/* =========================================================
   FINAL FIX — LEFT COURSE SIDEBAR SCROLL
   Keeps the sidebar visible and lets the mouse scrollbar
   reach the final chapter/subchapter without hiding the bottom.
   ========================================================= */

@media (min-width:1051px){
  .side{
    position:sticky;
    top:12px;
    height:calc(100vh - 24px);
    max-height:calc(100vh - 24px);
    display:flex;
    flex-direction:column;
    overflow:hidden;
  }

  .side > .hd{
    flex:0 0 auto;
  }

  .side > .bd{
    flex:1 1 auto;
    min-height:0;
    max-height:none;
    overflow:hidden;
    display:flex;
    flex-direction:column;
  }

  .side .top,
  .side .chapter-search,
  .side .search-empty,
  .side .head-row{
    flex:0 0 auto;
  }

  .side .course-scroll{
    flex:1 1 auto;
    min-height:0;
    max-height:none;
    height:auto;
    overflow-y:scroll;
    overflow-x:hidden;
    padding-right:6px;
    padding-bottom:32px;
    scrollbar-gutter:stable;
    overscroll-behavior:contain;
  }
}

@media (max-width:1050px){
  .side{
    display:flex;
    flex-direction:column;
  }

  .side > .hd{
    flex:0 0 auto;
  }

  .side > .bd{
    flex:1 1 auto;
    min-height:0;
    height:auto;
    max-height:none;
    overflow:hidden;
    display:flex;
    flex-direction:column;
  }

  .side .top,
  .side .chapter-search,
  .side .search-empty,
  .side .head-row{
    flex:0 0 auto;
  }

  .side .course-scroll{
    flex:1 1 auto;
    min-height:0;
    height:auto;
    max-height:none;
    overflow-y:auto;
    overflow-x:hidden;
    padding-right:5px;
    padding-bottom:32px;
    scrollbar-gutter:stable;
    overscroll-behavior:contain;
    -webkit-overflow-scrolling:touch;
  }
}

/* =========================================================
    border-radius:0 20px 20px 0;

    transform:translateX(-106%);
    transition:transform .3s ease;
  }

  .side.course-sidebar-open{
    transform:translateX(0);
  }

  .side .hd{
    flex:0 0 auto;
  }

  .side .bd{
    flex:1;
    min-height:0;
    height:auto;
    max-height:none;

    display:flex;
    flex-direction:column;

    overflow:hidden;
  }

  .course-scroll{
    flex:1;
    min-height:0;
    height:auto;
    max-height:none;

    overflow-y:auto;
    overflow-x:hidden;

    padding-right:5px;
    padding-bottom:35px;

    -webkit-overflow-scrolling:touch;
  }
}


/* =========================================================
   SMALL MOBILE
   ========================================================= */

@media(max-width:640px){

  .side{
    width:min(94vw,360px);
    height:100dvh;
    max-height:100dvh;
  }

  .side .bd{
    flex:1;
    min-height:0;
    height:auto;
    max-height:none;
    overflow:hidden;
  }

  .course-scroll{
    flex:1;
    min-height:0;
    height:auto;
    max-height:none;
    overflow-y:auto;
    padding-bottom:40px;
  }
}
Delete these old rules
You currently have conflicting rules like these:

.course-scroll{
  max-height:78vh;
}

.course-scroll{
  max-height:65vh;
}

.course-scroll{
  max-height:60vh;
}

.course-scroll{
  max-height:calc(100vh - 300px);
}
Also remove this desktop block:

@media (min-width:1051px){
  .side{position:sticky;top:12px;max-height:calc(100vh - 24px)}
  .side .bd{max-height:calc(100vh - 75px);overflow:hidden}
  .course-scroll{max-height:calc(100vh - 300px)}
}



