/* Sourcebound Prep hub (every course), engine v3. Design system v2 (November 2026).
   Type: Gambetta (display serif) + Author (interface sans), self-hosted from Fontshare.
   Palette: ink navy, warm paper, civic gold, vermilion accent. Light and dark. */

@font-face{font-family:'Gambetta';src:url('/assets/fonts/gambetta-400.woff2') format('woff2');font-weight:400;font-style:normal;font-display:swap}
@font-face{font-family:'Gambetta';src:url('/assets/fonts/gambetta-400i.woff2') format('woff2');font-weight:400;font-style:italic;font-display:swap}
@font-face{font-family:'Gambetta';src:url('/assets/fonts/gambetta-500.woff2') format('woff2');font-weight:500;font-style:normal;font-display:swap}
@font-face{font-family:'Gambetta';src:url('/assets/fonts/gambetta-700.woff2') format('woff2');font-weight:700;font-style:normal;font-display:swap}
@font-face{font-family:'Author';src:url('/assets/fonts/author-400.woff2') format('woff2');font-weight:400;font-style:normal;font-display:swap}
@font-face{font-family:'Author';src:url('/assets/fonts/author-500.woff2') format('woff2');font-weight:500;font-style:normal;font-display:swap}
@font-face{font-family:'Author';src:url('/assets/fonts/author-600.woff2') format('woff2');font-weight:600;font-style:normal;font-display:swap}
@font-face{font-family:'Author';src:url('/assets/fonts/author-700.woff2') format('woff2');font-weight:700;font-style:normal;font-display:swap}

:root{
  --paper:#f5f0e6; --paper-2:#ede6d6; --card:#fffcf6; --card-2:#f9f4ea;
  --ink:#13203a; --ink-2:#2a3a58; --muted:#5d6878; --line:#e1d8c5; --line-2:#cdc1a6;
  --navy:#13203a; --navy-2:#1d3557; --navy-3:#2a4a7a; --link:#1d3557;
  --gold:#c9a227; --gold-2:#e2b93b; --gold-3:#f3d77a; --gold-ink:#7a5c08;
  --accent:#c8552d; --accent-2:#dd6a40; --accent-ink:#fff;
  --ok:#2f7d5a; --ok-bg:#e4f2ea; --bad:#b4332a; --bad-bg:#fbe7e3; --flag:#d9a20b; --flag-bg:#fdf2d3;
  --sel:#e7edf8; --hero:#0f1a31; --hero-2:#1d3557;
  --r:14px; --r-lg:22px; --r-xl:30px;
  --sh-1:0 1px 2px rgba(19,32,58,.05),0 2px 10px rgba(19,32,58,.05);
  --sh-2:0 2px 4px rgba(19,32,58,.05),0 14px 36px rgba(19,32,58,.10);
  --sh-3:0 30px 70px rgba(19,32,58,.22);
  --serif:'Gambetta',Georgia,'Times New Roman',serif;
  --sans:'Author',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;
  --mono:ui-monospace,'SF Mono',Menlo,Consolas,monospace;
  --ease:cubic-bezier(.2,.7,.2,1); --spring:cubic-bezier(.34,1.56,.64,1);
  color-scheme:light;
}
:root[data-theme="dark"]{
  --paper:#0e1526; --paper-2:#121b30; --card:#172139; --card-2:#1c2740;
  --ink:#ece5d4; --ink-2:#d9d2c0; --muted:#a4adbf; --line:#283550; --line-2:#394a6d;
  --link:#9ab8e8; --navy-3:#9ab8e8; --sel:#223150; --hero:#0a1122; --hero-2:#13203a;
  --ok-bg:#163427; --bad-bg:#3a1f1b; --flag-bg:#3a3012; --gold-ink:#f3d77a;
  --sh-1:0 1px 2px rgba(0,0,0,.3),0 2px 10px rgba(0,0,0,.25);
  --sh-2:0 2px 4px rgba(0,0,0,.3),0 14px 36px rgba(0,0,0,.4);
  --sh-3:0 30px 70px rgba(0,0,0,.6);
  color-scheme:dark;
}

/* ---------- base ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
html,body{margin:0;padding:0}
body{background:var(--paper);color:var(--ink);font:16px/1.6 var(--sans);font-weight:400;-webkit-font-smoothing:antialiased;position:relative;min-height:100vh}
body::before{content:"";position:fixed;inset:0;pointer-events:none;z-index:0;opacity:.055;mix-blend-mode:multiply;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='240' height='240'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E")}
:root[data-theme="dark"] body::before{opacity:.07;mix-blend-mode:screen}
body>*{position:relative;z-index:1}
a{color:var(--link);text-decoration-thickness:1px;text-underline-offset:3px}
a svg,p svg,.small svg,.pill svg{width:1em;height:1em;display:inline-block;vertical-align:-.15em}
a:hover{text-decoration-thickness:2px}
button{font:inherit;color:inherit}
img,svg,video{max-width:100%;display:block}
h1,h2,h3,h4{font-family:var(--serif);font-weight:500;line-height:1.12;letter-spacing:-.012em;margin:0 0 .4em;color:var(--ink)}
h1{font-size:clamp(34px,4.6vw,56px)}
h2{font-size:clamp(26px,3vw,38px)}
h3{font-size:22px}
h4{font-size:18px;font-family:var(--sans);font-weight:600;letter-spacing:0}
p{margin:0 0 1em}
.lead{font-size:clamp(17px,1.4vw,20px);color:var(--muted);line-height:1.55;max-width:62ch}
.eyebrow{font-family:var(--sans);font-size:12.5px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--gold-ink);margin:0 0 12px}
.small{font-size:14px;color:var(--muted)}
.muted{color:var(--muted)}
.sr{position:absolute;left:-9999px;width:1px;height:1px;overflow:hidden}
.skip{position:absolute;left:12px;top:-60px;background:var(--navy-2);color:#fff;padding:10px 14px;border-radius:10px;z-index:100;font-weight:600}
.skip:focus{top:12px}
:focus-visible{outline:3px solid var(--gold);outline-offset:3px;border-radius:6px}
::selection{background:var(--gold-3);color:var(--navy)}
.wrap{max-width:1120px;margin:0 auto;padding:0 24px}
.narrow{max-width:800px;margin:0 auto;padding:0 20px}
main{display:block;min-height:50vh}
main.wrap,main.narrow{padding-top:28px;padding-bottom:72px}
hr.rule{border:0;height:1px;background:var(--line);margin:32px 0}

