/* The site's header and footer, the same on every page. The server puts site/partials/header.html and footer.html where
   a page has <!-- site:header --> and <!-- site:footer -->, adds this file and chrome.js, and marks the current page's
   menu link (server.py, page_html). Self-contained: the header reads the page's tokens when they exist and falls back otherwise; the footer
   keeps its own brand colours (--f-*), since a page's tokens can mean something else there (the grader's --stage is white). */

/* ---------- header ---------- */
.topbar{position:sticky;top:0;z-index:40;background:var(--ground,#EEF0F2);border-bottom:1px solid var(--rule,#D3D8DE)}
.topbar__in{max-width:1200px;margin-inline:auto;padding:6px clamp(16px,3vw,32px);display:flex;flex-wrap:wrap;align-items:center;gap:0 28px}
.logo{display:inline-flex;align-items:center;min-height:44px;text-decoration:none;color:var(--ink,#0F1B2D);
  font-family:var(--display,"Source Serif 4",Georgia,serif);font-weight:700;font-size:24px;letter-spacing:-.01em}
.logo span{font:400 13px var(--mono,"IBM Plex Mono",monospace);color:var(--ink2,#3C4757);margin-left:1px}
.site-nav{position:relative;display:flex;flex-wrap:wrap;align-items:center;gap:0 20px;margin-left:auto}
.site-nav > a{font:400 12px var(--mono,"IBM Plex Mono",monospace);letter-spacing:.08em;text-transform:uppercase;color:var(--ink2,#3C4757);text-decoration:none;padding:12px 0}
.site-nav > a:hover{color:var(--stamp,#C8321E)}
.site-nav > a[aria-current="page"]{color:var(--ink,#0F1B2D);box-shadow:inset 0 -2px 0 var(--stamp,#C8321E)}
/* a page's own links after the menu (the grader's Replay, Report…), shown only when it has some */
.topbar__page{display:flex;flex-wrap:wrap;gap:0 20px;padding-left:16px;border-left:1px solid var(--rule,#D3D8DE)}
.topbar__page a{font:400 12px var(--mono,"IBM Plex Mono",monospace);letter-spacing:.08em;text-transform:uppercase;color:var(--ink2,#3C4757);text-decoration:none;padding:12px 0}
.topbar__page a:hover{color:var(--stamp,#C8321E)}
.topbar__page a[hidden]{display:none}
.topbar__page:not(:has(a:not([hidden]))){display:none}

/* the Tools dropdown: a <details>, opening under the menu and aligned to its right edge, so it never runs off a phone
   (.site-nav in the selectors keeps the links' own look on pages whose header styles every nav link, like .bar) */
.nav-dd{position:static}
.nav-dd > summary{list-style:none;cursor:pointer;display:inline-flex;align-items:center;gap:6px;padding:12px 0;
  font:400 12px var(--mono,"IBM Plex Mono",monospace);letter-spacing:.08em;text-transform:uppercase;color:var(--ink2,#3C4757)}
.nav-dd > summary::-webkit-details-marker{display:none}
.nav-dd > summary::after{content:"▾";font-size:11px;transition:transform .15s}
.nav-dd[open] > summary::after{transform:rotate(180deg)}
.nav-dd > summary:hover{color:var(--stamp,#C8321E)}
.nav-dd.is-current > summary{color:var(--ink,#0F1B2D);box-shadow:inset 0 -2px 0 var(--stamp,#C8321E)}
.nav-dd > summary:focus-visible{outline:3px solid var(--stamp,#C8321E);outline-offset:2px}
.nav-dd-menu{position:absolute;z-index:60;top:calc(100% + 4px);right:0;min-width:270px;display:flex;flex-direction:column;padding:6px 0;
  background:var(--raised,#fff);border:1px solid var(--rule,#D3D8DE);border-top:3px solid var(--ink,#0F1B2D);box-shadow:0 24px 50px -28px rgba(15,27,45,.45)}
.site-nav .nav-dd-menu a{display:block;padding:11px 18px;border-radius:0;box-shadow:none;letter-spacing:0;text-transform:none;text-decoration:none;white-space:nowrap;font:500 15px var(--font,"Onest",system-ui,sans-serif);color:var(--ink,#0F1B2D)}
.site-nav .nav-dd-menu a:hover{background:var(--panel,#F6F7F8);color:var(--stamp,#C8321E)}
.site-nav .nav-dd-menu a[aria-current="page"]{box-shadow:inset 3px 0 0 var(--stamp,#C8321E);background:var(--panel,#F6F7F8)}
.site-nav .nav-dd-menu a.nav-dd-sub{padding-left:38px;font-size:14px;color:var(--ink2,#3C4757)}
.site-nav .nav-dd-menu a.nav-dd-sub::before{content:"↳ ";color:var(--ink3,#55606E)}

