.skip-link{position:absolute;top:-60px;left:20px;z-index:5;padding:12px;background:white}.skip-link:focus{top:10px}
.chapter-label{font-size:12px}body>footer{font-size:12px}.study-panel .example-answer{border-left:0;padding-left:0;font-weight:600}
.study-layout{display:grid;grid-template-columns:288px minmax(0,1fr);max-width:1400px;margin:auto;min-height:calc(100vh - 130px)}
.study-library{padding:32px 24px;border-right:1px solid var(--line)}.study-heading h1{font-size:24px;line-height:1.5}.study-heading>p:last-child{font-size:13px;line-height:1.8;color:var(--muted);margin-top:10px}
.study-search{display:block;margin:24px 0 12px}.study-search>span{display:block;font-size:13px;margin-bottom:8px}.study-search input{width:100%;padding:11px 12px;border:1px solid var(--line);border-radius:6px;background:var(--bg);color:var(--ink);font-size:14px}
.quiet{font-size:13px;line-height:1.85;color:var(--muted)}#search-status{margin-bottom:12px}.study-chapter{margin:0 0 7px;border-bottom:1px solid var(--line);padding-bottom:7px}.study-chapter summary{padding:11px 0;font-size:14px;font-weight:600;cursor:pointer;line-height:1.6}.study-chapter a{display:block;color:var(--ink);font-size:13px;line-height:1.7;padding:9px 12px;border-radius:5px;margin:2px 0}.study-chapter a[aria-current=page]{background:var(--primary-soft);color:var(--primary);font-weight:600}.study-chapter a:hover{background:var(--surface);text-decoration:none}.learned-dot{color:var(--primary);margin-right:5px}.study-progress{font-size:13px;margin-top:22px;line-height:1.8}.progress-actions{display:flex;gap:20px;margin:8px 0}.upload-label{cursor:pointer}.upload-label input{display:none}
.study-reading{min-width:0;max-width:920px;padding:36px 52px 48px;outline:none}.study-intro{margin-bottom:32px;padding-bottom:26px;border-bottom:1px solid var(--line)}.study-intro h2{font-size:27px;line-height:1.5}.study-intro>p{font-size:15px;line-height:1.9;margin-top:12px;max-width:65ch}.study-intro details{margin-top:16px;font-size:14px;line-height:1.9}.study-intro summary{cursor:pointer;color:var(--primary);padding:5px 0}.study-intro details p{margin:10px 0}.study-intro ol{padding-left:22px}.study-intro li{padding:4px 0}.study-intro input{max-width:100%;font-size:13px}
.unit-header h2{font-size:28px;line-height:1.5;margin-bottom:12px}.unit-question{font-size:18px;line-height:1.8}.unit-source{font-size:13px;color:var(--muted);line-height:1.8;margin-top:14px}.unit-source a{margin-left:12px}.unit-actions{margin:18px 0 24px}.unit-actions button[aria-pressed=true]{background:var(--primary-soft);color:var(--primary);border-color:var(--primary)}
.study-tabs{display:flex;gap:22px;border-bottom:1px solid var(--line);margin-bottom:28px}.study-tabs button{padding:12px 0 13px;border:0;border-bottom:2px solid transparent;background:transparent;font-size:14px;color:var(--muted);line-height:1.8}.study-tabs button[aria-selected=true]{color:var(--primary);border-bottom-color:var(--primary);font-weight:600}.study-tabs button:hover{color:var(--primary)}
.study-panel{font-size:16px;line-height:1.95;overflow-wrap:break-word}.study-panel p{margin:0 0 17px}.study-panel h3{font-size:19px;line-height:1.7;margin:28px 0 12px}.study-panel h3:first-child{margin-top:0}.study-panel ul,.study-panel ol{padding-left:24px;margin:12px 0 22px}.study-panel li{margin:9px 0;padding-left:3px}.study-panel .lesson-math{margin:15px 0 8px;padding:14px 16px}.formula-meaning{font-size:14px;color:var(--muted)}.example-answer{border-left:3px solid var(--primary);padding:4px 0 4px 16px;margin:24px 0}.study-panel details{border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:18px 0;margin:22px 0}.study-panel details summary{cursor:pointer;line-height:1.8}.study-panel details p{margin:16px 0 0}.model-connection{padding-top:22px;margin-top:25px;border-top:1px solid var(--line)}.model-connection p{font-size:14px;color:var(--muted);margin-top:9px}.unit-navigation{display:flex;justify-content:space-between;align-items:center;gap:15px;border-top:1px solid var(--line);padding-top:24px;margin-top:36px}.unit-navigation>span{font-size:13px;color:var(--muted)}
@media(min-width:1100px){.study-library{position:sticky;top:0;max-height:100vh;overflow-y:auto;align-self:start}}
@media(max-width:1000px){.study-layout{grid-template-columns:250px minmax(0,1fr)}.study-library{padding:25px 18px}.study-reading{padding:30px 28px}.topbar .top-right{gap:18px}}
@media(max-width:700px){.topbar{height:auto;min-height:65px;flex-wrap:wrap;padding:14px 18px;gap:13px}.topbar .top-right{gap:18px;flex-wrap:wrap}.topbar .text-button{font-size:12px}.study-layout{display:block}.study-library{padding:22px 18px;border-right:0;border-bottom:1px solid var(--line)}.study-heading h1{font-size:22px}.study-heading h1 br{display:none}.study-search{margin-top:18px}#study-nav{max-height:285px;overflow-y:auto}.study-library .quiet:last-child{display:none}.study-progress{margin-top:13px}.study-reading{padding:28px 18px 36px}.study-intro h2{font-size:25px}.unit-header h2{font-size:25px}.unit-question{font-size:17px}.study-tabs{gap:18px}.study-tabs button{font-size:13px}.unit-navigation{gap:7px}.unit-navigation .button{padding:9px 11px}.unit-navigation>span{font-size:12px}.study-panel .lesson-math{padding:12px 10px}}