.textbook-attribution{margin:18px 0;padding:14px 18px;border-radius:13px;background:#f2f6f4;color:#443a72;font-size:13px;line-height:1.6}.textbook-attribution>span{font-size:10px;letter-spacing:.12em;font-weight:700}.textbook-attribution p{margin:5px 0 0}.source-original{margin:18px 0;border:1px solid #d8d2f6;border-radius:14px;overflow:hidden;background:#fff}.source-original>summary{padding:16px 18px;font-size:14px;font-weight:600;cursor:pointer;background:#f7faf9;color:#3e3668}.source-page{margin:0;padding:12px;border-bottom:1px solid #e3dff8}.source-page:last-child{border-bottom:0}.source-page img{display:block;width:100%;height:auto;object-fit:contain;background:white}.source-page figcaption{padding-top:8px;text-align:right;font-size:11px;color:#482dcf}.teacher-review-note{border-left:3px solid #8674e1;background:#f3f8f6;color:#463c75;padding:13px 16px;font-size:13px;line-height:1.6}.textbook-task .learning-stepper{max-width:60%;overflow-x:auto;justify-content:flex-start;padding:6px;scrollbar-width:thin}.textbook-task .step-dot{flex-shrink:0}.textbook-task .feedback.try{background:#f2f6f4;color:#433a70;border-color:#d8d2f5}.source-reading>p{font-size:14px;line-height:1.7;color:#432ac0}@media(max-width:640px){.source-page{padding:5px}.textbook-task .learning-stepper{max-width:58%}.textbook-attribution{font-size:12px;padding:12px}}

.textbook-task .learning-stepper{flex-wrap:nowrap;overflow-y:hidden;min-height:36px;padding:10px;box-sizing:border-box}.textbook-task .task-prompt{font-size:clamp(19px,2vw,25px);margin-bottom:16px}

.source-zoom{display:block;margin:0 0 10px auto;padding:8px 13px;border:1px solid #c9c0f2;border-radius:9px;background:#f2f7f5;color:#3e3668;font:inherit;font-size:12px;cursor:pointer;min-height:36px}.source-image-frame{overflow:auto;max-width:100%;overscroll-behavior:contain}.source-page.zoomed .source-image-frame{max-height:70vh;border:1px solid #d8d2f6;border-radius:6px}.source-page.zoomed img{width:max(100%,900px);max-width:none}.source-image-frame:focus-visible,.source-zoom:focus-visible{outline:3px solid #725ddb;outline-offset:2px}