:root{--green:#1f9d65;--dark:#126b45;--pale:#eaf8f1;--ink:#20312a;--muted:#66756e;--line:#d9e8df;--white:#fff;--danger:#b42318;--warn:#b54708}*{box-sizing:border-box}body{margin:0;background:#f6fbf8;color:var(--ink);font:16px/1.55 Arial,sans-serif}.topbar{display:flex;justify-content:space-between;align-items:center;padding:14px 5%;background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}.brand{display:flex;gap:9px;align-items:center;text-decoration:none;color:var(--dark)}.brand span{font-size:30px}.brand strong{font-size:22px}.brand small{color:var(--muted)}nav{display:flex;gap:16px;align-items:center}nav a{color:var(--dark);text-decoration:none;font-weight:bold}.container{max-width:1180px;margin:28px auto;padding:0 18px}footer{text-align:center;padding:30px;color:var(--muted)}.hero,.card{background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:0 8px 28px rgba(20,70,45,.06)}.hero{padding:42px}.card{padding:22px;margin-bottom:18px}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:18px}.btn{display:inline-block;border:0;border-radius:10px;padding:10px 15px;background:var(--green);color:#fff;text-decoration:none;font-weight:bold;cursor:pointer}.btn.secondary{background:#eef6f1;color:var(--dark);border:1px solid var(--line)}.btn.danger{background:var(--danger)}.btn.small{padding:7px 10px;font-size:14px}.actions{display:flex;gap:8px;flex-wrap:wrap}.pagehead{display:flex;justify-content:space-between;align-items:center;gap:15px;margin-bottom:20px}label{display:block;font-weight:bold;margin:12px 0 5px}input,select,textarea{width:100%;padding:11px;border:1px solid #bdcec4;border-radius:9px;background:#fff;font:inherit}textarea{min-height:120px}.two{display:grid;grid-template-columns:1fr 1fr;gap:16px}.alert{padding:12px 16px;border-radius:10px;margin-bottom:18px}.success{background:#e8f8ef;color:#146c43}.error{background:#fff0ef;color:#9d1c14}.badge{display:inline-block;padding:4px 9px;border-radius:999px;background:var(--pale);color:var(--dark);font-size:13px;font-weight:bold}.lesson-layout{display:grid;grid-template-columns:340px 1fr;gap:20px}.block{border:1px solid var(--line);border-radius:13px;padding:14px;margin:12px 0;background:#fff}.block-head{display:flex;justify-content:space-between;gap:10px}.preview img{max-width:100%;height:auto;border-radius:12px}.fact,.tip,.warning,.summary{padding:16px;border-left:5px solid var(--green);background:var(--pale);border-radius:9px}.warning{border-color:#e27813;background:#fff7e8}.tip{border-color:#3b82f6;background:#eef6ff}.summary{border-color:#7357c8;background:#f4f1ff}.divider{border:0;border-top:2px solid var(--line);margin:28px 0}.file-link{display:inline-block;padding:12px 15px;background:var(--pale);border-radius:10px;color:var(--dark);font-weight:bold}.muted{color:var(--muted)}table.list{width:100%;border-collapse:collapse}table.list th,table.list td{padding:12px;border-bottom:1px solid var(--line);text-align:left}@media(max-width:800px){.lesson-layout,.two{grid-template-columns:1fr}.topbar{align-items:flex-start;gap:10px}.brand small{display:none}nav{flex-wrap:wrap;justify-content:flex-end}.hero{padding:25px}}

.builder-image-preview{margin-top:12px;padding:10px;background:#f6fbf8;border:1px solid var(--line);border-radius:12px}.builder-image-preview img{display:block;max-width:280px;max-height:180px;width:auto;height:auto;border-radius:10px;object-fit:contain}

/* Full-width student lesson reading view */
.lesson-page{
  width:calc(100vw - 48px);
  max-width:none;
  margin-left:50%;
  transform:translateX(-50%);
  padding:30px clamp(22px,4vw,64px);
}
.lesson-page figure{margin:24px 0;}
.lesson-page figure img{width:100%;max-width:100%;height:auto;object-fit:contain;}
.lesson-page iframe{border-radius:12px;}
@media(max-width:800px){
  .lesson-page{width:calc(100vw - 20px);padding:22px 16px;}
}


/* v1.3 - Automatically scale lesson blocks into responsive tiles */
.lesson-block-grid{
  display:grid;
  grid-template-columns:repeat(var(--lesson-cols,1),minmax(0,1fr));
  gap:18px;
  align-items:stretch;
  margin-top:24px;
}
.lesson-content-block{
  min-width:0;
  padding:18px;
  background:#fff;
  border:1px solid var(--line);
  border-radius:16px;
  box-shadow:0 5px 18px rgba(20,70,45,.05);
  overflow:hidden;
}
.lesson-content-block h2{margin-top:0;font-size:clamp(20px,1.7vw,28px);}
.lesson-content-block p:first-child{margin-top:0;}
.lesson-content-block p:last-child{margin-bottom:0;}
.lesson-content-block figure{margin:0;text-align:center;}
.lesson-content-block figure img{
  width:100%;
  max-height:380px;
  object-fit:contain;
}
.lesson-content-block figcaption{margin-top:8px;color:var(--muted);font-size:14px;}
.lesson-content-block .fact,.lesson-content-block .tip,.lesson-content-block .warning,.lesson-content-block .summary{
  height:100%;
  margin:0;
}
.video-wrap{position:relative;padding-bottom:56.25%;height:0;overflow:hidden;border-radius:12px;}
.video-wrap iframe{position:absolute;inset:0;width:100%;height:100%;border:0;}
.lesson-content-block.type-divider{display:flex;align-items:center;}
.lesson-content-block.type-divider .divider{width:100%;margin:0;}
@media(max-width:1100px){
  .lesson-block-grid{grid-template-columns:repeat(2,minmax(0,1fr));}
}
@media(max-width:650px){
  .lesson-block-grid{grid-template-columns:1fr;gap:12px;}
  .lesson-content-block{padding:14px;}
}

