/* SteadfastIQ design system v2 — test prep & labs. Original styling. */
@font-face{font-family:"Inter";src:url(/assets/inter-var.woff2) format("woff2");font-weight:100 900;font-display:swap}
:root{
 --font:"Inter",ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;--mono:ui-monospace,"SFMono-Regular","JetBrains Mono",Menlo,Consolas,monospace;
 --bg:#f7f8fa;--surface:#fff;--surface-2:#f1f4f7;--line:#e3e8ee;--line-2:#d3dae3;
 --text:#0f172a;--text-2:#475467;--text-3:#5f6b7a;
 --accent:#0d7a6f;--accent-600:#0a6a60;--accent-50:#e7f5f3;--accent-100:#cdebe6;--on-accent:#fff;
 --ok:#15803d;--ok-50:#eaf7ee;--bad:#c0262d;--bad-50:#fdeeee;--warn:#a15c07;--warn-50:#fff5e5;--info:#2557c7;--info-50:#ecf2fe;
 --violet:#6d4ae0;--violet-50:#f1edfd;
 --r-sm:8px;--r:12px;--r-lg:18px;--r-xl:24px;
 --sh-1:0 1px 2px rgba(16,24,40,.05),0 1px 3px rgba(16,24,40,.06);--sh-2:0 4px 12px -2px rgba(16,24,40,.08),0 2px 4px -2px rgba(16,24,40,.05);--sh-3:0 18px 40px -12px rgba(16,24,40,.18);
 --console:#0e1525;--console-2:#151e31;--console-text:#d7e1f0;--console-dim:#8796ad;--console-ok:#5ee0a6;--console-acc:#7cc7ff;
 --ease:cubic-bezier(.2,.7,.2,1);--maxw:1180px;color-scheme:light}
:root[data-theme=dark]{
 --bg:#0b1016;--surface:#121922;--surface-2:#18212c;--line:#24303d;--line-2:#2e3c4b;
 --text:#e8edf3;--text-2:#b3bfcc;--text-3:#94a3b3;
 --accent:#3cc6b5;--accent-600:#5ad3c4;--accent-50:#10302d;--accent-100:#174640;--on-accent:#04201c;
 --ok:#4ade80;--ok-50:#0f2a1a;--bad:#f87171;--bad-50:#341316;--warn:#fbbf24;--warn-50:#33240a;--info:#7aa7ff;--info-50:#14223f;--violet:#a78bfa;--violet-50:#221a3d;
 --sh-1:0 1px 2px rgba(0,0,0,.4);--sh-2:0 6px 16px -4px rgba(0,0,0,.5);--sh-3:0 20px 50px -12px rgba(0,0,0,.6);color-scheme:dark}
*{box-sizing:border-box}html{scroll-padding-top:88px;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.6 var(--font);-webkit-font-smoothing:antialiased;font-feature-settings:"cv11","ss01"}
img,svg{max-width:100%}a{color:var(--accent);text-underline-offset:3px}a:hover{color:var(--accent-600)}
h1,h2,h3,h4{line-height:1.2;letter-spacing:-.02em;margin:0 0 .5em;font-weight:700;color:var(--text)}
h1{font-size:clamp(2rem,4.6vw,3.25rem);letter-spacing:-.035em}h2{font-size:clamp(1.5rem,3vw,2.1rem);letter-spacing:-.03em}h3{font-size:1.15rem}h4{font-size:1rem}
p{margin:0 0 1em}.muted{color:var(--text-2)}.small{font-size:.875rem}.xs{font-size:.78rem}.mono{font-family:var(--mono)}
.wrap{width:min(var(--maxw),100% - 40px);margin-inline:auto}.narrow{width:min(760px,100% - 40px);margin-inline:auto}
.skip{position:absolute;left:-9999px;top:8px;z-index:100;background:var(--surface);color:var(--text);padding:10px 14px;border-radius:var(--r-sm);box-shadow:var(--sh-2)}.skip:focus{left:12px}
:focus-visible{outline:3px solid color-mix(in srgb,var(--accent) 70%,transparent);outline-offset:2px;border-radius:6px}
.ico{width:20px;height:20px;flex:none;vertical-align:-4px}.ico.sm{width:16px;height:16px;vertical-align:-3px}.ico.lg{width:28px;height:28px}
.sr{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
/* header */
.hdr{position:sticky;top:0;z-index:40;background:color-mix(in srgb,var(--bg) 82%,transparent);backdrop-filter:saturate(1.4) blur(12px);-webkit-backdrop-filter:saturate(1.4) blur(12px);border-bottom:1px solid var(--line)}
.hdr .wrap{display:flex;align-items:center;gap:20px;height:68px}
.brand{display:inline-flex;align-items:center;gap:10px;font-weight:750;font-size:1.13rem;letter-spacing:-.02em;color:var(--text);text-decoration:none}.brand:hover{color:var(--text)}
.brand .mark{width:32px;height:32px}.brand b{color:var(--accent);font-weight:750}
.nav{display:flex;gap:4px;margin-left:12px}.nav a{display:inline-flex;align-items:center;gap:8px;padding:9px 12px;border-radius:10px;color:var(--text-2);text-decoration:none;font-weight:550;font-size:.94rem;min-height:44px}
.nav a:hover{background:var(--surface-2);color:var(--text)}.nav a[aria-current=page]{color:var(--accent);background:var(--accent-50)}
