/* Course pages. Design system copied from the main portfolio page (index.html):
   same palette, fonts, header, hero, profile panel, kickers, cards and footer. */
:root{--blue:#0033A0;--deep:#00205B;--sky:#6EC1E4;--ink:#17233b;--muted:#596780;--body:#3b4961;--paper:#f3f6fb;--line:#dbe3ef;--white:#fff;--shadow:0 12px 34px rgba(0,32,91,.08);--green:#1f7a4d;--gold:#a8650f;--violet:#5b4fc4}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:88px}
body{margin:0;background:var(--paper);color:var(--ink);font:15px/1.75 'DM Sans',sans-serif}
a{color:inherit;text-decoration:none}button{font:inherit}
.wrap{width:min(1160px,calc(100% - 44px));margin:auto}
h1,h2,h3,h4{font-family:Manrope,sans-serif;line-height:1.25}
.skip{position:absolute;left:-999px}.skip:focus{left:12px;top:12px;background:#fff;padding:8px 12px;z-index:99}

/* header — identical to the main page */
header{position:sticky;top:0;z-index:20;background:rgba(0,51,160,.98);color:white;box-shadow:0 3px 18px #001b5030}
.nav{height:72px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.brand{font:800 15px Manrope;letter-spacing:.06em}.brand span{color:var(--sky)}
nav#nav{display:flex;align-items:center;gap:12px;min-width:0}
nav#nav a{font-size:10px;font-weight:800;letter-spacing:.035em;text-transform:uppercase;color:#e7eefb;white-space:nowrap}
nav#nav a:hover,nav#nav a.current{color:var(--sky)}
#menu{display:none;background:transparent;color:white;border:1px solid #ffffff66;border-radius:7px;padding:7px 12px}

/* hero — identical to the main page, with a compact variant for inner pages */
.hero{position:relative;overflow:hidden;color:white;background:radial-gradient(circle at 82% 15%,#6ec1e444,transparent 28%),linear-gradient(125deg,var(--blue),var(--deep));padding:30px 0 70px}
.hero:after{content:"";position:absolute;width:450px;height:450px;border:1px solid #ffffff15;border-radius:50%;right:-160px;bottom:-310px;pointer-events:none}
.hero-compact{padding-bottom:52px}
.crumbs{display:flex;flex-wrap:wrap;gap:9px;font-size:11px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:#a8def2;margin-bottom:34px}
.crumbs a{color:#fff}.crumbs a:hover{color:var(--sky)}.crumbs span{opacity:.55}
.hero-grid{display:grid;grid-template-columns:1.45fr .75fr;gap:68px;align-items:center;position:relative;z-index:1}
.eyebrow,.kicker{font-size:11px;font-weight:800;letter-spacing:.19em;text-transform:uppercase}
.eyebrow{color:#9fdaf2}
.eyebrow:before{content:"";display:inline-block;width:30px;height:1px;background:var(--sky);vertical-align:middle;margin-right:12px}
.hero h1{font-size:clamp(40px,5.4vw,64px);letter-spacing:-.055em;margin:17px 0 14px;line-height:1.04}
.hero h1.lec-title,.hero h1.page-h1{font-size:clamp(30px,3.8vw,46px);letter-spacing:-.045em;line-height:1.1}
.subtitle{font-size:18px;color:#d9e5f7;margin:0 0 9px}
.focus{font-size:11px;font-weight:800;letter-spacing:.1em;color:#a8def2;margin:0}
.actions{display:flex;gap:11px;flex-wrap:wrap;margin-top:26px}
.btn{display:inline-flex;align-items:center;justify-content:center;padding:11px 17px;border-radius:7px;font-size:10px;font-weight:800;letter-spacing:.09em;text-transform:uppercase;cursor:pointer;border:0;font-family:'DM Sans',sans-serif}
.btn-light{background:white;color:var(--blue)}
.btn-outline{border:1px solid #ffffff77;color:white;background:transparent}
.btn-outline:hover{background:#ffffff18}
.profile-panel{padding:25px;border:1px solid #ffffff38;border-radius:14px;background:#ffffff12;backdrop-filter:blur(8px)}
.profile-panel small{font-size:9px;color:#a8def2;font-weight:800;letter-spacing:.17em}
.profile-panel h3{font-size:20px;margin:11px 0 18px}
.profile-item{padding:12px 0;border-top:1px solid #ffffff30}
.profile-item strong{display:block;font-size:12px}
.profile-item span{display:block;color:#cad8ed;font-size:10.5px;line-height:1.55;margin-top:2px}
.profile-item a{color:#fff;border-bottom:1px solid #ffffff55}
a:focus-visible,button:focus-visible{outline:3px solid var(--sky);outline-offset:3px}