/* v1.4 - Feature lesson layout: large image left, stacked cards right */
.lesson-feature-layout{
  display:grid;
  grid-template-columns:minmax(360px,46%) minmax(0,54%);
  gap:24px;
  align-items:start;
  margin-top:24px;
}
.lesson-feature-image{
  position:sticky;
  top:92px;
  align-self:start;
  background:#fff;
  border:1px solid var(--line);
  border-radius:18px;
  padding:16px;
  box-shadow:0 8px 24px rgba(20,70,45,.07);
}
.lesson-feature-image figure{margin:0;text-align:center;}
.lesson-feature-image img{
  display:block;
  width:100%;
  height:min(68vh,720px);
  object-fit:contain;
  border-radius:14px;
  background:#f6fbf8;
}
.lesson-feature-image figcaption{margin-top:10px;color:var(--muted);font-size:14px;}
.lesson-side-stack{
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:16px;
  align-items:start;
}
.lesson-side-stack.no-hero{
  grid-template-columns:repeat(3,minmax(0,1fr));
  margin-top:24px;
}
.lesson-side-stack .lesson-content-block{
  margin:0;
  height:auto;
}
.lesson-side-stack .type-heading,
.lesson-side-stack .type-paragraph,
.lesson-side-stack .type-summary,
.lesson-side-stack .type-youtube,
.lesson-side-stack .type-divider{
  grid-column:1 / -1;
}
.lesson-side-stack .type-image figure img{
  width:100%;
  max-height:280px;
  object-fit:contain;
}
@media(max-width:1050px){
  .lesson-feature-layout{grid-template-columns:42% 58%;gap:18px;}
  .lesson-side-stack{grid-template-columns:1fr;}
  .lesson-side-stack.no-hero{grid-template-columns:repeat(2,minmax(0,1fr));}
}
@media(max-width:760px){
  .lesson-feature-layout{grid-template-columns:1fr;}
  .lesson-feature-image{position:static;}
  .lesson-feature-image img{height:auto;max-height:520px;}
  .lesson-side-stack,.lesson-side-stack.no-hero{grid-template-columns:1fr;}
  .lesson-side-stack .lesson-content-block{grid-column:1;}
}

/* Study Nest v1.5 preview navigation */
.preview-toolbar{display:flex;justify-content:flex-start;align-items:center;margin:0 0 14px}.preview-toolbar .btn{white-space:nowrap}
.video-wrap{position:relative;width:100%;aspect-ratio:16/9;overflow:hidden;border-radius:16px;background:#111}.video-wrap iframe{position:absolute;inset:0;width:100%;height:100%;border:0}

/* Study Nest v1.6 - manual block layout, sizing and drag/drop builder */
.layout-controls{margin-top:18px;padding:14px;background:#f6fbf8;border:1px solid var(--line);border-radius:13px}.layout-controls h3{margin:0 0 8px}.builder-list-head{display:flex;justify-content:space-between;align-items:flex-start;gap:12px}.builder-list-head h2{margin-bottom:4px}.drag-handle{font-size:20px;line-height:1;cursor:grab;color:var(--dark);padding:7px 8px;border-radius:8px;background:var(--pale);user-select:none}.drag-handle:active{cursor:grabbing}.block-ident{display:flex;align-items:center;gap:7px;flex-wrap:wrap}.layout-pill{display:inline-block;padding:3px 8px;border-radius:999px;background:#f2f4f7;color:#475467;font-size:12px;font-weight:bold}.sortable-block{transition:transform .12s ease,opacity .12s ease,box-shadow .12s ease}.sortable-block.dragging{opacity:.45;box-shadow:0 14px 30px rgba(20,70,45,.18);transform:scale(.99)}#sortable_blocks{min-height:70px}.builder-form input[type=range]{padding:0;accent-color:var(--green)}
.manual-stack{grid-template-columns:repeat(2,minmax(0,1fr));grid-auto-flow:row dense}.manual-stack .lesson-content-block{grid-column:span 1}.manual-stack .layout-full{grid-column:1/-1}.manual-stack .layout-half,.manual-stack .layout-auto{grid-column:span 1}.manual-stack .layout-left{grid-column:1}.manual-stack .layout-right{grid-column:2}.manual-stack .layout-feature{grid-column:1/-1}.manual-stack .type-heading.layout-auto,.manual-stack .type-paragraph.layout-auto,.manual-stack .type-summary.layout-auto,.manual-stack .type-youtube.layout-auto,.manual-stack .type-divider.layout-auto{grid-column:1/-1}.manual-no-feature{grid-template-columns:repeat(2,minmax(0,1fr));margin-top:24px}.controlled-image{display:block;width:100%;height:var(--img-h,420px)!important;max-height:none!important;object-fit:var(--img-fit,contain)!important;object-position:var(--img-pos,center)!important;background:#f6fbf8;border-radius:14px}.lesson-feature-image .controlled-image{height:min(var(--img-h,620px),72vh)!important}.lesson-feature-image .lesson-content-block{border:0;box-shadow:none;padding:0}.lesson-feature-image>figure{margin:0}.lesson-feature-image .controlled-image{width:100%}
@media(max-width:760px){.manual-stack,.manual-no-feature{grid-template-columns:1fr}.manual-stack .layout-left,.manual-stack .layout-right,.manual-stack .layout-half,.manual-stack .layout-auto,.manual-stack .layout-full,.manual-stack .layout-feature{grid-column:1}.builder-list-head{align-items:center}.block-head{flex-direction:column}.controlled-image{height:auto!important;max-height:520px!important}}