.hdr .right{margin-left:auto;display:flex;align-items:center;gap:8px}
.iconbtn{display:inline-grid;place-items:center;width:44px;height:44px;border-radius:12px;border:1px solid var(--line);background:var(--surface);color:var(--text-2);cursor:pointer;transition:background .2s,color .2s}.iconbtn:hover{color:var(--text);background:var(--surface-2)}
.menu-btn{display:none}
@media (max-width:900px){.nav{display:none;position:absolute;top:68px;left:0;right:0;flex-direction:column;background:var(--surface);border-bottom:1px solid var(--line);padding:10px 16px 16px;box-shadow:var(--sh-2);margin:0}.nav.open{display:flex}.menu-btn{display:inline-grid}.hdr .hide-sm{display:none}}
/* buttons */
.btn{--b:var(--accent);display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:10px 20px;border-radius:12px;border:1px solid transparent;background:var(--b);color:var(--on-accent);font:600 .97rem/1.2 var(--font);text-decoration:none;cursor:pointer;transition:transform .15s var(--ease),box-shadow .2s,background .2s;box-shadow:0 1px 2px rgba(16,24,40,.08),inset 0 1px 0 rgba(255,255,255,.12)}
.btn:hover{background:var(--accent-600);color:var(--on-accent);transform:translateY(-1px);box-shadow:var(--sh-2)}.btn:active{transform:translateY(0)}
.btn.lg{min-height:52px;padding:14px 26px;font-size:1.04rem;border-radius:14px}.btn.sm{min-height:36px;padding:7px 14px;font-size:.88rem;border-radius:10px}
.btn.ghost{background:var(--surface);color:var(--text);border-color:var(--line-2);box-shadow:var(--sh-1)}.btn.ghost:hover{background:var(--surface-2);color:var(--text)}
.btn.quiet{background:transparent;color:var(--text-2);box-shadow:none}.btn.quiet:hover{background:var(--surface-2);color:var(--text)}
.btn.danger{background:var(--bad);color:#fff}.btn[disabled],.btn[aria-disabled=true]{opacity:.55;cursor:not-allowed;transform:none}
.btn.block{width:100%}
/* layout pieces */
section.s{padding:80px 0}section.s.tight{padding:48px 0}.alt{background:var(--surface);border-block:1px solid var(--line)}
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:.8rem;font-weight:650;letter-spacing:.06em;text-transform:uppercase;color:var(--accent)}
.pill{display:inline-flex;align-items:center;gap:6px;padding:4px 10px;border-radius:999px;font-size:.78rem;font-weight:600;background:var(--surface-2);color:var(--text-2);border:1px solid var(--line)}
.pill.ai{background:var(--violet-50);color:var(--violet);border-color:transparent}.pill.ok{background:var(--ok-50);color:var(--ok);border-color:transparent}.pill.warn{background:var(--warn-50);color:var(--warn);border-color:transparent}.pill.acc{background:var(--accent-50);color:var(--accent);border-color:transparent}.pill.bad{background:var(--bad-50);color:var(--bad);border-color:transparent}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-lg);box-shadow:var(--sh-1);padding:24px;transition:box-shadow .25s var(--ease),transform .25s var(--ease),border-color .25s}
a.card,.card.hover{color:inherit;text-decoration:none;display:block}a.card:hover,.card.hover:hover{box-shadow:var(--sh-3);transform:translateY(-2px);border-color:var(--line-2)}
.grid{display:grid;gap:20px}.g2{grid-template-columns:repeat(auto-fill,minmax(min(100%,420px),1fr))}.g3{grid-template-columns:repeat(auto-fill,minmax(min(100%,300px),1fr))}.g4{grid-template-columns:repeat(auto-fill,minmax(min(100%,240px),1fr))}
.row{display:flex;align-items:center;gap:12px;flex-wrap:wrap}.between{justify-content:space-between}.stack>*+*{margin-top:12px}
.tile-ico{display:inline-grid;place-items:center;width:44px;height:44px;border-radius:12px;background:var(--accent-50);color:var(--accent);margin-bottom:14px}.tile-ico.v{background:var(--violet-50);color:var(--violet)}
/* hero */
.hero{padding:72px 0 64px;position:relative;overflow:hidden}
.hero::before{content:"";position:absolute;inset:-30% -10% auto auto;width:780px;height:780px;background:radial-gradient(closest-side,color-mix(in srgb,var(--accent) 16%,transparent),transparent);pointer-events:none}
