/* GradeChum Help Center — static replica of the GitBook "clean" theme */
@import url('https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&display=swap');

:root{
  --tint:#346ddb;              /* teachers / students */
  --tint-hover:#2b5bbd;
  --text:#1c1d1f;
  --muted:#6a6e77;
  --muted-2:#8a9099;
  --nav:rgba(28,29,31,.64);
  --border:#e2e6ec;
  --border-soft:#eceef1;
  --bg:#ffffff;
  --bg-subtle:#f7f8fa;
  --sidebar-w:288px;
  --content-w:768px;
  --radius:6px;
  --header-h:64px;
}
body.tint-green{ --tint:#38ca79; --tint-hover:#2fae67; }

*{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;}
body{
  margin:0;font-family:Inter,"Inter Fallback",system-ui,-apple-system,Segoe UI,Arial,sans-serif,
    "Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji";
  font-size:16px;line-height:26px;color:var(--text);background:var(--bg);
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
}
/* Render emoji glyphs via the platform colour-emoji font (matches GitBook's font-emoji) */
.emoji,.gb-nav .ico,.gb-pageemoji,.gb-ref .ref-emoji,.gb-body :is(h1,h2,h3,h4,p,li,span,td){
  font-family:Inter,"Inter Fallback",system-ui,-apple-system,Segoe UI,Arial,
    "Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji",sans-serif;
}
a{color:inherit;text-decoration:none;}
img{max-width:100%;}
button{font-family:inherit;}

/* ---------- Header ---------- */
.gb-header{
  position:sticky;top:0;z-index:30;height:var(--header-h);width:100%;
  display:flex;align-items:center;gap:24px;
  padding:0 20px;background:rgba(255,255,255,.88);backdrop-filter:saturate(1.2) blur(8px);
  border-bottom:1px solid transparent;transition:border-color .15s;
}
.gb-header.scrolled{border-bottom-color:var(--border);}
.gb-logo{display:flex;align-items:center;gap:10px;min-width:0;flex-shrink:0;}
.gb-logo img{height:28px;width:auto;display:block;}
.gb-logo .title{font-weight:600;font-size:18px;letter-spacing:-0.45px;color:var(--text);white-space:nowrap;}
.gb-header-spacer{flex:1;}
.gb-tabs{display:flex;align-items:center;gap:22px;}
.gb-tabs a{font-size:14px;color:var(--muted);white-space:nowrap;}
.gb-tabs a:hover{color:var(--text);}
.gb-search{
  display:flex;align-items:center;gap:8px;width:260px;max-width:38vw;height:36px;
  padding:0 10px;border:1px solid var(--border);border-radius:8px;color:var(--muted-2);
  background:var(--bg);font-size:14px;cursor:pointer;text-align:left;font-family:inherit;
}
.gb-search:hover{border-color:#d3d7dd;}
.gb-search svg{flex-shrink:0;}
.gb-search .ph{flex:1;}
.gb-search .kbd{display:flex;gap:3px;}
.gb-search .kbd span{border:1px solid var(--border);border-radius:4px;padding:0 5px;font-size:11px;line-height:16px;color:var(--muted-2);}

/* ---------- Layout ---------- */
.gb-shell{display:flex;align-items:flex-start;max-width:1536px;margin:0 auto;}
.gb-sidebar{
  position:sticky;top:var(--header-h);align-self:flex-start;
  width:var(--sidebar-w);flex-shrink:0;height:calc(100vh - var(--header-h));
  overflow-y:auto;padding:24px 12px 24px 24px;display:flex;flex-direction:column;
}
.gb-main{flex:1;min-width:0;display:flex;justify-content:center;padding:0 40px;}
.gb-article{width:100%;max-width:var(--content-w);padding:32px 0 80px;}
.gb-toc{
  position:sticky;top:var(--header-h);align-self:flex-start;
  width:224px;flex-shrink:0;height:calc(100vh - var(--header-h));
  overflow-y:auto;padding:34px 24px 24px 8px;
}

