/* Reading space first; course navigation stays in the right rail. */
.course-layout{display:grid;grid-template-columns:minmax(0,1fr) 280px;grid-template-areas:"content navigation";gap:28px;align-items:start}
.course-content{grid-area:content;min-width:0}
.course-navigation{grid-area:navigation;position:sticky;top:24px;max-height:calc(100dvh - 48px);overflow:auto}
.course-navigation>summary{display:flex;align-items:center;gap:12px;min-height:56px;padding:16px 20px;cursor:pointer;font-size:14px;font-weight:650;border-bottom:1px solid var(--line);list-style:none}
.course-navigation>summary::-webkit-details-marker{display:none}
.course-navigation>summary:after{content:'＋';margin-left:auto;font-size:22px;font-weight:400}
.course-navigation[open]>summary:after{content:'−'}
.course-tree{padding:12px}
.course-tree a,.course-section-link{display:flex;align-items:flex-start;gap:12px;min-height:48px;padding:12px;border-radius:8px;color:var(--ink);text-decoration:none;font-size:14px;line-height:1.5;overflow-wrap:anywhere}
.course-tree a:hover,.course-section-link:hover{background:var(--bg)}
.course-tree a[aria-current=page]{background:var(--accent);color:#263012;font-weight:650}
.course-tree .icon{width:22px;height:22px;margin-top:1px;flex:none}
.course-link-copy{display:block;min-width:0;flex:1}
.course-tree small{display:block;margin-top:5px;color:var(--muted);font-size:12px;line-height:1.5}
.course-tree a[aria-current=page] small{color:#46522f}
.course-tree ul{list-style:none;padding:0;margin:8px 0}
.course-tree ul ul{padding-left:8px;border-left:1px solid var(--line);margin-left:10px}
.course-tree ul ul ul .icon{display:none}
.course-tree h2{font-size:20px;margin:0 0 8px}
.course-tree .course-brand a{font-size:20px;font-weight:700}
.course-actions{margin-top:20px;padding-top:20px;border-top:1px solid var(--line)}
.course-actions h3{margin:0 12px 12px;font-size:13px;color:var(--muted);font-weight:600}
.course-section-link{width:100%;border:0;background:transparent;text-align:left;align-items:center;white-space:normal}
.course-subnav{display:grid;gap:8px}
.course-subnav .button{justify-content:flex-start;white-space:normal}
.course-subnav [aria-current=page]{background:var(--accent);color:#263012;border-color:var(--accent)}
.course-content>.page{margin-top:24px}
.course-overview{padding:32px}
.course-overview h2{margin:12px 0;font-size:24px;line-height:1.3}
.course-overview p{line-height:1.8}
.course-links{display:grid;gap:12px;margin:24px 0}
.course-links>a{display:flex;align-items:center;gap:16px;min-height:64px;padding:18px 20px;border:1px solid var(--line);border-radius:10px;font-size:16px;font-weight:600}
.course-links>a:hover{background:var(--bg);border-color:var(--accent)}
.course-links>a:after{content:'→';margin-left:auto;font-size:22px}
.course-content .task-columns{grid-template-columns:minmax(0,1fr)}
.course-context{margin-bottom:24px}
.course-context h2{font-size:24px}
.course-content .report-grid{grid-template-columns:minmax(0,1fr)}
.course-content .summary-content{gap:20px}
.course-content .environment-card dl{grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.task-evidence-intro h3{margin-top:24px;margin-bottom:12px}
.evidence-explanation-label{display:block;margin:24px 0;color:var(--ink);font-size:14px;line-height:1.5}
.evidence-explanation-label textarea{display:block;width:100%;margin-top:12px;padding:16px;border:1px solid var(--line);border-radius:10px;background:var(--surface);color:var(--ink);font:inherit;resize:vertical}
#task-send-panel>.card{border:0;box-shadow:none;padding:16px 0}
#evidence-send-status,#evidence-config-notice{margin:16px 0;color:var(--muted);line-height:1.7}
#evidence-send-panel>.linux-machine{position:static;border:1px solid var(--line);border-left:4px solid var(--accent);padding:20px;margin:24px 0}
.course-history-table{overflow-x:auto;margin:24px 0}
.course-history-table table{width:100%;border-collapse:collapse;table-layout:fixed}
.course-history-table th,.course-history-table td{padding:14px 10px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top;font-size:13px;line-height:1.6;overflow-wrap:anywhere}
.course-history-table th{color:var(--muted)}
.course-history-table th:nth-child(1){width:16%}.course-history-table th:nth-child(2){width:15%}.course-history-table th:nth-child(3){width:24%}.course-history-table th:nth-child(4){width:28%}.course-history-table th:nth-child(5){width:17%}
#evidence-conditions,#evidence-send-panel,#evidence-history,#linux-machine{scroll-margin-top:24px}
@media(max-width:1120px){
 .course-layout{grid-template-columns:minmax(0,1fr);grid-template-areas:"navigation" "content";gap:20px}
 .course-navigation{position:static;max-height:none}
 .course-tree{max-height:65dvh;overflow:auto}
 .course-navigation>summary{border-bottom:0}
 .course-navigation[open]>summary{border-bottom:1px solid var(--line)}
}
@media(max-width:640px){
 .course-overview{padding:24px 20px}
 .course-overview h2,.course-context h2{font-size:22px}
 .course-content .environment-card dl{grid-template-columns:minmax(0,1fr)}
 .course-tree a{font-size:14px}
 .course-links>a{padding:16px;font-size:15px}
 .course-history-table table,.course-history-table tbody,.course-history-table tr,.course-history-table td{display:block;width:100%}
 .course-history-table tr:has(th){display:none}
 .course-history-table tr{border:1px solid var(--line);border-radius:10px;margin-bottom:16px;padding:12px}
 .course-history-table td{padding:8px 4px;border:0}
 .course-history-table td:before{content:attr(data-label);display:block;margin-bottom:4px;color:var(--muted);font-size:12px;font-weight:600}
}
/* Inside the course, task actions live in its right-hand navigation. */


