.site-header{position:sticky;top:0;z-index:20;background:var(--paper);border-bottom:1px solid var(--line);padding:.7rem clamp(1rem,4vw,3rem);display:flex;align-items:center;justify-content:space-between;gap:1rem;flex-wrap:wrap}.site-header nav{display:flex;gap:.4rem;flex-wrap:wrap;align-items:center}.site-header nav a{font-size:.88rem;text-decoration:none;padding:.4rem .6rem;min-height:44px;display:inline-flex;align-items:center}.site-header nav a[aria-current=page]{background:var(--ink);color:var(--surface)}.site-main{max-width:1150px;margin:auto;padding:3rem clamp(1rem,4vw,3.5rem) 5rem}.site-main.wide{max-width:1400px}.site-header .brand{white-space:nowrap}.identity-strip{display:flex;justify-content:space-between;gap:.7rem;align-items:center;padding:.7rem 1rem;background:var(--soft);font-size:.85rem;flex-wrap:wrap}.identity-strip button{padding:.25rem .65rem;min-height:36px;font-size:.8rem}.site-main .hero h1{font-size:clamp(2.1rem,4.5vw,3.8rem)}.module-list{border-top:1px solid var(--ink)}.module-item{display:grid;grid-template-columns:3rem minmax(0,1fr) auto;gap:1.3rem;padding:1.5rem 0;border-bottom:1px solid var(--line)}.module-item h3{margin:0}.module-item .module-number{color:var(--accent);font:2rem Georgia,serif}.module-item .actions{margin:.7rem 0 0}.module-status{font-size:.83rem;color:var(--muted)}.module-item p{margin:.4rem 0}.practice-layout{display:grid;grid-template-columns:235px minmax(0,1fr);gap:2rem}.practice-nav{border-right:1px solid var(--line);padding-right:1rem}.practice-nav nav{display:flex;flex-direction:column;gap:.4rem}.practice-nav a{display:block;text-decoration:none;font-size:.9rem;padding:.5rem}.practice-nav a[aria-current=page]{background:var(--ink);color:var(--surface)}.task-tabs{display:flex;gap:.5rem;flex-wrap:wrap;border-bottom:1px solid var(--line);padding-bottom:.8rem}.task-tabs a{padding:.5rem .8rem;text-decoration:none;border:1px solid var(--line);font-size:.85rem}.task-tabs a[aria-current=page]{background:var(--ink);color:var(--surface)}.task-panel{min-width:0}.task-panel h2{margin:1.5rem 0 .7rem}.practice-editor{min-height:300px;max-height:70vh}.lab-controls{display:flex;gap:.6rem;flex-wrap:wrap;align-items:center}.lab-controls select{width:auto;min-width:12rem}.preview-frame{width:100%;height:330px;border:1px solid var(--line);background:var(--surface)}.notice-success{color:#244c38;background:#e4eddd;padding:1rem}.status.error{color:#8a3119}.status.success{color:#244c38}.task-feedback{background:#e6eddf;padding:1rem;margin:1rem 0}.task-feedback p{white-space:pre-wrap}.admin-login{max-width:460px;margin:2rem auto 4rem;border-top:2px solid var(--ink);padding-top:1rem}.admin-login input{margin-bottom:1.2rem}.admin-tabs{display:flex;gap:.6rem;flex-wrap:wrap;margin:1rem 0 2rem}.admin-tabs button[aria-pressed=true]{background:var(--ink);color:var(--surface)}.admin-toolbar{display:flex;gap:.7rem;flex-wrap:wrap;align-items:center}.admin-toolbar input{max-width:22rem}.admin-toolbar select{width:auto}.admin-list{display:grid;grid-template-columns:300px minmax(0,1fr);gap:1.5rem;margin:1.5rem 0}.admin-list .list-nav{max-height:75vh;overflow:auto;border:1px solid var(--line);background:var(--surface);align-self:start}.list-nav button{width:100%;background:transparent;color:var(--ink);text-align:left;justify-content:flex-start;border:0;border-bottom:1px solid var(--line);border-radius:0;font-weight:400;display:block;padding:.9rem 1rem}.list-nav button[aria-current=true]{background:var(--soft)}.list-nav strong{display:block}.list-nav small{color:var(--muted)}.detail-pane{min-width:0;border-top:2px solid var(--ink);padding-top:.7rem}.detail-pane h2{font-size:1.5rem;margin:.5rem 0 1rem}.detail-pane pre{max-height:380px;overflow:auto}.detail-pane .grade-controls select{min-width:9rem}.admin-summary{display:flex;gap:1.7rem;flex-wrap:wrap;padding:1rem 0;border-bottom:1px solid var(--line)}.admin-summary b{font-size:1.5rem;display:block}.admin-summary small{color:var(--muted);font-size:.8rem}.admin-question{border-top:1px solid var(--line);padding:.8rem 0}.admin-question p{white-space:pre-wrap;font-size:.9rem}.submission-note{font-size:.85rem;color:var(--muted)}.message{white-space:pre-wrap}.student-name-box{max-width:480px;background:var(--soft);padding:1.2rem;margin:1rem 0}.student-name-box input{margin:.5rem 0}.task-complete{color:#25533b}.task-pending{color:#8a3c20}.site-main a{text-underline-offset:.25em}input[type=password]{display:block;width:100%;padding:.65rem .8rem;border:1px solid #879c8d;background:var(--surface);border-radius:2px;color:var(--ink)}.sandbox-guide{font-size:.83rem;color:var(--muted)}.hosted-doc-banner{background:var(--soft);padding:1rem;margin:1rem 0}.save-bar{border-top:1px solid var(--line);margin-top:2rem;padding-top:1rem}.lesson-bottom{margin-top:3rem;border-top:2px solid var(--ink);padding-top:1.5rem}