/* ---------- Sidebar nav ---------- */
.gb-nav{display:flex;flex-direction:column;gap:1px;flex:1;}
.gb-nav a.nav-link{
  display:flex;align-items:center;gap:11px;padding:6px 6px 6px 12px;border-radius:var(--radius);
  font-size:14px;color:var(--nav);line-height:20px;position:relative;
}
.gb-nav a.nav-link:hover{background:var(--bg-subtle);color:var(--text);}
.gb-nav a.nav-link.active{color:var(--tint);font-weight:600;}
.gb-nav .ico{flex-shrink:0;width:20px;text-align:center;font-size:16px;line-height:20px;}
.gb-nav .ico.num{font-variant-numeric:tabular-nums;color:var(--muted-2);font-size:15px;font-weight:400;}
.gb-nav a.nav-link.active .ico.num{color:var(--tint);}
.gb-nav .label{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;}
.gb-nav .chev{flex-shrink:0;color:var(--muted-2);transition:transform .15s;}
.gb-nav details[open]>summary .chev{transform:rotate(90deg);}
.gb-section-label{
  font-size:12px;font-weight:600;letter-spacing:.3px;text-transform:uppercase;color:var(--text);
  padding:8px 10px;margin-top:16px;
}
.gb-nav details{margin:0;}
.gb-nav summary{list-style:none;cursor:pointer;}
.gb-nav summary::-webkit-details-marker{display:none;}
.gb-nav .children{margin-left:19px;padding-left:12px;border-left:1px solid var(--border);display:flex;flex-direction:column;gap:1px;margin-top:1px;}
.gb-nav .children a.nav-link .ico{width:18px;font-size:15px;}

/* ---------- Article content ---------- */
.gb-crumbs{font-size:12px;color:var(--tint);margin-bottom:10px;display:flex;align-items:center;gap:6px;flex-wrap:wrap;}
.gb-crumbs a,.gb-crumbs span{color:var(--tint);display:inline-flex;align-items:center;gap:4px;}
.gb-crumbs a:hover{text-decoration:underline;}
.gb-crumbs .sep{color:var(--muted-2);}
.gb-crumbs .cr-emoji{font-size:13px;line-height:1;}

/* sidebar "Back to …" button */
.gb-back{display:flex;align-items:center;gap:8px;padding:7px 10px;margin-bottom:14px;
  border:1px solid var(--border);border-radius:var(--radius);font-size:13px;color:var(--muted);
  white-space:nowrap;transition:background .12s,border-color .12s;}
.gb-back span{overflow:hidden;text-overflow:ellipsis;}
.gb-back:hover{background:var(--bg-subtle);border-color:#c9cdd4;color:var(--text);}
.gb-back svg{flex-shrink:0;width:16px;height:16px;}

.gb-titlerow{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;margin-bottom:22px;}
.gb-titlewrap{display:flex;align-items:center;gap:14px;min-width:0;}
.gb-pagenum{font-size:40px;line-height:1;font-weight:400;color:#c3c7cd;font-variant-numeric:tabular-nums;flex-shrink:0;}
.gb-pageemoji{font-size:34px;line-height:1;flex-shrink:0;}
h1.gb-h1{font-size:36px;line-height:45px;font-weight:700;letter-spacing:-0.9px;margin:0;color:var(--text);}