.lesson-copy p{margin:12px 0;line-height:1.75}.lesson-copy h3,.lesson-copy h4,.lesson-copy h5{margin:28px 0 12px;line-height:1.4}.lesson-copy ul,.lesson-copy ol{padding-left:24px;margin:12px 0}.lesson-copy li{margin:8px 0;line-height:1.6}.lesson-copy pre{padding:16px;white-space:pre-wrap;overflow-wrap:anywhere;max-width:100%;background:var(--bg);border:1px solid var(--line);border-radius:12px}.lesson-copy code{font-family:monospace;background:var(--bg);border-radius:4px;padding:2px 4px;overflow-wrap:anywhere}.lesson-copy pre code{padding:0}.lesson-copy blockquote{border-left:4px solid var(--accent,#abc253);padding:14px 18px;margin:18px 0;background:var(--bg);line-height:1.65}.linux-lesson #evidence-send-panel{border:2px solid var(--accent,#abc253)}
@media(min-width:1280px){#page-evidence.linux-lesson:not([hidden]){display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:20px;align-items:start}.linux-lesson #evidence-conditions{min-width:0}.linux-lesson #evidence-send-panel{position:sticky;top:24px;min-width:0;margin-top:0;padding:18px}.linux-lesson #evidence-history{grid-column:1/-1}.linux-lesson #evidence-send-panel .screenshot-actions{flex-direction:column;align-items:stretch}.linux-lesson #evidence-send-panel .button{max-width:100%;white-space:normal}}

.course-inline-task{border-top:1px solid var(--line);padding:28px 0;margin:20px 0}.inline-answer{background:var(--surface,#fff);border:1px solid var(--accent,#abc253);border-radius:12px;padding:18px;margin:16px 0 24px}.inline-answer h4{margin:0 0 12px!important}.inline-answer label{display:block;margin:12px 0}.inline-answer textarea{display:block;width:100%;box-sizing:border-box;min-height:70px;font:inherit;padding:10px;border:1px solid var(--line);border-radius:8px;background:var(--surface,#fff);color:inherit}.inline-answer small{display:block;color:var(--muted);margin:10px 0;line-height:1.5}.inline-answer input[type=checkbox]{width:20px;height:20px;margin-right:8px;vertical-align:middle}.inline-answer-history{margin-top:18px}.inline-answer-history summary{cursor:pointer;font-weight:600}.inline-answer-gallery{display:flex;flex-wrap:wrap;gap:12px;margin:12px 0}.inline-answer-gallery>div{max-width:180px;overflow-wrap:anywhere}.inline-answer img{max-width:160px;max-height:120px;object-fit:contain;display:block}.inline-answer-gallery span{display:block;margin:8px 0}.inline-saved-answer{border-top:1px solid var(--line);padding:12px 0}.inline-saved-answer a{display:inline-block;margin:8px}.course-inline-task pre{white-space:pre-wrap;overflow-wrap:anywhere}@media(max-width:650px){.inline-answer{padding:14px}.inline-answer .button{width:100%;white-space:normal}}