/* Study Nest v1.9 - reliable clickable image lightbox */
.lesson-image-button{position:relative;display:block;width:100%;padding:0;border:0;background:transparent;border-radius:14px;cursor:zoom-in;overflow:hidden;text-align:inherit}
.lesson-image-button .lesson-lightbox-image{cursor:zoom-in;transition:transform .18s ease,box-shadow .18s ease}
.lesson-image-button:hover .lesson-lightbox-image,.lesson-image-button:focus-visible .lesson-lightbox-image{transform:scale(1.012);box-shadow:0 10px 28px rgba(0,0,0,.16)}
.lesson-image-button:focus-visible{outline:3px solid var(--green);outline-offset:3px}
.image-zoom-hint{position:absolute;right:12px;bottom:12px;padding:7px 10px;border-radius:999px;background:rgba(8,18,13,.78);color:#fff;font-size:13px;font-weight:700;pointer-events:none}
.lesson-lightbox{position:fixed;inset:0;z-index:99999;background:rgba(8,18,13,.94);display:none;align-items:center;justify-content:center;padding:28px}
.lesson-lightbox.open{display:flex}
.lesson-lightbox-full{display:block;max-width:96vw;max-height:92vh;width:auto;height:auto;object-fit:contain;border-radius:12px;box-shadow:0 24px 70px rgba(0,0,0,.55)}
.lesson-lightbox-close{position:fixed;top:18px;right:22px;z-index:100000;width:48px;height:48px;border:0;border-radius:50%;background:#fff;color:#173f2d;font-size:32px;line-height:1;cursor:pointer;box-shadow:0 8px 24px rgba(0,0,0,.28)}
.lesson-lightbox-close:hover{transform:scale(1.05)}
body.lightbox-open{overflow:hidden}
@media(max-width:700px){.lesson-lightbox{padding:16px}.lesson-lightbox-close{top:10px;right:10px;width:44px;height:44px}.lesson-lightbox-full{max-width:98vw;max-height:88vh}.image-zoom-hint{right:8px;bottom:8px}}

/* Study Nest v2.0 - quiz engine and student lesson browser */
.student-subject>h2{margin:26px 0 12px;color:var(--dark)}.student-lesson-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:16px}.student-lesson-card{border:1px solid var(--line);border-radius:16px;padding:18px;background:#fff;display:flex;flex-direction:column;align-items:flex-start;gap:10px}.student-lesson-card h3,.student-lesson-card p{margin:0}.student-lesson-card .btn{margin-top:auto}.score-strip{width:100%;font-size:14px}.progress{height:9px;background:#e8efe9;border-radius:999px;overflow:hidden;margin-top:5px}.progress span{display:block;height:100%;background:var(--green);border-radius:999px}.quiz-builder-layout{grid-template-columns:minmax(320px,390px) 1fr}.quiz-admin-question{display:flex;justify-content:space-between;gap:16px;padding:16px 0;border-bottom:1px solid var(--line)}.quiz-admin-question h3{margin:8px 0}.tiny{font-size:13px}.quiz-section{max-width:1100px;margin:24px auto}.student-question{border:1px solid var(--line);border-radius:16px;padding:18px;margin:0 0 18px;background:#fff}.student-question legend{font-weight:700;padding:0 8px;font-size:18px}.question-number{display:inline-flex;width:30px;height:30px;border-radius:50%;align-items:center;justify-content:center;background:var(--pale);color:var(--dark);margin-right:8px}.answer-choice{display:flex;gap:10px;align-items:center;padding:11px 12px;border:1px solid var(--line);border-radius:10px;margin:8px 0;cursor:pointer;font-weight:400}.answer-choice input{width:auto;margin:0}.answer-choice:hover{background:#f7fbf8}.question-correct{border-color:#66b98d;background:#f1fbf5}.question-wrong{border-color:#e1a7a3;background:#fff7f6}.answer-feedback{margin-top:12px;padding:12px;border-radius:10px;background:#f6f8f7}.answer-feedback p{margin:6px 0 0}.quiz-result{padding:20px;border-radius:16px;margin-bottom:20px;text-align:center}.quiz-result h2{font-size:44px;margin:0}.quiz-pass{background:#e9f8ef;color:#146c43}.quiz-review{background:#fff4e8;color:#8b4a09}@media(max-width:800px){.quiz-builder-layout{grid-template-columns:1fr}.quiz-admin-question{flex-direction:column}}


/* Study Nest v2.1 - lesson back navigation in top header */
.topbar-left{display:flex;align-items:center;gap:18px;min-width:0}
.header-back-link{display:inline-flex;align-items:center;gap:6px;padding:9px 13px;border-radius:10px;background:rgba(255,255,255,.14);color:#fff;text-decoration:none;font-weight:700;white-space:nowrap;border:1px solid rgba(255,255,255,.22)}
.header-back-link:hover{background:rgba(255,255,255,.23);color:#fff}
@media(max-width:760px){.topbar-left{gap:9px;flex-wrap:wrap}.header-back-link{padding:7px 10px;font-size:14px}.brand small{display:none}}


/* Study Nest v2.3 - reliable visible lesson back button */
.header-back-link{display:inline-flex!important;align-items:center!important;gap:6px!important;padding:9px 13px!important;border-radius:10px!important;background:#eaf8f1!important;color:#126b45!important;text-decoration:none!important;font-weight:700!important;white-space:nowrap!important;border:1px solid #cfe7d9!important;box-shadow:none!important}
.header-back-link:hover{background:#dff3e8!important;color:#0f5d3c!important}
@media(max-width:760px){.header-back-link{padding:7px 10px!important;font-size:14px!important}}