.hero .wrap{position:relative;display:grid;gap:48px;align-items:center}@media(min-width:980px){.hero .wrap{grid-template-columns:1.05fr 1fr}}
.hero .lead{font-size:clamp(1.05rem,1.6vw,1.22rem);color:var(--text-2);max-width:560px}
.checks{list-style:none;padding:0;margin:20px 0 0;display:grid;gap:8px;color:var(--text-2)}.checks li{display:flex;gap:10px;align-items:flex-start}.checks .ico{color:var(--ok);margin-top:3px}
.preview{border-radius:var(--r-xl);background:var(--surface);border:1px solid var(--line);box-shadow:var(--sh-3);overflow:hidden}
.preview .bar{display:flex;gap:6px;align-items:center;padding:12px 14px;border-bottom:1px solid var(--line);background:var(--surface-2)}.preview .bar i{width:10px;height:10px;border-radius:50%;background:var(--line-2)}
.stat-row{display:flex;gap:32px;flex-wrap:wrap;margin-top:28px}.stat-row b{display:block;font-size:1.6rem;letter-spacing:-.03em}.stat-row span{color:var(--text-2);font-size:.88rem}
/* forms */
.field{display:grid;gap:6px;margin-bottom:16px}.field label{font-weight:600;font-size:.93rem}.hint{font-size:.84rem;color:var(--text-2)}
.input,select.input,textarea.input{width:100%;min-height:46px;padding:11px 14px;border-radius:12px;border:1px solid var(--line-2);background:var(--surface);color:var(--text);font:inherit;transition:border-color .2s,box-shadow .2s}
.input:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 4px color-mix(in srgb,var(--accent) 20%,transparent)}
.input[aria-invalid=true]{border-color:var(--bad)}.err{color:var(--bad);font-size:.86rem;font-weight:550}
.pw{position:relative}.pw .input{padding-right:52px}.pw button{position:absolute;right:4px;top:50%;transform:translateY(-50%);border:0;background:transparent;color:var(--text-2);width:44px;height:40px;border-radius:10px;cursor:pointer}
.rules{list-style:none;margin:8px 0 0;padding:0;display:grid;gap:4px;font-size:.85rem;color:var(--text-2)}.rules li{display:flex;gap:8px;align-items:center}.rules li.ok{color:var(--ok)}.rules li .dot{width:16px;height:16px;border-radius:50%;border:2px solid currentColor;display:inline-grid;place-items:center;flex:none}.rules li.ok .dot{background:currentColor}
.auth{min-height:calc(100vh - 69px);display:grid;place-items:center;padding:40px 16px}.auth .card{width:min(460px,100%);padding:32px}
.code-in{letter-spacing:.5em;font:600 1.5rem/1 var(--mono);text-align:center}
.notice{display:flex;gap:12px;align-items:flex-start;padding:14px 16px;border-radius:12px;background:var(--info-50);color:var(--text);border:1px solid color-mix(in srgb,var(--info) 25%,transparent);font-size:.93rem}
.notice.ok{background:var(--ok-50);border-color:color-mix(in srgb,var(--ok) 25%,transparent)}.notice.bad{background:var(--bad-50);border-color:color-mix(in srgb,var(--bad) 25%,transparent)}.notice.warn{background:var(--warn-50);border-color:color-mix(in srgb,var(--warn) 25%,transparent)}
/* cert cards */
.cert{display:flex;flex-direction:column;gap:10px;height:100%}.cert h3{margin:0;font-size:1.04rem}.cert .meta{display:flex;gap:8px;flex-wrap:wrap;margin-top:auto}
.rank{font:700 .8rem/1 var(--font);color:var(--text-3)}
.bar{height:8px;border-radius:99px;background:var(--surface-2);overflow:hidden}.bar>i{display:block;height:100%;background:var(--accent);border-radius:inherit;transition:width .6s var(--ease)}
.bar.v>i{background:var(--violet)}.bar.ok>i{background:var(--ok)}.bar.warn>i{background:var(--warn)}.bar.bad>i{background:var(--bad)}
.ring{--p:0;--c:var(--accent);width:96px;height:96px;border-radius:50%;background:conic-gradient(var(--c) calc(var(--p)*1%),var(--surface-2) 0);display:grid;place-items:center;flex:none}
.ring::before{content:attr(data-label);width:76px;height:76px;border-radius:50%;background:var(--surface);display:grid;place-items:center;font-weight:750;font-size:1.15rem;letter-spacing:-.02em}
.ring.sm{width:56px;height:56px}.ring.sm::before{width:44px;height:44px;font-size:.8rem}