.inline-point-answer{margin:10px 0 20px;border-left:3px solid var(--accent,#abc253);padding:8px 14px}.inline-point-answer>summary{cursor:pointer;font-weight:600;line-height:1.5;padding:8px 0;color:var(--ink)}.inline-point-answer .inline-answer{margin-top:12px}.inline-answer-history p{white-space:pre-wrap;overflow-wrap:anywhere}

.answer-placeholder{padding:18px;border:2px dashed var(--accent,#abc253);border-radius:12px;margin:18px 0}.answer-placeholder h4{margin:0 0 8px}.answer-placeholder p{font-size:14px;color:var(--muted)}

.frontend-update-banner{position:fixed;bottom:20px;left:50%;transform:translateX(-50%);z-index:1000;display:flex;gap:20px;align-items:center;padding:18px 22px;width:min(900px,calc(100% - 32px));box-sizing:border-box;background:var(--surface,#fff);color:var(--ink,#222);border:2px solid var(--accent,#abc253);border-radius:14px;box-shadow:0 8px 28px #0003}.frontend-update-banner span{line-height:1.6}.frontend-update-banner button{flex-shrink:0}@media(max-width:650px){.frontend-update-banner{flex-direction:column;align-items:stretch;bottom:12px}}

/* Expand the current branch, keep unrelated lessons out of the reading flow. */
.course-branch>summary,.course-topic>summary{cursor:pointer;padding:14px 12px;min-height:48px;font-weight:650;line-height:1.5;overflow-wrap:anywhere}
.course-branch>summary small{display:block;font-weight:400;margin-top:4px;color:var(--muted)}
.course-branch{border-top:1px solid var(--line);margin-top:8px}.course-topic>summary{font-size:14px}
.course-tree .course-brand{padding:8px 12px;font-size:17px;line-height:1.5}
.course-content #page-evidence.linux-lesson:not([hidden]){display:block}
.course-content .linux-lesson #evidence-send-panel{position:static;padding:24px;margin-top:24px}
.sidebar-account{border-top:1px solid var(--line);padding-top:20px;line-height:1.6}
.sidebar-account strong{display:block;font-size:16px;margin-bottom:4px!important}.sidebar-account p{font-size:13px;color:var(--muted);margin:4px 0 16px}.sidebar-account button{width:100%;min-height:44px}
.student-tools{margin:12px 0;padding-top:12px;border-top:1px solid var(--line)}.student-tools>summary{padding:12px;cursor:pointer;color:var(--muted);font-size:14px}.student-tools>a{display:flex;gap:12px;align-items:center;padding:12px;min-height:44px;border-radius:8px}.student-tools>a[aria-current=page]{background:var(--accent);color:#263012}
body:has(#page-course:not([hidden])) .student-tools{display:none}
@media(max-width:760px){.sidebar-account{margin-top:12px}.sidebar-account button{width:auto}.course-tree{max-height:55dvh}}

#account-panel.sidebar-account{display:grid;gap:6px;margin:0;padding:20px 0 0;background:transparent;border:0;border-top:1px solid var(--line);box-shadow:none}
#account-panel.sidebar-account button{margin:8px 0 0;width:100%;white-space:normal}
@media(max-width:640px){.sidebar-bottom{display:block;position:static;margin:12px 0;padding:0}.navigation{overflow:visible;flex-wrap:wrap}.student-tools{flex-basis:100%;margin:0}.student-tools>a{font-size:14px}.navigation>a{font-size:14px;min-height:44px}.navigation .icon{width:22px;height:22px}#account-panel.sidebar-account{grid-template-columns:minmax(0,1fr) auto;align-items:center;padding:12px 0;gap:8px}#account-panel.sidebar-account p{grid-column:1;order:0;width:auto}#account-panel.sidebar-account button{grid-column:2;grid-row:1/3;width:auto;margin:0;max-width:150px}}

