/* =====================================================================
   Teacher's Lounge — app.css
   Design tokens (SPEC §6), app shell, components, utilities, print.
   One file, no build step. Loaded on every page.
   ===================================================================== */

/* ---------- 1. Tokens ---------- */
:root{
  /* brand */
  --primary:#2F63BA; --primary-dark:#234F96; --primary-darker:#193A72;
  --primary-50:#EEF3FB; --primary-100:#D9E4F6; --primary-300:#8FB0E0;
  --navy:#0D1B2A; --ink:#1A1A1A;
  --gray-50:#F7F7F7; --gray-100:#EEEEEE; --gray-300:#D6D6D6; --gray-500:#8A8A8A; --gray-700:#616161;
  --success:#1E7B4A; --warning:#B26A00; --danger:#B3261E;
  /* semantic surfaces */
  --bg:#F5F7FA; --surface:#FFFFFF; --surface2:#EEF3F9; --text:#14213A; --muted:#5B6169; --line:#DCE3EC;
  --accent:var(--primary); --accent-ink:#FFFFFF; --accent-soft:var(--primary-50); --accent-text:var(--primary-dark);
  --ok:var(--success); --ok-soft:#E3F3EA; --warn:var(--warning); --warn-soft:#FBF0DC; --bad:var(--danger); --bad-soft:#FBE7E5;
  --nav-bg:#193A72; --nav-ink:#FFFFFF; --nav-muted:#C7D4EA; --nav-active:#2F63BA;
  /* domain chips */
  --math:#2F63BA; --data:#1E7B4A; --ai:#7A3E9D; --career:#B26A00;
  --math-soft:#EEF3FB; --data-soft:#E3F3EA; --ai-soft:#F0E8F8; --career-soft:#FBF0DC;
  --shadow:0 1px 2px rgba(13,27,42,.06),0 4px 14px rgba(13,27,42,.06);
  /* radii + spacing */
  --r-1:8px; --r-2:12px; --r-3:16px; --r-4:20px;
  --s-1:4px; --s-2:8px; --s-3:12px; --s-4:16px; --s-5:24px; --s-6:32px; --s-7:48px;
  /* type */
  --font:"Source Sans 3","Source Sans Pro",system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --serif:"Source Serif 4",Georgia,"Times New Roman",serif;
  --mono:ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;
  /* shell */
  --sidebar:260px; --rail:72px; --topbar:60px; --tabbar:64px; --content:1100px;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#0F1722; --surface:#172130; --surface2:#1F2B3D; --text:#E8EEF7; --muted:#A7B3C4; --line:#2B394D;
    --primary-50:#1B2A44; --primary-100:#233A5E; --gray-100:#2B394D; --gray-300:#3D4D63; --gray-50:#1A2536;
    --accent:#7FA6E6; --accent-ink:#0F1722; --accent-soft:#1B2A44; --accent-text:#A9C4F0;
    --ok:#6FCF97; --ok-soft:#153A29; --warn:#F2B85B; --warn-soft:#3D2C0F; --bad:#F28B82; --bad-soft:#44201D;
    --nav-bg:#0D1B2A; --nav-muted:#9FB2CC;
    --math:#8FB4F0; --data:#5FD0BF; --ai:#C5A7F0; --career:#F2B85B;
    --math-soft:#1B2A44; --data-soft:#123A35; --ai-soft:#2C2040; --career-soft:#3D2C0F;
    --shadow:0 1px 2px rgba(0,0,0,.4),0 6px 18px rgba(0,0,0,.35);
    color-scheme:dark;
  }
}
:root[data-theme="dark"]{
  --bg:#0F1722; --surface:#172130; --surface2:#1F2B3D; --text:#E8EEF7; --muted:#A7B3C4; --line:#2B394D;
  --primary-50:#1B2A44; --primary-100:#233A5E; --gray-100:#2B394D; --gray-300:#3D4D63; --gray-50:#1A2536;
  --accent:#7FA6E6; --accent-ink:#0F1722; --accent-soft:#1B2A44; --accent-text:#A9C4F0;
  --ok:#6FCF97; --ok-soft:#153A29; --warn:#F2B85B; --warn-soft:#3D2C0F; --bad:#F28B82; --bad-soft:#44201D;
  --nav-bg:#0D1B2A; --nav-muted:#9FB2CC;
  --math:#8FB4F0; --data:#5FD0BF; --ai:#C5A7F0; --career:#F2B85B;
  --math-soft:#1B2A44; --data-soft:#123A35; --ai-soft:#2C2040; --career-soft:#3D2C0F;
  --shadow:0 1px 2px rgba(0,0,0,.4),0 6px 18px rgba(0,0,0,.35);
  color-scheme:dark;
}

/* ---------- 2. Base ---------- */
*,*::before,*::after{box-sizing:border-box}
html{font-size:16px;-webkit-text-size-adjust:100%;overflow-x:hidden}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font);font-size:1rem;line-height:1.5;min-height:100vh;overflow-x:hidden;overflow-wrap:anywhere}
h1,h2,h3,h4{margin:0;line-height:1.2;font-weight:600;overflow-wrap:anywhere}
h1{font-size:clamp(1.5rem,1.2rem + 1.4vw,1.9rem)} h2{font-size:1.3rem} h3{font-size:1.1rem} h4{font-size:1rem}
p{margin:0}
a{color:var(--accent-text)}
button{font:inherit;color:inherit}
img,svg,video{max-width:100%}
svg{display:inline-block;vertical-align:middle}
hr{border:0;border-top:1px solid var(--line);margin:var(--s-5) 0}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:4px}
::selection{background:var(--primary-100);color:var(--ink)}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;padding:0;margin:-1px}
[hidden]{display:none!important}
.skip-link{position:absolute;left:8px;top:-80px;background:var(--surface);color:var(--text);padding:10px 14px;border-radius:var(--r-1);z-index:200;box-shadow:var(--shadow);font-weight:600;text-decoration:none}
.skip-link:focus{top:8px}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* ---------- 3. Shell layout ---------- */
body{display:grid;grid-template-columns:var(--sidebar) minmax(0,1fr);grid-template-rows:var(--topbar) 1fr;min-height:100vh}
#app-shell{display:contents}
.tl-sidebar{grid-column:1;grid-row:1/3;background:var(--nav-bg);color:var(--nav-ink);display:flex;flex-direction:column;padding:16px 12px;gap:2px;position:sticky;top:0;height:100vh;overflow-y:auto;scrollbar-width:thin}
.tl-brand{display:flex;align-items:center;gap:10px;padding:6px 8px 16px;text-decoration:none;color:inherit;min-height:44px}
.tl-brand img{width:36px;height:36px;flex:none;border-radius:10px}
.tl-brand .name{font-weight:700;font-size:1.05rem;line-height:1.1;display:block}
.tl-brand .sub{font-size:.72rem;color:var(--nav-muted);letter-spacing:.05em;text-transform:uppercase;display:block}
.tl-nav{display:flex;flex-direction:column;gap:2px}
.tl-nav a{display:flex;align-items:center;gap:12px;padding:9px 12px;border-radius:10px;color:var(--nav-muted);text-decoration:none;font-weight:600;min-height:44px;position:relative}
.tl-nav a svg{width:22px;height:22px;flex:none}
.tl-nav a:hover{background:rgba(255,255,255,.08);color:#fff}
.tl-nav a[aria-current="page"]{background:var(--nav-active);color:#fff}
.tl-nav a[aria-current="page"]::before{content:"";position:absolute;left:-12px;top:10px;bottom:10px;width:4px;border-radius:0 4px 4px 0;background:#E5E5E5}
.tl-nav .nav-label{font-size:.7rem;letter-spacing:.08em;text-transform:uppercase;color:var(--nav-muted);opacity:.85;padding:14px 12px 4px;font-weight:700}
.tl-nav.secondary a{font-weight:500;font-size:.95rem;min-height:40px;padding:7px 12px}
.tl-nav .badge{margin-left:auto;background:#fff;color:var(--primary-darker);font-size:.7rem;font-weight:700;border-radius:999px;padding:1px 7px;min-width:20px;text-align:center}
.tl-sidebar .spacer{flex:1}
.tl-sidebar .me-link{display:flex;align-items:center;gap:10px;padding:8px 10px;color:#fff;text-decoration:none;border-radius:10px;min-height:44px}
.tl-sidebar .me-link:hover{background:rgba(255,255,255,.08)}
.tl-sidebar .me-link>svg{width:24px;height:24px;flex:none}
.tl-sidebar .me-link .who{min-width:0;font-size:.9rem;line-height:1.2}
.tl-sidebar .me-link .who small{display:block;color:var(--nav-muted);font-size:.75rem;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.tl-sidebar .foot{font-size:.72rem;color:var(--nav-muted);padding:6px 10px 0}
.tl-sidebar .foot a{color:inherit}
.avatar{width:32px;height:32px;border-radius:50%;background:var(--primary-100);color:var(--primary-darker);display:inline-grid;place-items:center;font-weight:700;font-size:.8rem;flex:none;line-height:1;letter-spacing:.02em;text-decoration:none}
.avatar.lg{width:56px;height:56px;font-size:1.2rem}
.avatar.xl{width:80px;height:80px;font-size:1.7rem}

