:root{
  --bg:#f4f6f8; --surface:#ffffff; --ink:#142131; --muted:#55657a; --line:#dbe1e8; --line-strong:#c3ccd7;
  --brand:#0a6683; --brand-ink:#ffffff; --shadow:0 1px 2px rgba(20,33,49,.06),0 8px 24px -12px rgba(20,33,49,.18);
  --f-body:"IBM Plex Sans",system-ui,-apple-system,"Segoe UI",sans-serif;
  --f-display:"IBM Plex Sans Condensed","IBM Plex Sans",system-ui,sans-serif;
  --f-mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,monospace;
  --bar:46px;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#0e141c; --surface:#141c26; --ink:#e2e8ef; --muted:#97a5b6; --line:#253140; --line-strong:#33424f;
    --brand:#5bbfdb; --brand-ink:#0b1a20; --shadow:0 1px 2px rgba(0,0,0,.3),0 10px 28px -14px rgba(0,0,0,.6);
    color-scheme:dark;
  }
}
:root[data-theme="dark"]{
  --bg:#0e141c; --surface:#141c26; --ink:#e2e8ef; --muted:#97a5b6; --line:#253140; --line-strong:#33424f;
  --brand:#5bbfdb; --brand-ink:#0b1a20; --shadow:0 1px 2px rgba(0,0,0,.3),0 10px 28px -14px rgba(0,0,0,.6);
  color-scheme:dark;
}
*,*::before,*::after{box-sizing:border-box}
html,body{margin:0}
body{background:var(--bg);color:var(--ink);font:15px/1.55 var(--f-body);-webkit-font-smoothing:antialiased}
a{color:var(--brand)}
:focus-visible{outline:2px solid var(--brand);outline-offset:2px;border-radius:4px}

/* ---- the bar on every page ---- */
.hubbar{position:sticky;top:0;z-index:50;display:flex;align-items:center;gap:10px;height:calc(var(--bar) + env(safe-area-inset-top,0px));
  padding:env(safe-area-inset-top,0px) max(14px,env(safe-area-inset-right,0px)) 0 max(14px,env(safe-area-inset-left,0px));
  background:var(--surface);border-bottom:1px solid var(--line)}
.hb-home{display:flex;align-items:center;gap:8px;text-decoration:none;color:var(--ink);font:700 15px var(--f-display);letter-spacing:.01em;white-space:nowrap}
.hb-logo{display:grid;place-items:center;width:26px;height:26px;border-radius:6px;background:var(--brand);color:var(--brand-ink);font-size:15px;line-height:1}
.hb-menu{position:relative;min-width:0}
.hb-menu summary{list-style:none;display:flex;align-items:center;gap:8px;cursor:pointer;min-width:0;max-width:min(52vw,420px);
  padding:6px 10px;border:1px solid var(--line-strong);border-radius:8px;background:var(--bg);font:600 14px var(--f-body);user-select:none}
.hb-menu summary::-webkit-details-marker{display:none}
.hb-menu summary:hover{border-color:var(--brand)}
.hb-menu[open] summary{border-color:var(--brand)}
.hb-code,.hm-code,.c-code{font:600 11.5px var(--f-mono);letter-spacing:.03em;padding:2px 7px;border-radius:4px;white-space:nowrap;
  background:var(--accent,var(--brand));color:#fff}
.hb-cur{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.hb-caret{color:var(--muted);font-size:12px;transition:transform .15s}
.hb-menu[open] .hb-caret{transform:rotate(180deg)}
.hm{position:absolute;top:calc(100% + 6px);left:0;width:min(360px,calc(100vw - 28px));max-height:min(70vh,520px);overflow:auto;
  background:var(--surface);border:1px solid var(--line-strong);border-radius:10px;box-shadow:var(--shadow);padding:6px}
.hm-item{display:flex;align-items:center;gap:10px;padding:9px 10px;border-radius:7px;text-decoration:none;color:var(--ink)}
.hm-item:hover,.hm-item:focus-visible{background:var(--bg)}
.hm-item.on{background:var(--bg);box-shadow:inset 3px 0 0 var(--accent,var(--brand))}
.hm-t{display:flex;flex-direction:column;min-width:0}
.hm-t b{font-weight:600;font-size:14px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.hm-t small{color:var(--muted);font-size:12px}
.hm-all{display:block;margin-top:4px;padding:9px 10px;border-top:1px solid var(--line);font:600 13px var(--f-body);text-decoration:none}
.hb-full{font:600 13px var(--f-body);text-decoration:none;color:var(--muted);white-space:nowrap}
.hb-full:hover{color:var(--brand)}