@media(max-width:640px){.app-shell>.topbar{height:auto;min-height:77px;align-items:flex-start;flex-wrap:wrap;gap:12px;padding:16px}.app-shell .breadcrumbs{display:block;flex-basis:100%;min-width:0;font-size:12px;line-height:1.6}.app-shell .breadcrumbs strong{display:block}.app-shell .breadcrumbs span{display:none}}

/* Compact learner outline, with task actions separate from course structure. */
.course-layout{grid-template-columns:minmax(0,1fr) 320px}
.course-navigation{scrollbar-width:thin;scrollbar-color:var(--line) transparent}
.course-tree{padding:12px}
.course-tree .course-brand{padding:8px 10px 2px;margin:0;font-size:18px}
.course-home-link{margin-bottom:12px}
.course-outline{padding-top:12px!important;border-top:1px solid var(--line)}
.course-branch{border:0;margin:4px 0}
.course-branch>summary,.course-topic>summary{display:flex;align-items:flex-start;gap:10px;list-style:none;position:relative;padding:12px 8px 12px 28px;border-radius:9px;min-height:48px;font-size:14px;line-height:1.5}
.course-branch>summary::-webkit-details-marker,.course-topic>summary::-webkit-details-marker{display:none}
.course-branch>summary:before,.course-topic>summary:before{content:'';position:absolute;left:10px;top:20px;width:7px;height:7px;border-right:2px solid var(--muted);border-bottom:2px solid var(--muted);transform:rotate(-45deg)}
.course-branch[open]>summary:before,.course-topic[open]>summary:before{transform:rotate(45deg);top:18px}
.course-branch>summary:hover,.course-topic>summary:hover{background:var(--bg)}
.course-branch-copy{min-width:0;flex:1;overflow-wrap:anywhere}
.course-branch>summary small{font-size:12px;font-weight:400;margin-top:4px}
.course-tree .icon{width:20px;height:20px;flex:none;margin-top:1px}
.course-tree ul ul{padding-left:6px;margin:4px 0 8px 12px}
.course-tree ul ul ul .icon{display:block}
.course-tree .course-overview-link{margin:2px 0 8px 28px;min-height:40px;padding:8px;font-size:12px;color:var(--muted)}
.course-overview-link .icon{width:16px;height:16px}
.course-task-link{padding:10px!important;gap:8px!important;margin:4px 0;border-left:3px solid transparent}
.course-task-link .course-link-copy{font-size:13px;line-height:1.5}
.course-task-link small{font-size:11px;margin-top:4px}
.course-tree a[aria-current=page]{border-left-color:var(--accent);box-shadow:0 0 0 1px var(--accent)}
.course-actions{margin:0 0 12px;padding:0;border:1px solid var(--line);border-radius:10px}
.course-actions>summary{display:flex;align-items:center;gap:12px;min-height:44px;padding:12px;list-style:none;cursor:pointer;font-size:13px;font-weight:650;color:var(--ink)}
.course-actions>summary::-webkit-details-marker{display:none}
.course-actions>summary:after{content:'＋';margin-left:auto;font-size:20px;color:var(--muted)}
.course-actions[open]>summary:after{content:'−'}
.course-actions[open]>summary{border-bottom:1px solid var(--line);margin-bottom:6px}
.course-actions .course-section-link{min-height:44px;margin:4px 6px;width:calc(100% - 12px);padding:10px;font-size:13px;background:transparent;border:0}
.course-actions .course-subnav{padding:6px;gap:6px}
.course-tree :is(a,button,summary):focus-visible{outline:3px solid var(--accent);outline-offset:2px}
@media(max-width:1120px){.course-layout{grid-template-columns:minmax(0,1fr)}.course-tree{max-height:55dvh}}
.course-links .course-link-copy small{display:block;margin-top:6px;color:var(--muted);font-size:12px;font-weight:400;line-height:1.5}

.lesson-videos{display:grid;gap:20px;margin:24px 0}.lesson-videos figure{margin:0}.lesson-videos video{display:block;width:100%;max-height:480px;border:1px solid var(--line);border-radius:12px;background:#101010}.lesson-videos figcaption{margin-top:8px;font-size:13px;color:var(--muted);overflow-wrap:anywhere}