/* body section and cards */
section.white{background:white}
.course-body{padding:56px 0 80px}
.course-shell{display:grid;grid-template-columns:250px minmax(0,1fr);gap:46px;align-items:start}
.card{background:white;border:1px solid var(--line);border-radius:12px;padding:22px;box-shadow:var(--shadow)}
.kicker{color:var(--blue)}
.course-side{position:sticky;top:96px;display:grid;gap:15px;max-height:calc(100vh - 110px);overflow:auto;padding:2px}
.side-toggle{display:none}
.course-menu{display:flex;flex-direction:column;padding:18px 12px}
.course-menu .kicker{padding:0 10px 10px}
.course-menu a{display:flex;gap:12px;align-items:center;padding:9px 10px;border-radius:8px;font-size:13px;font-weight:700;color:var(--ink)}
.course-menu a span{font:800 10px Manrope;letter-spacing:.12em;color:#9aa6bd}
.course-menu a:hover{background:#f3f6fb}
.course-menu a.active{background:#e8effb;color:var(--blue)}.course-menu a.active span{color:var(--blue)}
.tags{display:flex;gap:7px;flex-wrap:wrap;margin-top:10px}
.tag{font-size:9px;font-weight:800;color:var(--blue);background:#e8effb;border-radius:30px;padding:6px 10px}
.toc-box .kicker{margin-bottom:8px}
#toc{margin:0;padding-left:18px;font-size:12.5px;line-height:1.45;color:var(--muted)}#toc li{margin:7px 0}
#toc a{color:#45536c}#toc a:hover,#toc a.on{color:var(--blue);font-weight:700}

/* section heads — as on the main page */
.section-head{display:flex;justify-content:space-between;align-items:end;gap:25px;margin:0 0 26px}
.section-head h2{font-size:clamp(26px,3vw,36px);letter-spacing:-.04em;margin:7px 0 0}
.section-intro{max-width:420px;color:var(--muted);font-size:12px;margin:0}
.notes.home+.section-head{margin-top:54px}

/* notes typography — DM Sans like the main page */
.course-main{min-width:0}
.notes{font-size:16px;line-height:1.8;color:var(--body)}
.notes h1{display:none}
.notes h2{font-size:clamp(21px,2.2vw,25px);letter-spacing:-.03em;color:var(--ink);margin:46px 0 12px}
.notes h3{font-size:17px;letter-spacing:-.01em;color:var(--ink);margin:30px 0 8px}
.notes h4{font-size:15px;margin:22px 0 6px}
.notes>*:first-child,.notes>section:first-child>h2{margin-top:0}
.notes p{margin:0 0 15px}
.notes ul,.notes ol{padding-left:24px;margin:0 0 16px}.notes li{margin:6px 0}
.notes li::marker{color:var(--blue);font-weight:700}
.notes strong{color:var(--ink)}
.notes a{color:var(--blue);font-weight:600;border-bottom:1px solid #b9cbee}
.notes a:hover{border-color:var(--blue)}
.notes .lead{font-size:18px;color:var(--ink);line-height:1.7}
.notes blockquote{margin:18px 0;padding:10px 18px;border-left:2px solid var(--blue);background:#f7f9fd}
.notes code{font:13.5px/1.5 ui-monospace,SFMono-Regular,Menlo,monospace;background:#eef2f9;border-radius:4px;padding:1px 5px;overflow-wrap:anywhere}
.notes pre{background:#0f1a33;color:#e6edf8;border-radius:10px;padding:16px 18px;overflow:auto;font-size:13.5px;line-height:1.6}.notes pre code{background:none;color:inherit;padding:0}
.notes table{border-collapse:collapse;width:100%;margin:12px 0 24px;font-size:14px;line-height:1.55;border:1px solid var(--line)}
.notes th{background:#f3f6fb;color:var(--deep);text-align:left;font-size:10px;font-weight:800;letter-spacing:.1em;text-transform:uppercase}
.notes th,.notes td{padding:10px 13px;border-bottom:1px solid var(--line);vertical-align:top}
.notes tr:last-child td{border-bottom:0}
.notes hr{border:0;border-top:1px solid var(--line);margin:30px 0}
.notes div.arithmatex{margin:6px 0 16px;overflow-x:auto;overflow-y:hidden}
mjx-container[display="true"]{overflow-x:auto;overflow-y:hidden;padding:2px 0}