.tl-topbar{grid-column:2;grid-row:1;min-width:0;display:flex;align-items:center;gap:10px;padding:0 20px;background:var(--surface);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}
.tl-topbar .title{flex:1;min-width:0;display:flex;align-items:center;gap:8px;white-space:nowrap;overflow:hidden}
.tl-topbar .title .cur{font-weight:600;overflow:hidden;text-overflow:ellipsis}
.tl-topbar .title a{color:var(--muted);text-decoration:none}
.tl-topbar .title a:hover{text-decoration:underline;color:var(--text)}
.tl-topbar .title .sep{color:var(--muted)}
.tl-search{display:flex;align-items:center;gap:8px;background:var(--surface2);border:1px solid var(--line);border-radius:999px;padding:0 6px 0 12px;height:44px;width:min(380px,36vw);flex:none}
.tl-search input{border:0;background:transparent;flex:1;min-width:0;font:inherit;color:inherit;outline:none;min-height:40px;padding:0}
.tl-search input::placeholder{color:var(--muted)}
.tl-search .go{width:36px;height:36px;border:0;background:transparent;border-radius:50%;display:grid;place-items:center;cursor:pointer;color:var(--muted)}
.tl-search .go:hover{color:var(--accent-text);background:var(--surface)}
.tl-search svg{width:18px;height:18px}
.iconbtn{width:44px;height:44px;border-radius:50%;border:0;background:transparent;display:inline-grid;place-items:center;cursor:pointer;color:var(--muted);text-decoration:none;position:relative;padding:0}
.iconbtn:hover{background:var(--surface2);color:var(--text)}
.iconbtn svg{width:22px;height:22px}
.iconbtn .dot{position:absolute;top:9px;right:9px;width:9px;height:9px;border-radius:50%;background:var(--bad);border:2px solid var(--surface)}
.tl-menu{position:relative}
.tl-menu .menu{position:absolute;right:0;top:calc(100% + 6px);background:var(--surface);border:1px solid var(--line);border-radius:var(--r-2);box-shadow:var(--shadow);min-width:220px;padding:6px;z-index:40;display:none}
.tl-menu .menu[data-open="true"]{display:block}
.tl-menu .menu a,.tl-menu .menu button{display:flex;align-items:center;gap:10px;width:100%;text-align:left;padding:10px 12px;min-height:44px;border:0;background:transparent;border-radius:8px;color:var(--text);text-decoration:none;cursor:pointer;font-weight:500}
.tl-menu .menu a:hover,.tl-menu .menu button:hover{background:var(--surface2)}
.tl-menu .menu .hd{padding:8px 12px 4px;font-size:.85rem;color:var(--muted);border-bottom:1px solid var(--line);margin-bottom:4px}
.tl-menu .menu .hd b{display:block;color:var(--text);font-size:.95rem}
.tl-menu .menu hr{margin:4px 0}

main#main{grid-column:2;grid-row:2;padding:24px;padding-block:24px 40px;width:100%;max-width:calc(var(--content) + 48px);min-width:0;justify-self:start}
main#main:focus{outline:none}
.tl-tabbar{display:none}

/* Rail (768–1199) */
@media (max-width:1199px){
  body{grid-template-columns:var(--rail) minmax(0,1fr)}
  .tl-sidebar{padding:10px 6px;align-items:center;gap:2px}
  .tl-brand{padding:6px 0 10px;justify-content:center}
  .tl-brand .name,.tl-brand .sub,.tl-sidebar .me-link .who,.tl-sidebar .foot,.tl-nav .nav-label,.tl-nav.secondary{display:none}
  .tl-nav{width:100%;align-items:center}
  .tl-nav a{flex-direction:column;gap:3px;padding:6px 2px;font-size:.62rem;width:60px;justify-content:center;text-align:center;line-height:1.05}
  .tl-nav a[aria-current="page"]::before{left:-6px}
  .tl-nav .badge{position:absolute;top:4px;right:6px;margin:0}
  .tl-sidebar .me-link{padding:6px;justify-content:center}
  .tl-search{width:min(300px,34vw)}
}
/* Phone (<768) */
@media (max-width:767px){
  body{grid-template-columns:minmax(0,1fr);grid-template-rows:var(--topbar) 1fr}
  .tl-sidebar{display:none}
  .tl-topbar{grid-column:1;padding:0 12px;gap:6px}
  main#main{grid-column:1;padding:16px;padding-block:16px calc(var(--tabbar) + 24px);max-width:100%}
  .tl-search{width:auto;flex:1;min-width:0}
  .tl-topbar .title{display:none}
  .tl-topbar .title.always{display:flex}
  .tl-tabbar{display:flex;position:fixed;left:0;right:0;bottom:0;height:calc(var(--tabbar) + env(safe-area-inset-bottom,0px));background:var(--surface);border-top:1px solid var(--line);z-index:30;padding:0 4px env(safe-area-inset-bottom,0px)}
  .tl-tabbar a{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;text-decoration:none;color:var(--muted);font-size:.7rem;font-weight:600;min-height:44px;position:relative}
  .tl-tabbar a svg{width:24px;height:24px}
  .tl-tabbar a[aria-current="page"]{color:var(--accent-text)}
  .tl-tabbar a[aria-current="page"] svg{color:var(--accent)}
  .tl-tabbar a[aria-current="page"]::after{content:"";position:absolute;top:0;left:25%;right:25%;height:3px;border-radius:0 0 3px 3px;background:var(--accent)}
  body.immersive .tl-tabbar{display:none}
  body.immersive main#main{padding-bottom:24px}
}
/* No-shell pages (login, register) */
body.bare{display:block}
body.bare main#main{max-width:520px;margin:0 auto;padding:24px 16px 48px}
body.bare .tl-topbar,body.bare .tl-sidebar,body.bare .tl-tabbar{display:none}
.auth-card{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-4);padding:28px 24px;box-shadow:var(--shadow);margin-top:var(--s-4)}
.auth-brand{display:flex;align-items:center;gap:12px;text-decoration:none;color:inherit;justify-content:center;margin-top:var(--s-5)}
.auth-brand img{width:44px;height:44px}
.auth-brand b{font-size:1.3rem}
.auth-brand span{display:block;font-size:.85rem;color:var(--muted)}

/* ---------- 4. Page primitives ---------- */
.page-head{display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;gap:12px 24px;margin-bottom:20px}
.page-head .lead{color:var(--muted);max-width:62ch;margin-top:4px}
.eyebrow{font-size:.75rem;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:700}
.lead{color:var(--muted)}
.section{margin-top:28px}
.section > h2{margin-bottom:12px}
.section-head{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:12px;flex-wrap:wrap}
.serif{font-family:var(--serif)}
.big{font-family:var(--serif);font-size:1.15rem;line-height:1.5}

/* Buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:0 18px;border-radius:14px;border:1px solid transparent;font-weight:600;cursor:pointer;text-decoration:none;background:var(--surface2);color:var(--text);white-space:nowrap;line-height:1.2}
.btn:hover{filter:brightness(.97)}
.btn.primary{background:var(--accent);color:var(--accent-ink)}
.btn.primary:hover{filter:brightness(1.06)}
.btn.secondary{background:var(--surface);border-color:var(--line);color:var(--accent-text)}
.btn.ghost{background:transparent;color:var(--accent-text)}
.btn.danger{background:var(--bad-soft);color:var(--bad)}
.btn.danger.solid{background:var(--bad);color:#fff}
.btn.sm{min-height:36px;padding:0 12px;border-radius:10px;font-size:.9rem}
.btn.block{width:100%}
.btn svg{width:18px;height:18px;flex:none}
.btn[disabled],.btn[aria-disabled="true"]{opacity:.5;cursor:not-allowed;pointer-events:none}
.btn.active,.btn[aria-pressed="true"]{background:var(--accent-soft);color:var(--accent-text);border-color:var(--accent)}
.btn.loading{position:relative;color:transparent!important}
.btn.loading::after{content:"";position:absolute;width:18px;height:18px;border:2px solid currentColor;border-color:var(--muted) transparent var(--muted) transparent;border-radius:50%;animation:spin .8s linear infinite}
.btn-group{display:inline-flex;gap:6px;flex-wrap:wrap}

/* Chips */
.chip{display:inline-flex;align-items:center;gap:6px;padding:3px 10px;border-radius:999px;font-size:.78rem;font-weight:600;background:var(--surface2);color:var(--muted);border:1px solid transparent;line-height:1.4;white-space:nowrap;max-width:100%}
.chip.math{background:var(--math-soft);color:var(--math)}
.chip.data{background:var(--data-soft);color:var(--data)}
.chip.ai{background:var(--ai-soft);color:var(--ai)}
.chip.career{background:var(--career-soft);color:var(--career)}
/* tiers: filled / outlined / dashed — never color-only; text always says the tier */
.chip.major{background:var(--accent);color:var(--accent-ink);border-color:var(--accent)}
.chip.supporting{background:var(--surface);color:var(--accent-text);border-color:var(--accent)}
.chip.additional{background:transparent;color:var(--muted);border:1px dashed var(--gray-500)}
.chip.sample{background:var(--gray-100);color:var(--gray-700)}
.chip.ok{background:var(--ok-soft);color:var(--ok)}
.chip.warn{background:var(--warn-soft);color:var(--warn)}
.chip.bad{background:var(--bad-soft);color:var(--bad)}
.chip.grade,.chip.course{background:var(--primary-darker);color:#fff}
.chip.verified{background:var(--ok-soft);color:var(--ok)}
.chip .x{width:18px;height:18px;display:grid;place-items:center;border-radius:50%;cursor:pointer}
a.chip{text-decoration:none}
a.chip:hover,button.chip:hover{border-color:var(--accent)}
button.chip,a.chip.lg{cursor:pointer;min-height:36px;padding:0 14px;font-size:.88rem}
button.chip[aria-pressed="true"],a.chip[aria-current="page"]{background:var(--accent);color:var(--accent-ink);border-color:var(--accent)}
.chips{display:flex;flex-wrap:wrap;gap:6px}
.chips.scroll{flex-wrap:nowrap;overflow-x:auto;scrollbar-width:none;padding-bottom:4px;margin-inline:-4px;padding-inline:4px}
.chips.scroll::-webkit-scrollbar{display:none}

/* Cards */
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-4);padding:18px;box-shadow:var(--shadow);min-width:0}
.card.flat{box-shadow:none}
.card.tint{background:var(--accent-soft);border-color:transparent}
.card.pad-sm{padding:14px}
.card h3{margin-bottom:6px}
.card .meta,.meta{color:var(--muted);font-size:.9rem}
a.card{display:block;color:inherit;text-decoration:none}
a.card:hover{border-color:var(--accent)}
.card .ico{width:40px;height:40px;border-radius:12px;background:var(--accent-soft);color:var(--accent-text);display:grid;place-items:center;margin-bottom:12px}
.card .ico svg{width:22px;height:22px}
.card.feature{display:flex;flex-direction:column;gap:6px}
.card.feature p{color:var(--muted)}
.card.feature .foot{margin-top:auto;padding-top:10px}
.hero-card{background:linear-gradient(135deg,var(--primary-darker),var(--primary));color:#fff;border-radius:var(--r-4);padding:24px;position:relative;overflow:hidden}
.hero-card .eyebrow{color:#C7D4EA}
.hero-card h2,.hero-card h1{font-family:var(--serif);color:#fff;margin:6px 0 8px}
.hero-card h2{font-size:1.6rem}
.hero-card p{color:#E1E9F6;max-width:56ch}
.hero-card a{color:#fff}
.hero-card .btn.primary{background:#fff;color:var(--primary-darker)}
.hero-card .btn.ghost{color:#fff;border-color:rgba(255,255,255,.4)}
.hero-card .chip{background:rgba(255,255,255,.16);color:#fff}
.hero-card .art{position:absolute;right:-30px;bottom:-40px;width:220px;height:220px;opacity:.16;pointer-events:none}
.stat{display:flex;flex-direction:column;gap:2px;text-decoration:none;color:inherit}
.stat b{font-size:1.5rem;font-family:var(--serif);font-variant-numeric:tabular-nums;line-height:1.1}
.stat span{color:var(--muted);font-size:.85rem}
.progress{height:6px;border-radius:999px;background:var(--surface2);overflow:hidden}
.progress i{display:block;height:100%;background:var(--accent);border-radius:999px}

/* Lists / items */
.list{display:flex;flex-direction:column;gap:10px}
.item{display:flex;gap:12px;align-items:flex-start;padding:12px 14px;border:1px solid var(--line);border-radius:var(--r-2);background:var(--surface);text-decoration:none;color:inherit;min-width:0}
a.item:hover,.item.link:hover{border-color:var(--accent)}
.item .num{font-family:var(--serif);font-weight:700;color:var(--accent-text);min-width:3ch;font-variant-numeric:tabular-nums}
.item .body{flex:1;min-width:0}
.item .title{font-weight:600;display:block}
.item .sub{color:var(--muted);font-size:.9rem;display:block}
.item .end{flex:none;display:flex;gap:6px;align-items:center}
.item.compact{padding:8px 12px}
.kv{display:grid;grid-template-columns:auto 1fr;gap:6px 14px;font-size:.95rem;margin:0}
.kv dt{color:var(--muted);font-weight:600} .kv dd{margin:0}

/* Tabs */
.tabs{display:flex;gap:4px;border-bottom:1px solid var(--line);overflow-x:auto;scrollbar-width:none;margin-bottom:20px}
.tabs::-webkit-scrollbar{display:none}
.tabs a,.tabs button{flex:none;padding:10px 14px;min-height:44px;border:0;border-bottom:3px solid transparent;background:transparent;color:var(--muted);font-weight:600;text-decoration:none;cursor:pointer;white-space:nowrap;border-radius:0}
.tabs a:hover,.tabs button:hover{color:var(--text)}
.tabs a[aria-current="page"],.tabs button[aria-selected="true"]{color:var(--accent-text);border-bottom-color:var(--accent)}
.tabs .count{margin-left:6px;background:var(--surface2);border-radius:999px;padding:0 7px;font-size:.75rem}
[role="tabpanel"][hidden]{display:none}

/* Empty state, notices */
.empty{text-align:center;padding:40px 20px;border:1px dashed var(--line);border-radius:var(--r-4);color:var(--muted);background:var(--surface)}
.empty .ico{width:48px;height:48px;margin:0 auto 10px;color:var(--accent);opacity:.85;font-size:2rem;line-height:48px}
.empty .ico svg{width:48px;height:48px}
.empty h3,.empty h1{color:var(--text);margin-bottom:6px}
.empty.page h1{font-size:1.3rem}
.empty p{max-width:46ch;margin:0 auto 14px}
.empty .cta{display:flex;justify-content:center;gap:8px;flex-wrap:wrap}
.notice{padding:12px 16px;border-radius:12px;background:var(--warn-soft);color:var(--warn);font-size:.92rem;display:flex;gap:10px;align-items:flex-start}
.notice.info{background:var(--accent-soft);color:var(--accent-text)}
.notice.ok{background:var(--ok-soft);color:var(--ok)}
.notice.bad{background:var(--bad-soft);color:var(--bad)}
.notice svg{width:20px;height:20px;flex:none;margin-top:2px}
.notice a{color:inherit}
.ai-banner{display:flex;gap:10px;align-items:flex-start;padding:10px 14px;border-radius:12px;background:var(--ai-soft);color:var(--ai);border:1px solid transparent;font-size:.9rem;font-weight:600}
.ai-banner svg{width:20px;height:20px;flex:none;margin-top:1px}
.offline{padding:28px 20px;text-align:center;border-radius:var(--r-4);background:var(--surface);border:1px solid var(--line)}