.lesson-media{margin:24px 0;max-width:100%}.lesson-media img,.lesson-media video{display:block;max-width:100%;width:100%;height:auto;border-radius:12px}.lesson-media video{max-height:480px;background:#101010}.lesson-media img{object-fit:contain}.lesson-media figcaption{margin-top:8px;font-size:13px;color:var(--muted);overflow-wrap:anywhere}

.vm-card-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,280px),1fr));gap:20px;margin:24px 0}.vm-card{padding:20px}.vm-card .button{margin:8px 8px 0 0}#vm-add-form{display:flex;flex-wrap:wrap;gap:16px;align-items:end}#vm-add-form label{flex:1;min-width:220px}#vm-add-form select{width:100%}#evidence-vm-targets{display:grid;gap:12px;margin:16px 0}.inline-answer select{width:100%;min-height:44px;margin:8px 0 16px}

/* Learner VM library: assignment selection remains inside each answer. */
.vm-workspace{display:grid;gap:24px}.vm-workspace-heading{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:28px;border:1px solid var(--line);border-radius:16px;background:var(--surface)}.vm-workspace-heading h2{font-size:24px;margin:10px 0 12px}.vm-workspace-heading p{max-width:680px;line-height:1.7;color:var(--muted)}.vm-workspace .button{min-height:44px;padding:12px 18px;white-space:normal}.vm-workspace-heading>.button{flex-shrink:0}.vm-section-heading{display:flex;align-items:center;justify-content:space-between;gap:16px}.vm-section-heading h3{font-size:18px}.vm-count{min-width:30px;height:30px;display:grid;place-items:center;border-radius:9px;background:var(--surface);border:1px solid var(--line);font-weight:650}.vm-workspace .vm-card-grid{margin:0;grid-template-columns:repeat(auto-fit,minmax(min(100%,360px),1fr));gap:20px}.vm-workspace .vm-card{display:flex;flex-direction:column;gap:20px;padding:24px;background:var(--surface);border:1px solid var(--line);border-radius:16px;min-width:0}.vm-card-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;flex-wrap:wrap}.vm-card-identity{display:flex;align-items:center;gap:14px;min-width:0}.vm-card-identity h3{font-size:18px;line-height:1.4;overflow-wrap:anywhere}.vm-symbol{display:grid;place-items:center;width:48px;height:48px;border-radius:12px;background:var(--bg);border:1px solid var(--line);color:var(--ink);font-size:15px;font-weight:750;flex-shrink:0}.vm-connection{padding:7px 10px;border-radius:20px;font-size:12px;font-weight:650;background:var(--bg);color:var(--muted)}.vm-connection:before{content:'●';margin-right:6px}.vm-connection.is-connected{background:var(--green-bg);color:var(--green)}.vm-connection.is-error{background:var(--orange-bg);color:var(--orange)}.vm-address{display:grid;gap:8px}.vm-address code{font-size:19px;font-weight:650;overflow-wrap:anywhere}.vm-connection-copy{font-size:14px;line-height:1.7;flex:1}.vm-check-time{color:var(--muted);font-size:12px;line-height:1.5}.vm-card-actions{display:flex;flex-wrap:wrap;gap:10px;padding-top:16px;border-top:1px solid var(--line)}.vm-card-actions .button{margin:0}.vm-remove{color:var(--red)}.vm-remove-confirm{padding:16px;border:1px solid var(--line);border-radius:10px;background:var(--bg)}.vm-remove-confirm p{margin-bottom:12px;line-height:1.6}.vm-empty{grid-column:1/-1;display:grid;justify-items:center;text-align:center;gap:18px;padding:44px 24px;border:1px dashed var(--line);border-radius:16px;background:var(--surface)}.vm-empty p{max-width:500px;line-height:1.7;color:var(--muted)}.vm-add-panel{display:grid;gap:20px;padding:28px;border:1px solid var(--line);border-radius:16px;background:var(--surface)}.vm-add-panel p{line-height:1.7}.vm-add-panel #vm-add-form{align-items:end;gap:20px}.vm-add-panel label{display:grid;gap:10px;font-weight:650}.vm-add-panel select{min-height:48px;padding:12px;font-weight:400;background:var(--bg);color:var(--ink);border:1px solid var(--line);max-width:100%}.vm-next-step{display:flex;align-items:center;gap:18px;padding:24px;border:1px solid var(--line);border-radius:16px}.vm-next-step>div{flex:1;min-width:0}.vm-next-step p{margin-top:8px;color:var(--muted);line-height:1.7}.vm-notice:empty{display:none}.vm-notice:not(:empty){padding:16px;border-radius:12px;background:var(--surface);border:1px solid var(--line);line-height:1.6}
@media(max-width:640px){.vm-workspace-heading{align-items:stretch;flex-direction:column;padding:22px}.vm-workspace .vm-card{padding:20px}.vm-card-actions{flex-direction:column}.vm-add-panel{padding:20px}.vm-add-panel #vm-add-form{flex-direction:column;align-items:stretch}.vm-add-panel #vm-add-form label{min-width:0}.vm-next-step{flex-wrap:wrap;padding:20px}.vm-next-step>.button{width:100%;text-align:center}}