.gb-body{font-size:16px;line-height:26px;color:var(--text);overflow-wrap:break-word;}
/* nothing in the content may widen the page: wide blocks scroll inside their box */
.gb-body a{overflow-wrap:break-word;}
.gb-body pre{overflow-x:auto;max-width:100%;background:var(--bg-subtle);border:1px solid var(--border);
  border-radius:6px;padding:12px 14px;font-size:14px;line-height:1.5;margin-top:20px;}
.gb-body pre code{background:none;border:0;padding:0;font-size:inherit;white-space:pre;}
.gb-body table{display:block;overflow-x:auto;max-width:100%;}
.gb-inline-img{display:block;max-width:100%;height:auto;border-radius:8px;
  border:1px solid var(--border-soft);margin:10px 0 0;}
/* GitBook vertical rhythm: uniform 20px top margins, no bottom margins */
.gb-body>*{margin:20px 0 0;}
.gb-body>*:first-child{margin-top:0;}
.gb-body p{margin:20px 0 0;}
.gb-body h2{font-size:30px;line-height:38px;font-weight:600;letter-spacing:-0.5px;scroll-margin-top:80px;}
.gb-body h3{font-size:24px;line-height:32px;font-weight:600;letter-spacing:-0.3px;scroll-margin-top:80px;}
.gb-body h4{font-size:20px;line-height:28px;font-weight:600;letter-spacing:-0.25px;scroll-margin-top:80px;}
.gb-body a.inline{color:var(--tint);text-decoration:none;}
.gb-body a.inline:hover{text-decoration:underline;}
.gb-body strong{font-weight:700;}
.gb-body ul,.gb-body ol{padding-left:28px;}
.gb-body li{margin:0 0 8px;line-height:24px;}
.gb-body li>p{margin:0 0 8px;}
.gb-body li>ul,.gb-body li>ol{margin-top:8px;}
.gb-body hr{border:none;border-top:1px solid var(--border);margin:20px 0 0;}
.gb-body code{background:var(--bg-subtle);border:1px solid var(--border);border-radius:4px;padding:1px 5px;font-size:.86em;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;}
.gb-body mark{background:transparent;padding:0;}
.gb-body blockquote{border-left:3px solid var(--border);padding:2px 0 2px 16px;color:var(--muted);}

/* figures */
.gb-body figure{margin:20px 0 0;}
.gb-body figure img{display:block;border-radius:8px;border:1px solid var(--border-soft);max-width:100%;height:auto;}
.gb-body figcaption{font-size:14px;color:var(--muted);margin-top:8px;text-align:center;}
.gb-body li figure{margin:12px 0;}

/* hints / callouts — dark body text, tinted bg + subtle border, coloured icon */
.gb-hint{display:flex;gap:12px;padding:14px 16px;border-radius:6px;border:1px solid;
  font-size:14px;line-height:20px;color:var(--text);}
.gb-hint .hint-ico{flex-shrink:0;margin-top:1px;}
.gb-hint .hint-content>*:first-child{margin-top:0;}
.gb-hint.warning{background:#fff5ec;border-color:#f2d3b6;}
.gb-hint.warning .hint-ico{color:#e8912a;}
.gb-hint.info{background:#eef4ff;border-color:#d3ddf5;}
.gb-hint.info .hint-ico{color:#3f7fe0;}
.gb-hint.success{background:#eafaf1;border-color:#c2e8d3;}
.gb-hint.success .hint-ico{color:#25a56a;}
.gb-hint.danger{background:#fdeeee;border-color:#f3d0d0;}
.gb-hint.danger .hint-ico{color:#e05555;}
.gb-hint .hint-content>*{margin-top:8px;}
.gb-hint strong{font-weight:700;}

/* content-ref cards */
.gb-ref{
  display:flex;align-items:center;gap:14px;border:1px solid var(--border);border-radius:4px;
  padding:12px 20px;margin:8px 0 0;color:var(--text);transition:border-color .15s,box-shadow .15s;
}
.gb-body :not(.gb-ref)+.gb-ref{margin-top:20px;}
.gb-ref:hover{border-color:#c9cdd4;box-shadow:0 1px 2px rgba(0,0,0,.04);}
.gb-ref .ref-emoji{font-size:20px;flex-shrink:0;line-height:1;}
.gb-ref .ref-title{flex:1;font-size:16px;font-weight:400;}
.gb-ref .ref-chev{color:var(--muted-2);flex-shrink:0;}

/* card grid (data-view=cards) */
.gb-cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:16px;margin:20px 0;}
.gb-card{border:1px solid var(--border);border-radius:10px;overflow:hidden;display:flex;flex-direction:column;transition:box-shadow .15s;}
.gb-card:hover{box-shadow:0 4px 14px rgba(0,0,0,.07);}
.gb-card .cover{aspect-ratio:16/10;background:var(--bg-subtle);overflow:hidden;}
.gb-card .cover img{width:100%;height:100%;object-fit:cover;display:block;}
.gb-card .card-title{padding:14px 16px;font-size:15px;color:var(--text);border-top:1px solid var(--border);}