/* Study Nest v2.4 - progress tracking and parent dashboard */
.metric-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px;margin:0 0 22px}.metric-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:18px;box-shadow:0 6px 20px rgba(20,70,45,.05)}.metric-card>span{display:block;color:var(--muted);font-size:14px;margin-bottom:8px}.metric-card>strong{display:block;font-size:30px;color:var(--dark);line-height:1.1}.metric-card .progress{margin-top:13px}.progress-lg{height:12px}.progress-list{display:grid;gap:18px}.progress-row-head{display:flex;justify-content:space-between;gap:16px;align-items:center;margin-bottom:7px}.progress-row-head span{color:var(--muted);font-size:14px;text-align:right}.dashboard-two-col{display:grid;grid-template-columns:1.25fr .75fr;gap:20px;margin:0 0 20px}.student-summary-banner{display:flex;justify-content:space-between;align-items:center;gap:20px;background:linear-gradient(135deg,#167a50,#22a06b);color:#fff;border-radius:20px;padding:24px 28px;margin-bottom:20px}.student-summary-banner h2{font-size:30px;margin:3px 0 0}.eyebrow{text-transform:uppercase;letter-spacing:.08em;font-size:12px;font-weight:800;opacity:.8}.big-progress-ring{width:112px;height:112px;border-radius:50%;display:flex;flex-direction:column;align-items:center;justify-content:center;background:#fff;color:#167a50;box-shadow:inset 0 0 0 9px rgba(34,160,107,.16)}.big-progress-ring strong{font-size:28px}.big-progress-ring span{font-size:12px}.topic-insights{display:grid;gap:18px}.topic-insights h3{margin:0 0 8px}.insight-row{display:flex;justify-content:space-between;gap:12px;padding:9px 0;border-bottom:1px solid var(--line)}.insight-row:last-child{border-bottom:0}.activity-list{display:grid}.activity-item{display:grid;grid-template-columns:1fr auto 150px;gap:18px;align-items:center;padding:13px 0;border-bottom:1px solid var(--line)}.activity-item:last-child{border-bottom:0}.activity-item small{display:block;color:var(--muted);margin-top:3px}.activity-item time{color:var(--muted);font-size:13px;text-align:right}.activity-score{min-width:64px;text-align:center;font-weight:800;padding:7px 9px;border-radius:999px}.activity-score.good{background:#e8f7ee;color:#167a50}.activity-score.review{background:#fff3e7;color:#9a550b}.student-switch label{font-weight:700}.student-switch select{margin-left:8px;min-width:180px}.lesson-completion-bar{display:flex;justify-content:space-between;gap:16px;align-items:center;margin-top:22px;padding:14px 16px;border-radius:14px;background:#f5faf7;border:1px solid var(--line)}.lesson-completion-bar form{margin:0}.completion-check{display:inline-flex;align-items:center;gap:6px;color:#167a50;font-weight:800}.lesson-page>.alert{margin-top:14px}
@media(max-width:1000px){.metric-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.dashboard-two-col{grid-template-columns:1fr}}@media(max-width:650px){.metric-grid{grid-template-columns:1fr}.student-summary-banner{align-items:flex-start}.big-progress-ring{width:88px;height:88px;flex:0 0 auto}.progress-row-head{align-items:flex-start;flex-direction:column;gap:4px}.progress-row-head span{text-align:left}.activity-item{grid-template-columns:1fr auto}.activity-item time{grid-column:1/-1;text-align:left}.lesson-completion-bar{align-items:flex-start;flex-direction:column}}

/* Study Nest v2.5 - assignments and homework */
.assignment-layout{grid-template-columns:minmax(320px,.78fr) minmax(0,1.22fr);align-items:start}.assignment-list{display:grid;gap:14px}.assignment-card{border:1px solid var(--line);border-left:5px solid #d5e3db;border-radius:15px;padding:16px;background:#fff}.assignment-card.pending{border-left-color:#e7a21a}.assignment-card.overdue{border-left-color:#c93f35;background:#fffafa}.assignment-card.completed{border-left-color:var(--green);background:#fbfefc}.assignment-card-top{display:flex;justify-content:space-between;gap:14px;align-items:flex-start}.assignment-card h2,.assignment-card h3{margin:7px 0 2px}.assignment-status{display:inline-flex;align-items:center;padding:6px 10px;border-radius:999px;font-size:12px;font-weight:800;white-space:nowrap}.assignment-status.pending{background:#fff5d9;color:#8b6100}.assignment-status.overdue{background:#fdebea;color:#a12b24}.assignment-status.completed{background:#e8f7ee;color:#167a50}.assignment-meta{display:flex;gap:10px 18px;flex-wrap:wrap;color:var(--muted);font-size:13px;margin:12px 0}.assignment-instructions{padding:12px 14px;border-radius:11px;background:#f6faf7;margin:12px 0}.assignment-instructions p{margin:4px 0 0}.assignment-metrics{grid-template-columns:repeat(3,minmax(0,1fr));max-width:760px}.student-assignment-list{max-width:980px}.student-assignment-list .assignment-card{padding:20px}.assignment-card .btn{margin-top:4px}
@media(max-width:900px){.assignment-layout{grid-template-columns:1fr}}@media(max-width:650px){.assignment-card-top{flex-direction:column}.assignment-metrics{grid-template-columns:1fr}}

/* Study Nest v2.6 - achievements and certificates */
.achievement-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:16px;margin-bottom:24px}.achievement-card{background:#fff;border:1px solid var(--line);border-radius:18px;padding:22px;text-align:center;position:relative;overflow:hidden}.achievement-card.earned{box-shadow:0 10px 28px rgba(20,70,45,.08);border-color:#b9dec9}.achievement-card.locked{opacity:.58;filter:grayscale(.35)}.achievement-icon{font-size:48px;line-height:1;margin-bottom:10px}.achievement-card h2{font-size:19px;margin:8px 0}.achievement-card p{color:var(--muted);min-height:48px}.muted-badge{background:#eef1ef;color:#6b756f}.certificate-list{display:grid}.certificate-row{display:flex;justify-content:space-between;align-items:center;gap:16px;padding:14px 0;border-bottom:1px solid var(--line)}.certificate-row:last-child{border-bottom:0}.certificate-row small,.certificate-row span{display:block;color:var(--muted);font-size:13px;margin-top:3px}.certificate-body{background:#edf5f0;padding:28px}.certificate-actions{max-width:1100px;margin:0 auto 16px;display:flex;gap:10px}.certificate-sheet{max-width:1100px;min-height:720px;margin:0 auto;background:#fff;border:14px solid #1f9d65;outline:3px solid #b8dfc8;outline-offset:-28px;padding:78px 80px;text-align:center;display:flex;flex-direction:column;justify-content:center;box-shadow:0 20px 60px rgba(20,70,45,.16);position:relative}.certificate-leaf{font-size:54px}.certificate-brand{font-size:24px;font-weight:800;color:var(--dark);letter-spacing:.03em}.certificate-kicker{text-transform:uppercase;letter-spacing:.22em;color:var(--green);font-weight:800;margin-top:28px}.certificate-sheet h1{font-size:46px;margin:18px 0;color:#173f2d}.certificate-presented{color:var(--muted);font-size:18px;margin:10px}.certificate-sheet h2{font-family:Georgia,serif;font-size:48px;margin:5px 0 20px;color:#126b45}.certificate-description{font-size:20px;max-width:760px;margin:0 auto 16px}.certificate-subject{font-size:18px;font-weight:800;color:var(--green)}.certificate-footer{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:54px;border-top:1px solid var(--line);padding-top:22px}.certificate-footer span{display:block;color:var(--muted);font-size:12px;text-transform:uppercase;letter-spacing:.08em}.certificate-footer strong{display:block;margin-top:6px}@media(max-width:700px){.certificate-row{align-items:flex-start;flex-direction:column}.certificate-body{padding:10px}.certificate-sheet{padding:50px 30px;min-height:620px}.certificate-sheet h1{font-size:34px}.certificate-sheet h2{font-size:38px}.certificate-footer{grid-template-columns:1fr}}@media print{body.certificate-body{background:#fff;padding:0}.no-print{display:none!important}.certificate-sheet{box-shadow:none;max-width:none;width:100%;min-height:95vh;margin:0;page-break-inside:avoid}}