/* Forms */
.form{display:flex;flex-direction:column;gap:16px}
.field{display:flex;flex-direction:column;gap:6px;min-width:0}
.field label,.field > .label{font-weight:600;font-size:.92rem}
.field .help{color:var(--muted);font-size:.85rem}
.field .error{color:var(--bad);font-size:.88rem;font-weight:600}
.field.invalid input,.field.invalid select,.field.invalid textarea{border-color:var(--bad)}
.form-error{padding:12px 14px;border-radius:12px;background:var(--bad-soft);color:var(--bad);font-weight:600}
.form-error:empty{display:none}
.form-actions{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-top:4px}
.req{color:var(--bad)}
input:not([type=checkbox]):not([type=radio]):not([type=range]):not([type=file]),select,textarea{font:inherit;color:var(--text);background:var(--surface);border:1px solid var(--gray-300);border-radius:12px;padding:10px 12px;min-height:44px;width:100%;max-width:100%}
select{appearance:none;-webkit-appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%238A8A8A' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 10px center;background-size:18px;padding-right:36px}
textarea{min-height:110px;resize:vertical;line-height:1.5}
input:focus,select:focus,textarea:focus{outline:3px solid var(--accent);outline-offset:1px;border-color:var(--accent)}
input[type=file]{padding:8px 0}
.check{display:flex;gap:10px;align-items:flex-start;padding:8px 0;cursor:pointer;min-height:44px;font-weight:500}
.check input{width:20px;height:20px;margin:3px 0 0;accent-color:var(--accent);flex:none}
.toggle{display:inline-flex;align-items:center;gap:10px;cursor:pointer;font-weight:600;min-height:44px}
.toggle input{appearance:none;-webkit-appearance:none;width:44px;height:26px;border-radius:999px;background:var(--gray-300);position:relative;cursor:pointer;flex:none;margin:0;padding:0;min-height:0;border:0}
.toggle input::after{content:"";position:absolute;top:3px;left:3px;width:20px;height:20px;border-radius:50%;background:#fff;transition:transform .15s}
.toggle input:checked{background:var(--accent)} .toggle input:checked::after{transform:translateX(18px)}
.inline-form{display:flex;gap:8px;flex-wrap:wrap;align-items:flex-end}
.inline-form .field{flex:1;min-width:160px}

/* Tables */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:12px;background:var(--surface);max-width:100%}
table{border-collapse:collapse;width:100%;font-size:.92rem;font-variant-numeric:tabular-nums}
th,td{text-align:left;padding:8px 12px;border-bottom:1px solid var(--line);vertical-align:top}
th{background:var(--surface2);font-weight:700;white-space:nowrap}
tr:last-child td{border-bottom:0}
td.num,th.num{text-align:right}

/* Details / accordions */
details{border:1px solid var(--line);border-radius:12px;background:var(--surface)}
details+details{margin-top:8px}
details>summary{cursor:pointer;padding:12px 14px;font-weight:600;list-style:none;display:flex;justify-content:space-between;align-items:center;gap:8px;min-height:44px}
details>summary::-webkit-details-marker{display:none}
details>summary::after{content:"+";color:var(--muted);font-size:1.2rem;flex:none}
details[open]>summary::after{content:"–"}
details>.inner{padding:0 14px 14px}

/* Teach player steps */
.steps{display:flex;gap:6px;overflow-x:auto;padding-bottom:6px;scrollbar-width:thin;margin-inline:-4px;padding-inline:4px}
.steps button{flex:none;display:flex;flex-direction:column;align-items:flex-start;gap:2px;min-width:120px;max-width:180px;padding:8px 12px;border-radius:12px;border:1px solid var(--line);background:var(--surface);cursor:pointer;text-align:left;min-height:44px;color:var(--text)}
.steps button small{color:var(--muted);font-size:.7rem;text-transform:uppercase;letter-spacing:.05em}
.steps button[aria-current="step"]{border-color:var(--accent);background:var(--accent-soft)}
.steps button.done small::before{content:"\2713  ";color:var(--ok)}
.steps button.hidden-step{opacity:.5;text-decoration:line-through}
.step{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-4);padding:24px;margin-top:16px}
.step .kind{display:inline-flex;align-items:center;gap:8px;font-size:.78rem;font-weight:700;text-transform:uppercase;letter-spacing:.06em;padding:4px 10px;border-radius:999px;background:var(--surface2);color:var(--muted)}
.step .kind.math{background:var(--math-soft);color:var(--math)} .step .kind.data{background:var(--data-soft);color:var(--data)} .step .kind.ai{background:var(--ai-soft);color:var(--ai)} .step .kind.career{background:var(--career-soft);color:var(--career)}
.step h2{font-family:var(--serif);font-size:1.45rem;margin:10px 0 14px}
.step .md{font-size:1.05rem}
.step-foot{display:flex;justify-content:space-between;gap:8px;margin-top:20px;flex-wrap:wrap}
.step-note{margin-top:14px;padding:10px 12px;border-left:3px solid var(--ai);background:var(--ai-soft);border-radius:0 10px 10px 0}
.teacher-only{border:1px dashed var(--accent);border-radius:12px;padding:12px 14px;background:var(--accent-soft);margin-top:14px}
.teacher-only .eyebrow{color:var(--accent-text)}
.reveal{margin-top:8px;padding:10px 12px;border-left:3px solid var(--ok);background:var(--ok-soft);border-radius:0 10px 10px 0;font-size:.95rem}

/* Lesson header */
.lesson-head{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-4);padding:22px;margin-bottom:20px}
.lesson-head h1{font-family:var(--serif);font-size:clamp(1.5rem,2.4vw,2rem);margin:6px 0 10px}
.lesson-head .actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:16px}
.crumbs{display:flex;flex-wrap:wrap;gap:6px;font-size:.9rem;color:var(--muted);margin-bottom:8px}
.crumbs a{color:var(--muted);text-decoration:none}
.crumbs a:hover{color:var(--text);text-decoration:underline}
.split{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,320px);gap:24px;align-items:start}
@media (max-width:1023px){.split{grid-template-columns:minmax(0,1fr)}}
.aside .card+.card{margin-top:16px}
.sticky{position:sticky;top:calc(var(--topbar) + 12px)}

/* Rendered markdown (.md) */
.md{max-width:72ch;line-height:1.6;min-width:0;overflow-wrap:anywhere}
.md.wide{max-width:none}
.md h1,.md h2,.md h3,.md h4{font-family:var(--serif);margin:1.4em 0 .5em;line-height:1.25}
.md h1{font-size:1.6rem} .md h2{font-size:1.35rem} .md h3{font-size:1.15rem} .md h4{font-size:1rem;font-family:var(--font)}
.md > :first-child{margin-top:0}
.md p{margin:0 0 .85em}
.md ol,.md ul{margin:.4em 0 .9em 1.5em;padding:0}
.md li+li{margin-top:.3em}
.md li>p{margin:0}
.md strong{font-weight:700}
.md a{text-decoration:underline}
.md code{font-family:var(--mono);font-size:.9em;background:var(--surface2);padding:1px 5px;border-radius:5px}
.md pre{font-family:var(--mono);font-size:.85rem;background:var(--surface2);padding:12px 14px;border-radius:10px;overflow-x:auto;white-space:pre-wrap;margin:0 0 1em}
.md pre code{background:transparent;padding:0}
.md blockquote{margin:0 0 1em;padding:8px 16px;border-left:4px solid var(--accent);background:var(--accent-soft);border-radius:0 10px 10px 0;color:var(--text)}
.md blockquote p:last-child{margin-bottom:0}
.md .table-scroll{overflow-x:auto;max-width:100%;margin:0 0 1em;border-radius:10px}
.md .table-scroll:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.md table{width:max-content;max-width:100%;margin:0;border:1px solid var(--line);border-radius:10px;font-size:.92rem}
.md .table-scroll table{margin:0}
.md th,.md td{padding:7px 10px}
.md hr{margin:1.5em 0}
.md img{border-radius:10px}
.md input[type=checkbox]{width:16px;height:16px;min-height:0;margin-right:6px}
.md .katex-display{overflow-x:auto;overflow-y:hidden;padding:4px 0;margin:.6em 0}
.md .katex{font-size:1.05em}
.katex-display>.katex{white-space:normal}