/* ---------- header ---------- */
.top{position:sticky;top:0;z-index:40;background:color-mix(in srgb,var(--paper) 82%,transparent);backdrop-filter:saturate(1.4) blur(12px);-webkit-backdrop-filter:saturate(1.4) blur(12px);border-bottom:1px solid color-mix(in srgb,var(--line) 70%,transparent)}
.top .in{max-width:1120px;margin:0 auto;padding:0 24px;height:66px;display:flex;align-items:center;justify-content:space-between;gap:16px}
.brand{display:flex;align-items:center;gap:11px;text-decoration:none;color:var(--ink);font-weight:600;letter-spacing:.01em}
.brand .mark{width:36px;height:36px;border-radius:10px;background:linear-gradient(145deg,var(--navy-2),var(--navy));display:grid;place-items:center;color:#f3d77a;font-family:var(--serif);font-weight:700;font-size:20px;box-shadow:inset 0 0 0 1.5px rgba(243,215,122,.55),0 2px 6px rgba(19,32,58,.25)}
.brand .name{font-family:var(--serif);font-size:19px;font-weight:500;letter-spacing:.005em}
.brand .name b{font-weight:700}
.topnav{display:flex;align-items:center;gap:4px}
.topnav a{text-decoration:none;color:var(--ink-2);font-weight:500;font-size:15px;padding:8px 12px;border-radius:10px;transition:background .18s var(--ease),color .18s}
.topnav a:hover{background:color-mix(in srgb,var(--navy) 7%,transparent);color:var(--ink)}
.topnav a.cta{background:var(--accent);color:#fff;margin-left:6px;box-shadow:0 2px 8px rgba(200,85,45,.3)}
.topnav a.cta:hover{background:var(--accent-2)}
.iconbtn{width:38px;height:38px;border-radius:10px;border:1px solid var(--line);background:var(--card);display:grid;place-items:center;cursor:pointer;color:var(--ink-2);transition:transform .18s var(--spring),background .18s}
.iconbtn:hover{transform:translateY(-1px);background:var(--card-2)}
.iconbtn svg{width:18px;height:18px}
.menubtn{display:none}
:root[data-theme="dark"] .sun{display:block} :root[data-theme="dark"] .moon{display:none}
.sun{display:none}
@media (max-width:860px){
  .topnav{position:fixed;inset:66px 0 auto 0;background:var(--card);border-bottom:1px solid var(--line);flex-direction:column;align-items:stretch;padding:10px 16px 16px;gap:2px;box-shadow:var(--sh-2);transform:translateY(-8px);opacity:0;pointer-events:none;transition:opacity .2s,transform .25s var(--ease)}
  .topnav.open{transform:none;opacity:1;pointer-events:auto}
  .topnav a{padding:12px 12px;font-size:16px}
  .topnav a.cta{margin:8px 0 0;text-align:center}
  .menubtn{display:grid}
  .brand .name{font-size:17px}
}

/* ---------- buttons ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:1px solid transparent;background:var(--navy-2);color:#fff;padding:12px 20px;border-radius:12px;text-decoration:none;cursor:pointer;font-family:var(--sans);font-weight:600;font-size:15px;line-height:1.2;transition:transform .18s var(--spring),box-shadow .2s,background .18s;box-shadow:0 1px 2px rgba(19,32,58,.15),0 4px 12px rgba(19,32,58,.12);white-space:nowrap}
.btn:hover{transform:translateY(-1.5px);box-shadow:0 2px 4px rgba(19,32,58,.15),0 10px 22px rgba(19,32,58,.18)}
.btn:active{transform:translateY(0) scale(.98)}
.btn.primary{background:linear-gradient(180deg,var(--accent-2),var(--accent));box-shadow:0 1px 2px rgba(200,85,45,.3),0 6px 16px rgba(200,85,45,.28)}
.btn.primary:hover{box-shadow:0 2px 4px rgba(200,85,45,.3),0 12px 26px rgba(200,85,45,.34)}
.btn.gold{background:linear-gradient(180deg,var(--gold-2),var(--gold));color:var(--navy);box-shadow:0 1px 2px rgba(201,162,39,.3),0 6px 16px rgba(201,162,39,.3)}
.btn.ghost{background:transparent;color:var(--ink);border-color:var(--line-2);box-shadow:none}
.btn.ghost:hover{background:color-mix(in srgb,var(--navy) 6%,transparent);box-shadow:none}
.btn.onink{background:rgba(255,255,255,.08);color:#fff;border-color:rgba(255,255,255,.25);box-shadow:none;backdrop-filter:blur(4px)}
.btn.onink:hover{background:rgba(255,255,255,.14)}
.btn.small{padding:8px 14px;font-size:14px;border-radius:10px}
.btn.lg{padding:15px 26px;font-size:16px;border-radius:14px}
.btn:disabled,.btn[aria-disabled="true"]{opacity:.45;cursor:default;transform:none;box-shadow:none}
.btn svg{width:16px;height:16px}
.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.row.between{justify-content:space-between}
.pill{display:inline-flex;align-items:center;gap:6px;padding:4px 10px;border-radius:999px;border:1px solid var(--line);background:var(--card);font-size:12.5px;font-weight:500;color:var(--muted);white-space:nowrap}
.pill.ok{color:var(--ok);border-color:color-mix(in srgb,var(--ok) 35%,transparent);background:var(--ok-bg)}
.pill.warn{color:var(--gold-ink);border-color:color-mix(in srgb,var(--gold) 50%,transparent);background:var(--flag-bg)}
.pill.navy{color:#fff;background:var(--navy-2);border-color:var(--navy-2)}
.pill .dot{width:7px;height:7px;border-radius:50%;background:currentColor}

/* ---------- cards ---------- */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r-lg);padding:22px;box-shadow:var(--sh-1);position:relative}
.card.lift{transition:transform .25s var(--ease),box-shadow .25s var(--ease),border-color .25s}
.card.lift:hover{transform:translateY(-3px);box-shadow:var(--sh-2);border-color:var(--line-2)}
.card h3{margin-top:0}
.card .meta{color:var(--muted);font-size:14.5px}
.grid{display:grid;gap:18px;grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.grid.three{grid-template-columns:repeat(3,1fr)} .grid.four{grid-template-columns:repeat(4,1fr)} .grid.two{grid-template-columns:repeat(2,1fr)}
@media (max-width:900px){.grid.three,.grid.four{grid-template-columns:repeat(2,1fr)}}
@media (max-width:560px){.grid.three,.grid.four,.grid.two{grid-template-columns:1fr}}

/* ---------- sections ---------- */
.section{padding:72px 0}
.section.tight{padding:48px 0}
.section.alt{background:var(--paper-2)}
.section.ink{background:var(--hero);color:#ece5d4}
.section.ink h2,.section.ink h3{color:#fff}
.section.ink .lead,.section.ink .muted{color:#b8c0d2}
.section.ink .eyebrow{color:var(--gold-3)}
.section.ink a{color:#f3d77a}
.sec-head{max-width:720px;margin-bottom:34px}
.sec-head.center{margin-left:auto;margin-right:auto;text-align:center}
@media (max-width:700px){.section{padding:52px 0}}