/* app shell */
.page-h{padding:32px 0 8px}.page-h p{color:var(--text-2);max-width:720px}
.tabs{display:flex;gap:4px;border-bottom:1px solid var(--line);margin:8px 0 24px;overflow-x:auto}.tabs button,.tabs a{border:0;background:none;padding:12px 14px;font:600 .94rem var(--font);color:var(--text-2);border-bottom:2px solid transparent;cursor:pointer;white-space:nowrap;text-decoration:none;min-height:44px}
.tabs [aria-selected=true],.tabs [aria-current=page]{color:var(--accent);border-color:var(--accent)}
.empty{text-align:center;padding:40px 20px;border:1px dashed var(--line-2);border-radius:var(--r-lg);color:var(--text-2);background:var(--surface)}.empty .tile-ico{margin-inline:auto}
table.t{width:100%;border-collapse:collapse;font-size:.93rem}table.t th,table.t td{padding:12px 10px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}table.t th{font-size:.8rem;text-transform:uppercase;letter-spacing:.05em;color:var(--text-3);font-weight:650}
.kbd,kbd{font:600 .78rem var(--mono);padding:2px 6px;border-radius:6px;border:1px solid var(--line-2);background:var(--surface-2)}
/* exam player */
.exam{display:grid;grid-template-rows:auto 1fr auto;min-height:calc(100vh - 69px)}
.exam-top{position:sticky;top:68px;z-index:30;background:var(--surface);border-bottom:1px solid var(--line)}.exam-top .wrap{display:flex;align-items:center;gap:14px;min-height:60px;flex-wrap:wrap}
.timer{display:inline-flex;align-items:center;gap:8px;font:650 1rem var(--mono);padding:8px 12px;border-radius:10px;background:var(--surface-2);min-height:44px;border:1px solid var(--line);cursor:pointer;color:var(--text)}.timer.low{background:var(--warn-50);color:var(--warn)}
.q-wrap{padding:28px 0 120px}.q-stem{font-size:1.1rem;line-height:1.6;margin-bottom:20px;white-space:pre-wrap}
.q-type{font-size:.8rem;font-weight:650;color:var(--text-3);text-transform:uppercase;letter-spacing:.05em;margin-bottom:8px}
.opts{display:grid;gap:10px;list-style:none;margin:0;padding:0}
.opt{display:flex;gap:14px;align-items:flex-start;padding:14px 16px;border:1px solid var(--line-2);border-radius:14px;background:var(--surface);cursor:pointer;transition:border-color .15s,background .15s,box-shadow .15s;min-height:52px}
.opt:hover{border-color:var(--accent);background:color-mix(in srgb,var(--accent-50) 50%,var(--surface))}.opt input{width:20px;height:20px;margin-top:2px;accent-color:var(--accent);flex:none}
.opt.sel{border-color:var(--accent);background:var(--accent-50);box-shadow:0 0 0 1px var(--accent) inset}.opt.right{border-color:var(--ok);background:var(--ok-50)}.opt.wrong{border-color:var(--bad);background:var(--bad-50)}
.opt .letter{font:700 .85rem var(--mono);color:var(--text-3);min-width:18px;margin-top:2px}
.order-list{list-style:none;padding:0;margin:0;display:grid;gap:8px}.order-list li{display:flex;align-items:center;gap:10px;padding:10px 12px;border:1px solid var(--line-2);border-radius:12px;background:var(--surface)}.order-list .n{font:700 .85rem var(--mono);color:var(--accent);width:24px}.order-list .txt{flex:1}
.order-list li.drag{opacity:.5}.order-list .mv{width:40px;height:40px;border-radius:10px;border:1px solid var(--line);background:var(--surface-2);cursor:pointer;color:var(--text-2);display:grid;place-items:center}
.match{display:grid;gap:10px}.match .mrow{display:grid;grid-template-columns:1fr minmax(180px,260px);gap:12px;align-items:center;padding:12px 14px;border:1px solid var(--line-2);border-radius:12px;background:var(--surface)}@media(max-width:640px){.match .mrow{grid-template-columns:1fr}}
.match .mrow.right{border-color:var(--ok);background:var(--ok-50)}.match .mrow.wrong{border-color:var(--bad);background:var(--bad-50)}
.explain{margin-top:20px;border-radius:14px;border:1px solid var(--line);background:var(--surface);overflow:hidden}.explain .hd{display:flex;gap:10px;align-items:center;padding:14px 16px;font-weight:650}.explain .hd.ok{background:var(--ok-50);color:var(--ok)}.explain .hd.bad{background:var(--bad-50);color:var(--bad)}