/* Toasts */
.toasts{position:fixed;left:50%;transform:translateX(-50%);bottom:calc(var(--tabbar) + 16px);z-index:80;display:flex;flex-direction:column;gap:8px;width:min(480px,calc(100vw - 32px));pointer-events:none}
@media (min-width:768px){.toasts{bottom:24px}}
.toast{display:flex;gap:10px;align-items:center;background:var(--navy);color:#fff;padding:10px 10px 10px 16px;border-radius:14px;box-shadow:var(--shadow);animation:up .2s ease-out;pointer-events:auto}
.toast p{flex:1;font-weight:500}
.toast .btn{min-height:36px;padding:0 12px;background:rgba(255,255,255,.14);color:#fff;border-radius:10px;font-size:.9rem}
.toast .iconbtn{color:#fff;width:36px;height:36px}
.toast .iconbtn:hover{background:rgba(255,255,255,.14);color:#fff}
.toast.bad{background:var(--danger)}
@keyframes up{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
@keyframes spin{to{transform:rotate(360deg)}}

/* Modal / sheet */
.backdrop{position:fixed;inset:0;background:rgba(13,27,42,.55);z-index:70;display:flex;align-items:flex-end;justify-content:center}
@media (min-width:768px){.backdrop{align-items:center;padding:24px}}
.modal{background:var(--surface);color:var(--text);border-radius:20px 20px 0 0;width:100%;max-height:92vh;overflow:auto;padding:22px;box-shadow:var(--shadow);min-width:0}
@media (min-width:768px){.modal{border-radius:20px;max-width:640px}.modal.wide{max-width:880px}}
.modal-head{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:14px}
.modal-head h2{font-size:1.2rem}
.modal-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:18px;flex-wrap:wrap}
.sheet{position:fixed;top:0;right:0;bottom:0;width:min(480px,100vw);background:var(--surface);border-left:1px solid var(--line);box-shadow:var(--shadow);z-index:75;display:flex;flex-direction:column;transform:translateX(0);animation:slide .2s ease-out}
.sheet .sheet-head{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:14px 16px;border-bottom:1px solid var(--line)}
.sheet .sheet-body{flex:1;overflow:auto;padding:16px}
.sheet .sheet-foot{padding:12px 16px;border-top:1px solid var(--line)}
@keyframes slide{from{transform:translateX(40px);opacity:0}to{transform:none;opacity:1}}

/* Spinner */
.spinner{display:inline-block;width:22px;height:22px;border:3px solid var(--line);border-top-color:var(--accent);border-radius:50%;animation:spin .8s linear infinite;vertical-align:middle}
.loading-block{display:flex;align-items:center;justify-content:center;gap:10px;padding:32px;color:var(--muted)}

/* Pager */
.pager{display:flex;align-items:center;justify-content:center;gap:8px;margin-top:20px;flex-wrap:wrap}
.pager .status{color:var(--muted);font-size:.9rem;padding:0 8px}

/* Thread / community bits */
.thread-reply{display:flex;gap:10px;padding:12px 0;border-top:1px solid var(--line)}
.thread-reply .body{flex:1;min-width:0}
.thread-reply .who{font-weight:600;font-size:.92rem}
.thread-reply .when{color:var(--muted);font-size:.82rem}
.thread-reply.child{margin-left:40px;border-top:1px dashed var(--line)}
.pill-count{background:var(--accent);color:var(--accent-ink);font-size:.7rem;border-radius:999px;padding:1px 6px;font-weight:700}
.prompt-list{list-style:none;margin:12px 0 0;padding:0;display:flex;flex-direction:column;gap:8px}
.prompt-list li{padding:10px 14px;border-radius:12px;background:var(--surface2);border-left:3px solid var(--accent)}
.aibubble{font-size:.95rem;background:var(--ai-soft);color:var(--text);border-radius:14px 14px 14px 4px;padding:14px;margin-top:10px;max-width:100%}
.aibubble .from{font-weight:700;color:var(--ai);font-size:.78rem;text-transform:uppercase;letter-spacing:.06em;margin-bottom:6px}
.mebubble{background:var(--accent-soft);color:var(--text);border-radius:14px 14px 4px 14px;padding:12px 14px;margin-top:10px;margin-left:auto;max-width:85%}

/* Course tiles / grade tiles */
.tiles{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:12px}
.tile{display:flex;flex-direction:column;gap:4px;padding:16px;border-radius:var(--r-2);background:var(--surface);border:1px solid var(--line);text-decoration:none;color:inherit;min-height:96px}
.tile:hover{border-color:var(--accent)}
.tile b{font-family:var(--serif);font-size:1.3rem}
.tile span{color:var(--muted);font-size:.85rem}
.tile.on{border-color:var(--accent);background:var(--accent-soft)}

/* Pacing grid */
.pacing-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(140px,1fr));gap:10px}
.week{border:1px solid var(--line);border-radius:12px;background:var(--surface);min-height:110px;padding:8px}
.week .wk{font-size:.75rem;color:var(--muted);font-weight:700;text-transform:uppercase;letter-spacing:.05em;margin-bottom:6px;display:flex;justify-content:space-between}
.week .les{display:block;font-size:.82rem;padding:6px 8px;border-radius:8px;margin-top:4px;background:var(--accent-soft);color:var(--accent-text);text-decoration:none;font-weight:600;line-height:1.25}
.week .les.over{background:var(--warn-soft);color:var(--warn)}
.legend{display:flex;gap:14px;flex-wrap:wrap;font-size:.85rem;color:var(--muted)}
.legend i{display:inline-block;width:12px;height:12px;border-radius:3px;margin-right:6px;vertical-align:-1px}

/* ---------- 5. Utilities ---------- */
.row{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.row.between{justify-content:space-between}
.row.end{justify-content:flex-end}
.row.center{justify-content:center}
.stack{display:flex;flex-direction:column;gap:12px}
.grid{display:grid;gap:16px;grid-template-columns:repeat(auto-fill,minmax(260px,1fr))}
.grid-2{display:grid;gap:16px;grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{display:grid;gap:16px;grid-template-columns:repeat(3,minmax(0,1fr))}
@media (max-width:1023px){.grid-3{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:767px){.grid-2,.grid-3{grid-template-columns:minmax(0,1fr)}}
.muted{color:var(--muted)}
.small{font-size:.88rem}
.tiny{font-size:.78rem}
.bold{font-weight:700}
.nowrap{white-space:nowrap}
.truncate{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.mt-1{margin-top:var(--s-1)} .mt-2{margin-top:var(--s-2)} .mt-3{margin-top:var(--s-3)} .mt-4{margin-top:var(--s-4)} .mt-5{margin-top:var(--s-5)} .mt-6{margin-top:var(--s-6)}
.mb-1{margin-bottom:var(--s-1)} .mb-2{margin-bottom:var(--s-2)} .mb-3{margin-bottom:var(--s-3)} .mb-4{margin-bottom:var(--s-4)} .mb-5{margin-bottom:var(--s-5)}
.ml-auto{margin-left:auto}
.w-100{width:100%}
.hide-sm{display:initial}
@media (max-width:767px){.hide-sm{display:none!important}.only-sm{display:initial}}
@media (min-width:768px){.only-sm{display:none!important}}
.text-center{text-align:center}
.ok-text{color:var(--ok)} .warn-text{color:var(--warn)} .bad-text{color:var(--bad)}
.prose{max-width:68ch;line-height:1.6}
.prose p+p,.prose ul+p,.prose p+ul{margin-top:.75em}
.prose ul,.prose ol{margin:.5em 0 .5em 1.4em;padding:0}
.prose h2{margin-top:1.6em;margin-bottom:.5em;font-family:var(--serif)}
.prose h3{margin-top:1.2em;margin-bottom:.4em}
.prose li+li{margin-top:.25em}