/* ---------- hero ---------- */
.hero{position:relative;overflow:hidden;background:var(--hero);color:#ece5d4;isolation:isolate}
.hero .bg{position:absolute;inset:0;z-index:-1;overflow:hidden}
.hero .bg video,.hero .bg img.loop{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;opacity:.55}
.hero .bg .blob{position:absolute;border-radius:50%;filter:blur(70px);opacity:.55;animation:drift 22s ease-in-out infinite alternate}
.hero .bg .b1{width:62vw;height:62vw;max-width:900px;max-height:900px;left:-14vw;top:-26vw;background:radial-gradient(circle at 40% 40%,#2a4a7a,transparent 62%)}
.hero .bg .b2{width:50vw;height:50vw;max-width:760px;max-height:760px;right:-12vw;top:-8vw;background:radial-gradient(circle at 50% 50%,rgba(201,162,39,.55),transparent 62%);animation-duration:28s;animation-delay:-9s}
.hero .bg .b3{width:46vw;height:46vw;max-width:700px;max-height:700px;left:28vw;bottom:-30vw;background:radial-gradient(circle at 50% 50%,#1d3557,transparent 62%);animation-duration:26s;animation-delay:-16s}
.hero .bg .word{position:absolute;left:-2vw;bottom:-6vw;font-family:var(--serif);font-style:italic;font-size:clamp(120px,22vw,320px);line-height:1;color:#fff;opacity:.035;white-space:nowrap;user-select:none;letter-spacing:-.02em}
.hero .bg .grid-lines{position:absolute;inset:0;background-image:linear-gradient(rgba(255,255,255,.035) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.035) 1px,transparent 1px);background-size:72px 72px;mask-image:radial-gradient(ellipse at 50% 0%,#000 20%,transparent 75%);-webkit-mask-image:radial-gradient(ellipse at 50% 0%,#000 20%,transparent 75%)}
@keyframes drift{0%{transform:translate3d(0,0,0) scale(1)}50%{transform:translate3d(4vw,2vw,0) scale(1.08)}100%{transform:translate3d(-3vw,4vw,0) scale(.96)}}
.hero .in{max-width:1120px;margin:0 auto;padding:76px 24px 64px;display:grid;grid-template-columns:1.05fr .95fr;gap:48px;align-items:center}
.hero h1{color:#fff;font-size:clamp(40px,5.4vw,66px);margin:0 0 18px;text-wrap:balance}
.hero h1 em{font-style:italic;color:#f3d77a;font-weight:400}
.hero .lead{color:#c7cedd;font-size:clamp(17px,1.5vw,20px);max-width:54ch;margin-bottom:28px}
.hero .eyebrow{color:#f3d77a}
.hero .ctas{display:flex;gap:12px;flex-wrap:wrap;align-items:center;margin-bottom:34px}
.hero .ctas .hint{font-size:13.5px;color:#9aa6bd;flex-basis:100%}
.nums{display:flex;gap:28px;flex-wrap:wrap}
.nums div{display:flex;flex-direction:column;gap:2px}
.nums b{font-family:var(--serif);font-size:30px;font-weight:500;color:#fff;line-height:1}
.nums span{font-size:13px;color:#9aa6bd;letter-spacing:.02em}
.window-chip{display:inline-flex;align-items:center;gap:8px;background:rgba(255,255,255,.07);border:1px solid rgba(255,255,255,.14);color:#e9e2d0;padding:7px 12px 7px 9px;border-radius:999px;font-size:13.5px;margin-bottom:22px;backdrop-filter:blur(6px)}
.window-chip .dot{width:8px;height:8px;border-radius:50%;background:#f3d77a;box-shadow:0 0 0 4px rgba(243,215,122,.18);animation:pulse 2.4s ease-in-out infinite}
@keyframes pulse{0%,100%{box-shadow:0 0 0 3px rgba(243,215,122,.15)}50%{box-shadow:0 0 0 7px rgba(243,215,122,.05)}}
.hero .visual{perspective:1400px}
.demo{background:var(--card);color:var(--ink);border-radius:var(--r-xl);padding:26px 26px 22px;box-shadow:var(--sh-3),0 0 0 1px rgba(255,255,255,.08);transform:rotateY(-7deg) rotateX(3deg);transition:transform .6s var(--ease);position:relative}
.demo:hover{transform:rotateY(0) rotateX(0)}
.demo .tag{display:flex;justify-content:space-between;align-items:center;font-size:12.5px;color:var(--muted);font-weight:600;letter-spacing:.06em;text-transform:uppercase;margin-bottom:14px}
.demo .tag .n{font-family:var(--mono);letter-spacing:0;text-transform:none;font-weight:500}
.demo .stim{font-family:var(--serif);font-style:italic;font-size:15.5px;line-height:1.5;color:var(--ink-2);border-left:3px solid var(--gold);padding:2px 0 2px 14px;margin:0 0 14px;white-space:pre-line}
.demo .stem{font-family:var(--serif);font-size:19px;line-height:1.35;margin:0 0 14px;color:var(--ink)}
.demo .opts{display:grid;gap:8px}
.demo .reveal{margin-top:14px;padding:12px 14px;border-radius:12px;background:var(--card-2);border:1px solid var(--line);font-size:14.5px;line-height:1.5;display:none}
.demo .reveal.show{display:block;animation:rise .35s var(--ease)}
.demo .reveal .v{font-weight:700;margin-bottom:4px}
.demo .reveal .v.ok{color:var(--ok)} .demo .reveal .v.bad{color:var(--bad)}
.demo .reveal .src{color:var(--muted);font-size:13px;margin-top:6px}
.demo .dfoot{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-top:14px;font-size:13px;color:var(--muted)}
.demo .dfoot a{font-weight:600;white-space:nowrap}
.demo .seal{position:absolute;top:-14px;right:22px;background:linear-gradient(180deg,var(--gold-2),var(--gold));color:var(--navy);font-weight:700;font-size:12px;letter-spacing:.08em;text-transform:uppercase;padding:6px 11px;border-radius:999px;box-shadow:0 4px 12px rgba(201,162,39,.4)}
@media (max-width:980px){.hero .in{grid-template-columns:1fr;gap:34px;padding:56px 20px 48px}.demo{transform:none}.hero h1{font-size:clamp(36px,8vw,52px)}}

/* options (shared: demo, test, study, review) */
.opt{display:flex;gap:14px;align-items:flex-start;width:100%;text-align:left;padding:13px 14px;border:1.5px solid var(--line);background:var(--card);color:var(--ink);border-radius:14px;cursor:pointer;font-size:16px;line-height:1.45;transition:border-color .15s,background .15s,transform .15s var(--spring),box-shadow .15s;font-family:var(--sans)}
.opt .l{flex:none;width:28px;height:28px;border-radius:50%;border:1.5px solid var(--line-2);display:grid;place-items:center;font-weight:700;font-size:13px;color:var(--navy-3);background:var(--card-2);transition:background .15s,color .15s,border-color .15s;margin-top:-1px}
.opt:hover:not(:disabled){border-color:var(--navy-3);transform:translateY(-1px);box-shadow:var(--sh-1)}
.opt.sel{background:var(--sel);border-color:var(--navy-2);box-shadow:0 0 0 3px color-mix(in srgb,var(--navy-2) 14%,transparent)}
.opt.sel .l{background:var(--navy-2);color:#fff;border-color:var(--navy-2)}
.opt.correct{background:var(--ok-bg);border-color:var(--ok)} .opt.correct .l{background:var(--ok);color:#fff;border-color:var(--ok)}
.opt.wrong{background:var(--bad-bg);border-color:var(--bad)} .opt.wrong .l{background:var(--bad);color:#fff;border-color:var(--bad)}
.opt:disabled{cursor:default}
.opt.pop{animation:pop .35s var(--spring)}
.opt.shake{animation:shake .4s var(--ease)}
@keyframes pop{0%{transform:scale(.985)}60%{transform:scale(1.015)}100%{transform:scale(1)}}
@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-5px)}75%{transform:translateX(5px)}}
@keyframes rise{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* ---------- trust strip ---------- */
.trust{border-bottom:1px solid var(--line);background:var(--paper)}
.trust .in{max-width:1120px;margin:0 auto;padding:16px 24px;display:flex;gap:10px 34px;flex-wrap:wrap;justify-content:center;font-size:14px;color:var(--muted);font-weight:500}
.trust span{display:inline-flex;align-items:center;gap:8px}
.trust svg{width:16px;height:16px;color:var(--gold-ink)}