/* ---- course viewer ---- */
.hub-course{height:100dvh;display:flex;flex-direction:column;overflow:hidden;position:relative}
.course-frame{flex:1;width:100%;border:0;display:block;background:var(--bg)}
.noscript{padding:16px}

/* ---- home ---- */
.home{max-width:1080px;margin:0 auto;padding:clamp(28px,6vw,64px) max(16px,env(safe-area-inset-right,0px)) 64px max(16px,env(safe-area-inset-left,0px))}
.eyebrow{margin:0;font:600 12px var(--f-mono);letter-spacing:.08em;text-transform:uppercase;color:var(--brand)}
.intro h1{margin:6px 0 8px;font:700 clamp(30px,5vw,44px)/1.1 var(--f-display);letter-spacing:-.01em}
.lede{margin:0;max-width:60ch;color:var(--muted);font-size:16px}
.continue{margin:16px 0 0}
.continue a{display:inline-block;font-weight:600;text-decoration:none;padding:8px 14px;border-radius:8px;background:var(--brand);color:var(--brand-ink)}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(min(100%,300px),1fr));gap:16px;margin-top:32px}
.course{position:relative;display:flex;flex-direction:column;gap:10px;padding:20px 20px 18px;border-radius:12px;text-decoration:none;color:var(--ink);
  background:var(--surface);border:1px solid var(--line);box-shadow:var(--shadow);overflow:hidden;transition:border-color .15s,transform .15s}
.course::before{content:"";position:absolute;inset:0 0 auto 0;height:4px;background:var(--accent,var(--brand))}
.course:hover{border-color:var(--accent,var(--brand));transform:translateY(-2px)}
.c-top{display:flex;align-items:center;gap:8px}
.c-issuer{font:600 12px var(--f-mono);color:var(--muted);text-transform:uppercase;letter-spacing:.06em}
.c-title{font:700 22px/1.2 var(--f-display)}
.c-sum{color:var(--muted);font-size:14.5px}
.c-facts{display:flex;flex-wrap:wrap;gap:6px}
.c-facts span{font:500 12px var(--f-mono);padding:3px 8px;border-radius:999px;border:1px solid var(--line-strong);color:var(--muted)}
.c-go{margin-top:auto;padding-top:6px;font-weight:600;color:var(--accent,var(--brand))}
@media (prefers-color-scheme:dark){ :root:not([data-theme="light"]) .c-go{color:var(--ink)} }
:root[data-theme="dark"] .c-go{color:var(--ink)}
.empty{color:var(--muted)}

@media (max-width:560px){
  .hb-name{display:none}
  .hb-full{display:none}
}
@media (prefers-reduced-motion:reduce){ .course,.hb-caret{transition:none} .course:hover{transform:none} }

/* ===== accounts & admin ===== */
:root{--ok:#1d7a3a;--ok-bg:#e6f4ea;--bad:#a1302a;--bad-bg:#fbecea;--warn:#875800;--warn-bg:#fbf3e1}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){--ok:#7fd49a;--ok-bg:#13261a;--bad:#f08a80;--bad-bg:#2c1716;--warn:#e6b458;--warn-bg:#29220f}}
:root[data-theme="dark"]{--ok:#7fd49a;--ok-bg:#13261a;--bad:#f08a80;--bad-bg:#2c1716;--warn:#e6b458;--warn-bg:#29220f}

.hb-spacer{flex:1}
.hb-user summary{max-width:none;gap:7px;padding:4px 8px 4px 4px}
.hb-avatar{display:grid;place-items:center;width:26px;height:26px;border-radius:50%;background:var(--brand);color:var(--brand-ink);font:600 13px var(--f-mono)}
.hb-uname{font-weight:600;max-width:12ch;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.badge{display:inline-block;min-width:18px;padding:1px 6px;border-radius:999px;background:var(--bad);color:#fff;font:600 11px var(--f-mono);text-align:center}
.hm-right{left:auto;right:0;width:min(260px,calc(100vw - 28px))}
.hm-who{padding:8px 10px 10px;border-bottom:1px solid var(--line);margin-bottom:4px;display:flex;flex-direction:column}
.hm-who small{color:var(--muted)}
.hm-link{display:block;width:100%;text-align:left;padding:9px 10px;border-radius:7px;color:var(--ink);text-decoration:none;font:500 14px var(--f-body);background:none;border:0;cursor:pointer}
.hm-link:hover,.hm-link:focus-visible{background:var(--bg)}
.hm-out{color:var(--bad)}
.hm-filter,.home-filter{width:100%;font:14px var(--f-body);color:var(--ink);background:var(--bg);border:1px solid var(--line-strong);border-radius:7px;padding:8px 10px;margin:0 0 6px}
.home-filter{max-width:420px;margin-top:18px}
.hm-empty{margin:8px 10px;color:var(--muted);font-size:14px}