/* TypeScript course sidebar — same chapter structure as the Python course */
:root{--ts-blue:#3178c6;--ts-dark:#235a97;--ts-bg:#f4f8fc;--ts-text:#18324d;--ts-muted:#6f8195;--ts-border:rgba(49,120,198,.17);--ts-white:#fff}
.course-list{list-style:none;margin:0;padding:0}
.chapter-group{list-style:none;margin:0 0 9px;padding:0;border:1px solid var(--ts-border);border-radius:15px;background:#fff;overflow:hidden}
.chapter-group>.link{display:flex;align-items:center;gap:11px;padding:12px;text-decoration:none;color:var(--ts-text);background:#fff;transition:.2s}
.chapter-group>.link:hover{background:#eef6ff}
.chapter-group>.link.active{background:linear-gradient(135deg,#e7f3ff,#edf0ff);color:#124f8b}
.chapter-group .num{display:grid;place-items:center;flex:0 0 50px;min-height:38px;border-radius:11px;background:#e9f3fd;color:#216bad;font-size:12px;font-weight:900}
.chapter-group>.link.active .num{background:linear-gradient(135deg,#3178c6,#5b8fe3);color:#fff}
.chapter-group .txt{min-width:0}
.chapter-group .txt b,.chapter-group .txt em{display:block}
.chapter-group .txt b{font-size:13px;margin-bottom:3px}
.chapter-group .txt em{font-size:11px;line-height:1.35;color:var(--ts-muted);font-style:normal;font-weight:700}
.subchapter-list{display:none;list-style:none;margin:0;padding:7px 8px 10px;border-top:1px solid var(--ts-border);background:#fbfdff}
.chapter-group:hover>.subchapter-list,.chapter-group:focus-within>.subchapter-list,.chapter-group>.link.active+.subchapter-list{display:block}
.subchapter-list li{margin:3px 0}
.subchapter-list a{display:block;padding:8px 10px;border-radius:9px;color:#35516f;text-decoration:none;font-size:12px;line-height:1.4}
.subchapter-list a:hover{background:#eaf4ff;color:#125994}
.t:checked~.wrap .chapter-group{background:#26374b;border-color:rgba(255,255,255,.10)}
.t:checked~.wrap .chapter-group>.link{background:#26374b;color:#eef6ff}
.t:checked~.wrap .chapter-group>.link:hover{background:#334155}
.t:checked~.wrap .chapter-group>.link.active{background:linear-gradient(135deg,#1f4770,#453f75);color:#fff}
.t:checked~.wrap .chapter-group .txt em{color:#c5d3e4}
.t:checked~.wrap .subchapter-list{background:#1f2d3d;border-top-color:rgba(255,255,255,.10)}
.t:checked~.wrap .subchapter-list a{color:#dbe8f6}
.t:checked~.wrap .subchapter-list a:hover{background:#334155;color:#fff}
@media(max-width:900px){
  .chapter-group>.link{padding:11px 10px}
  .chapter-group .num{flex-basis:46px}
  .subchapter-list{display:none}
  .chapter-group.open>.subchapter-list,.chapter-group>.link.active+.subchapter-list{display:block}
}