/* semantic boxes (assigned by heading) — styled like the main page's cards */
.box{background:white;border:1px solid var(--line);border-radius:12px;padding:6px 26px 10px;margin:30px 0;box-shadow:var(--shadow)}
.box>h2{font-size:11px;font-weight:800;letter-spacing:.19em;text-transform:uppercase;margin:18px 0 10px!important;color:var(--blue)}
.box.objectives{background:#f3f6fb;box-shadow:none}
.box.example{border-left:3px solid var(--green)}.box.example>h2{color:var(--green)}
.box.problems{border-left:3px solid var(--gold)}.box.problems>h2{color:var(--gold)}
.box.lab{border-left:3px solid var(--violet)}.box.lab>h2{color:var(--violet)}
.box.reading{border-left:3px solid var(--blue)}
.theorem,.definition,.proof,.remark{margin:20px 0;padding:14px 20px;border-radius:10px}
.theorem{background:#f3f6fb;border-left:3px solid var(--blue)}
.definition{background:#f2f8f5;border-left:3px solid var(--green)}
.remark{background:#fbf7ef;border-left:3px solid var(--gold)}
.proof{border-left:2px solid var(--line);padding-left:20px}
details.solution{margin:8px 0 20px;border:1px solid var(--line);border-radius:9px;padding:10px 16px;background:#fbfcfe}
details.solution summary{cursor:pointer;font-size:10px;font-weight:800;letter-spacing:.12em;text-transform:uppercase;color:var(--blue)}
details.solution[open] summary{margin-bottom:8px}

/* course home */
.units{display:grid;gap:12px;margin:10px 0 26px}
.unit{background:white;border:1px solid var(--line);border-radius:12px;padding:16px 22px 10px;box-shadow:var(--shadow)}
.unit h3{font-size:14px;margin:0 0 6px;color:var(--ink)}
.unit h3 small{font:800 9px 'DM Sans';letter-spacing:.14em;text-transform:uppercase;color:var(--blue);margin-left:8px}
.unit ol{margin:0 0 6px;padding-left:24px;font-size:14px}.unit li{margin:4px 0}
.unit a{color:#45536c;font-weight:500;border:0}.unit a:hover{color:var(--blue)}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:15px}
.card.mat{display:block;transition:transform .15s ease,border-color .15s ease}
.card.mat:hover{transform:translateY(-2px);border-color:#b9cbee}
.card .number{font:800 10px Manrope;letter-spacing:.16em;color:var(--blue)}
.card.mat h3{font-size:16px;margin:8px 0 8px}
.card.mat p{margin:0;color:var(--muted);font-size:11.5px;line-height:1.7}

/* session tables */
table.sessions td.num{font:800 12px Manrope;color:var(--blue);width:60px;text-align:center}
table.sessions .sum{font-size:12.5px;color:var(--muted);margin-top:3px}
table.sessions tr.unit-row td{background:#f3f6fb;font-size:10px;font-weight:800;letter-spacing:.12em;text-transform:uppercase;color:var(--deep)}
table.sessions td.fmt{white-space:nowrap;color:var(--muted);font-size:12px}
table.sessions a{border:0}

/* pager */
.pager{display:grid;grid-template-columns:1fr 1fr;gap:15px;margin-top:46px}
.pager a{display:block;font:700 14px/1.4 Manrope;color:var(--ink);padding:18px 20px}
.pager a:hover{border-color:#b9cbee}
.pager small{display:block;font:800 9px 'DM Sans';letter-spacing:.16em;text-transform:uppercase;color:var(--blue);margin-bottom:6px}
.pager .next{grid-column:2;text-align:right}