.vm-add-panel #vm-add-form{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(0,1fr) 120px auto}.vm-add-panel #vm-add-form label{min-width:0}.vm-add-panel input{width:100%;min-height:48px;padding:12px;border:1px solid var(--line);border-radius:9px;background:var(--bg);color:var(--ink);font:inherit}.vm-add-panel input:focus-visible{outline:3px solid #78933d;outline-offset:3px}
@media(max-width:900px){.vm-add-panel #vm-add-form{grid-template-columns:1fr 1fr}}
@media(max-width:640px){.vm-add-panel #vm-add-form{grid-template-columns:minmax(0,1fr)}}

.vm-form-error:empty{display:none}.vm-form-error{color:var(--red);line-height:1.6}

/* Learner navigation: persistent destinations, task actions stay inside the course. */
.sidebar .learner-navigation{display:grid;grid-template-columns:minmax(0,1fr);gap:8px;margin-top:28px;overflow:visible}
.sidebar .learner-navigation>a{min-height:64px;padding:12px;border-radius:12px;gap:12px;white-space:normal;font-size:15px;line-height:1.35;transition:background .15s ease}
.sidebar .learner-navigation .icon{width:26px;height:26px;flex-shrink:0}
.learner-navigation .nav-label{min-width:0;overflow-wrap:anywhere;font-weight:600}
.learner-navigation .nav-label small{display:block;margin-top:5px;font-size:12px;font-weight:400;color:var(--muted);line-height:1.4}
.learner-navigation>a.active .nav-label small{color:inherit;opacity:.8}
.learner-navigation .nav-section-label{padding:18px 12px 4px;color:var(--muted);font-size:11px;font-weight:700;letter-spacing:1px}
.learner-navigation>a:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
.sidebar .sidebar-account{border-top:0}
@media(max-width:640px){
 .sidebar .learner-navigation{grid-template-columns:repeat(2,minmax(0,1fr));margin-top:16px;padding-bottom:8px}
 .sidebar .learner-navigation>a{min-height:68px;font-size:13px;padding:10px;gap:8px}
 .learner-navigation .nav-section-label{grid-column:1/-1;padding:10px 10px 2px}
 .learner-navigation .nav-label small{font-size:11px}
 .sidebar .learner-navigation .nav-count{display:none}
}