/* ===== Standalone EasyTutorGuide page CSS ===== */
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:Arial,Helvetica,sans-serif;background:#f4f8fc;color:#18324d;line-height:1.6}
a{color:inherit}
img{max-width:100%;height:auto}
.t,.m{position:absolute;opacity:0;pointer-events:none}
.t-btn{position:fixed;right:14px;bottom:14px;z-index:1500;padding:10px 15px;border-radius:999px;background:#18324d;color:#fff;font-size:13px;font-weight:900;cursor:pointer;box-shadow:0 10px 24px rgba(0,0,0,.2)}
.m-btn,.ov{display:none}
.wrap{width:min(1500px,100%);margin:auto;padding:12px 18px 28px}
.top-badge-bar{display:flex;align-items:center;justify-content:center;gap:16px;flex-wrap:wrap;padding:9px 14px;margin-bottom:12px;border-radius:14px;background:linear-gradient(135deg,#235a97,#3178c6 55%,#5b8fe3);color:#fff;box-shadow:0 10px 24px rgba(49,120,198,.18)}
.top-badge-bar p{margin:0;font-size:13px;font-weight:700;text-align:center}
.top-pill{display:inline-flex;align-items:center;gap:7px;padding:6px 10px;border:1px solid rgba(255,255,255,.25);border-radius:999px;background:rgba(255,255,255,.14);font-size:11px;font-weight:900}
.site-header{position:relative;display:grid;grid-template-columns:auto 1fr auto;align-items:center;gap:18px;padding:10px 16px;margin-bottom:16px;border:1px solid rgba(49,120,198,.14);border-radius:18px;background:#fff;box-shadow:0 10px 24px rgba(20,60,100,.08)}
.site-logo-link{display:flex;align-items:center;gap:8px;text-decoration:none}
.site-logo-image{display:flex;width:150px;max-width:26vw}
.site-logo-image img{display:block;width:100%;object-fit:contain}
.site-logo-text,.logo-tagline{display:block;color:#235a97;font-size:12px;font-weight:900;white-space:nowrap}
.main-nav{min-width:0}
.nav-links{display:flex;justify-content:flex-end;align-items:center;gap:4px;flex-wrap:wrap;list-style:none;margin:0;padding:0}
.nav-links a{display:block;padding:8px 9px;border-radius:10px;text-decoration:none;color:#27425f;font-size:12px;font-weight:800}
.nav-links a:hover,.nav-links a.active{background:#eaf4ff;color:#125994}
.menu-toggle{display:none;border:0;border-radius:11px;background:linear-gradient(135deg,#3178c6,#5b8fe3);color:#fff;width:44px;height:44px;font-size:24px;cursor:pointer}
.sidebar,.sidebar-overlay{display:none}
.hero{padding:clamp(22px,4vw,42px);margin-bottom:18px;border-radius:22px;background:linear-gradient(135deg,#235a97,#3178c6 55%,#5b8fe3);color:#fff;box-shadow:0 18px 38px rgba(49,120,198,.22)}
.hero h1{margin:0 0 10px;color:#fff;font-size:clamp(28px,4vw,44px);line-height:1.15}
.hero .sub{margin:0 0 14px;color:#fff;font-size:16px}
.meta{display:flex;gap:9px;flex-wrap:wrap}
.pill{display:inline-flex;padding:6px 11px;border:1px solid rgba(255,255,255,.26);border-radius:999px;background:rgba(255,255,255,.15);font-size:12px;font-weight:900}
.lay{display:grid;grid-template-columns:minmax(300px,380px) minmax(0,1fr);gap:18px;align-items:start}
.card{overflow:hidden;border:1px solid rgba(49,120,198,.15);border-radius:18px;background:#fff;box-shadow:0 12px 28px rgba(20,60,100,.08)}
.card>.hd{padding:14px 17px;border-bottom:1px solid rgba(49,120,198,.12);background:linear-gradient(180deg,#f8fbff,#eef6ff)}
.card>.hd h2{margin:0;color:#18324d;font-size:20px}
.card>.bd{padding:16px}
.side{position:sticky;top:12px}
.top{display:grid;gap:12px;margin-bottom:14px}
.book,.info-box{padding:13px;border:1px solid rgba(49,120,198,.12);border-radius:14px;background:#f8fbff}
.book small,.book strong,.book span,.info-box strong,.info-box span{display:block}
.book small{color:#3178c6;font-size:11px;font-weight:900;text-transform:uppercase}
.book strong{margin:3px 0;color:#18324d}
.book span,.info-box span{color:#6f8195;font-size:12px;font-weight:700}
.head-row{display:flex;align-items:center;justify-content:space-between;gap:10px;margin:6px 0 12px}
.head-row h3{margin:0;font-size:17px}
.head-row .note{color:#6f8195;font-size:11px;font-weight:800;text-align:right}
.content .bd{min-height:420px}
.foot{text-align:center;margin:18px 0;color:#6f8195;font-size:13px;font-weight:800}
.ml-footer{padding:24px 18px 20px;border-radius:20px;background:linear-gradient(135deg,#18324d,#235a97);color:#fff;box-shadow:0 15px 30px rgba(20,60,100,.2)}
.ml-footer-menu{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px;max-width:1000px;margin:auto}
.ml-col{display:grid;gap:8px}
.ml-col a{color:#fff;text-decoration:none;font-size:13px;font-weight:800;opacity:.9}
.ml-col a:hover{opacity:1;text-decoration:underline}
.ml-footer-social{display:flex;justify-content:center;gap:10px;flex-wrap:wrap;margin:22px 0 14px}
.ml-footer-social a{display:grid;place-items:center;width:40px;height:40px;border:1px solid rgba(255,255,255,.2);border-radius:50%;background:rgba(255,255,255,.1);color:#fff}
.ml-footer-social a:hover{background:rgba(255,255,255,.2);transform:translateY(-2px)}
.ml-footer-social svg{width:20px;height:20px}
.ml-copy{margin:0;text-align:center;font-size:12px;font-weight:700;opacity:.85}
.t:checked~.wrap{color:#e9f1fa}
.t:checked~.wrap{background:#111827}
.t:checked~.wrap .site-header,.t:checked~.wrap .card{background:#1f2937;border-color:rgba(255,255,255,.1)}
.t:checked~.wrap .card>.hd{background:#273449;border-color:rgba(255,255,255,.08)}
.t:checked~.wrap .card>.hd h2,.t:checked~.wrap .head-row h3,.t:checked~.wrap .book strong{color:#fff}
.t:checked~.wrap .book,.t:checked~.wrap .info-box{background:#273449;border-color:rgba(255,255,255,.08)}
.t:checked~.wrap .nav-links a{color:#e9f1fa}
.t:checked~.wrap .nav-links a:hover,.t:checked~.wrap .nav-links a.active{background:#334155;color:#fff}
.t:checked~.wrap .content .bd{color:#dbe6f5}
@media(max-width:1050px){
  .site-header{grid-template-columns:auto auto}.main-nav{display:none}.menu-toggle{display:block;justify-self:end}
  .sidebar-overlay{position:fixed;inset:0;z-index:1900;background:rgba(4,15,28,.62)}
  .sidebar{position:fixed;right:0;top:0;z-index:2000;width:min(88vw,340px);height:100dvh;padding:74px 18px 22px;background:#fff;box-shadow:-15px 0 35px rgba(0,0,0,.2);transform:translateX(105%);transition:transform .28s ease}
  .sidebar ul{list-style:none;margin:0;padding:0;display:grid;gap:6px}.sidebar a{display:block;padding:11px 12px;border-radius:10px;text-decoration:none;color:#18324d;font-weight:800}.sidebar a:hover,.sidebar a.active{background:#eaf4ff;color:#125994}
  .close-btn{position:absolute;right:16px;top:16px;width:42px;height:42px;border:0;border-radius:50%;background:#eaf4ff;color:#125994;font-size:20px;cursor:pointer}
  body.menu-open{overflow:hidden}body.menu-open .sidebar-overlay{display:block}body.menu-open .sidebar{display:block;transform:translateX(0)}
  .lay{grid-template-columns:1fr}
}
@media(max-width:640px){
  .wrap{padding:8px}.top-badge-bar{gap:7px}.top-badge-bar p{width:100%;font-size:11px}.site-header{padding:8px 10px}.site-logo-image{width:120px;max-width:50vw}.site-logo-text{display:none}
  .hero{padding:20px 14px}.lay{gap:12px}.card>.bd{padding:12px}.ml-footer-menu{grid-template-columns:repeat(2,minmax(0,1fr));text-align:center}
  .t-btn{right:8px;bottom:8px;padding:8px 11px;font-size:11px}
}