/* ---------- 6. Print ---------- */
@media print{
  body{display:block;background:#fff;color:#000}
  .tl-sidebar,.tl-topbar,.tl-tabbar,.toasts,.backdrop,.sheet,.skip-link,.no-print,.ai-banner,.btn,.pager,.tabs{display:none!important}
  main#main{padding:0;max-width:none;width:auto}
  .card,.item,.step,.lesson-head,.table-wrap{box-shadow:none;border-color:#bbb;break-inside:avoid}
  .md{max-width:none}
  a{color:#000;text-decoration:none}
  .print-only{display:block!important}
  .chip{border:1px solid #888;color:#000;background:#fff}
  .chip.major{background:#000;color:#fff}
  @page{margin:16mm}
}
.print-only{display:none}

/* === community & admin === */
/* thread list rows */
.thread-item{align-items:flex-start}
.thread-item .avatar{margin-top:2px}
.thread-item .meta-row{display:flex;flex-wrap:wrap;gap:6px 8px;align-items:center;margin-top:6px;font-size:.85rem;color:var(--muted)}
.thread-item .meta-row .chip{font-size:.72rem;padding:1px 8px}
.thread-item .excerpt{color:var(--muted);font-size:.92rem;margin-top:4px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.thread-item .counts{display:flex;gap:10px;flex:none;color:var(--muted);font-size:.85rem;align-items:center;white-space:nowrap}
.thread-item .counts svg{width:16px;height:16px;margin-right:3px;vertical-align:-3px}
.tag{display:inline-block;font-size:.75rem;color:var(--accent-text);background:var(--accent-soft);border-radius:6px;padding:1px 6px}
.verified-ico{display:inline-grid;place-items:center;width:16px;height:16px;border-radius:50%;background:var(--ok);color:#fff;vertical-align:-3px;margin-left:3px}
.verified-ico svg{width:11px;height:11px;stroke-width:3}
.filter-bar{display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin-bottom:14px}
.filter-bar .search{flex:1 1 220px;min-width:0}
.filter-bar select{width:auto;min-width:140px}

/* thread page */
.thread-head{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-4);padding:22px;margin-bottom:16px}
.thread-head h1{font-family:var(--serif);font-size:clamp(1.35rem,2vw,1.8rem);margin:8px 0 10px}
.thread-head .byline{display:flex;align-items:center;gap:10px;color:var(--muted);font-size:.92rem;flex-wrap:wrap}
.thread-head .byline a{font-weight:600;color:var(--text);text-decoration:none}
.thread-head .actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:16px}
.thread-reply .avatar{flex:none}
.thread-reply .reply-body{margin-top:4px}
.thread-reply .reply-foot{display:flex;flex-wrap:wrap;gap:4px 8px;align-items:center;margin-top:6px}
.thread-reply.answer{background:var(--ok-soft);border-radius:12px;padding:12px;border-top:0;margin-top:8px}
.thread-reply.answer .child{margin-left:0}
.reply-form{margin-top:10px}
.reply-form textarea{min-height:88px}
@media (max-width:767px){.thread-reply.child{margin-left:20px}}
.helpful-btn[aria-pressed="true"]{color:var(--ok);background:var(--ok-soft);border-color:transparent}

/* people */
.person-card{display:flex;flex-direction:column;gap:10px;align-items:flex-start}
.person-card .who{display:flex;gap:12px;align-items:center;min-width:0;width:100%}
.person-card .who .nm{min-width:0}
.person-card .who .nm a{font-weight:700;color:var(--text);text-decoration:none}
.person-card .who .nm .sub{display:block;color:var(--muted);font-size:.85rem}
.person-card .chips{gap:4px}
.person-card .chips .chip{font-size:.72rem;padding:1px 8px}
.profile-head{display:flex;gap:18px;align-items:flex-start;flex-wrap:wrap}
.profile-head .info{flex:1;min-width:220px}
.profile-head h1{font-family:var(--serif)}
.profile-stats{display:flex;gap:22px;flex-wrap:wrap;margin-top:12px}
.avatar-row{display:flex;flex-wrap:wrap;gap:6px}
.avatar-row .avatar{width:36px;height:36px;font-size:.8rem}

/* events */
.event-item .date-block{flex:none;width:58px;border-radius:12px;background:var(--accent-soft);color:var(--accent-text);text-align:center;padding:6px 4px;line-height:1.1}
.event-item .date-block b{display:block;font-family:var(--serif);font-size:1.4rem}
.event-item .date-block span{display:block;font-size:.7rem;text-transform:uppercase;letter-spacing:.06em;font-weight:700}
.event-item.past .date-block{background:var(--surface2);color:var(--muted)}
.event-item .end{flex-direction:column;align-items:flex-end;gap:4px}
@media (max-width:767px){.event-item{flex-wrap:wrap}.event-item .end{width:100%;flex-direction:row;justify-content:flex-start;padding-left:70px}}
.chip.cancelled{background:var(--bad-soft);color:var(--bad)}

/* resources */
.res-card{display:flex;flex-direction:column;gap:8px}
.res-card .kind-ico{width:36px;height:36px;border-radius:10px;display:grid;place-items:center;background:var(--accent-soft);color:var(--accent-text);flex:none}
.res-card .kind-ico svg{width:20px;height:20px}
.res-card .top{display:flex;gap:10px;align-items:flex-start}
.res-card .top h3{margin:0;font-size:1.02rem}
.res-card .top h3 a{color:inherit;text-decoration:none}
.res-card .foot{display:flex;flex-wrap:wrap;gap:6px 12px;align-items:center;color:var(--muted);font-size:.85rem;margin-top:auto}
.stars{display:inline-flex;gap:1px;color:var(--warn);vertical-align:-2px}
.stars svg{width:15px;height:15px}
.stars svg.off{opacity:.25}
.star-input{display:inline-flex;gap:2px}
.star-input button{width:40px;height:40px;border:0;background:transparent;color:var(--gray-300);cursor:pointer;border-radius:8px;display:grid;place-items:center;padding:0}
.star-input button svg{width:26px;height:26px}
.star-input button.on,.star-input button:hover{color:var(--warn)}
.rating-row{display:flex;gap:10px;padding:10px 0;border-top:1px solid var(--line)}
.rating-row .body{flex:1;min-width:0}
.rating-row .who{font-weight:600;font-size:.92rem}
.step-dots{display:flex;gap:6px;align-items:center;margin-bottom:16px;flex-wrap:wrap}
.step-dots span{display:inline-flex;align-items:center;gap:6px;font-size:.85rem;color:var(--muted);font-weight:600}
.step-dots span i{display:inline-grid;place-items:center;width:24px;height:24px;border-radius:50%;background:var(--surface2);font-style:normal;font-size:.75rem}
.step-dots span[aria-current="step"]{color:var(--accent-text)} .step-dots span[aria-current="step"] i{background:var(--accent);color:var(--accent-ink)}
.step-dots span.done i{background:var(--ok);color:#fff}
.picker{position:relative}
.picker .picker-list{position:absolute;left:0;right:0;top:calc(100% + 4px);background:var(--surface);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);z-index:30;max-height:260px;overflow:auto;padding:4px}
.picker .picker-list button{display:block;width:100%;text-align:left;border:0;background:transparent;padding:8px 10px;border-radius:8px;cursor:pointer;min-height:40px}
.picker .picker-list button:hover,.picker .picker-list button:focus{background:var(--surface2)}
.picker .picker-list small{display:block;color:var(--muted)}
.drop-zone{border:2px dashed var(--line);border-radius:14px;padding:22px;text-align:center;color:var(--muted);background:var(--surface)}
.drop-zone.over{border-color:var(--accent);background:var(--accent-soft)}
.drop-zone b{color:var(--text)}
.kind-choice{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
.kind-choice button{display:flex;flex-direction:column;align-items:flex-start;gap:6px;padding:16px;border-radius:14px;border:1px solid var(--line);background:var(--surface);cursor:pointer;text-align:left;min-height:88px;color:var(--text)}
.kind-choice button[aria-pressed="true"]{border-color:var(--accent);background:var(--accent-soft)}
.kind-choice button svg{width:24px;height:24px;color:var(--accent-text)}
.kind-choice button small{color:var(--muted)}
@media (max-width:480px){.kind-choice{grid-template-columns:minmax(0,1fr)}}

