;gap:12px}.textbook-heading h2{margin:0}.textbook-filters{display:grid;grid-template-columns:1fr 1fr;gap:12px}.textbook-filters label{display:grid;gap:4px}.textbook-filters select{width:100%;min-width:0;padding:9px;border:1px solid #a8c5d3;border-radius:6px;font:inherit}.textbook-units{display:grid;gap:8px;margin:14px 0}.textbook-units label{display:flex;gap:10px;align-items:center;border:1px solid #d7e5ec;padding:12px;border-radius:8px;background:#f5fafc;cursor:pointer}.textbook-units input{width:18px;height:18px;flex-shrink:0}.textbook-actions{display:flex;justify-content:flex-end;gap:10px;margin-top:14px}.textbook-preview{max-height:240px;overflow:auto}.textbook-preview p{margin:0;padding:8px;border-bottom:1px solid #e0eaf0;font-size:14px}.textbook-dialog button:disabled{opacity:.5;cursor:default}@media(max-width:600px){.textbook-dialog{padding:16px}.textbook-filters{grid-template-columns:1fr}.textbook-bar span{flex-basis:100%}}
.textbook-bar #textbookOpen{border:1px solid #b76612;border-bottom-color:#98500a;border-radius:11px;background:linear-gradient(180deg,#fff098 0%,#ffd05a 48%,#ffb53b 100%);color:#573008;font-weight:850;text-shadow:0 1px 0 rgba(255,255,255,.65);box-shadow:inset 0 2px 0 rgba(255,255,255,.85),0 5px 0 #a65b12,0 7px 10px rgba(133,76,13,.2);transition:transform .12s ease,box-shadow .12s ease;white-space:nowrap}
.textbook-bar #textbookOpen:hover{background:linear-gradient(180deg,#fff4b0 0%,#ffda73 48%,#ffc04d 100%);transform:translateY(-1px);box-shadow:inset 0 2px 0 rgba(255,255,255,.9),0 6px 0 #a65b12,0 9px 13px rgba(133,76,13,.24)}
.textbook-bar #textbookOpen:active{transform:translateY(3px);box-shadow:inset 0 2px 0 rgba(255,255,255,.65),0 2px 0 #a65b12,0 3px 5px rgba(133,76,13,.18)}
.textbook-bar #textbookOpen:focus-visible{outline:3px solid #176383;outline-offset:4px}
@media(prefers-reduced-motion:reduce){.textbook-bar #textbookOpen{transition:none}}
.textbook-levels{display:flex;gap:12px;margin:16px 0 20px}.textbook-levels button{flex:1;min-height:46px;border-radius:10px;font-weight:800;background:#eef5f8;box-shadow:0 3px 0 #bccdd6}.textbook-levels button[aria-pressed=true]{background:linear-gradient(180deg,#fff09b,#ffc14a);border-color:#ad6a1b;color:#573008;box-shadow:inset 0 1px 0 #fff8cf,0 4px 0 #ad6a1b}.textbook-levels button:focus-visible{outline:3px solid #176383;outline-offset:4px}