/* ===== Fully responsive TypeScript course sidebar ===== */
.course-sidebar-toggle{
  display:none;
  align-items:center;
  justify-content:center;
  gap:9px;
  width:100%;
  min-height:48px;
  margin:0 0 12px;
  padding:11px 15px;
  border:0;
  border-radius:14px;
  background:linear-gradient(135deg,#235a97,#3178c6 58%,#5b8fe3);
  color:#fff;
  font:inherit;
  font-size:14px;
  font-weight:900;
  cursor:pointer;
  box-shadow:0 10px 24px rgba(49,120,198,.22);
}
.course-sidebar-toggle .course-toggle-icon{
  display:inline-grid;
  width:24px;
  height:24px;
  place-items:center;
  border-radius:8px;
  background:rgba(255,255,255,.16);
  font-size:17px;
}
.course-sidebar-overlay{
  position:fixed;
  inset:0;
  z-index:2150;
  display:none;
  background:rgba(4,15,28,.62);
  backdrop-filter:blur(3px);
}
.course-sidebar-close{
  display:none;
  position:sticky;
  top:0;
  z-index:6;
  width:42px;
  height:42px;
  margin:0 0 10px auto;
  border:0;
  border-radius:50%;
  background:#eaf4ff;
  color:#125994;
  font-size:20px;
  font-weight:900;
  cursor:pointer;
}
.side .hd{position:relative}