@media(max-width:850px){.practice-layout{grid-template-columns:1fr;gap:1rem}.practice-nav{border:0;padding:0}.practice-nav nav{flex-direction:row;flex-wrap:wrap}.practice-nav a{font-size:.78rem;padding:.35rem .55rem;border:1px solid var(--line)}.admin-list{grid-template-columns:1fr}.admin-list .list-nav{max-height:260px}.module-item{grid-template-columns:2rem minmax(0,1fr)}.module-item>.module-status{grid-column:2}.site-header{position:static}.site-header .brand{font-size:.85rem}.site-header nav{gap:.1rem}.site-header nav a{font-size:.8rem;padding:.3rem .45rem}.site-main{padding-top:2rem}.practice-editor{min-height:260px}.admin-toolbar input{max-width:none}.task-tabs a{font-size:.78rem}.lab-controls select{width:100%}}
@media print{.site-header,.identity-strip,.practice-nav,.task-tabs,.lab-controls,.admin-tabs,.admin-toolbar,.list-nav,.student-name-box,.preview-frame,.save-bar,.hosted-doc-banner{display:none!important}.site-main{padding:0;max-width:none}.practice-layout,.admin-list{display:block}.site-main .hero h1{font-size:28pt}.module-item{break-inside:avoid}.task-panel textarea{display:none}.site-main .output{color:var(--ink);background:#eef0e7}.detail-pane{border:0}.admin-summary{break-inside:avoid}}
.lab-grid{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,1fr);gap:1rem}.lab-grid>section{min-width:0}.lab-grid .output{min-height:300px;max-height:70vh;overflow:auto;margin:0;white-space:pre-wrap}.lab-grid label.block{margin-top:.5rem}.editor-head{display:flex;justify-content:space-between;gap:.5rem;align-items:center}.editor-head small{color:var(--muted)}.code-tools{display:flex;gap:.4rem;flex-wrap:wrap}.code-tools button{font-size:.8rem}.compiled-code{font-size:.8rem;max-height:220px;overflow:auto}.task-answer{min-height:130px}.execution-label{display:flex;align-items:center;justify-content:space-between}.execution-label h3{margin:.5rem 0}.lab-error{color:#8a3119}.task-nav-name{font-size:.8rem}.lab-grid .preview-frame{height:360px}
@media(max-width:1050px){.lab-grid{grid-template-columns:1fr}.lab-grid .output{min-height:170px}}
@media print{.lab-grid{display:block}.lab-grid .output{min-height:0;max-height:none}.code-tools{display:none}}
.editor-head{min-height:44px}.editor-head label.block{margin:.5rem 0}.practice-nav h2{font-size:1.3rem}.site-header~*{scroll-margin-top:80px}
/* Classroom: the same material links and contents as the printable handouts. */
.classroom-layout{display:grid;grid-template-columns:minmax(0,1fr) 232px;gap:clamp(2rem,4vw,3.5rem);align-items:start}.classroom-content{min-width:0}.classroom-nav{position:sticky;top:90px;max-height:calc(100dvh - 110px);overflow-y:auto;border-left:1px solid var(--line);padding-left:1.25rem;font-size:.85rem;scrollbar-width:thin}.classroom-nav details{margin:0}.classroom-nav summary{font-size:.92rem;margin-bottom:1.2rem}.classroom-nav nav{display:flex;flex-direction:column;gap:.2rem;margin:.7rem 0 1.8rem}.classroom-nav a{display:block;text-decoration:none;padding:.35rem .55rem;min-height:36px;border-radius:2px}.classroom-nav a[aria-current=page]{background:var(--ink);color:var(--surface);font-weight:700}.classroom-nav .classroom-toc{line-height:1.5}.classroom-toc a{border-bottom:1px solid var(--line);border-radius:0}.classroom-toc a[aria-current=location]{color:var(--accent);font-weight:750;border-bottom-color:var(--accent)}.classroom-content [id]{scroll-margin-top:100px}.classroom-nav .hint{font-size:.8rem;line-height:1.8}
@media(max-width:1050px){.classroom-layout{grid-template-columns:1fr;gap:2rem}.classroom-nav{grid-row:1;position:static;max-height:none;border-left:0;border-bottom:1px solid var(--line);padding:0 0 .7rem}.classroom-content{grid-row:2}.classroom-nav summary{margin-bottom:0;min-height:44px;padding:.4rem 0}.classroom-nav details[open] summary{margin-bottom:1rem}.classroom-nav nav{margin-bottom:1.3rem}.classroom-nav a{min-height:44px}.classroom-nav .classroom-toc{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:.2rem .8rem}.classroom-nav .hint{display:none}}
@media print{.classroom-layout{display:block}.classroom-nav{display:none!important}}

.admin-needs{flex-basis:100%;margin:0}.admin-needs summary{font-size:.9rem}.admin-needs li{font-size:.88rem}

fieldset.practice-fields{border:0;padding:0;margin:0;min-width:0}