/* InternLab handbook */
.handbook-hero{padding:32px;margin-bottom:24px;background:var(--surface)}
.handbook-hero h2{margin:12px 0;font-size:28px;line-height:1.3}
.handbook-hero p{max-width:760px;line-height:1.8;color:var(--muted);margin-bottom:22px;font-size:15px}
.handbook-layout{display:grid;grid-template-columns:240px minmax(0,1fr);gap:24px;align-items:start}
.handbook-index{position:sticky;top:24px;padding:20px;display:grid;gap:6px}
.handbook-index h2{font-size:17px;margin:0 0 8px}
.handbook-index a{padding:12px 10px;border-radius:8px;font-size:14px;line-height:1.5;color:var(--ink)}
.handbook-index a:hover,.handbook-index a:focus-visible{background:var(--bg);text-decoration:underline}
.handbook-content{display:grid;gap:24px;min-width:0}
.handbook-section{padding:28px;scroll-margin-top:24px;line-height:1.8;overflow-wrap:anywhere}
.handbook-section h2{font-size:22px;line-height:1.4;margin:8px 0 18px}
.handbook-section h3{font-size:16px;display:flex;align-items:center;gap:10px;margin:0 0 10px}
.handbook-section p,.handbook-section li,.handbook-section dd{font-size:14px;line-height:1.8}
.handbook-section p{margin:12px 0}
.handbook-section ol{padding-left:22px;margin:12px 0 18px}
.handbook-section li{padding-left:6px;margin:10px 0}
.handbook-note{padding:16px 18px;border-left:3px solid var(--accent);border-radius:0 8px 8px 0;background:var(--bg)}
.handbook-methods{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px;margin:20px 0}
.handbook-methods>div{padding:20px;border:1px solid var(--line);border-radius:12px;min-width:0}
.handbook-statuses{margin:16px 0;display:grid;gap:12px}
.handbook-statuses>div{padding:14px 18px;background:var(--bg);border-radius:10px}
.handbook-statuses dt{font-size:14px;font-weight:700}
.handbook-statuses dd{margin:5px 0 0;color:var(--muted)}
.handbook-faq{margin-top:12px}
.handbook-faq summary{cursor:pointer;font-weight:600;font-size:14px;line-height:1.6;padding:12px 0;min-height:44px}
.handbook-faq summary:focus-visible,.handbook-index a:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
.handbook-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:20px}
.handbook-demo{margin-top:0}
@media(max-width:1100px){.handbook-layout{grid-template-columns:minmax(0,1fr)}.handbook-index{position:static;grid-template-columns:repeat(2,minmax(0,1fr))}.handbook-index h2{grid-column:1/-1}.handbook-methods{grid-template-columns:minmax(0,1fr)}}
@media(max-width:640px){.handbook-hero,.handbook-section{padding:22px 18px}.handbook-hero h2{font-size:23px}.handbook-index{grid-template-columns:minmax(0,1fr);padding:18px}.handbook-section h2{font-size:20px}.handbook-layout,.handbook-content{gap:18px}.handbook-methods>div{padding:16px}}

/* Independently collapsible reading panels. */
body.main-navigation-collapsed .app-shell{margin-left:0}
body.main-navigation-collapsed #main-navigation{display:none}
body:has(#page-course:not([hidden])) main{max-width:none}
.course-panel-actions{display:flex;justify-content:flex-end;margin-bottom:16px}
.course-layout.course-navigation-collapsed{grid-template-columns:minmax(0,1fr);grid-template-areas:"content";gap:0}
.panel-toggle{flex-shrink:0;min-height:44px;white-space:normal}
#course-navigation[hidden]{display:none}
@media(max-width:640px){.course-panel-actions{justify-content:flex-start}.panel-toggle{font-size:13px}.course-layout.course-navigation-collapsed{grid-template-areas:"content"}}

/* Quiet panel controls, with a comfortable pointer and touch target. */
button.panel-toggle{display:inline-flex;align-items:center;justify-content:center;width:44px;height:44px;min-height:44px;padding:10px;border:1px solid transparent;border-radius:9px;background:transparent;color:var(--muted);box-shadow:none}
button.panel-toggle:hover{background:var(--surface);border-color:var(--line);color:var(--ink)}
button.panel-toggle:focus-visible{outline:2px solid var(--accent);outline-offset:2px;color:var(--ink)}
.panel-toggle svg{width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round}
.panel-toggle[aria-expanded="false"] .panel-chevron{transform:rotate(180deg);transform-box:fill-box;transform-origin:center}
.course-panel-actions{margin-bottom:6px}

button.panel-toggle{background:transparent!important;border-color:transparent!important;color:var(--muted)!important}
button.panel-toggle:hover,button.panel-toggle:focus-visible{background:var(--surface)!important;border-color:var(--line)!important;color:var(--ink)!important}

button.panel-toggle{padding:10px!important}
.panel-toggle svg{flex:none;min-width:22px}

button.panel-toggle{padding:10px!important}
.panel-toggle svg{flex:none;min-width:22px}

