/* ==========================================================================
   ECL & ALCPT English Trainer - website styles
   Navy carries the structure, brass marks action and state, the answer
   sheet (A-D bubbles, scanner timing marks) is the one signature element.
   ========================================================================== */
@font-face{font-family:'Barlow';font-style:normal;font-weight:400;font-display:swap;src:url('fonts/barlow-400.woff2') format('woff2')}
@font-face{font-family:'Barlow';font-style:italic;font-weight:400;font-display:swap;src:url('fonts/barlow-400-italic.woff2') format('woff2')}
@font-face{font-family:'Barlow';font-style:normal;font-weight:500;font-display:swap;src:url('fonts/barlow-500.woff2') format('woff2')}
@font-face{font-family:'Barlow';font-style:normal;font-weight:600;font-display:swap;src:url('fonts/barlow-600.woff2') format('woff2')}
@font-face{font-family:'Barlow Semi Condensed';font-style:normal;font-weight:600;font-display:swap;src:url('fonts/barlow-semi-condensed-600.woff2') format('woff2')}
@font-face{font-family:'Barlow Semi Condensed';font-style:normal;font-weight:700;font-display:swap;src:url('fonts/barlow-semi-condensed-700.woff2') format('woff2')}

:root{
  --paper:#EDF1F6; --paper-2:#E3E9F1; --sheet:#FFFFFF; --sheet-2:#F5F7FA;
  --ink:#14243D; --ink-2:#4F5F77; --rule:#D3DCE8; --rule-2:#E4E9F1;
  --navy:#142B4D; --navy-deep:#0B1A30; --on-navy:#FFFFFF; --navy-mut:#B9C6DA;
  --brass:#C08A2E; --brass-ink:#8A5F14; --on-brass:#24180A; --brass-soft:#F3E5C8;
  --link:#0B6E99; --kw:#0B6E99; --kw-bg:#E2F1F8;
  --ok:#1E8657; --ok-bg:#E6F4EC; --bad:#C0392B; --bad-bg:#FBEAE8;
  --mark:#14243D;
  --shadow:0 1px 2px rgba(20,36,61,.06),0 10px 28px rgba(20,36,61,.09);
  --display:'Barlow Semi Condensed','Arial Narrow',sans-serif;
  --text:'Barlow',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;
  --wrap:1160px; --measure:42rem;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --paper:#0A1830; --paper-2:#0D1F3B; --sheet:#13294C; --sheet-2:#102443;
    --ink:#EEF3FA; --ink-2:#A9B9D1; --rule:#23416B; --rule-2:#1B355B;
    --navy:#183463; --navy-deep:#06101F; --navy-mut:#BCCAE0;
    --brass:#D9A441; --brass-ink:#EBC572; --on-brass:#0A1830; --brass-soft:#3A3014;
    --link:#5BD0F0; --kw:#5BD0F0; --kw-bg:rgba(91,208,240,.14);
    --ok:#3DB37A; --ok-bg:rgba(61,179,122,.16); --bad:#E36A5E; --bad-bg:rgba(227,106,94,.15);
    --mark:#EEF3FA; --shadow:0 12px 30px rgba(0,0,0,.35);
    color-scheme:dark;
  }
}
:root[data-theme="dark"]{
  --paper:#0A1830; --paper-2:#0D1F3B; --sheet:#13294C; --sheet-2:#102443;
  --ink:#EEF3FA; --ink-2:#A9B9D1; --rule:#23416B; --rule-2:#1B355B;
  --navy:#183463; --navy-deep:#06101F; --navy-mut:#BCCAE0;
  --brass:#D9A441; --brass-ink:#EBC572; --on-brass:#0A1830; --brass-soft:#3A3014;
  --link:#5BD0F0; --kw:#5BD0F0; --kw-bg:rgba(91,208,240,.14);
  --ok:#3DB37A; --ok-bg:rgba(61,179,122,.16); --bad:#E36A5E; --bad-bg:rgba(227,106,94,.15);
  --mark:#EEF3FA; --shadow:0 12px 30px rgba(0,0,0,.35);
  color-scheme:dark;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:88px}
body{margin:0;background:var(--paper);color:var(--ink);font:400 17px/1.6 var(--text);
  text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased}
img,svg{max-width:100%;height:auto}
a{color:var(--link);text-underline-offset:.18em;text-decoration-thickness:1px}
a:hover{text-decoration-thickness:2px}
h1,h2,h3,h4{font-family:var(--display);font-weight:700;line-height:1.12;margin:0 0 .5em;letter-spacing:.005em}
h1{font-size:clamp(2.1rem,1.5rem + 2.2vw,3.2rem)}
h2{font-size:clamp(1.6rem,1.3rem + 1vw,2.1rem)}
h3{font-size:1.3rem;font-weight:600}
p{margin:0 0 1em}
:focus-visible{outline:3px solid var(--brass);outline-offset:2px;border-radius:6px}
.skip{position:absolute;left:-999px;top:8px;background:var(--sheet);padding:8px 14px;border-radius:8px;z-index:100}
.skip:focus{left:12px}
.wrap{max-width:var(--wrap);margin:0 auto;padding:0 24px}
.muted{color:var(--ink-2)}
[hidden]{display:none!important}
.visually-hidden{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* ------------------------------- buttons -------------------------------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:.55em;min-height:48px;padding:0 22px;
  border-radius:10px;border:2px solid transparent;font:600 1.08rem/1 var(--display);letter-spacing:.01em;
  text-decoration:none;cursor:pointer;transition:background-color .15s,border-color .15s,color .15s}
.btn svg{width:20px;height:20px;flex:none}
.btn-brass{background:var(--brass);color:var(--on-brass)}
.btn-brass:hover{background:#B07C24;color:var(--on-brass)}
.btn-navy{background:var(--navy);color:var(--on-navy)}
.btn-navy:hover{background:#0F2140;color:var(--on-navy)}
.btn-line{background:transparent;color:var(--ink);border-color:var(--rule)}
.btn-line:hover{border-color:var(--ink)}
.btn-small{min-height:40px;padding:0 16px;font-size:1rem}
.text-link{font-weight:600}