.explain .bd{padding:14px 16px}.explain .take{display:flex;gap:10px;font-weight:600}.explain details{margin-top:10px}.explain summary{cursor:pointer;color:var(--accent);font-weight:600;min-height:32px}
.exam-foot{position:fixed;bottom:0;left:0;right:0;z-index:30;background:var(--surface);border-top:1px solid var(--line);box-shadow:0 -6px 18px -10px rgba(16,24,40,.2)}.exam-foot .wrap{display:flex;gap:10px;align-items:center;min-height:68px;padding-block:10px}
.qnav{display:grid;grid-template-columns:repeat(auto-fill,minmax(44px,1fr));gap:8px}.qnav button{height:44px;border-radius:10px;border:1px solid var(--line-2);background:var(--surface);font:600 .9rem var(--font);color:var(--text);cursor:pointer;position:relative}
.qnav button.ans{background:var(--accent-50);border-color:var(--accent-100)}.qnav button.cur{outline:2px solid var(--accent)}.qnav button.flag::after{content:"";position:absolute;top:4px;right:4px;width:8px;height:8px;border-radius:50%;background:var(--warn)}
.qnav button.right{background:var(--ok-50);border-color:var(--ok)}.qnav button.wrong{background:var(--bad-50);border-color:var(--bad)}
dialog{border:0;border-radius:var(--r-lg);padding:0;box-shadow:var(--sh-3);width:min(560px,calc(100% - 24px));background:var(--surface);color:var(--text)}dialog::backdrop{background:rgba(8,12,20,.5);backdrop-filter:blur(2px)}dialog .dh{padding:20px 22px 0}dialog .db{padding:12px 22px}dialog .df{display:flex;gap:10px;justify-content:flex-end;padding:14px 22px 20px;flex-wrap:wrap}
/* labs */
.lab{display:grid;gap:0;min-height:calc(100vh - 69px)}@media(min-width:1024px){.lab{grid-template-columns:minmax(320px,400px) 1fr}}
.lab-side{background:var(--surface);border-right:1px solid var(--line);padding:22px;overflow:auto}@media(min-width:1024px){.lab-side{position:sticky;top:68px;height:calc(100vh - 68px)}}
.lab-main{padding:20px;min-width:0;background:var(--bg)}
.tasks{list-style:none;padding:0;margin:12px 0;display:grid;gap:8px;counter-reset:t}.tasks li{counter-increment:t;display:grid;grid-template-columns:28px 1fr;gap:10px;padding:12px;border-radius:12px;border:1px solid var(--line);background:var(--surface-2);font-size:.93rem}
.tasks li::before{content:counter(t);width:26px;height:26px;border-radius:50%;display:grid;place-items:center;background:var(--surface);border:1px solid var(--line-2);font-weight:700;font-size:.8rem}
.tasks li.ok{border-color:color-mix(in srgb,var(--ok) 40%,transparent);background:var(--ok-50)}.tasks li.ok::before{content:"✓";background:var(--ok);color:#fff;border-color:var(--ok)}
.tasks li.bad{border-color:color-mix(in srgb,var(--bad) 40%,transparent);background:var(--bad-50)}.tasks .fb{grid-column:2;font-size:.85rem;color:var(--text-2);margin-top:4px}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-lg);box-shadow:var(--sh-1);overflow:hidden}.panel>.ph{display:flex;align-items:center;gap:10px;padding:12px 16px;border-bottom:1px solid var(--line);font-weight:650;background:var(--surface-2)}.panel>.pb{padding:16px}
.console{background:var(--console);color:var(--console-text);border-radius:var(--r-lg);font:14px/1.55 var(--mono);box-shadow:var(--sh-3);overflow:hidden;border:1px solid #1d2840}
.console .ch{display:flex;align-items:center;gap:8px;padding:10px 14px;background:var(--console-2);color:var(--console-dim);font:600 12px var(--font);border-bottom:1px solid #1d2840}.console .ch i{width:10px;height:10px;border-radius:50%;background:#2a3753}
.console .out{padding:14px 16px;height:min(56vh,520px);overflow:auto;white-space:pre-wrap;word-break:break-word}.console .ln{display:flex;gap:8px;align-items:center;padding:0 16px 14px}
.console .pr{color:var(--console-ok);white-space:nowrap}.console input{flex:1;background:transparent;border:0;color:var(--console-text);font:inherit;outline:none;min-height:32px}.console .dim{color:var(--console-dim)}.console .acc{color:var(--console-acc)}.console .er{color:#ff8f8f}.console .okc{color:var(--console-ok)}