/* Study Nest v2.8 - lesson-to-random-quiz flow */
.finish-lesson-card{margin-top:28px;padding:22px;border:1px solid var(--line);border-radius:18px;background:linear-gradient(135deg,#f1fbf5,#fff);display:flex;align-items:center;justify-content:space-between;gap:22px}.finish-lesson-card strong{display:block;font-size:20px;color:var(--dark);margin-bottom:5px}.finish-lesson-card p{margin:0;color:var(--muted)}.finish-quiz-btn{white-space:nowrap;font-size:16px;padding:13px 18px}.standalone-quiz{margin-top:24px}.quiz-after-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:20px}.btn.secondary{background:#eef7f1;color:var(--dark);border:1px solid var(--line)}
@media(max-width:720px){.finish-lesson-card{align-items:stretch;flex-direction:column}.finish-quiz-btn{text-align:center;width:100%}}

/* Study Nest v2.9 - student dashboard */
.student-dashboard-hero{margin:8px 0 18px;padding:28px 30px;border-radius:22px;background:linear-gradient(135deg,#176f4a,#24a36c);color:#fff;display:flex;justify-content:space-between;align-items:center;gap:24px;box-shadow:0 16px 38px rgba(20,90,60,.16)}
.student-dashboard-hero h1{font-size:34px;margin:5px 0 8px}.student-dashboard-hero p{margin:0;opacity:.9;max-width:680px}.dashboard-eyebrow{text-transform:uppercase;letter-spacing:.1em;font-size:11px;font-weight:800;color:var(--green)}.student-dashboard-hero .dashboard-eyebrow{color:#dff7e9}.dashboard-overall{width:128px;height:128px;flex:0 0 128px;border-radius:50%;background:rgba(255,255,255,.14);border:9px solid rgba(255,255,255,.32);display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center}.dashboard-overall strong{font-size:30px}.dashboard-overall span{font-size:12px;opacity:.9}.student-dashboard-metrics{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px;margin-bottom:18px}.student-metric-card{text-decoration:none;color:inherit;background:#fff;border:1px solid var(--line);border-radius:17px;padding:17px;display:flex;gap:13px;align-items:center;transition:.18s ease}.student-metric-card:hover{transform:translateY(-2px);box-shadow:0 10px 26px rgba(20,70,45,.08)}.student-metric-card>span{font-size:27px}.student-metric-card strong{display:block;font-size:22px;color:var(--dark)}.student-metric-card small{display:block;color:var(--muted);margin-top:2px}.student-dashboard-grid{display:grid;grid-template-columns:1.35fr .65fr;gap:18px;margin-bottom:18px}.dashboard-card-heading{display:flex;justify-content:space-between;align-items:flex-start;gap:14px;margin-bottom:13px}.dashboard-card-heading h2{margin:3px 0}.dashboard-card-heading>a{white-space:nowrap;font-size:14px}.dashboard-card-icon{font-size:30px}.dashboard-recommend-card h3{font-size:24px;margin:13px 0 6px}.dashboard-recommend-card p{color:var(--muted)}.dashboard-meta{display:flex;flex-wrap:wrap;gap:8px 16px;color:var(--muted);font-size:13px;margin:13px 0 16px}.todays-goal-card{background:linear-gradient(145deg,#fff,#f4fbf7)}.todays-goal-card.goal-complete{border-color:#b9dec9;background:linear-gradient(145deg,#f7fff9,#ecf9f1)}.goal-progress{height:12px;background:#e4eee8;border-radius:999px;overflow:hidden;margin:18px 0 8px}.goal-progress span{display:block;height:100%;background:var(--green);border-radius:999px;transition:width .3s}.todays-goal-card small{color:var(--muted)}.continue-learning-card{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-bottom:18px;border-left:5px solid var(--green)}.continue-learning-card h2{margin:3px 0 5px}.continue-learning-card p{margin:0;color:var(--muted)}.lower-dashboard-grid{grid-template-columns:1.1fr .9fr}.dashboard-subject-row{padding:12px 0;border-bottom:1px solid var(--line)}.dashboard-subject-row:last-child{border-bottom:0}.dashboard-subject-head{display:flex;justify-content:space-between;gap:14px;margin-bottom:7px}.dashboard-subject-head span{font-size:13px;color:var(--muted);text-align:right}.dashboard-result-list{display:grid}.dashboard-result{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:11px 0;border-bottom:1px solid var(--line)}.dashboard-result:last-child{border-bottom:0}.dashboard-result small{display:block;color:var(--muted);margin-top:3px}.result-score{font-weight:800;padding:7px 9px;border-radius:999px;min-width:58px;text-align:center}.result-score.good{background:#e8f7ee;color:#167a50}.result-score.review{background:#fff3e7;color:#9a550b}.dashboard-achievements{margin-bottom:24px}.mini-achievement-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.mini-achievement{display:flex;align-items:center;gap:12px;padding:13px;border:1px solid var(--line);border-radius:14px;background:#fbfefc}.mini-achievement>span{font-size:30px}.mini-achievement small{display:block;color:var(--muted);margin-top:3px}.lessons-browser-heading{margin-top:34px}.lesson-completed-card{border-color:#b8ddc7;background:#fbfefc}.completed-badge{background:#e7f7ed!important;color:#167a50!important}
@media(max-width:1000px){.student-dashboard-metrics{grid-template-columns:repeat(2,minmax(0,1fr))}.student-dashboard-grid,.lower-dashboard-grid{grid-template-columns:1fr}.mini-achievement-grid{grid-template-columns:1fr 1fr}}
@media(max-width:650px){.student-dashboard-hero{padding:22px;align-items:flex-start}.dashboard-overall{width:90px;height:90px;flex-basis:90px;border-width:6px}.dashboard-overall strong{font-size:22px}.student-dashboard-hero h1{font-size:27px}.student-dashboard-metrics{grid-template-columns:1fr}.mini-achievement-grid{grid-template-columns:1fr}.continue-learning-card{align-items:flex-start;flex-direction:column}.continue-learning-card .btn{width:100%;text-align:center}.dashboard-subject-head{flex-direction:column}.dashboard-subject-head span{text-align:left}}