/* =========================================================
   COURSE SIDEBAR SCROLL — SINGLE AUTHORITATIVE RULESET
   ========================================================= */
.side{
  display:flex;
  flex-direction:column;
}

.side > .hd{
  flex:0 0 auto;
}

.side > .bd{
  flex:1 1 auto;
  min-height:0;
  max-height:none;
  display:flex;
  flex-direction:column;
  overflow:hidden;
}

.side .top,
.side .chapter-search,
.side .search-empty,
.side .head-row{
  flex:0 0 auto;
}

.course-scroll{
  flex:1 1 auto;
  min-height:0;
  height:auto;
  max-height:none;
  overflow-y:auto;
  overflow-x:hidden;
  padding-right:6px;
  padding-bottom:36px;
  scrollbar-width:thin;
  scrollbar-color:#9fc3e8 transparent;
  scrollbar-gutter:stable;
  overscroll-behavior:contain;
  -webkit-overflow-scrolling:touch;
}

.course-scroll::-webkit-scrollbar{
  width:8px;
}

.course-scroll::-webkit-scrollbar-track{
  background:transparent;
}

.course-scroll::-webkit-scrollbar-thumb{
  background:#9fc3e8;
  border-radius:99px;
}

.course-scroll::-webkit-scrollbar-thumb:hover{
  background:#6fa7db;
}

@media (min-width:1051px){
  .side{
    position:sticky;
    top:12px;
    height:calc(100vh - 24px);
    max-height:calc(100vh - 24px);
    overflow:hidden;
  }
}

@media (max-width:1050px){
  .course-sidebar-toggle{display:flex}
  .lay{display:block}
  .side{
    position:fixed;
    left:0;
    top:0;
    z-index:2200;
    width:min(92vw,390px);
    height:100dvh;
    max-height:100dvh;
    border-radius:0 20px 20px 0;
    transform:translateX(-106%);
    transition:transform .3s ease;
    overflow:hidden;
    box-shadow:18px 0 42px rgba(0,0,0,.24);
  }
  .side.course-sidebar-open{transform:translateX(0)}
  .course-sidebar-overlay.course-sidebar-open{display:block}
  .course-sidebar-close{display:grid;place-items:center}
  .side > .bd{
    flex:1 1 auto;
    min-height:0;
    height:auto;
    max-height:none;
    overflow:hidden;
    display:flex;
    flex-direction:column;
    padding:12px;
  }
  .side .top{margin-bottom:10px}
  .side .book,.side .info-box{padding:10px}
  .side .head-row{margin:4px 0 9px}
  body.course-sidebar-active{overflow:hidden}
  .content{width:100%}
}