/* details / accordion — flush-stacked (shared borders, no gap between items) */
.gb-body details{border-bottom:1px solid var(--border);margin-top:0;}
.gb-body :not(details)+details{margin-top:20px;border-top:1px solid var(--border);}
.gb-body details summary{
  list-style:none;cursor:pointer;display:flex;align-items:center;gap:10px;
  padding:16px 4px;font-size:16px;font-weight:500;color:var(--text);
}
.gb-body details summary::-webkit-details-marker{display:none;}
.gb-body details summary::before{
  content:"";width:8px;height:8px;border-right:1.6px solid var(--muted);border-bottom:1.6px solid var(--muted);
  transform:rotate(-45deg);transition:transform .15s;flex-shrink:0;margin-left:4px;
}
.gb-body details[open] summary::before{transform:rotate(45deg);}
.gb-body details .details-body{padding:0 4px 18px 22px;}
.gb-body details .details-body>*:last-child{margin-bottom:0;}

/* tables */
.gb-body table{width:100%;border-collapse:collapse;margin:0 0 16px;font-size:15px;}
.gb-body th,.gb-body td{border:1px solid var(--border);padding:8px 12px;text-align:left;vertical-align:top;}
.gb-body th{background:var(--bg-subtle);font-weight:600;}

/* prev / next footer */
.gb-pager{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:40px;}
.gb-pager a{border:1px solid var(--border);border-radius:4px;padding:16px;display:flex;align-items:center;gap:12px;transition:border-color .15s;}
.gb-pager a:hover{border-color:#c9cdd4;}
.gb-pager a.next{grid-column:2;text-align:right;justify-content:flex-end;}
.gb-pager .dir{font-size:12px;color:var(--muted);}
.gb-pager .pg-title{font-size:16px;color:var(--text);font-weight:400;}
.gb-pager .arrow{color:var(--muted-2);flex-shrink:0;}
.gb-updated{margin-top:28px;font-size:14px;color:var(--muted);}

/* TOC right rail */
.gb-toc-title{display:flex;align-items:center;gap:8px;font-size:12px;font-weight:600;text-transform:uppercase;color:var(--muted);margin-bottom:12px;}
.gb-toc a{display:block;font-size:14px;line-height:20px;color:var(--muted);padding:4px 0;}
.gb-toc a:hover{color:var(--text);}
.gb-toc a.lvl3{padding-left:14px;}
.gb-toc a.active{color:var(--tint);}

/* ---------- Search modal ---------- */
.gb-modal{position:fixed;inset:0;z-index:100;display:none;}
.gb-modal.open{display:block;}
.gb-modal-backdrop{position:absolute;inset:0;background:rgba(17,20,24,.4);backdrop-filter:blur(2px);}
.gb-modal-panel{
  position:relative;max-width:640px;width:calc(100% - 32px);margin:12vh auto 0;
  background:var(--bg);border:1px solid var(--border);border-radius:12px;
  box-shadow:0 16px 48px rgba(0,0,0,.24);overflow:hidden;display:flex;flex-direction:column;
  max-height:70vh;
}
.gb-modal-input{display:flex;align-items:center;gap:10px;padding:14px 16px;border-bottom:1px solid var(--border);}
.gb-modal-input svg{color:var(--muted-2);flex-shrink:0;}
.gb-modal-input input{
  flex:1;border:none;outline:none;font-size:16px;font-family:inherit;color:var(--text);background:transparent;
}
.gb-modal-input .esc{border:1px solid var(--border);border-radius:5px;padding:1px 6px;font-size:11px;color:var(--muted-2);}
.gb-results{overflow-y:auto;padding:8px;}
.gb-results a{
  display:block;padding:10px 12px;border-radius:8px;color:var(--text);text-decoration:none;
}
.gb-results a.sel,.gb-results a:hover{background:var(--bg-subtle);}
.gb-results .r-crumb{font-size:12px;color:var(--muted);margin-bottom:2px;}
.gb-results .r-title{font-size:15px;font-weight:500;}
.gb-results .r-title mark{background:rgba(52,109,219,.16);color:inherit;border-radius:2px;padding:0 1px;}
body.tint-green .gb-results .r-title mark{background:rgba(56,202,121,.2);}
.gb-results .r-snip{font-size:13px;color:var(--muted);margin-top:3px;line-height:19px;
  display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;}
.gb-results .r-snip mark{background:rgba(52,109,219,.16);color:inherit;font-weight:600;padding:0;}
.gb-empty{padding:28px 16px;text-align:center;color:var(--muted);font-size:14px;}
.gb-modal-foot{display:flex;gap:16px;padding:9px 16px;border-top:1px solid var(--border);
  font-size:12px;color:var(--muted-2);}
.gb-modal-foot kbd{border:1px solid var(--border);border-radius:4px;padding:0 5px;font-family:inherit;font-size:11px;}