/* messages */
.msg-layout{display:grid;grid-template-columns:minmax(0,300px) minmax(0,1fr);gap:16px;align-items:start;min-height:60vh}
.msg-list{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-3);overflow:hidden}
.msg-list a{display:flex;gap:10px;padding:10px 12px;align-items:center;text-decoration:none;color:inherit;border-bottom:1px solid var(--line);min-height:56px}
.msg-list a:last-child{border-bottom:0}
.msg-list a:hover{background:var(--surface2)}
.msg-list a[aria-current="page"]{background:var(--accent-soft)}
.msg-list .who{flex:1;min-width:0}
.msg-list .who b{display:block;font-size:.95rem}
.msg-list .who span{display:block;color:var(--muted);font-size:.82rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.msg-list .when{color:var(--muted);font-size:.75rem;flex:none}
.msg-thread{display:flex;flex-direction:column;background:var(--surface);border:1px solid var(--line);border-radius:var(--r-3);min-height:60vh;max-height:calc(100vh - var(--topbar) - 80px)}
.msg-head{display:flex;gap:10px;align-items:center;padding:10px 14px;border-bottom:1px solid var(--line)}
.msg-head b a{color:inherit;text-decoration:none}
.msg-body{flex:1;overflow:auto;padding:14px;display:flex;flex-direction:column;gap:8px}
.msg-bubble{max-width:78%;background:var(--surface2);border-radius:14px 14px 14px 4px;padding:8px 12px;align-self:flex-start;font-size:.95rem;white-space:pre-wrap}
.msg-bubble.mine{background:var(--accent-soft);color:var(--text);border-radius:14px 14px 4px 14px;align-self:flex-end}
.msg-bubble .when{display:block;font-size:.72rem;color:var(--muted);margin-top:3px}
.msg-compose{display:flex;gap:8px;padding:10px;border-top:1px solid var(--line);align-items:flex-end}
.msg-compose textarea{min-height:44px;max-height:160px;flex:1}
@media (max-width:767px){
  .msg-layout{grid-template-columns:minmax(0,1fr)}
  .msg-layout.has-thread .msg-list{display:none}
  .msg-layout:not(.has-thread) .msg-thread{display:none}
  .msg-thread{max-height:none;min-height:calc(100vh - var(--topbar) - var(--tabbar) - 60px)}
}

/* notifications */
.notif{display:flex;gap:12px;align-items:flex-start;padding:12px 14px;border:1px solid var(--line);border-radius:12px;background:var(--surface)}
.notif.unread{border-left:4px solid var(--accent)}
.notif .k-ico{width:36px;height:36px;border-radius:10px;background:var(--surface2);color:var(--muted);display:grid;place-items:center;flex:none}
.notif.unread .k-ico{background:var(--accent-soft);color:var(--accent-text)}
.notif .k-ico svg{width:18px;height:18px}
.notif .body{flex:1;min-width:0}
.notif .body a{font-weight:600;color:var(--text);text-decoration:none}
.notif .body p{color:var(--muted);font-size:.9rem}
.notif .when{color:var(--muted);font-size:.8rem;white-space:nowrap}

/* AI page */
.ai-layout{display:grid;grid-template-columns:minmax(0,260px) minmax(0,1fr);gap:16px;align-items:start}
.ai-convos{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-3);overflow:hidden}
.ai-convos .hd{padding:10px 12px;border-bottom:1px solid var(--line)}
.ai-convos .list-scroll{max-height:60vh;overflow:auto}
.ai-convos a{display:flex;gap:8px;padding:10px 12px;border-bottom:1px solid var(--line);text-decoration:none;color:inherit;align-items:center;min-height:48px}
.ai-convos a:last-child{border-bottom:0}
.ai-convos a:hover{background:var(--surface2)}
.ai-convos a[aria-current="page"]{background:var(--accent-soft)}
.ai-convos .t{flex:1;min-width:0}
.ai-convos .t b{display:block;font-size:.92rem;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.ai-convos .t span{display:block;color:var(--muted);font-size:.78rem}
.ai-convos .del{width:36px;height:36px}
.ai-chat{display:flex;flex-direction:column;gap:10px}
.ai-ctx{display:flex;gap:10px;align-items:center;padding:10px 14px;border-radius:12px;background:var(--surface);border:1px solid var(--line);flex-wrap:wrap}
.ai-ctx .t{flex:1;min-width:160px}
.ai-ctx .t a{font-weight:600;text-decoration:none}
.ai-msgs{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-3);padding:14px;min-height:320px;max-height:calc(100vh - 340px);overflow:auto;display:flex;flex-direction:column}
.ai-msgs .aibubble,.ai-msgs .mebubble{position:relative}
.ai-msgs .aibubble .md{max-width:none;font-size:.95rem}
.ai-msgs .aibubble .md>:last-child{margin-bottom:0}
.ai-msgs .copy{position:absolute;top:8px;right:8px;width:32px;height:32px;opacity:.6}
.ai-msgs .copy:hover{opacity:1}
.ai-msgs .mebubble{white-space:pre-wrap}
.ai-msgs .thinking{display:flex;gap:6px;align-items:center;color:var(--ai);font-size:.9rem;margin-top:10px}
.ai-compose{display:flex;gap:8px;align-items:flex-end}
.ai-compose textarea{flex:1;min-height:56px;max-height:200px}
.ai-actions{display:flex;gap:6px;flex-wrap:nowrap;overflow-x:auto;scrollbar-width:none;padding-bottom:4px}
.ai-actions::-webkit-scrollbar{display:none}
.ai-actions button.chip{flex:none}
.ai-usage{color:var(--muted);font-size:.82rem;text-align:right}
@media (max-width:1023px){.ai-layout{grid-template-columns:minmax(0,1fr)}.ai-convos .list-scroll{max-height:200px}.ai-convos details>summary{list-style:none}}

/* register */
.reg-form{gap:20px}
.reg-panel{display:flex;flex-direction:column;gap:16px;padding:22px 20px}
.reg-panel > h2{font-family:var(--serif);font-size:1.35rem;display:flex;align-items:baseline;gap:10px;padding-bottom:12px;border-bottom:1px solid var(--line)}
.reg-num{font-family:var(--font);font-size:.8rem;font-weight:700;letter-spacing:.08em;color:var(--accent-text);background:var(--accent-soft);border-radius:999px;padding:3px 9px;line-height:1.2}
fieldset.field{border:0;padding:0;margin:0;min-width:0}
fieldset.field > legend{font-weight:600;font-size:.92rem;padding:0;margin-bottom:6px}
.check-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:0 12px}
.check-grid .check{padding:6px 0}
.field .error:empty{display:none}
.field.invalid .check input{outline:2px solid var(--bad);outline-offset:2px;border-radius:4px}
.reg-steps{margin:10px 0 0;padding-left:1.3em;display:flex;flex-direction:column;gap:12px}
.reg-steps li::marker{font-weight:700;color:var(--accent-text)}
#reg-status:empty{display:none}

/* me / profile */
.course-checks{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:0 12px}
.course-checks .check{min-height:40px;padding:4px 0}

/* admin */
.stat-cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(140px,1fr));gap:10px;margin-bottom:20px}
.stat-cards .stat{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:10px 12px}
.stat-cards .stat.warn{border-color:var(--warn)}
.stat-cards .stat.bad{border-color:var(--bad)}
tr.missing td{background:var(--bad-soft);color:var(--bad)}
td .btn.sm,td select,td .toggle{margin:0}
td select{min-height:36px;padding:4px 30px 4px 8px;width:auto;font-size:.88rem}
.admin-table td{vertical-align:middle}
.admin-table .row{gap:6px;flex-wrap:nowrap}
.mod-item{display:flex;gap:12px;align-items:flex-start;padding:12px 14px;border:1px solid var(--line);border-radius:12px;background:var(--surface);flex-wrap:wrap}
.mod-item .body{flex:1;min-width:200px}
.mod-item .acts{display:flex;gap:6px;flex-wrap:wrap}
.checklist li{display:flex;gap:8px;align-items:flex-start;padding:6px 0}
.checklist li svg{width:20px;height:20px;flex:none}
.checklist li.ok{color:var(--ok)} .checklist li.bad{color:var(--bad)} .checklist li.warn{color:var(--warn)}
.checklist li span{color:var(--text)}
.copy-box{display:flex;gap:8px;align-items:center}
.copy-box input{font-family:var(--mono);font-size:.85rem}