@media (max-width:640px){
  .course-sidebar-toggle{position:sticky;top:6px;z-index:90;min-height:46px;margin-bottom:10px}
  .side{width:min(94vw,360px);border-radius:0 16px 16px 0}
  .side .hd{padding:12px 14px}
  .side .hd h2{font-size:18px}
  .side .bd{padding:10px}
  .chapter-group{margin-bottom:7px;border-radius:12px}
  .chapter-group>.link{gap:8px;padding:10px 9px}
  .chapter-group .num{flex-basis:43px;min-height:34px;font-size:11px}
  .chapter-group .txt b{font-size:12px}
  .chapter-group .txt em{font-size:10px}
  .subchapter-list a{padding:8px 9px;font-size:11px}
}


/* ===== Course reading tools and navigation ===== */
#readingProgress{position:fixed;left:0;top:0;width:0;height:4px;z-index:5000;background:linear-gradient(90deg,#3178c6,#6c63ff);transition:width .08s linear}
.course-tools{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;margin:-4px 0 18px;padding:12px 14px;border:1px solid rgba(49,120,198,.15);border-radius:16px;background:#fff;box-shadow:0 9px 22px rgba(20,60,100,.07)}
.breadcrumbs{display:flex;align-items:center;gap:7px;flex-wrap:wrap;color:#64748b;font-size:12px;font-weight:800}
.breadcrumbs a{text-decoration:none;color:#235a97}.breadcrumbs a:hover{text-decoration:underline}.breadcrumbs span[aria-hidden="true"]{opacity:.55}
.reading-meta{display:flex;align-items:center;gap:8px;flex-wrap:wrap;color:#52677f;font-size:12px;font-weight:800}
.tool-actions{display:flex;align-items:center;gap:7px;flex-wrap:wrap}
.tool-btn{min-height:38px;padding:8px 11px;border:1px solid rgba(49,120,198,.19);border-radius:10px;background:#f7fbff;color:#174c7d;font:inherit;font-size:12px;font-weight:900;cursor:pointer;transition:.2s}
.tool-btn:hover{background:#e9f4ff;transform:translateY(-1px)}
.tool-btn:focus-visible,#goTopBtn:focus-visible,.chapter-search input:focus-visible{outline:3px solid rgba(49,120,198,.3);outline-offset:2px}
.chapter-search{position:relative;margin:0 0 13px}
.chapter-search label{display:block;margin-bottom:6px;color:#334e68;font-size:12px;font-weight:900}
.chapter-search input{width:100%;min-height:42px;padding:9px 38px 9px 11px;border:1px solid rgba(49,120,198,.2);border-radius:11px;background:#fff;color:#18324d;font:inherit;font-size:13px}
.chapter-search button{position:absolute;right:5px;bottom:5px;width:32px;height:32px;border:0;border-radius:8px;background:transparent;color:#64748b;font-size:17px;cursor:pointer}
.search-empty{display:none;margin:10px 0;padding:11px;border-radius:10px;background:#fff4e8;color:#92400e;font-size:12px;font-weight:800;text-align:center}.search-empty.show{display:block}
.subchapter-list a.current-section{background:#dceeff;color:#0b4f91;font-weight:900;box-shadow:inset 3px 0 #3178c6}
.chapter-group.search-hidden,.subchapter-list li.search-hidden{display:none!important}
.chapter-nav{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:24px}
.chapter-nav a{display:flex;flex-direction:column;justify-content:center;min-height:72px;padding:12px 15px;border:1px solid rgba(49,120,198,.16);border-radius:14px;background:#f7fbff;text-decoration:none;color:#18324d;transition:.2s}
.chapter-nav a:hover{background:#eaf4ff;transform:translateY(-2px)}
.chapter-nav a:last-child{text-align:right}.chapter-nav small{color:#6f8195;font-size:11px;font-weight:900;text-transform:uppercase}.chapter-nav strong{font-size:14px}
#goTopBtn{position:fixed;right:22px;bottom:74px;z-index:2500;width:52px;height:52px;border:0;border-radius:50%;background:linear-gradient(135deg,#3178c6,#5b8fe3);color:#fff;font-size:22px;font-weight:900;cursor:pointer;box-shadow:0 10px 24px rgba(35,90,151,.32);opacity:0;visibility:hidden;transform:translateY(14px);transition:.25s}
#goTopBtn.show{opacity:1;visibility:visible;transform:translateY(0)}#goTopBtn:hover{transform:translateY(-2px) scale(1.05)}
.share-status{min-height:18px;margin-top:8px;color:#16724b;font-size:12px;font-weight:800}



