/* ---------- paths / test cards ---------- */
.tcard{display:grid;grid-template-columns:1fr auto;gap:16px;align-items:start}
.tcard .ring-wrap{display:grid;place-items:center}
.tcard h3{font-size:22px;margin-bottom:6px}
.tcard .meta{margin-bottom:14px}
.tcard .status{margin-top:10px}
.chips{display:flex;gap:6px;flex-wrap:wrap;margin:0 0 12px}
.ccard{display:flex;flex-direction:column;gap:12px}
.ccard .ico{width:48px;height:48px;border-radius:14px;background:linear-gradient(145deg,var(--navy-2),var(--navy));display:grid;place-items:center;color:#f3d77a;box-shadow:inset 0 0 0 1px rgba(243,215,122,.35)}
.ccard .ico svg{width:24px;height:24px}
.ccard .ico img{width:48px;height:48px;border-radius:14px}
.ccard h3{font-size:20px;margin:0}
.ccard .mastery{display:flex;align-items:center;gap:10px;font-size:13.5px;color:var(--muted)}
.bar{height:8px;background:var(--line);border-radius:999px;overflow:hidden;flex:1}
.bar i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--navy-3),var(--navy-2));border-radius:999px;transition:width 1.1s var(--ease)}
.bar.gold i{background:linear-gradient(90deg,var(--gold-2),var(--gold))}
.bar.ok i{background:var(--ok)}

/* rings */
.ring{position:relative;width:64px;height:64px;display:grid;place-items:center}
.ring svg{position:absolute;inset:0;width:100%;height:100%;transform:rotate(-90deg)}
.ring circle{fill:none;stroke-width:6;stroke-linecap:round}
.ring .track{stroke:var(--line)}
.ring .val{stroke:var(--navy-2);stroke-dasharray:1 1;stroke-dashoffset:1;transition:stroke-dashoffset 1.2s var(--ease)}
.ring .val.ok{stroke:var(--ok)} .ring .val.gold{stroke:var(--gold)} .ring .val.bad{stroke:var(--bad)}
.ring .num{font-family:var(--sans);font-weight:700;font-size:13px;color:var(--ink);font-variant-numeric:tabular-nums}
.ring.lg{width:200px;height:200px} .ring.lg circle{stroke-width:9} .ring.lg .num{font-family:var(--serif);font-weight:500;font-size:52px;letter-spacing:-.02em;line-height:1}
.ring.lg .num small{display:block;font-family:var(--sans);font-weight:600;font-size:13px;color:var(--muted);letter-spacing:.08em;text-transform:uppercase;margin-top:4px}

/* ---------- how it works ---------- */
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;counter-reset:s}
.step{padding:24px;border-radius:var(--r-lg);background:var(--card);border:1px solid var(--line);position:relative;overflow:hidden}
.step::before{counter-increment:s;content:counter(s,decimal-leading-zero);position:absolute;right:16px;top:8px;font-family:var(--serif);font-size:64px;line-height:1;color:var(--line);font-weight:500}
.step h3{font-size:20px;position:relative}
.step p{position:relative;margin:0;color:var(--muted);font-size:15px}
@media (max-width:860px){.steps{grid-template-columns:1fr}}

/* score gauge demo */
.gauge{display:grid;grid-template-columns:auto 1fr;gap:28px;align-items:center}
.gauge .scale{height:14px;border-radius:999px;background:linear-gradient(90deg,var(--bad-bg) 0 60%,var(--ok-bg) 60% 100%);position:relative;border:1px solid var(--line)}
.gauge .scale .cut{position:absolute;left:60%;top:-10px;bottom:-10px;width:2px;background:var(--gold);box-shadow:0 0 0 3px color-mix(in srgb,var(--gold) 25%,transparent)}
.gauge .scale .lab{position:absolute;left:60%;top:-34px;transform:translateX(-50%);font-size:12.5px;font-weight:700;color:var(--gold-ink);white-space:nowrap}
.gauge .ticks{display:flex;justify-content:space-between;font-size:12px;color:var(--muted);margin-top:8px;font-variant-numeric:tabular-nums}
@media (max-width:640px){.gauge{grid-template-columns:1fr}}

/* ---------- book ---------- */
.bookhero{display:grid;grid-template-columns:.9fr 1.1fr;gap:56px;align-items:center}
.book3d{perspective:1600px;display:grid;place-items:center;padding:30px 0}
.book3d .b{position:relative;width:min(300px,70vw);aspect-ratio:2/3;transform:rotateY(-24deg) rotateX(4deg);transform-style:preserve-3d;transition:transform .7s var(--ease);border-radius:4px 10px 10px 4px}
.book3d:hover .b{transform:rotateY(-10deg) rotateX(2deg)}
.book3d .b img{width:100%;height:100%;object-fit:cover;border-radius:4px 10px 10px 4px;box-shadow:0 40px 70px rgba(0,0,0,.45),0 0 0 1px rgba(255,255,255,.05);backface-visibility:hidden}
.book3d .b::before{content:"";position:absolute;left:0;top:1.5%;height:97%;width:46px;background:linear-gradient(90deg,#0b1428,#1d3557 60%,#0b1428);transform:rotateY(-90deg) translateX(-23px) translateZ(23px);transform-origin:left;border-radius:3px 0 0 3px}
.book3d .b::after{content:"";position:absolute;right:0;top:1.5%;height:97%;width:40px;background:repeating-linear-gradient(90deg,#f8f4ea 0 1.5px,#d9d2c2 1.5px 3px);transform:rotateY(90deg) translateX(20px) translateZ(-20px);transform-origin:right;opacity:.95}
.book3d .shadow{position:absolute;bottom:4px;width:60%;height:28px;border-radius:50%;background:radial-gradient(rgba(0,0,0,.45),transparent 70%);filter:blur(8px)}
.bookhero .inside li{margin-bottom:8px}
@media (max-width:900px){.bookhero{grid-template-columns:1fr;gap:28px}}

/* ---------- facts ---------- */
.facts{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:14px}
.fact{display:block;text-decoration:none;color:var(--ink);background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:18px 20px;transition:transform .22s var(--ease),box-shadow .22s,border-color .22s}
.fact:hover{transform:translateY(-2px);box-shadow:var(--sh-2);border-color:var(--line-2)}
.fact b{display:block;font-family:var(--serif);font-weight:500;font-size:18px;margin-bottom:6px;line-height:1.3}
.fact span{color:var(--muted);font-size:14.5px}
.fact .arrow{display:inline-block;margin-top:10px;color:var(--gold-ink);font-weight:600;font-size:13.5px}

/* ---------- footer ---------- */
.foot{background:var(--hero);color:#b8c0d2;padding:56px 0 30px;margin-top:0}
.foot .in{max-width:1120px;margin:0 auto;padding:0 24px}
.foot .cols{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:28px;margin-bottom:36px}
.foot h4{color:#fff;font-size:14px;letter-spacing:.08em;text-transform:uppercase;margin-bottom:12px}
.foot a{color:#d9dfeb;text-decoration:none;display:block;padding:4px 0;font-size:15px}
.foot a:hover{color:#f3d77a}
.foot .brand{color:#fff;margin-bottom:12px}
.foot .brand .name{color:#fff}
.foot p{font-size:14px;line-height:1.6}
.foot .legal{border-top:1px solid rgba(255,255,255,.1);padding-top:20px;font-size:13px;color:#8f9ab2;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
.foot .legal a{display:inline;color:#aab3c7;font-size:13px;padding:0}
@media (max-width:860px){.foot .cols{grid-template-columns:1fr 1fr}}
@media (max-width:520px){.foot .cols{grid-template-columns:1fr}}