/* Study Nest v3.0 - GCSE Exam Centre */
.exam-centre-intro{display:flex;justify-content:space-between;align-items:center;gap:24px}.exam-centre-intro h2{margin-top:0}.exam-builder-shell{display:grid;grid-template-columns:minmax(360px,43%) minmax(0,57%);gap:20px;align-items:start}.exam-reference-panel{position:sticky;top:92px}.exam-reference-tabs{display:flex;gap:8px;margin-bottom:12px}.exam-pdf-frame{display:none;width:100%;height:75vh;border:1px solid var(--line);border-radius:12px;background:#f2f4f7}.exam-pdf-frame.active{display:block}.exam-pdf-empty{display:none;height:320px;place-items:center;border:1px dashed var(--line);border-radius:12px;color:var(--muted);background:#f8fbf9}.exam-pdf-empty.active{display:grid}.exam-builder-question{display:grid;grid-template-columns:72px 1fr auto;gap:14px;align-items:center;padding:14px 0;border-bottom:1px solid var(--line)}.exam-builder-question:last-child{border-bottom:0}.exam-question-number{display:grid;place-items:center;min-height:46px;border-radius:10px;background:var(--pale);font-weight:800;color:var(--dark)}.exam-builder-question-main small{color:var(--green);font-weight:bold}.exam-card-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(290px,1fr));gap:18px}.exam-student-card{display:flex;flex-direction:column}.exam-student-card .btn{margin-top:auto;align-self:flex-start}.exam-paper-head{display:flex;justify-content:space-between;gap:20px;align-items:flex-start}.exam-paper-head h1{margin:.4rem 0}.exam-timer-box{min-width:100px;text-align:center;background:var(--pale);border-radius:16px;padding:14px}.exam-timer-box strong{display:block;font-size:32px;color:var(--dark)}.exam-timer-box span{color:var(--muted)}.exam-instructions{margin-top:18px;padding:16px;border-left:5px solid var(--green);background:var(--pale);border-radius:10px}.exam-paper-meta{display:flex;gap:18px;margin-top:14px;color:var(--muted);font-weight:bold}.online-exam-question{padding:26px}.online-question-head{display:flex;justify-content:space-between;align-items:flex-start;gap:14px;margin-bottom:14px}.online-question-head>span{white-space:nowrap;background:var(--pale);padding:4px 9px;border-radius:999px;color:var(--dark);font-weight:bold}.online-question-text{font-size:18px;margin-bottom:16px}.exam-question-image{display:block;max-width:100%;max-height:520px;object-fit:contain;margin:16px auto;border-radius:12px}.exam-answer-long{min-height:180px}.exam-submit-card{text-align:center;padding:30px}.exam-result-summary{text-align:center}.exam-score-big strong{display:block;font-size:64px;line-height:1;color:var(--green)}.exam-score-big span{display:block;font-size:18px;color:var(--muted)}.exam-pending-result{max-width:650px;margin:20px auto;padding:18px;border-radius:14px;background:#fff7e8;border:1px solid #f5d6a5}.exam-answer-review{padding:18px 0;border-bottom:1px solid var(--line)}.exam-answer-review:last-child{border-bottom:0}.exam-answer-review.correct{border-left:5px solid var(--green);padding-left:14px}.exam-answer-review.wrong{border-left:5px solid var(--danger);padding-left:14px}.exam-answer-review.pending{border-left:5px solid #e27813;padding-left:14px}.mark-scheme-note{padding:14px;background:#f6fbf8;border:1px solid var(--line);border-radius:10px}.exam-marking-layout{display:grid;grid-template-columns:minmax(350px,40%) minmax(0,60%);gap:20px;align-items:start}.exam-mark-scheme-side{position:sticky;top:92px}.exam-marking-pdf{width:100%;height:78vh;border:1px solid var(--line);border-radius:12px}.student-written-answer{padding:14px;background:#f8fbf9;border-radius:10px;margin:12px 0}.marking-question .marking-form{margin-top:14px;border-top:1px solid var(--line);padding-top:12px}@media(max-width:950px){.exam-builder-shell,.exam-marking-layout{grid-template-columns:1fr}.exam-reference-panel,.exam-mark-scheme-side{position:static}.exam-pdf-frame,.exam-marking-pdf{height:62vh}}@media(max-width:650px){.exam-centre-intro,.exam-paper-head{display:block}.exam-builder-question{grid-template-columns:52px 1fr}.exam-builder-question .actions{grid-column:1/-1}.online-exam-question{padding:18px}}