/* === lessons & tools === */
.lesson-head .chips .chip{white-space:normal;text-align:left}
.item .num svg,.item .end svg,.crumbs svg{width:20px;height:20px}
h1 svg,h2 svg,h3 svg,.sheet-head svg,.small svg,.step-note svg,.quantile-note svg{width:1.1em;height:1.1em}
.unit-block{margin-top:24px}
.unit-block .unit-head{display:flex;flex-wrap:wrap;align-items:baseline;justify-content:space-between;gap:6px 16px;margin-bottom:10px}
.unit-block .unit-head h2{font-family:var(--serif);font-size:1.25rem}
.unit-block .unit-head h2 a{color:inherit;text-decoration:none}
.unit-block .unit-head h2 a:hover{text-decoration:underline}
.unit-block .big-idea{color:var(--muted);font-size:.95rem;max-width:70ch}
.lesson-row .std{display:flex;flex-wrap:wrap;gap:4px;margin-top:6px}
.lesson-row .end .btn{min-height:36px}
.item .sub.clamp{display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.search-box{display:flex;gap:8px;align-items:center;max-width:520px}
.search-box input{flex:1}
.jump{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:16px}
.jump a{font-size:.85rem;font-weight:600;text-decoration:none;padding:6px 10px;border-radius:999px;background:var(--surface2);color:var(--accent-text);min-height:32px;display:inline-flex;align-items:center}
.section-card{margin-top:16px}
.section-card>summary h2,.section-card h2.sec-title{font-family:var(--serif);font-size:1.2rem;font-weight:600;margin:0}
.section-card>summary .letter{font-family:var(--serif);color:var(--muted);font-weight:700;margin-right:8px;min-width:2ch;display:inline-block}
.section-card>.inner{padding-top:8px}
.sec-static{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:14px;margin-top:16px}
.sec-static h2.sec-title{margin-bottom:10px}
.obj-list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:8px}
.obj-list li{padding:8px 12px;border-left:3px solid var(--line);background:var(--surface2);border-radius:0 10px 10px 0}
.obj-list li .chip{margin-right:6px;vertical-align:middle}
.quantile-note{font-size:.9rem;color:var(--muted);margin-top:8px}
.lesson-foot{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;margin-top:32px;padding-top:16px;border-top:1px solid var(--line)}
.lesson-foot a{flex:1;min-width:200px;max-width:48%}
.lesson-foot a .sub{display:block}
@media (max-width:767px){.lesson-foot a{max-width:100%}}
/* AI drawer */
.sheet.bottom{width:min(520px,100vw)}
@media (max-width:1199px){.sheet.bottom{top:auto;left:0;right:0;width:100%;height:min(88vh,100%);border-left:0;border-top:1px solid var(--line);border-radius:20px 20px 0 0}}
.sheet .sheet-head h2{font-size:1.1rem}
.sheet .chips .chip{cursor:pointer}
.sheet .sheet-foot textarea{min-height:72px}
.sheet .sheet-foot .row{margin-top:8px}
.aibubble .md{max-width:none;font-size:.95rem}
.aibubble .md>:last-child{margin-bottom:0}
.aibubble .acts{display:flex;gap:6px;flex-wrap:wrap;margin-top:10px}
.prompt-card{padding:12px 14px;border-radius:12px;background:var(--surface2);border-left:3px solid var(--accent);margin-top:8px}
.prompt-card pre{white-space:pre-wrap;font-family:inherit;font-size:.9rem;margin:6px 0 8px;max-height:160px;overflow:auto}
/* Teach player */
.teach-bar{display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:12px}
.teach-bar .progress{flex:1;min-width:120px}
.teach-bar .pos{color:var(--muted);font-size:.88rem;white-space:nowrap}
.teach-bar .ttl{min-width:0;flex:1 1 200px}
.teach-bar .ttl h1{display:block;font-size:1rem;font-weight:700;line-height:1.3;font-family:var(--font)}
@media (max-width:767px){.teach-bar .ttl{order:3;flex-basis:100%}}
.teach-layout{display:grid;grid-template-columns:minmax(0,1fr);gap:16px}
@media (min-width:1024px){.teach-layout{grid-template-columns:240px minmax(0,1fr)}.teach-layout .steps{flex-direction:column;overflow:visible;position:sticky;top:calc(var(--topbar) + 12px);margin:0;padding:0}.teach-layout .steps button{max-width:none;width:100%}}
.step-body .md{max-width:none}
.step-note .eyebrow{color:var(--ai)}
.teacher-off .teacher-only{display:none!important}
/* Adapt editor */
.adapt-step{display:flex;gap:12px;align-items:flex-start;padding:12px 14px;border:1px solid var(--line);border-radius:12px;background:var(--surface)}
.adapt-step.off{opacity:.6;background:var(--surface2)}
.adapt-step .body{flex:1;min-width:0}
.adapt-step textarea{min-height:60px;margin-top:8px}
.adapt-step .check{padding:0;min-height:36px}
/* Search */
.result-group{margin-top:24px}
/* Standards */
.std-row summary .desc{font-weight:400;color:var(--muted);flex:1;min-width:0;font-size:.92rem}
.std-row summary .code{font-family:var(--mono);font-weight:700;font-size:.9rem;white-space:nowrap}
.std-row summary .meta{display:flex;gap:6px;flex-wrap:wrap;align-items:center}
.std-row summary{flex-wrap:wrap}
.cov-bar{height:10px;border-radius:999px;background:var(--surface2);overflow:hidden}
.cov-bar i{display:block;height:100%;background:var(--ok)}
/* Quantile */
.qrow.outside{opacity:.7}
.qrow.outside td:first-child::before{content:"";}
/* Pacing */
.table-wrap{position:relative} /* keeps .sr-only labels inside the scroll box */
.pacing-table{min-width:600px}
.qtable{min-width:640px}
.cov-table{min-width:720px}
.pacing-table input[type=number]{width:72px;min-height:40px;padding:6px 8px}
.pacing-table input[type=text]{min-height:40px;padding:6px 8px;min-width:140px}
.pacing-table tr.week-start td{border-top:2px solid var(--accent)}
.pacing-table td.over,.pacing-table .over{background:var(--warn-soft);color:var(--warn);font-weight:600}
.pacing-table .wk-band{font-size:.72rem;text-transform:uppercase;letter-spacing:.05em;color:var(--accent-text);font-weight:700}
.pacing-totals{display:flex;gap:16px;flex-wrap:wrap}
.pacing-totals .stat.over b{color:var(--warn)}
/* Exit ticket */
.et-item{display:flex;gap:10px;align-items:flex-start;padding:10px 12px;border:1px solid var(--line);border-radius:12px;background:var(--surface)}
.et-item.on{border-color:var(--accent);background:var(--accent-soft)}
.et-item .body{flex:1;min-width:0}
.et-item .chips{margin-bottom:4px}
.et-print{display:none}
@media print{.et-print{display:block!important}.et-print .line{border-bottom:1px solid #000;height:1.6em;margin-top:.6em}.et-print ol li{margin-bottom:1.8em}.et-print .name-row{display:flex;gap:24px;margin-bottom:18px}.et-print .name-row span{flex:1;border-bottom:1px solid #000;padding-bottom:4px}.no-print{display:none!important}.teacher-off .teacher-only{display:none!important}}
/* Differentiation */
.diff-block{margin-top:16px}
.diff-block h2{font-family:var(--serif);font-size:1.15rem;margin-bottom:8px;display:flex;align-items:center;gap:8px}
.diff-block .md{max-width:none}
/* IM */
.im-note{font-size:.9rem;color:var(--muted)}
.ai-ctx>svg{width:22px;height:22px;flex:none;color:var(--accent-text)}
.ai-msgs .empty .ico svg{width:48px;height:48px}
@media (max-width:767px){.thread-item{flex-wrap:wrap}.thread-item .counts{width:100%;padding-left:44px;margin-top:-4px}}
.admin-table{min-width:760px}
.admin-table td,.admin-table th{overflow-wrap:normal;word-break:normal}
.admin-table td .row>span{white-space:nowrap}