/* ---------- app: test bar ---------- */
.testbar{position:sticky;top:66px;z-index:30;background:color-mix(in srgb,var(--paper) 88%,transparent);backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);border-bottom:1px solid var(--line);margin:0 -20px 22px;padding:0 20px}
.testbar .prog{height:4px;background:var(--line);margin:0 -20px}
.testbar .prog i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--gold),var(--accent));transition:width .4s var(--ease)}
.testbar .in{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:10px 0;flex-wrap:wrap}
.testbar .t{font-size:14px;color:var(--muted);font-weight:500}
.testbar .t b{color:var(--ink);font-weight:600}
.timer{display:inline-flex;align-items:center;gap:8px;font-family:var(--mono);font-variant-numeric:tabular-nums;font-weight:600;font-size:15px;color:var(--ink);background:var(--card);border:1px solid var(--line);padding:5px 12px 5px 8px;border-radius:999px}
.timer .ring{width:20px;height:20px} .timer .ring circle{stroke-width:3}
.timer.low{color:var(--bad);border-color:color-mix(in srgb,var(--bad) 40%,transparent);background:var(--bad-bg)}
.timer.low .ring .val{stroke:var(--bad)}
.section-head{font-family:var(--sans);font-size:12.5px;letter-spacing:.12em;text-transform:uppercase;color:var(--gold-ink);font-weight:600;margin:6px 0 10px;display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.section-head .topic{color:var(--muted);text-transform:none;letter-spacing:0;font-weight:500;font-size:13px}
.section-head .topic::before{content:"·";margin-right:8px}
.qcard{background:var(--card);border:1px solid var(--line);border-radius:var(--r-xl);padding:28px;box-shadow:var(--sh-1);animation:rise .3s var(--ease)}
.stimulus{font-family:var(--serif);font-style:italic;font-size:17px;line-height:1.55;color:var(--ink-2);border-left:3px solid var(--gold);padding:4px 0 4px 18px;margin:4px 0 18px;white-space:pre-wrap;background:linear-gradient(90deg,color-mix(in srgb,var(--gold) 8%,transparent),transparent 60%);border-radius:0 10px 10px 0}
.stem{font-family:var(--serif);font-size:clamp(20px,2vw,24px);line-height:1.35;margin:0 0 18px;color:var(--ink);text-wrap:pretty}
.opts{display:grid;gap:10px}
.keys{display:flex;gap:14px;flex-wrap:wrap;font-size:12.5px;color:var(--muted);margin-top:16px}
.keys kbd{font-family:var(--mono);font-size:11.5px;background:var(--card-2);border:1px solid var(--line-2);border-bottom-width:2px;border-radius:6px;padding:1px 6px;color:var(--ink-2)}
@media (max-width:700px){.keys{display:none}.qcard{padding:20px 18px;border-radius:20px}}
.actions{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-top:18px;flex-wrap:wrap}
@media (max-width:600px){.toast{bottom:92px}.actions{position:sticky;bottom:0;background:color-mix(in srgb,var(--paper) 92%,transparent);backdrop-filter:blur(10px);padding:10px 0;margin:14px -20px 0;padding-left:20px;padding-right:20px;border-top:1px solid var(--line)}}
.explain{margin-top:18px;padding:18px 20px;border-radius:18px;background:var(--card-2);border:1px solid var(--line);animation:rise .35s var(--ease)}
.explain .verdict{font-weight:700;font-size:15px;display:flex;align-items:center;gap:8px;margin-bottom:8px}
.explain .verdict.ok{color:var(--ok)} .explain .verdict.bad{color:var(--bad)}
.explain .verdict svg{width:18px;height:18px}
.explain p{font-size:15.5px;line-height:1.6;margin-bottom:8px}
.cites{margin:8px 0 0;padding-left:18px;color:var(--muted);font-size:14px}
.cites li{margin-bottom:3px}
.cites a{color:var(--link)}
.explain .small{margin-top:8px}

/* palette drawer */
.drawer-bg{position:fixed;inset:0;background:rgba(10,17,34,.45);z-index:60;opacity:0;pointer-events:none;transition:opacity .25s}
.drawer-bg.open{opacity:1;pointer-events:auto}
.drawer{position:fixed;top:0;right:0;bottom:0;width:min(420px,92vw);background:var(--card);z-index:61;box-shadow:var(--sh-3);transform:translateX(102%);visibility:hidden;transition:transform .32s var(--ease),visibility 0s .32s;padding:22px;overflow:auto;display:flex;flex-direction:column;gap:16px}
.drawer.open{transform:none;visibility:visible;transition:transform .32s var(--ease),visibility 0s}
.drawer h3{margin:0;font-size:22px}
.drawer .legend{display:flex;gap:14px;flex-wrap:wrap;font-size:12.5px;color:var(--muted)}
.drawer .legend i{display:inline-block;width:12px;height:12px;border-radius:4px;border:1px solid var(--line-2);vertical-align:-1px;margin-right:5px}
.navgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(42px,1fr));gap:7px}
.navgrid button{height:42px;border-radius:10px;border:1.5px solid var(--line);background:var(--card);color:var(--ink);cursor:pointer;font-family:var(--sans);font-weight:600;font-size:13.5px;position:relative;transition:transform .15s var(--spring),border-color .15s}
.navgrid button:hover{transform:translateY(-1px);border-color:var(--navy-3)}
.navgrid button.answered{background:var(--sel);border-color:var(--navy-2)}
.navgrid button.flagged::after{content:"";position:absolute;right:5px;top:5px;width:7px;height:7px;border-radius:50%;background:var(--flag)}
.navgrid button.current{outline:2.5px solid var(--gold);outline-offset:1px}
.navgrid button.ok{background:var(--ok-bg);border-color:var(--ok)} .navgrid button.bad{background:var(--bad-bg);border-color:var(--bad)}
.drawer .foot-actions{margin-top:auto;display:flex;flex-direction:column;gap:10px}

/* modal */
.modal-bg{position:fixed;inset:0;background:rgba(10,17,34,.5);z-index:70;display:none;place-items:center;padding:20px;backdrop-filter:blur(4px)}
.modal-bg.open{display:grid}
.modal{background:var(--card);border-radius:var(--r-lg);padding:26px;max-width:460px;width:100%;box-shadow:var(--sh-3);animation:modalin .3s var(--spring)}
.modal h3{margin-top:0}
.modal .row{justify-content:flex-end;margin-top:18px}
@keyframes modalin{from{opacity:0;transform:translateY(10px) scale(.97)}to{opacity:1;transform:none}}

/* start screen */
.start{display:grid;grid-template-columns:1.2fr .8fr;gap:24px;align-items:start}
.start .facts-list{list-style:none;padding:0;margin:0 0 18px;display:grid;gap:10px}
.start .facts-list li{display:flex;gap:10px;align-items:flex-start;font-size:15px}
.start .facts-list svg{width:18px;height:18px;flex:none;color:var(--gold-ink);margin-top:3px}
.seg{display:inline-flex;background:var(--card-2);border:1px solid var(--line);border-radius:12px;padding:4px;gap:4px;flex-wrap:wrap}
.seg button{border:0;background:transparent;padding:8px 12px;border-radius:9px;cursor:pointer;font-weight:500;font-size:14px;color:var(--muted);transition:background .15s,color .15s}
.seg button[aria-pressed="true"]{background:var(--card);color:var(--ink);box-shadow:var(--sh-1);font-weight:600}
@media (max-width:760px){.start{grid-template-columns:1fr}}