/* Study Nest v3.1 automatic exam importer */
.exam-import-status{display:flex;align-items:center;justify-content:space-between;gap:18px;border-left:5px solid var(--primary,#22a06b)}
.exam-import-status.import-not-ready{border-left-color:#d97706;background:#fffaf0}
.exam-import-actions{display:flex;gap:18px;align-items:center;flex-wrap:wrap;margin:14px 0}.exam-import-actions.bottom{justify-content:flex-end;margin-top:20px}
.exam-import-actions label{display:flex;gap:8px;align-items:center;font-weight:600}.exam-import-actions input[type=checkbox],.exam-import-check input{width:auto}
.exam-import-list{display:grid;gap:10px}.exam-import-item{display:grid;grid-template-columns:36px 70px minmax(0,1fr) 120px;gap:12px;align-items:center;padding:14px;border:1px solid #dfe8e3;border-radius:14px;background:#fff}
.exam-import-check{text-align:center}.exam-import-main small{display:block;margin-top:5px}.import-warning{color:#b45309!important}.exam-import-visual{text-align:right}
@media(max-width:760px){.exam-import-item{grid-template-columns:34px 55px 1fr}.exam-import-visual{grid-column:3;text-align:left}.exam-import-actions{align-items:flex-start;flex-direction:column}}


/* Study Nest v3.7 interactive exam tick boxes */
.tick-instruction{font-weight:700;color:#246b4a;margin:14px 0 8px}
.answer-choice.tick-choice{display:flex;align-items:center;gap:12px;cursor:pointer}
.tick-choice .exam-tick{position:absolute;opacity:0;pointer-events:none}
.tick-choice .tick-box{
  width:25px;height:25px;min-width:25px;border:2px solid #5c7669;border-radius:4px;
  display:inline-flex;align-items:center;justify-content:center;background:#fff;
  color:transparent;font-weight:900;font-size:18px;transition:.15s ease;
}
.tick-choice:hover .tick-box{border-color:#22a06b;background:#f0fbf6}
.tick-choice .exam-tick:checked + .tick-box{background:#22a06b;border-color:#22a06b;color:#fff}
.tick-choice .exam-tick:focus-visible + .tick-box{outline:3px solid rgba(34,160,107,.25);outline-offset:2px}


/* Study Nest v4.0 matching and drawing questions */
.matching-board{position:relative;display:grid;grid-template-columns:1fr 1fr;gap:120px;padding:18px 8px;min-height:180px}
.matching-lines{position:absolute;inset:0;width:100%;height:100%;pointer-events:none;overflow:visible}
.matching-line{stroke:#22a06b;stroke-width:4;stroke-linecap:round}
.matching-column{display:flex;flex-direction:column;gap:12px;z-index:2}
.matching-node{display:flex;align-items:center;justify-content:space-between;gap:12px;width:100%;text-align:left;border:2px solid #cfe3d9;background:#fff;border-radius:12px;padding:12px 14px;color:#18372b;cursor:pointer;font:inherit}
.matching-node:hover,.matching-node.selected{border-color:#22a06b;background:#eef9f3}
.matching-node.connected{border-color:#79c5a3}
.match-dot{width:14px;height:14px;border-radius:50%;background:#fff;border:3px solid #22a06b;flex:0 0 auto}
.matching-actions{display:flex;align-items:center;gap:12px;margin-top:8px}
.exam-drawing-canvas{display:block;width:100%;max-width:900px;aspect-ratio:2/1;border:2px solid #cfe3d9;border-radius:12px;background:#fff;touch-action:none}
@media(max-width:700px){.matching-board{gap:45px}.matching-node{padding:10px;font-size:.94rem}}

/* Study Nest v4.7 student exam visual display */
.exam-question-visual{display:block;width:100%;margin:18px 0 22px;padding:12px;background:#fff;border:1px solid #d7e9df;border-radius:14px;text-align:center}
.exam-question-visual .exam-question-image{display:block!important;width:auto!important;max-width:100%!important;max-height:650px!important;height:auto!important;margin:0 auto!important;object-fit:contain!important;visibility:visible!important;opacity:1!important}

.review-import-item{border-left:4px solid #c88927;background:#fffdf8}
.review-excluded summary{padding:5px 0}


/* Study Nest v5.2 split-screen student exam */
.student-exam-split{
  width:min(1900px,calc(100vw - 28px));
  max-width:none;
  margin:18px 0 40px 0;
  position:relative;
  left:calc((100vw - 100%) / -2 + 12px);
  display:grid;
  grid-template-columns:minmax(390px,44%) minmax(560px,56%);
  gap:18px;
  align-items:start;
}
.student-exam-split.no-paper{display:block;max-width:1100px}
.student-paper-panel{
  position:sticky;
  top:88px;
  height:calc(100vh - 138px);
  min-height:520px;
  background:#fff;
  border:1px solid #d8e8df;
  border-radius:16px;
  overflow:hidden;
  box-shadow:0 8px 26px rgba(20,70,50,.08);
  display:flex;
  flex-direction:column;
}
.student-paper-toolbar{
  padding:11px 14px;
  border-bottom:1px solid #d8e8df;
  background:#f6fbf8;
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:12px;
}
.student-paper-toolbar>div:first-child{display:flex;flex-direction:column;gap:2px}
.student-paper-frame{border:0;width:100%;height:100%;flex:1;background:#eef3f0}
.student-answer-panel{min-width:0}
.student-answer-panel .exam-paper,
.student-answer-panel .exam-online-form{width:100%;max-width:none;margin-left:0;margin-right:0}
.student-exam-split.paper-hidden{grid-template-columns:1fr;max-width:1050px}
.student-exam-split.paper-hidden .student-paper-panel{display:none}
.student-exam-split.paper-hidden .student-answer-panel{width:100%}
@media(max-width:1050px){
 .student-exam-split{display:block;width:calc(100% - 20px);margin:10px;left:0}
 .student-paper-panel{position:relative;top:auto;height:65vh;min-height:480px;margin-bottom:18px}
}
@media(max-width:650px){
 .student-paper-toolbar{align-items:flex-start;flex-direction:column}
 .student-paper-panel{height:58vh;min-height:420px}
}

.show-paper-row{display:none;margin:0 0 12px}
.student-exam-split.paper-hidden .show-paper-row{display:flex}


/* Study Nest v5.7 parent exam marking */
.parent-marking-alert{border-left:5px solid #22a06b}
.parent-exam-ready{grid-template-columns:minmax(220px,1fr) auto auto auto;align-items:center}
.parent-marking-summary{display:flex;gap:18px;align-items:center;flex-wrap:wrap;margin-bottom:18px}
.parent-marking-summary strong{font-size:1.05rem}
@media(max-width:850px){.parent-exam-ready{grid-template-columns:1fr;gap:8px}}