.kv{display:grid;grid-template-columns:auto 1fr;gap:6px 14px;font-size:.9rem}.kv dt{color:var(--text-2)}.kv dd{margin:0;font-weight:550}
.chip-list{display:flex;flex-wrap:wrap;gap:8px}.chip{display:inline-flex;align-items:center;gap:6px;padding:8px 12px;border-radius:999px;border:1px solid var(--line-2);background:var(--surface);cursor:pointer;font:550 .88rem var(--font);color:var(--text);min-height:40px}.chip[aria-pressed=true]{background:var(--accent-50);border-color:var(--accent);color:var(--accent)}
.log-table{font:12.5px/1.45 var(--mono);width:100%;border-collapse:collapse}.log-table td,.log-table th{padding:6px 8px;border-bottom:1px solid var(--line);text-align:left;white-space:nowrap}.log-table tr.hl td{background:var(--warn-50)}.scroll-x{overflow-x:auto}
.toggle{position:relative;display:inline-flex;align-items:center;gap:10px;cursor:pointer;min-height:44px}.toggle input{appearance:none;width:44px;height:26px;border-radius:99px;background:var(--line-2);position:relative;cursor:pointer;transition:background .2s;flex:none;margin:0}.toggle input::after{content:"";position:absolute;top:3px;left:3px;width:20px;height:20px;border-radius:50%;background:#fff;box-shadow:var(--sh-1);transition:transform .2s var(--ease)}.toggle input:checked{background:var(--accent)}.toggle input:checked::after{transform:translateX(18px)}
/* guide */
.guide{display:grid;gap:32px;padding:24px 0 80px}@media(min-width:1024px){.guide{grid-template-columns:260px minmax(0,1fr)}}
.toc{position:sticky;top:92px;align-self:start;font-size:.9rem;max-height:calc(100vh - 110px);overflow:auto}.toc ol{list-style:none;padding:0;margin:0;display:grid;gap:2px}.toc a{display:flex;gap:8px;align-items:center;padding:8px 10px;border-radius:8px;color:var(--text-2);text-decoration:none;min-height:36px}.toc a:hover{background:var(--surface-2);color:var(--text)}.toc a.active{color:var(--accent);background:var(--accent-50);font-weight:600}.toc a.done::after{content:"✓";margin-left:auto;color:var(--ok);font-weight:700}
@media(max-width:1023px){.toc{position:static;max-height:none}}
.prose{max-width:72ch;font-size:1.04rem;line-height:1.75}.prose h2{margin-top:2em;padding-top:8px}.prose h3{margin-top:1.6em}.prose code{font:.9em var(--mono);background:var(--surface-2);padding:2px 6px;border-radius:6px}.prose pre{background:var(--console);color:var(--console-text);padding:16px;border-radius:12px;overflow:auto;font-size:.88rem}.prose pre code{background:none;padding:0}
.prose table{border-collapse:collapse;width:100%;font-size:.93rem;margin:1em 0}.prose th,.prose td{border:1px solid var(--line);padding:8px 10px;text-align:left}.prose blockquote{margin:1em 0;padding:12px 16px;border-left:4px solid var(--accent);background:var(--accent-50);border-radius:0 12px 12px 0}
.sec-links{display:flex;gap:8px;flex-wrap:wrap;margin:14px 0 4px;padding:12px;border-radius:12px;background:var(--surface-2);font-size:.88rem}
/* flashcards */
.flash{perspective:1200px;max-width:640px;margin:0 auto}.fcard{position:relative;min-height:280px;transform-style:preserve-3d;transition:transform .5s var(--ease);cursor:pointer}.fcard.flip{transform:rotateY(180deg)}
.fcard .face{position:absolute;inset:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;display:grid;place-items:center;text-align:center;padding:32px;border-radius:var(--r-xl);background:var(--surface);border:1px solid var(--line);box-shadow:var(--sh-2);font-size:1.15rem;line-height:1.55}.fcard .back{transform:rotateY(180deg);background:var(--accent-50)}
.boxes{display:flex;gap:6px}.boxes span{flex:1;height:6px;border-radius:99px;background:var(--surface-2)}.boxes span.on{background:var(--accent)}
/* footer */