/* results */
.score-hero{display:grid;grid-template-columns:auto 1fr;gap:34px;align-items:center;background:var(--card);border:1px solid var(--line);border-radius:var(--r-xl);padding:30px;box-shadow:var(--sh-1);position:relative;overflow:hidden}
.score-hero .msg h2{margin-bottom:8px}
.stamp{position:absolute;right:26px;top:22px;font-family:var(--serif);font-weight:700;font-size:22px;letter-spacing:.14em;text-transform:uppercase;color:var(--ok);border:3px solid var(--ok);border-radius:8px;padding:4px 12px;transform:rotate(-10deg) scale(1.8);opacity:0;animation:stamp .55s var(--spring) .9s forwards;mix-blend-mode:multiply}
.stamp.not{color:var(--gold-ink);border-color:var(--gold)}
:root[data-theme="dark"] .stamp{mix-blend-mode:normal}
@keyframes stamp{to{transform:rotate(-10deg) scale(1);opacity:.9}}
.comps{display:grid;gap:12px;margin:22px 0}
.comp{display:grid;grid-template-columns:1fr auto;gap:8px 16px;align-items:center;background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:14px 18px}
.comp .name{font-weight:600;font-size:15px}
.comp .n{font-family:var(--mono);font-size:14px;color:var(--muted);font-variant-numeric:tabular-nums}
.comp .bar{grid-column:1/-1}
.comp .act{grid-column:1/-1;display:flex;gap:8px;align-items:center;justify-content:space-between;font-size:13px;color:var(--muted)}
.earned{display:flex;gap:10px;flex-wrap:wrap;margin:8px 0 0}
@media (max-width:640px){.score-hero{grid-template-columns:1fr;justify-items:center;text-align:center;padding:24px 18px}.stamp{position:static;transform:rotate(-6deg) scale(1.8);margin-top:8px}}
canvas.confetti{position:fixed;inset:0;pointer-events:none;z-index:80}

/* badges */
.badges{display:grid;grid-template-columns:repeat(auto-fill,minmax(120px,1fr));gap:14px}
.badge{display:flex;flex-direction:column;align-items:center;text-align:center;gap:8px;padding:14px 8px;border-radius:var(--r);background:var(--card);border:1px solid var(--line);transition:transform .2s var(--spring)}
.badge:hover{transform:translateY(-2px)}
.badge .coin{width:62px;height:62px;border-radius:50%;display:grid;place-items:center;background:radial-gradient(circle at 35% 30%,#fbe58a,#c9a227 55%,#8d6c0d);box-shadow:inset 0 0 0 3px rgba(255,255,255,.35),inset 0 0 0 5px rgba(141,108,13,.5),0 6px 14px rgba(141,108,13,.35);color:#3d2d05}
.badge .coin svg{width:28px;height:28px}
.badge.locked .coin{background:var(--card-2);box-shadow:inset 0 0 0 2px var(--line-2);color:var(--line-2);filter:grayscale(1)}
.badge.locked b{color:var(--muted)}
.badge b{font-size:13px;font-weight:600;line-height:1.25}
.badge span{font-size:11.5px;color:var(--muted);line-height:1.3}
.badge.new .coin{animation:coin .8s var(--spring)}
@keyframes coin{0%{transform:scale(.4) rotate(-30deg);opacity:0}70%{transform:scale(1.15) rotate(6deg);opacity:1}100%{transform:none}}
.toast{pointer-events:none;position:fixed;left:50%;bottom:24px;transform:translateX(-50%) translateY(20px);background:var(--navy);color:#fff;padding:12px 16px 12px 12px;border-radius:14px;box-shadow:var(--sh-3);display:flex;gap:12px;align-items:center;z-index:90;opacity:0;transition:opacity .3s,transform .4s var(--spring);max-width:92vw}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}
.toast .coin{width:36px;height:36px;border-radius:50%;background:radial-gradient(circle at 35% 30%,#fbe58a,#c9a227 55%,#8d6c0d);display:grid;place-items:center;color:#3d2d05;flex:none}
.toast .coin svg{width:18px;height:18px}
.toast b{display:block;font-size:14px} .toast span{font-size:13px;color:#c7cedd}
.streak{display:inline-flex;align-items:center;gap:8px;font-weight:600;font-size:14px}
.streak .flame{color:var(--accent)}
.dash{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-bottom:26px}
.dash .k{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:16px 18px}
.dash .k b{display:block;font-family:var(--serif);font-size:32px;font-weight:500;line-height:1;margin-bottom:6px}
.dash .k span{font-size:13px;color:var(--muted)}
@media (max-width:760px){.dash{grid-template-columns:1fr 1fr}}
.history{width:100%;border-collapse:collapse;font-size:14px}
.history td,.history th{padding:9px 10px;border-bottom:1px solid var(--line);text-align:left}
.history th{font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.spark{display:inline-block;vertical-align:middle}

/* flashcards */
.fcwrap{perspective:1500px;margin:8px 0 14px}
.fc{position:relative;min-height:280px;transform-style:preserve-3d;transition:transform .55s var(--ease);cursor:pointer;outline:none}
.fc.flipped{transform:rotateY(180deg)}
.fc .face{position:absolute;inset:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;background:var(--card);border:1px solid var(--line);border-radius:var(--r-xl);box-shadow:var(--sh-2);display:grid;place-items:center;text-align:center;padding:30px 28px;overflow:auto}
.fc .face.back{transform:rotateY(180deg);background:var(--card-2)}
.fc .side{position:absolute;top:16px;left:20px;font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--gold-ink);font-weight:600}
.fc .term{font-family:var(--serif);font-size:clamp(24px,3vw,32px);line-height:1.25;font-weight:500}
.fc .def{font-size:17px;line-height:1.55;max-width:56ch}
.fc .cite{display:block;margin-top:12px;font-size:13px;color:var(--muted)}
.fc .hintflip{position:absolute;bottom:14px;right:18px;font-size:12px;color:var(--muted)}
.fc:focus-visible{outline:none} .fc:focus-visible .face{outline:3px solid var(--gold);outline-offset:2px}
.deckbar{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:12px}
.deckbar .bar{max-width:260px}

/* ---------- articles (fact pages) ---------- */
.article{max-width:800px;margin:0 auto;padding:0 20px}
.article h1{font-size:clamp(32px,4vw,46px);margin-top:10px}
.article p,.article li{font-size:17px;line-height:1.65}
.article .answer{border-left:4px solid var(--gold);background:var(--card);padding:18px 22px;margin:18px 0 26px;font-size:19px;border-radius:0 var(--r) var(--r) 0;font-family:var(--serif);line-height:1.5;box-shadow:var(--sh-1)}
.article .answer p{margin:0;font-size:inherit}
.article table{border-collapse:collapse;width:100%;font-size:15px;margin:10px 0 22px;background:var(--card);border-radius:var(--r);overflow:hidden;border:1px solid var(--line)}
.article td,.article th{border-bottom:1px solid var(--line);padding:10px 12px;text-align:left;vertical-align:top}
.article th{background:var(--card-2);font-size:12.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}
.article tr:last-child td{border-bottom:0}
.article ul.src li{font-size:14.5px;margin-bottom:6px;word-break:break-word;color:var(--muted)}
.article ul.cols{columns:2;column-gap:28px} @media (max-width:600px){.article ul.cols{columns:1}}
.article .more dt{font-weight:600;margin-top:14px;font-size:17px} .article .more dd{margin:4px 0 0 0;color:var(--ink-2)}
.article .note,.article .checked{color:var(--muted);font-size:14.5px}
.crumb{font-size:13.5px;color:var(--muted);margin:0 0 10px;display:flex;gap:6px;align-items:center}
.crumb a{color:var(--muted)}
.related{margin-top:36px}
.related h2{font-size:24px}
.bookgrid{display:grid;grid-template-columns:260px 1fr;gap:34px;align-items:start}
@media (max-width:700px){.bookgrid{grid-template-columns:1fr}}
.page-hero{padding:48px 0 30px}
.page-hero h1{margin-bottom:10px}
.table-wrap{overflow:auto}