/* Study Nest v5.8 - large split-screen parent marking */
body:has(.parent-marking-screen) main,
body:has(.parent-marking-screen) .container{
  max-width:none !important;
  width:100% !important;
}

.parent-marking-screen{
  width:calc(100vw - 24px);
  max-width:none;
  margin:14px 0 36px 12px;
}

.parent-marking-screen .exam-marking-layout{
  display:grid;
  grid-template-columns:minmax(430px,44%) minmax(560px,56%);
  gap:18px;
  align-items:start;
  width:100%;
  max-width:none;
}

.parent-marking-screen .exam-mark-scheme-side{
  position:sticky;
  top:86px;
  height:calc(100vh - 105px);
  min-height:620px;
  display:flex;
  flex-direction:column;
  overflow:hidden;
  padding:12px;
}

.parent-marking-screen .exam-marking-pdf{
  width:100% !important;
  height:auto !important;
  min-height:0 !important;
  flex:1 1 auto;
  border:1px solid #d8e8df;
  border-radius:10px;
  background:#eef3f0;
}

.parent-marking-screen .parent-mark-answers{
  min-width:0;
}

.parent-marking-screen .marking-question{
  width:100%;
  max-width:none;
}

@media(max-width:1050px){
  .parent-marking-screen{
    width:calc(100% - 20px);
    margin:10px;
  }
  .parent-marking-screen .exam-marking-layout{
    display:block;
  }
  .parent-marking-screen .exam-mark-scheme-side{
    position:relative;
    top:auto;
    height:68vh;
    min-height:500px;
    margin-bottom:18px;
  }
}

/* v5.9 MCQ marking display */
.chosen-answer{display:flex;align-items:center;gap:10px;margin:10px 0 0}
.choice-letter{display:inline-flex;align-items:center;justify-content:center;min-width:36px;height:36px;border-radius:8px;background:#e7f6ee;color:#087443;font-weight:800;font-size:1.05rem}


/* Study Nest v6.0 void exam questions */
.question-mark-actions{display:flex;align-items:center;gap:10px;flex-wrap:wrap;justify-content:flex-end}
.inline-form{display:inline;margin:0}
.voided-badge{background:#fff1df;color:#8b4b00}
.marking-question:has(.voided-badge){opacity:.78;border-style:dashed}
.voided-question-note{padding:12px 14px;border-radius:10px;background:#fff6e8;color:#744100;font-weight:600;margin-top:12px}


/* Study Nest v6.2 Parent Exam Results & Progress */
.parent-exam-progress-card{margin-top:18px}
.exam-metric-grid{margin:14px 0 18px}
.exam-trend-wrap{margin:18px 0 22px}
.exam-trend-chart{
  display:flex;
  align-items:flex-end;
  gap:10px;
  min-height:240px;
  padding:18px 10px 8px;
  border:1px solid #dfece5;
  border-radius:14px;
  background:#fbfefc;
  overflow-x:auto;
}
.exam-trend-col{
  flex:1 0 64px;
  min-width:64px;
  max-width:100px;
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:6px;
}
.exam-trend-value{font-weight:700;font-size:.9rem}
.exam-trend-bar-wrap{
  width:28px;
  height:150px;
  display:flex;
  align-items:flex-end;
  border-radius:10px;
  background:#eef5f1;
  overflow:hidden;
}
.exam-trend-bar{
  width:100%;
  min-height:4px;
  background:currentColor;
  border-radius:10px 10px 0 0;
}
.exam-history-table-wrap{overflow-x:auto}
.exam-history-table td,.exam-history-table th{white-space:nowrap}
@media(max-width:800px){
 .exam-trend-chart{min-height:220px}
 .exam-history-table{min-width:760px}
}

/* Study Nest v6.3 weak topics */
.weak-topic-card{height:100%}.topic-recommendation-list{display:flex;flex-direction:column;gap:12px}.topic-recommendation-row{padding:14px;border:1px solid #dfece5;border-radius:13px;background:#fbfefc}.topic-recommendation-row.needs-revision{border-left:5px solid #b85b43}.topic-recommendation-row.needs-practice{border-left:5px solid #c9972f}.topic-recommendation-row.strong{border-left:5px solid #4c9a72}.topic-recommendation-main,.topic-score-line,.topic-recommendation-action{display:flex;align-items:center;justify-content:space-between;gap:12px}.topic-recommendation-main>div{display:flex;flex-direction:column}.topic-recommendation-main small{margin-top:3px;color:#66796f}.topic-score-line{margin-top:10px}.topic-score-line .progress{flex:1}.topic-status-pill{font-size:.82rem;font-weight:700;padding:5px 9px;border-radius:999px;background:#eef5f1}.needs-revision .topic-status-pill{background:#fff0eb;color:#8b3d2d}.needs-practice .topic-status-pill{background:#fff7e2;color:#785900}.strong .topic-status-pill{background:#e9f7ef;color:#17613f}.topic-recommendation-action{margin-top:10px;border-top:1px solid #e8f0eb;padding-top:10px}.weak-topic-student-note{display:inline-flex;align-items:center;gap:6px;margin:10px 0;padding:7px 10px;border-radius:10px;background:#fff7e2;color:#695000}@media(max-width:700px){.topic-recommendation-action,.topic-recommendation-main{align-items:flex-start;flex-direction:column}}

#subjectQuizFields{padding:12px 14px;border:1px solid #dfece5;border-radius:12px;background:#f9fcfa;margin:10px 0}.subject-quiz-source{margin:-4px 0 12px;font-size:.9rem}

/* Study Nest v6.5 GCSE exam subject filters & assignments */
.exam-subject-filter{display:flex;align-items:center;gap:14px;flex-wrap:wrap;margin-bottom:18px}
.exam-filter-buttons{display:flex;gap:8px;flex-wrap:wrap}
.assigned-exam-badge{background:#fff3cf;color:#6c5100}
#examAssignmentFields{padding:12px 14px;border:1px solid #dfece5;border-radius:12px;background:#f9fcfa;margin:10px 0}