.ftr{border-top:1px solid var(--line);background:var(--surface);padding:40px 0 28px;margin-top:40px;font-size:.92rem;color:var(--text-2)}.ftr .cols{display:grid;gap:28px;grid-template-columns:repeat(auto-fit,minmax(180px,1fr))}.ftr h4{font-size:.85rem;text-transform:uppercase;letter-spacing:.06em;color:var(--text-3)}.ftr a{color:var(--text-2);text-decoration:none;display:inline-block;padding:4px 0}.ftr a:hover{color:var(--accent)}.ftr .legal{margin-top:28px;padding-top:20px;border-top:1px solid var(--line);font-size:.82rem;color:var(--text-3)}
.reveal{opacity:0;transform:translateY(12px);transition:opacity .6s var(--ease),transform .6s var(--ease)}.reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}.reveal{opacity:1;transform:none}}
.spin{width:18px;height:18px;border-radius:50%;border:2px solid currentColor;border-right-color:transparent;animation:sp .8s linear infinite;display:inline-block}@keyframes sp{to{transform:rotate(360deg)}}
.toast{position:fixed;left:50%;bottom:90px;transform:translateX(-50%);background:var(--text);color:var(--bg);padding:10px 16px;border-radius:12px;box-shadow:var(--sh-3);z-index:80;font-weight:550;font-size:.92rem}
/* v2.1 additions: readiness, video facade, tooltip, misc */
.free{display:inline-flex;align-items:center;gap:4px;padding:2px 8px;border-radius:999px;font:700 .7rem/1.4 var(--font);letter-spacing:.06em;text-transform:uppercase;background:var(--ok-50);color:var(--ok)}
.rd-pill{display:inline-flex;align-items:center;gap:8px;padding:6px 12px 6px 6px;border-radius:999px;background:var(--surface-2);border:1px solid var(--line);font-weight:650;font-size:.88rem;color:var(--text);text-decoration:none;min-height:44px}
.rd-pill .ring.xs{width:32px;height:32px}.ring.xs::before{width:24px;height:24px;font-size:.62rem}
.tip{position:relative;display:inline-flex}.tip>button{border:0;background:none;color:var(--text-3);cursor:help;width:32px;height:32px;display:grid;place-items:center;border-radius:8px}.tip>button:hover{color:var(--text)}
.tip .tipbox{position:absolute;z-index:60;top:calc(100% + 6px);right:0;width:min(340px,86vw);padding:14px 16px;border-radius:12px;background:var(--text);color:var(--bg);font-size:.84rem;line-height:1.5;box-shadow:var(--sh-3);display:none;text-align:left;font-weight:450}
.tip:hover .tipbox,.tip:focus-within .tipbox,.tip.open .tipbox{display:block}.tipbox b{color:inherit}.tipbox ul{margin:6px 0 0;padding-left:18px}
.yt{position:relative;aspect-ratio:16/9;border-radius:14px;overflow:hidden;background:#000;max-width:640px;margin:14px 0}.yt button{all:unset;cursor:pointer;position:absolute;inset:0;display:block}
.yt img{width:100%;height:100%;object-fit:cover;opacity:.85;transition:opacity .2s}.yt button:hover img{opacity:1}.yt .play{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);width:68px;height:48px;border-radius:14px;background:rgba(220,38,38,.92);display:grid;place-items:center;color:#fff}
.yt .cap{position:absolute;left:0;right:0;bottom:0;padding:28px 14px 10px;background:linear-gradient(transparent,rgba(0,0,0,.8));color:#fff;font-size:.86rem;line-height:1.35}.yt iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.vid-block{border:1px solid var(--line);border-radius:14px;padding:14px 16px;background:var(--surface);margin:16px 0}.vid-block h4{display:flex;align-items:center;gap:8px;margin:0 0 4px;font-size:.95rem}.vid-grid{display:grid;gap:14px;grid-template-columns:repeat(auto-fill,minmax(min(100%,260px),1fr))}.vid-grid .yt{margin:6px 0}
.readiness{display:grid;gap:24px}@media(min-width:860px){.readiness{grid-template-columns:auto 1fr}}.ring.xl{width:150px;height:150px}.ring.xl::before{width:118px;height:118px;font-size:2rem}
.dom-row{display:grid;grid-template-columns:minmax(0,1fr) 54px;gap:4px 12px;align-items:center;padding:8px 0;border-bottom:1px solid var(--line)}.dom-row .bar{grid-column:1/-1}.dom-row .nm{font-size:.92rem;font-weight:550}.dom-row .pc{text-align:right;font-weight:700;font-size:.9rem}
.next{border-radius:var(--r-lg);padding:18px 20px;background:linear-gradient(135deg,var(--accent-50),var(--surface));border:1px solid var(--accent-100)}