/* header burger + mobile drawer chrome (hidden on desktop) */
.gb-burger{display:none;align-items:center;justify-content:center;width:36px;height:36px;
  margin-left:-6px;border:none;background:transparent;color:var(--text);cursor:pointer;border-radius:8px;flex-shrink:0;}
.gb-burger:hover{background:var(--bg-subtle);}
.gb-drawer-tabs{display:none;}
.gb-nav-backdrop{position:fixed;inset:0;z-index:40;background:rgba(17,20,24,.4);
  opacity:0;visibility:hidden;transition:opacity .2s;}
body.nav-open .gb-nav-backdrop{opacity:1;visibility:visible;}

/* responsive */
@media (max-width:1200px){ .gb-toc{display:none;} }

@media (max-width:960px){
  .gb-burger{display:flex;}
  .gb-tabs{display:none;}
  .gb-header{gap:12px;}
  /* search collapses to an icon button */
  .gb-search{width:36px;padding:0;justify-content:center;flex-shrink:0;}
  .gb-search .ph,.gb-search .kbd{display:none;}

  .gb-main{padding:0 20px;}
  .gb-article{padding:24px 0 72px;}

  /* sidebar becomes an off-canvas drawer */
  .gb-sidebar{
    position:fixed;top:0;left:0;bottom:0;z-index:50;width:300px;max-width:86vw;height:100%;
    background:var(--bg);box-shadow:0 10px 40px rgba(0,0,0,.18);
    padding:16px 16px 24px;overflow-y:auto;
    transform:translateX(-100%);transition:transform .22s ease;align-self:auto;
  }
  body.nav-open .gb-sidebar{transform:translateX(0);}
  body.nav-open{overflow:hidden;}
  .gb-drawer-tabs{display:flex;gap:6px;margin-bottom:14px;}
  .gb-drawer-tabs a{flex:1;text-align:center;padding:7px 10px;border:1px solid var(--border);
    border-radius:var(--radius);font-size:13px;color:var(--muted);}
  .gb-drawer-tabs a.active{color:var(--tint);border-color:var(--tint);font-weight:600;}
}

@media (max-width:600px){
  .gb-header{padding:0 14px;gap:8px;}
  .gb-logo .title{font-size:16px;letter-spacing:-0.3px;white-space:normal;line-height:19px;}
  .gb-logo img{height:26px;}
  .gb-main{padding:0 16px;}
  h1.gb-h1{font-size:28px;line-height:34px;letter-spacing:-0.6px;}
  .gb-pagenum{font-size:30px;}
  .gb-pageemoji{font-size:26px;}
  .gb-body h3{font-size:21px;line-height:28px;}
  .gb-body h4{font-size:18px;line-height:25px;}
  .gb-pager{grid-template-columns:1fr;gap:12px;}
  .gb-pager a.next{grid-column:1;}
  .gb-modal-panel{margin-top:7vh;max-height:80vh;}
  .gb-cards{grid-template-columns:1fr;}
}