.flashes{position:relative;z-index:40;display:flex;flex-direction:column;gap:6px;padding:10px max(14px,env(safe-area-inset-left,0px)) 0}
.hub-course .flashes{position:absolute;top:calc(var(--bar) + 8px);left:50%;transform:translateX(-50%);width:min(560px,calc(100% - 28px));padding:0}
.flash{display:flex;gap:10px;align-items:flex-start;justify-content:space-between;margin:0 0 12px;padding:10px 12px;border-radius:8px;border:1px solid var(--line-strong);background:var(--surface);font-size:14px;box-shadow:var(--shadow)}
.flash small{display:block;color:var(--muted);margin-top:2px}
.flashes .flash{margin:0;max-width:960px;width:100%;align-self:center}
.flash-ok{border-color:var(--ok);background:var(--ok-bg)}
.flash-error{border-color:var(--bad);background:var(--bad-bg)}
.flash-info{border-color:var(--brand)}
.flash-secret{border-color:var(--warn);background:var(--warn-bg);font-family:var(--f-mono);word-break:break-all}
.flash-secret small{font-family:var(--f-body);word-break:normal}
.flash-x{background:none;border:0;color:var(--muted);font-size:20px;line-height:1;cursor:pointer;padding:0 2px}

/* sign-in pages */
.auth{min-height:100dvh;display:grid;place-items:center;padding:24px 16px}
.auth-card{width:min(400px,100%);background:var(--surface);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow);padding:28px 26px}
.auth-brand{display:flex;align-items:center;gap:9px;margin-bottom:18px;text-decoration:none;color:var(--ink);font:700 16px var(--f-display)}
.auth-card h1{margin:0 0 6px;font:700 28px/1.15 var(--f-display)}
.auth-alt{margin:18px 0 0;font-size:14px;color:var(--muted)}

/* forms */
.form{display:flex;flex-direction:column;gap:14px;margin-top:14px}
.form.inline{flex-direction:row;flex-wrap:wrap;align-items:flex-end}
.form label{display:flex;flex-direction:column;gap:5px;font:600 13px var(--f-body)}
.form label small{font-weight:400;color:var(--muted)}
input:not([type=radio]):not([type=checkbox]),select,textarea{font:15px var(--f-body);color:var(--ink);background:var(--bg);border:1px solid var(--line-strong);border-radius:8px;padding:9px 11px;max-width:100%}
input:focus,select:focus,textarea:focus{outline:2px solid var(--brand);outline-offset:0;border-color:var(--brand)}
textarea{resize:vertical}
.trap{position:absolute!important;left:-10000px;width:1px;height:1px;overflow:hidden}
fieldset{border:1px solid var(--line);border-radius:10px;padding:10px 14px 12px;margin:0;display:flex;flex-direction:column;gap:8px}
legend{font:600 12px var(--f-mono);text-transform:uppercase;letter-spacing:.06em;color:var(--muted);padding:0 4px}
.form label.radio{flex-direction:row;align-items:center;gap:9px;font-weight:400}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;font:600 14px var(--f-body);color:var(--ink);background:var(--surface);border:1px solid var(--line-strong);border-radius:8px;padding:9px 14px;cursor:pointer;text-decoration:none;white-space:nowrap}
.btn:hover{border-color:var(--brand)}
.btn.primary{background:var(--brand);border-color:var(--brand);color:var(--brand-ink)}
.btn.small{padding:5px 10px;font-size:13px}
.btn.danger-btn{background:var(--bad);border-color:var(--bad);color:#fff}

/* pages */
.page{max-width:1080px;margin:0 auto;padding:28px max(16px,env(safe-area-inset-right,0px)) 64px max(16px,env(safe-area-inset-left,0px))}
.page.narrow{max-width:640px}
.page h1{margin:0 0 14px;font:700 clamp(26px,4vw,34px)/1.15 var(--f-display);display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:18px 20px;margin:16px 0}
.card h2{margin:0 0 6px;font:700 19px var(--f-display)}
.warn-card{border-color:var(--warn)}
.facts{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:12px;margin:0}
.facts dt{font:600 11px var(--f-mono);text-transform:uppercase;letter-spacing:.07em;color:var(--muted)}
.facts dd{margin:2px 0 0}
.muted{color:var(--muted)}
.mono,code{font-family:var(--f-mono);font-size:.92em}
.note{margin:6px 0 0;color:var(--muted);font-size:13.5px;font-style:italic}
.crumbs{margin:0 0 6px;font-size:14px}
.crumbs a{text-decoration:none}