/* footer — identical to the main page */
footer{background:var(--deep);color:#c5d2e7;padding:27px 0 15px}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr;gap:30px}
.footer-grid strong{color:white;font:700 12px Manrope}
.footer-grid p,.footer-grid a{display:block;color:#c5d2e7;font-size:10px;margin:6px 0}
.footer-grid a:hover{color:var(--sky)}
.copyright{grid-column:1/-1;border-top:1px solid #ffffff25;padding-top:12px;margin-top:5px;font-size:9px;color:#aabbd7}

@media(max-width:980px){
  .hero-grid{grid-template-columns:1fr;gap:30px}.profile-panel{max-width:600px}
  .course-shell{grid-template-columns:1fr;gap:20px}
  .course-side{position:static;max-height:none;overflow:visible}
  .side-toggle{display:block;width:100%;text-align:left;font-size:10px;font-weight:800;letter-spacing:.14em;text-transform:uppercase;padding:14px 18px;border:1px solid var(--line);border-radius:12px;background:white;color:var(--blue);cursor:pointer;box-shadow:var(--shadow)}
  .course-side>.card{display:none}.course-side.open>.card{display:block}.course-side.open>.course-menu{display:flex}
  .cards{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:1100px){
  .nav{height:64px}#menu{display:block}
  nav#nav{display:none;position:absolute;top:64px;left:0;right:0;background:var(--blue);padding:17px 22px;flex-direction:column;align-items:flex-start;gap:15px;max-height:calc(100vh - 64px);overflow-y:auto}nav#nav.show{display:flex}
}
@media(max-width:650px){
  .wrap{width:calc(100% - 34px)}
  .hero{padding:24px 0 48px}.crumbs{margin-bottom:24px}.hero h1{font-size:42px}.subtitle{font-size:15px}
  .course-body{padding:30px 0 56px}
  .section-head{display:block}.section-intro{margin-top:10px}
  .cards{grid-template-columns:1fr}
  .notes{font-size:15.5px}.box{padding:4px 18px 8px}
  .notes span.arithmatex{display:inline-block;max-width:100%;overflow-x:auto;overflow-y:hidden;vertical-align:middle}
  .notes table{display:block;overflow-x:auto}
  .pager{grid-template-columns:1fr}.pager .next{grid-column:1}
  .footer-grid{grid-template-columns:1fr;gap:16px}.copyright{grid-column:1}
}
@media print{
  header,.hero,.course-side,.pager,footer{display:none!important}
  body{background:#fff}.course-body{padding:0}.course-shell{display:block}
  .box{break-inside:avoid;box-shadow:none}details.solution>*{display:block}
}

/* teaching catalogue page */
.hero-copy{max-width:690px;color:#d4e0f2;margin:22px 0 0}
.course-tile{display:flex;flex-direction:column;min-height:270px;transition:transform .15s ease,border-color .15s ease}
.course-tile:hover{transform:translateY(-2px);border-color:#b9cbee}
.course-tile h3{font-size:19px;letter-spacing:-.02em;margin:10px 0 10px}
.course-tile p{color:var(--muted);font-size:12.5px;line-height:1.75;margin:0 0 18px;flex:1}
.tile-link{align-self:flex-start;background:var(--blue);color:#fff;border-radius:7px;padding:10px 16px;font-size:10px;font-weight:800;letter-spacing:.09em;text-transform:uppercase}
.course-tile:hover .tile-link{background:var(--deep)}
.tools-strip{margin-top:18px;display:flex;align-items:center;gap:18px;flex-wrap:wrap;box-shadow:none;background:#f3f6fb}
.tools-strip .tags{margin:0}
.notes pre{position:relative}
.copy-btn{position:absolute;top:8px;right:8px;font:800 9px 'DM Sans';letter-spacing:.12em;text-transform:uppercase;background:#ffffff1a;color:#cfe0ff;border:1px solid #ffffff33;border-radius:6px;padding:5px 9px;cursor:pointer;opacity:.75}
.copy-btn:hover{opacity:1;background:#ffffff2e}
@media print{.copy-btn{display:none}}