.inputs{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:10px}.inputs div{padding:12px;border-radius:12px;background:var(--surface-2)}.inputs b{display:block;font-size:1.2rem}.inputs span{font-size:.8rem;color:var(--text-2)}
.lab-card .meta{display:flex;gap:6px;flex-wrap:wrap;margin-top:10px}
.form-grid{display:grid;gap:14px;grid-template-columns:repeat(auto-fit,minmax(min(100%,220px),1fr))}
.edit-table{width:100%;border-collapse:collapse;font-size:.9rem}.edit-table th,.edit-table td{padding:6px;border-bottom:1px solid var(--line);text-align:left}.edit-table .input{min-height:40px;padding:7px 10px;font-size:.9rem}
textarea.code{font:13px/1.5 var(--mono);min-height:320px;background:var(--console);color:var(--console-text);border-color:#1d2840;tab-size:2}
.sim-row{display:flex;justify-content:space-between;gap:10px;padding:8px 10px;border-radius:10px;font-size:.88rem;align-items:center}.sim-row:nth-child(odd){background:var(--surface-2)}
.gantt{display:grid;gap:6px;font-size:.82rem}.gantt .gr{display:grid;grid-template-columns:28px 1fr;gap:8px;align-items:center}.gantt .gb{height:18px;border-radius:6px;background:var(--line-2)}.gantt .gb.c{background:var(--accent)}
.email-view{border:1px solid var(--line);border-radius:14px;background:var(--surface);overflow:hidden}.email-view .eh{padding:14px 18px;border-bottom:1px solid var(--line);font-size:.9rem}.email-view .eb{padding:20px 18px}
.fake-btn{display:inline-block;background:#2457d6;color:#fff;padding:10px 18px;border-radius:6px;text-decoration:none;font-weight:600}
.headers{font:12px/1.5 var(--mono);white-space:pre-wrap;background:var(--surface-2);padding:14px;border-radius:12px;max-height:340px;overflow:auto}
.console-bench{background:var(--console);color:var(--console-text);border-radius:14px;padding:14px;font-size:.88rem}.console-bench .msg{padding:10px 12px;border-radius:10px;background:var(--console-2);margin:8px 0}.console-bench .u{color:var(--console-acc)}.console-bench .blk{color:#ffb86b}
.ai-console{display:grid;gap:16px}@media(min-width:1200px){.ai-console{grid-template-columns:1fr 1fr}}
.slider{width:100%;accent-color:var(--accent);min-height:32px}
.sticky-actions{position:sticky;bottom:0;padding:12px 0;background:linear-gradient(transparent,var(--surface) 30%);display:flex;gap:10px;flex-wrap:wrap}
.logo-word{font-weight:750}
.feature-ico{display:inline-grid;place-items:center;width:40px;height:40px;border-radius:12px;background:var(--accent-50);color:var(--accent)}
.disclaimer{font-size:.82rem;color:var(--text-3)}
.mode-cards{display:grid;gap:14px;grid-template-columns:repeat(auto-fit,minmax(min(100%,220px),1fr))}.mode-cards label{display:block;cursor:pointer}.mode-cards input{position:absolute;opacity:0}.mode-cards .card{height:100%}.mode-cards input:checked+.card{border-color:var(--accent);box-shadow:0 0 0 2px var(--accent) inset}.mode-cards input:focus-visible+.card{outline:3px solid var(--accent)}
.streak{display:flex;gap:4px}.streak i{width:14px;height:14px;border-radius:4px;background:var(--surface-2)}.streak i.on{background:var(--accent)}
/* subscriber content is not printable (no downloads/exports); screen readers and on-screen use are unaffected */
@media print{body.gated main,body.gated .exam-foot{display:none!important}body.gated::after{content:"SteadfastIQ subscriber content can't be printed. Study online at steadfastiq.com.";display:block;padding:40px;font:16px/1.5 sans-serif}}
.sample .opt{width:100%;text-align:left;font:inherit;color:inherit}
.paywall{max-width:560px;margin:40px auto;text-align:center}
/* v2.2 lab UI helpers */
.grid.two{grid-template-columns:repeat(auto-fit,minmax(min(100%,380px),1fr))}
.switch{display:inline-flex;align-items:center;gap:10px;cursor:pointer;font-size:.92rem;min-height:36px}.switch input{width:20px;height:20px;accent-color:var(--accent)}
.console .ln:focus-within{box-shadow:inset 0 -2px 0 var(--console-acc)}
#lab-ui input[type=range]{width:100%;accent-color:var(--accent)}
.edit-table input[type=checkbox]{width:20px;height:20px;accent-color:var(--accent)}