.sticky-lesson-title{position:sticky;top:0;z-index:20}
.t:checked~.wrap .course-tools{background:#26374b;border-color:rgba(255,255,255,.1)}
.t:checked~.wrap .breadcrumbs,.t:checked~.wrap .reading-meta{color:#d0dbea}.t:checked~.wrap .breadcrumbs a{color:#8ec5ff}
.t:checked~.wrap .tool-btn,.t:checked~.wrap .chapter-search input{background:#334155;border-color:rgba(255,255,255,.12);color:#f8fafc}
.t:checked~.wrap .chapter-search label{color:#e6eef9}.t:checked~.wrap .subchapter-list a.current-section{background:#294e7d;color:#fff}
.t:checked~.wrap .chapter-nav a{background:#334155;border-color:rgba(255,255,255,.1);color:#f8fafc}.t:checked~.wrap .chapter-nav small{color:#c5d3e4}
@media(max-width:760px){.course-tools{align-items:flex-start}.tool-actions{width:100%}.tool-btn{flex:1 1 auto}.chapter-nav{grid-template-columns:1fr}#goTopBtn{right:14px;bottom:70px;width:46px;height:46px}.sticky-lesson-title{position:static}}
@media print{.top-badge-bar,.site-header,.sidebar,.sidebar-overlay,.side,.course-tools,.t-btn,.course-sidebar-toggle,.course-sidebar-overlay,#goTopBtn,.ml-footer,.foot,#readingProgress{display:none!important}.wrap{width:100%;padding:0}.lay{display:block}.content{box-shadow:none;border:0}.content .bd{font-size:12pt}.hero{box-shadow:none}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto!important}*,*::before,*::after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}



/* Center chapter and subchapter content inside each rounded bar */
.chapter-group>.link{
  display:grid;
  grid-template-columns:50px minmax(0,1fr) 50px;
  align-items:center;
  justify-content:center;
  text-align:center;
}
.chapter-group>.link::after{content:"";display:block;width:50px;height:1px}
.chapter-group .num{justify-self:center;align-self:center;text-align:center}
.chapter-group .txt{width:100%;text-align:center}
.chapter-group .txt b,.chapter-group .txt em{text-align:center}
.subchapter-list li{display:flex;justify-content:center}
.subchapter-list a{
  width:100%;
  min-height:38px;
  display:flex;
  align-items:center;
  justify-content:center;
  text-align:center;
}
@media(max-width:520px){
  .chapter-group>.link{grid-template-columns:43px minmax(0,1fr) 43px}
  .chapter-group>.link::after{width:43px}
}