/* ---------- utilities / motion ---------- */
.rv{opacity:0;transform:translateY(16px);transition:opacity .7s var(--ease),transform .7s var(--ease)}
.rv.in{opacity:1;transform:none}
.rv.d1{transition-delay:.08s}.rv.d2{transition-delay:.16s}.rv.d3{transition-delay:.24s}.rv.d4{transition-delay:.32s}
.center{text-align:center}
.mt{margin-top:18px}.mt2{margin-top:30px}.mb0{margin-bottom:0}
.hide{display:none!important}
.tabular{font-variant-numeric:tabular-nums}
.count{font-variant-numeric:tabular-nums}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important;scroll-behavior:auto!important}
  .rv{opacity:1;transform:none}
  .stamp{opacity:.9;transform:rotate(-10deg)}
  .demo{transform:none}
  .hero .bg video{display:none}
}
@media print{.top,.foot,.testbar,.actions,.keys{display:none}body::before{display:none}}
/* rings on ink sections */
.section.ink .ring .track{stroke:rgba(255,255,255,.14)} .section.ink .ring .num{color:#fff} .section.ink .ring .num small{color:#b8c0d2}
.section.ink .gauge .scale{background:linear-gradient(90deg,rgba(180,51,42,.35) 0 60%,rgba(47,125,90,.45) 60% 100%);border-color:rgba(255,255,255,.15)}
.section.ink .gauge .lab{color:#f3d77a} .section.ink .gauge .ticks{color:#9aa6bd}
.app-view{animation:rise .3s var(--ease)}

body.in-test .foot{display:none} body.in-test main.narrow,body.in-test #main{padding-bottom:40px}

/* review fixes */
.dash .k span svg{width:14px;height:14px;vertical-align:-2px;color:var(--accent);margin-left:2px}
select{font:inherit;font-size:14px;padding:8px 32px 8px 12px;border:1px solid var(--line-2);border-radius:10px;background:var(--card);color:var(--ink);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='%235d6878' stroke-width='2'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 10px center;background-size:14px}
.fact span{display:block}
.fact .arrow{display:inline-flex;align-items:center;gap:6px}
.bookpage .bookhero{align-items:start} .bookpage .book3d{position:sticky;top:96px}
@media (max-width:900px){.bookpage .book3d{position:static}}
.fc .face .side{text-align:left}

.app-view:focus{outline:none}

/* ---------- hub engine additions (v3): item types, points, levels, per-course theme hooks ---------- */
.opt .l.box{border-radius:7px}
.opt.sel .l.box::after,.opt.correct .l.box::after{content:"";width:10px;height:6px;border-left:2.5px solid #fff;border-bottom:2.5px solid #fff;transform:rotate(-45deg);margin-top:-3px}
.pts{display:inline-flex;align-items:center;gap:6px;font-family:var(--sans);font-size:12.5px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--gold-ink);background:var(--flag-bg);border:1px solid color-mix(in srgb,var(--gold) 45%,transparent);border-radius:999px;padding:3px 9px}
.part{margin-top:18px;padding-top:16px;border-top:1px dashed var(--line-2)}
.part:first-of-type{margin-top:0;padding-top:0;border-top:0}
.part .plab{font-family:var(--sans);font-size:12.5px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--navy-3);margin:0 0 6px}
.part .stem{font-size:clamp(18px,1.8vw,21px);margin-bottom:12px}
.lead-in{font-family:var(--serif);font-style:italic;color:var(--muted);font-size:16px;margin:0 0 14px}
.stimulus .attr{display:block;font-style:normal;font-family:var(--sans);font-size:13px;color:var(--muted);margin-top:8px}
.stimulus.data{font-style:normal;font-family:var(--sans);font-size:15px}
.navgrid button.two::before{content:"2";position:absolute;left:5px;top:3px;font-size:9px;font-weight:700;color:var(--gold-ink);line-height:1}
.explain .pts-line{font-size:13.5px;color:var(--muted);margin:0 0 6px}
.levels{display:flex;gap:6px;margin:14px 0 6px;height:14px;border-radius:999px;overflow:hidden;border:1px solid var(--line)}
.levels i{display:block;height:100%}
.levels .l0{background:var(--bad-bg)} .levels .l1{background:var(--flag-bg)} .levels .l2{background:var(--ok-bg)} .levels .l3{background:color-mix(in srgb,var(--ok) 55%,var(--ok-bg))}
.levels-ticks{display:flex;justify-content:space-between;font-size:12px;color:var(--muted);font-variant-numeric:tabular-nums}
.section.ink .levels{border-color:rgba(255,255,255,.18)}
.section.ink .levels .l0{background:rgba(180,51,42,.45)} .section.ink .levels .l1{background:rgba(201,162,39,.45)} .section.ink .levels .l2{background:rgba(47,125,90,.5)} .section.ink .levels .l3{background:rgba(47,125,90,.8)}
.section.ink .levels-ticks{color:#9aa6bd}
.keys kbd.wide{letter-spacing:.02em}
/* level gauge on the course page scoring section */
.gauge .scale.levels3{background:linear-gradient(90deg,var(--bad-bg) 0 29.5%,var(--flag-bg) 29.5% 47.4%,var(--ok-bg) 47.4% 65.4%,color-mix(in srgb,var(--ok) 55%,var(--ok-bg)) 65.4% 100%)}
.section.ink .gauge .scale.levels3{background:linear-gradient(90deg,rgba(180,51,42,.35) 0 29.5%,rgba(201,162,39,.4) 29.5% 47.4%,rgba(47,125,90,.45) 47.4% 65.4%,rgba(47,125,90,.75) 65.4% 100%)}
.gauge .scale .cut.c2{left:47.4%} .gauge .scale .cut.c3{left:65.4%} .gauge .scale .cut.c1{left:29.5%}
.gauge .scale .lab.c1{left:29.5%} .gauge .scale .lab.c2{left:47.4%} .gauge .scale .lab.c3{left:65.4%}