.admin-nav{display:flex;gap:4px;border-bottom:1px solid var(--line);margin:0 0 16px;overflow-x:auto;scrollbar-width:none}
.admin-nav a{padding:9px 14px;text-decoration:none;color:var(--muted);font-weight:600;border-bottom:3px solid transparent;margin-bottom:-1px;white-space:nowrap}
.admin-nav a[aria-current]{color:var(--ink);border-bottom-color:var(--brand)}
.toolbar{display:flex;flex-wrap:wrap;gap:12px;align-items:center;justify-content:space-between;margin:0 0 12px}
.toolbar p{margin:0}
.tabs{display:flex;flex-wrap:wrap;gap:6px}
.tabs a{padding:6px 12px;border-radius:999px;border:1px solid var(--line-strong);text-decoration:none;color:var(--ink);font-size:14px;font-weight:500}
.tabs a[aria-current]{background:var(--brand);border-color:var(--brand);color:var(--brand-ink)}
.tabs .n{font:600 12px var(--f-mono);opacity:.75}
.tabs .n.hot{color:var(--bad);opacity:1}
.tabs a[aria-current] .n.hot{color:inherit}
.search-form input{width:min(260px,100%)}

.tw{overflow-x:auto;border:1px solid var(--line);border-radius:10px;background:var(--surface);margin:10px 0}
table{width:100%;border-collapse:collapse;font-size:14px}
th{text-align:left;font:600 11px var(--f-mono);text-transform:uppercase;letter-spacing:.06em;color:var(--muted);background:var(--bg);padding:9px 12px;border-bottom:1px solid var(--line);white-space:nowrap}
td{padding:10px 12px;border-bottom:1px solid var(--line);vertical-align:middle}
tr:last-child td{border-bottom:0}
td.m,th.m{text-align:right;font-family:var(--f-mono)}
tr.is-pending td{background:color-mix(in srgb,var(--warn-bg) 60%,transparent)}
tr.warn td{color:var(--bad)}
.row-actions{display:flex;gap:6px;justify-content:flex-end;flex-wrap:wrap}
.row-actions form,.actions form,.orphans form{display:inline}
.actions{display:flex;flex-wrap:wrap;gap:8px;margin:10px 0}
.pill{display:inline-block;padding:2px 9px;border-radius:999px;font:600 12px var(--f-body);border:1px solid var(--line-strong);color:var(--muted);white-space:nowrap;vertical-align:middle}
.pill-active,.pill-ok{border-color:var(--ok);color:var(--ok);background:var(--ok-bg)}
.pill-pending{border-color:var(--warn);color:var(--warn);background:var(--warn-bg)}
.pill-disabled,.pill-off{border-color:var(--bad);color:var(--bad);background:var(--bad-bg)}
.pill-admin{border-color:var(--brand);color:var(--brand)}
.hm-code.big{font-size:15px;padding:3px 9px}
.seg{display:inline-flex;border:1px solid var(--line-strong);border-radius:8px;overflow:hidden}
.seg label{position:relative;cursor:pointer}
.seg input{position:absolute;opacity:0;inset:0;margin:0;cursor:pointer}
.seg span{display:block;padding:6px 11px;font-size:13px;font-weight:600;color:var(--muted);border-left:1px solid var(--line-strong)}
.seg label:first-child span{border-left:0}
.seg input:checked+span{background:var(--brand);color:var(--brand-ink)}
.seg input:focus-visible+span{outline:2px solid var(--brand);outline-offset:-2px}
details.danger{margin-top:14px;border-top:1px solid var(--line);padding-top:12px}
details.danger summary{cursor:pointer;color:var(--bad);font-weight:600}
.pager{display:flex;gap:14px;align-items:center;justify-content:center;margin:14px 0;font-size:14px}
.access-list{list-style:none;margin:8px 0 0;padding:0;display:flex;flex-direction:column;gap:8px}
.orphans{list-style:none;padding:0;display:flex;flex-direction:column;gap:8px}
.group{margin-top:28px}
.group-h{margin:0 0 -16px;font:600 13px var(--f-mono);text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}

@media (max-width:560px){
  .hb-uname{display:none}
  .hb-courses summary{max-width:calc(100vw - 130px)}
  .row-actions{justify-content:flex-start}
  .opt-col{display:none}
  .users td,.users th{padding:9px 8px}
}