/* ===== FIX: full-page Night View =====
 JavaScript adds .night-mode to <body>, allowing the dark background
 to cover the complete viewport and document from top to bottom. */
html,body{min-height:100%;}
body{transition:background-color .25s ease,color .25s ease;}
body.night-mode{background:#111827;color:#e9f1fa;color-scheme:dark;}
body.night-mode .wrap{background:#111827;}
body.night-mode .t-btn{background:#f8fafc;color:#111827;}

/* Dark mobile navigation as well */
@media(max-width:1050px){
body.night-mode .sidebar{background:#1f2937;color:#e9f1fa;}
body.night-mode .sidebar a{color:#e9f1fa;}
body.night-mode .sidebar a:hover,
body.night-mode .sidebar a.active{background:#334155;color:#fff;}
body.night-mode .close-btn{background:#334155;color:#fff;}
}

/* =========================================================
 FINAL NIGHT VIEW FIX — full page and horizontal button
 ========================================================= */
html,
body{
min-height:100%;
}

html.night-mode,
body.night-mode{
background-color:#111827 !important;
color:#e9f1fa;
color-scheme:dark;
}

body.night-mode{
min-height:100vh;
}

body.night-mode .wrap{
min-height:100vh;
background-color:#111827 !important;
}

.t-btn{
writing-mode:horizontal-tb !important;
text-orientation:mixed !important;
white-space:nowrap !important;
width:auto;
height:auto;
}

body.night-mode .site-header,
body.night-mode .card,
body.night-mode .course-tools{
background-color:#1f2937;
border-color:rgba(255,255,255,.10);
}

body.night-mode .card>.hd{
background:#273449;
border-color:rgba(255,255,255,.08);
}

body.night-mode .book,
body.night-mode .info-box{
background:#273449;
border-color:rgba(255,255,255,.08);
}

body.night-mode .card>.hd h2,
body.night-mode .head-row h3,
body.night-mode .book strong{
color:#fff;
}

body.night-mode .nav-links a,
body.night-mode .content .bd{
color:#e9f1fa;
}

body.night-mode .nav-links a:hover,
body.night-mode .nav-links a.active{
background:#334155;
color:#fff;
}

body.night-mode .chapter-group{
background:#26374b;
border-color:rgba(255,255,255,.10);
}

body.night-mode .chapter-group>.link{
background:#26374b;
color:#eef6ff;
}

body.night-mode .chapter-group>.link:hover{
background:#334155;
}

body.night-mode .chapter-group>.link.active{
background:linear-gradient(135deg,#1f4770,#453f75);
color:#fff;
}

body.night-mode .chapter-group .txt em{
color:#c5d3e4;
}

body.night-mode .subchapter-list{
background:#1f2d3d;
border-top-color:rgba(255,255,255,.10);
}

body.night-mode .subchapter-list a{
color:#dbe8f6;
}

body.night-mode .subchapter-list a:hover{
background:#334155;
color:#fff;
}

body.night-mode .breadcrumbs,
body.night-mode .reading-meta{
color:#d0dbea;
}

body.night-mode .breadcrumbs a{
color:#8ec5ff;
}

body.night-mode .tool-btn,
body.night-mode .chapter-search input{
background:#334155;
border-color:rgba(255,255,255,.12);
color:#f8fafc;
}

body.night-mode .chapter-search label{
color:#e6eef9;
}

body.night-mode .subchapter-list a.current-section{
background:#294e7d;
color:#fff;
}

body.night-mode .chapter-nav a{
background:#334155;
border-color:rgba(255,255,255,.10);
color:#f8fafc;
}

body.night-mode .chapter-nav small{
color:#c5d3e4;
}

@media(max-width:1050px){
body.night-mode .sidebar{
  background:#1f2937;
  color:#e9f1fa;
}
body.night-mode .sidebar a{
  color:#e9f1fa;
}
body.night-mode .sidebar a:hover,
body.night-mode .sidebar a.active{
  background:#334155;
  color:#fff;
}
body.night-mode .close-btn{
  background:#334155;
  color:#fff;
}
}