/* A centered reading column, with gentle sizing based on its actual width. */
body:has(#page-course:not([hidden])) main{max-width:1600px;--course-rail-space:348px}
body:has(#page-course:not([hidden])):has(.course-navigation-collapsed) main{max-width:1240px;--course-rail-space:0px}
body:has(#page-course:not([hidden])) .page-heading{width:min(1120px,calc(100% - var(--course-rail-space)));margin-inline-start:max(0px,calc((100% - var(--course-rail-space) - 1120px)/2))}
.course-content{width:100%;max-width:1120px;margin-inline:auto;justify-self:center;container-type:inline-size;--reading-size:clamp(16px,calc(14px + .35cqw),19px)}
.course-content :is(.body-copy,.lesson-copy,.course-overview){font-size:var(--reading-size);max-width:100%;line-height:1.8}
.course-content :is(p,li,blockquote,pre,td,th,label,.inline-point-answer>summary,.inline-answer-history>summary){font-size:var(--reading-size);line-height:1.8}
.course-content .lesson-copy :is(p,ul,ol,blockquote){max-width:100%}
.course-content .lesson-copy :is(p,li){margin-block:.65em}
.course-content :is(.screenshot-card,.course-overview){padding:clamp(24px,3cqw,40px)}
.course-content :is(h2,.course-overview h2){font-size:calc(var(--reading-size) * 1.5);line-height:1.35}
.course-content :is(h3,h4,h5){font-size:calc(var(--reading-size) * 1.15);line-height:1.5}
.course-content .inline-answer{padding:1.2em}
.course-content .inline-answer :is(textarea,select){font-size:inherit}
.course-content .inline-answer small{font-size:.85em}
.course-content .lesson-copy pre{font-size:.9em}
.course-content .lesson-copy code{font-size:.95em}
.course-content .inline-point-answer{padding:.5em 1em;margin-block:1em}
@media(max-width:1120px){body:has(#page-course:not([hidden])) main{--course-rail-space:0px}}
@media(max-width:640px){
 #course-content{--reading-size:16px}
 .course-content :is(.screenshot-card,.course-overview){padding:22px 18px}
 .course-content .inline-answer{padding:16px}
 .course-content .inline-point-answer{padding:8px 10px}
}

/* Clear submission states, with the existing theme variables. */
.learner-route,.submission-guide {line-height:1.7; margin:16px 0;}
#course-overview.course-context {display:flex;flex-wrap:wrap;gap:12px;align-items:center;}
#course-overview.course-context .learner-route {flex-basis:100%;order:-1;}
.submission-vm {margin:16px 0;border:1px solid var(--line);border-radius:12px;padding:14px;}
.submission-vm summary {cursor:pointer;min-height:28px;font-weight:600;}
.submission-vm .card {margin-top:16px;}
.draft-hint,.field-optional {font-size:.85rem;color:var(--muted);line-height:1.6;}
.field-optional {font-weight:400;margin-left:8px;}
.inline-answer {padding:22px;display:flex;flex-direction:column;gap:14px;}
.inline-answer label,.evidence-explanation-label {display:flex;flex-direction:column;gap:10px;}
.inline-answer label:has(input[type=checkbox]) {flex-direction:row;align-items:center;min-height:44px;}
.inline-answer button,.inline-answer summary,.course-section-link {min-height:44px;}
.inline-answer textarea,#evidence-explanation {font-size:1rem;line-height:1.6;width:100%;box-sizing:border-box;}
.inline-answer-history summary {cursor:pointer;font-weight:600;padding:12px 0;}
.evidence-criterion {border-left:4px solid var(--accent);padding:18px;margin:18px 0;}
.evidence-criterion[data-state=needs_operator],.evidence-criterion[data-state=conflict_review] {border-left-color:#bd9142;}
.evidence-criterion[data-state=not_matched],.evidence-criterion[data-state=technical_error] {border-left-color:#d37770;}
.criterion-next-action {font-weight:600;padding:12px;border-radius:8px;background:var(--surface);}
#evidence-send-panel .icon,.course-section-link .icon {width:24px;height:24px;flex-shrink:0;}
#evidence-ready-hint {padding:12px 16px;border:1px solid var(--line);border-radius:10px;}
@media(max-width:600px){.inline-answer {padding:16px;}.inline-answer button,#evidence-submit {width:100%;}.submission-vm {padding:10px;}#course-overview.course-context {align-items:stretch;flex-direction:column;}#course-overview.course-context .learner-route {flex-basis:auto;}.screenshot-actions {flex-wrap:wrap;gap:12px;}.evidence-image-text pre {overflow-wrap:anywhere;white-space:pre-wrap;}}