/* ---------- footer: dark, the brand on the left (logo, one line, social links), three columns of links, a bottom line ---------- */
.foot{--f-bg:#0F1B2D;--f-ink:#E8ECF0;--f-soft:#C9D1E0;--f-mute:#98A3B1;--f-rule:#2C343E;--f-red:#C8321E;--f-red-hi:#FF6B57;
  margin-top:clamp(56px,8vw,112px);background:var(--f-bg);color:var(--f-soft);border-top:3px solid var(--f-red)}
.foot__in{max-width:1200px;margin-inline:auto;padding:clamp(48px,6vw,72px) clamp(16px,3vw,32px) 28px;display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,1.6fr);gap:40px clamp(32px,6vw,96px);
  font:15px/1.55 var(--font,"Onest",system-ui,sans-serif)}
.foot__brand{display:flex;flex-direction:column;align-items:flex-start;gap:16px}
.foot__logo{font-family:var(--display,"Source Serif 4",Georgia,serif);font-weight:700;font-size:30px;letter-spacing:-.01em;color:#fff;text-decoration:none;line-height:1}
.foot__logo span{font:400 15px var(--mono,"IBM Plex Mono",monospace);color:var(--f-mute);margin-left:1px}
.foot__brand p{color:var(--f-soft)}
.foot__social{display:flex;gap:10px;margin-top:4px}
.foot__social a{width:42px;height:42px;display:grid;place-items:center;border:1px solid var(--f-rule);color:var(--f-ink);transition:background-color .2s,border-color .2s,color .2s}
.foot__social a:hover{background:var(--f-red);border-color:var(--f-red);color:#fff}
.foot__social svg{width:18px;height:18px;fill:currentColor}
.foot__cols{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:28px 32px}
.foot__cols > div{display:flex;flex-direction:column;align-items:flex-start;gap:2px}
.foot__h{font:500 11px var(--mono,"IBM Plex Mono",monospace);letter-spacing:.12em;text-transform:uppercase;color:var(--f-red-hi);margin-bottom:10px}
.foot__cols a,.foot__cols button{padding:6px 0;color:var(--f-ink);text-decoration:none;font:inherit;background:none;border:0;cursor:pointer;text-align:left}
.foot__cols a:hover,.foot__cols button:hover{color:#fff;text-decoration:underline;text-underline-offset:4px;text-decoration-color:var(--f-red-hi)}
.foot__cols a[aria-current="page"]{color:#fff;box-shadow:inset 2px 0 0 var(--f-red-hi);padding-left:10px}
.foot__bottom{grid-column:1 / -1;display:flex;flex-wrap:wrap;justify-content:space-between;gap:8px 24px;padding-top:22px;border-top:1px solid var(--f-rule);
  font:12px var(--mono,"IBM Plex Mono",monospace);letter-spacing:.04em;color:var(--f-mute)}
.foot a:focus-visible,.foot button:focus-visible{outline:3px solid var(--f-red-hi);outline-offset:2px}
@media (max-width:860px){
  .foot__in{grid-template-columns:minmax(0,1fr)}
}
@media (max-width:520px){
  .foot__cols{grid-template-columns:repeat(2,minmax(0,1fr))}
}