/* ---------- hub catalog ---------- */
.hubhero{position:relative;overflow:hidden;background:var(--hero);color:#ece5d4;isolation:isolate}
.hubhero .in{max-width:1120px;margin:0 auto;padding:64px 24px 48px;position:relative}
.hubhero h1{color:#fff;font-size:clamp(36px,5vw,60px);margin:0 0 14px;text-wrap:balance;max-width:20ch}
.hubhero h1 em{font-style:italic;color:#f3d77a;font-weight:400}
.hubhero .lead{color:#c7cedd;max-width:60ch}
.hubhero .eyebrow{color:#f3d77a}
.searchbar{position:relative;max-width:640px;margin:26px 0 0}
.searchbar input{width:100%;font:inherit;font-size:17px;padding:15px 52px 15px 18px;border-radius:14px;border:1.5px solid rgba(255,255,255,.22);background:rgba(255,255,255,.08);color:#fff;backdrop-filter:blur(6px);outline:none;transition:border-color .15s,background .15s}
.searchbar input::placeholder{color:#9aa6bd}
.searchbar input:focus{border-color:var(--gold);background:rgba(255,255,255,.12)}
.searchbar kbd{position:absolute;right:14px;top:50%;transform:translateY(-50%);font-family:var(--mono);font-size:12px;color:#c7cedd;border:1px solid rgba(255,255,255,.3);border-radius:6px;padding:2px 7px}
.catbar{display:flex;flex-wrap:wrap;gap:10px 18px;align-items:center;justify-content:space-between;margin:0 0 22px}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{display:inline-flex;align-items:center;gap:6px;padding:7px 12px;border-radius:999px;border:1.5px solid var(--line-2);background:var(--card);color:var(--ink-2);font:inherit;font-size:13.5px;font-weight:500;cursor:pointer;transition:background .15s,border-color .15s,color .15s}
.chip:hover{border-color:var(--navy-3)}
.chip[aria-pressed="true"]{background:var(--navy-2);border-color:var(--navy-2);color:#fff}
.chip .n{font-size:11.5px;opacity:.75}
.chipgroup{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.chipgroup .lab{font-size:12.5px;letter-spacing:.1em;text-transform:uppercase;font-weight:600;color:var(--muted);margin-right:4px}
.viewseg{display:inline-flex;background:var(--card-2);border:1px solid var(--line);border-radius:12px;padding:4px;gap:4px}
.viewseg button{border:0;background:transparent;padding:7px 11px;border-radius:9px;cursor:pointer;font:inherit;font-weight:500;font-size:13.5px;color:var(--muted);display:inline-flex;align-items:center;gap:6px}
.viewseg button[aria-pressed="true"]{background:var(--card);color:var(--ink);box-shadow:var(--sh-1);font-weight:600}
.viewseg svg{width:15px;height:15px}
.catgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:18px}
.course{display:flex;flex-direction:column;gap:12px;text-decoration:none;color:var(--ink);background:var(--card);border:1px solid var(--line);border-radius:var(--r-lg);padding:22px;box-shadow:var(--sh-1);position:relative;overflow:hidden;transition:transform .22s var(--ease),box-shadow .22s,border-color .22s}
.course::before{content:"";position:absolute;left:0;top:0;bottom:0;width:6px;background:var(--acc,var(--navy-2))}
.course:hover{transform:translateY(-3px);box-shadow:var(--sh-2);border-color:var(--line-2)}
.course .top{display:flex;justify-content:space-between;gap:10px;align-items:flex-start}
.course .state{display:inline-flex;align-items:center;gap:6px;font-size:12.5px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.course .state i{width:9px;height:9px;border-radius:50%;background:var(--acc,var(--navy-2));display:inline-block}
.course h3{font-size:22px;margin:0;line-height:1.2}
.course .blurb{color:var(--muted);font-size:14.5px;margin:0}
.course .facts{display:flex;flex-wrap:wrap;gap:6px;margin:0}
.course .facts span{font-size:12.5px;border:1px solid var(--line);border-radius:999px;padding:3px 9px;color:var(--ink-2);background:var(--card-2)}
.course .cfoot{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-top:auto;padding-top:6px;font-size:13px}
.course .go{font-weight:600;color:var(--link);display:inline-flex;align-items:center;gap:6px}
.course .go svg{width:16px;height:16px}
.course .aliases{font-size:12.5px;color:var(--muted)}
.catlist{display:flex;flex-direction:column;gap:26px}
.catlist h2{font-size:22px;margin:0 0 8px;padding-bottom:6px;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;align-items:baseline}
.catlist h2 .n{font-family:var(--sans);font-size:13px;color:var(--muted);font-weight:500}
.catlist .rows{display:flex;flex-direction:column}
.crow{display:grid;grid-template-columns:8px 1fr auto auto;gap:14px;align-items:center;padding:12px 6px;border-bottom:1px solid var(--line);text-decoration:none;color:var(--ink);transition:background .15s}
.crow:hover{background:var(--card)}
.crow i{width:8px;height:8px;border-radius:50%;background:var(--acc,var(--navy-2))}
.crow b{font-family:var(--serif);font-weight:500;font-size:17px}
.crow .sub{display:block;font-size:13px;color:var(--muted)}
.crow .st{font-size:12.5px;color:var(--muted);white-space:nowrap}
.crow .go{color:var(--link);font-weight:600;font-size:14px;white-space:nowrap}
@media (max-width:640px){.crow{grid-template-columns:8px 1fr;gap:10px}.crow .st,.crow .go{grid-column:2}}
.empty{padding:40px 20px;text-align:center;color:var(--muted);background:var(--card);border:1px dashed var(--line-2);border-radius:var(--r-lg)}
.count{font-size:14px;color:var(--muted)}
.families{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px}
.family{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:16px 18px}
.family b{display:block;font-family:var(--serif);font-weight:500;font-size:17px;margin-bottom:4px}
.family span{font-size:13.5px;color:var(--muted)}
.family .n{display:inline-block;margin-top:8px;font-size:12.5px;color:var(--gold-ink);font-weight:600}
mark{background:color-mix(in srgb,var(--gold) 40%,transparent);color:inherit;border-radius:3px;padding:0 1px}

/* ---------- installable app (PWA) control: hidden until src/pwa.js decides to show it ---------- */
.pwa-install{display:flex;align-items:center;gap:6px;flex-wrap:wrap;margin-top:14px;flex-basis:100%}
.pwa-install.hide{display:none}
.pwa-btn{display:inline-flex;align-items:center;gap:9px;min-height:44px;padding:10px 16px;border-radius:12px;border:1.5px solid rgba(255,255,255,.35);background:rgba(255,255,255,.08);color:#fff;font-family:var(--sans);font-size:14.5px;font-weight:600;cursor:pointer;backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);transition:border-color .15s,background .15s}
.pwa-btn:hover,.pwa-btn:focus-visible{border-color:var(--gold);background:rgba(255,255,255,.14)}
.pwa-btn svg{width:18px;height:18px;flex:none}
.pwa-x{width:44px;height:44px;border-radius:50%;border:0;background:transparent;color:#c7cedd;font-size:24px;line-height:1;cursor:pointer}
.pwa-x:hover{color:#fff;background:rgba(255,255,255,.1)}
.pwa-hint{flex-basis:100%;margin:2px 0 0;font-size:14px;line-height:1.5;color:#c7cedd;max-width:52ch}
.pwa-hint svg{width:16px;height:16px;vertical-align:-3px;margin:0 2px}
.pwa-hint b{color:#fff;font-weight:600}

/* ---------- phone widths and installed-app safe areas (viewport-fit=cover) ---------- */
.toast{bottom:calc(24px + env(safe-area-inset-bottom,0px))}
.drawer{padding-bottom:calc(22px + env(safe-area-inset-bottom,0px));padding-right:calc(22px + env(safe-area-inset-right,0px))}
.modal-bg{padding:calc(20px + env(safe-area-inset-top,0px)) 20px calc(20px + env(safe-area-inset-bottom,0px))}
.foot{padding-bottom:calc(24px + env(safe-area-inset-bottom,0px))}
html.pwa-standalone .top .in{height:calc(66px + env(safe-area-inset-top,0px));padding-top:env(safe-area-inset-top,0px)}
html.pwa-standalone .testbar{top:calc(66px + env(safe-area-inset-top,0px))}
html.pwa-standalone .topnav{inset:calc(66px + env(safe-area-inset-top,0px)) 0 auto 0}
@media (max-width:420px){
  .navgrid button{height:44px}
  .hubhero .in{padding:44px 16px 36px}
  .hubhero h1{font-size:clamp(30px,9vw,36px)}
  .searchbar input{font-size:16px;padding:14px 46px 14px 15px}
  .course{padding:18px}
  .course h3{font-size:20px}
  .modal{padding:20px 18px}
  .viewseg button{min-height:40px}
  .chip{min-height:38px;padding:7px 11px}
  .catbar{gap:10px 12px}
  .pwa-btn{width:100%;justify-content:center}
  .pwa-x{position:absolute;right:0;top:0}
  .pwa-install{position:relative;padding-right:0}
}
/* touch devices: 44 px targets for the small controls (top-bar icon buttons, secondary buttons, segments, chips) */
@media (pointer:coarse){
  .iconbtn{width:44px;height:44px}
  .btn.small,.btn.ghost{min-height:44px}
  .seg button{min-height:44px;padding:10px 12px}
  .chip,.viewseg button{min-height:44px}
  .navgrid button{height:44px}
}