/* -------------------------------- header -------------------------------- */
.site-header{position:sticky;top:0;z-index:50;background:color-mix(in srgb,var(--paper) 92%,transparent);
  backdrop-filter:saturate(1.4) blur(10px);-webkit-backdrop-filter:saturate(1.4) blur(10px);border-bottom:1px solid var(--rule)}
.site-header .wrap{display:flex;align-items:center;gap:20px;height:68px}
.brand{display:flex;align-items:center;gap:12px;color:var(--ink);text-decoration:none;min-width:0}
.brand img{width:38px;height:38px;border-radius:10px;flex:none;box-shadow:0 1px 4px rgba(10,24,48,.25)}
.brand span{font:700 1.22rem/1.05 var(--display);white-space:nowrap}
.brand small{display:block;font:500 .78rem/1.2 var(--text);color:var(--ink-2)}
.nav{display:flex;align-items:center;gap:4px;margin-left:auto}
.nav a{color:var(--ink);text-decoration:none;font-weight:500;padding:8px 12px;border-radius:8px}
.nav a:hover{background:var(--paper-2)}
.nav a[aria-current="page"]{color:var(--brass-ink);font-weight:600}
.nav .btn{margin-left:10px}
.nav a.btn-navy{color:var(--on-navy);padding:0 16px}
.nav a.btn-navy:hover{background:#0F2140}
.menu-btn{display:none;margin-left:auto;background:none;border:1px solid var(--rule);border-radius:10px;
  width:44px;height:44px;color:var(--ink);cursor:pointer}
.menu-btn svg{width:22px;height:22px}
@media (max-width:900px){
  .site-header .wrap{height:60px;gap:12px}
  .brand span{font-size:1.06rem}
  .brand small{display:none}
  .menu-btn{display:inline-grid;place-items:center}
  .nav{display:none;position:absolute;left:0;right:0;top:60px;flex-direction:column;align-items:stretch;
    background:var(--sheet);border-bottom:1px solid var(--rule);padding:8px 16px 16px;box-shadow:var(--shadow)}
  .nav.open{display:flex}
  .nav a{padding:12px}
  .nav .btn{margin:8px 0 0}
}

/* --------------------------------- hero --------------------------------- */
.hero{padding:56px 0 64px}
.hero .wrap{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);gap:56px;align-items:center}
.hero h1{max-width:17ch;margin-bottom:.4em}
.lede{font-size:1.18rem;color:var(--ink-2);max-width:34rem}
.cta-row{display:flex;flex-wrap:wrap;align-items:center;gap:14px 18px;margin:28px 0 14px}
.fine{font-size:.92rem;color:var(--ink-2)}
@media (max-width:980px){
  .hero{padding:32px 0 48px}
  .hero .wrap{grid-template-columns:1fr;gap:36px}
}

/* ------------------- answer sheet (signature element) ------------------- */
.sheet{position:relative;background:var(--sheet);border-radius:16px;box-shadow:var(--shadow);
  padding:22px 26px 22px 54px;border:1px solid var(--rule-2)}
.sheet::before{content:"";position:absolute;left:18px;top:22px;bottom:22px;width:12px;
  background:repeating-linear-gradient(to bottom,var(--mark) 0 7px,transparent 7px 24px);opacity:.88;border-radius:1px}
.sheet-head{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:12px;color:var(--ink-2);font-size:.95rem}
.sheet-head b{font:700 1.05rem var(--display);color:var(--ink)}
.listen{display:inline-flex;align-items:center;gap:6px;background:var(--sheet-2);border:1px solid var(--rule);color:var(--ink);
  border-radius:999px;padding:6px 14px;font:600 .95rem var(--display);cursor:pointer}
.listen svg{width:18px;height:18px}
.listen[aria-pressed="true"]{border-color:var(--brass);color:var(--brass-ink)}
.sheet-q{font-size:1.24rem;line-height:1.45;margin:0 0 16px;font-weight:500}
.sheet-q .kw,.kw{color:var(--kw);background:var(--kw-bg);border-radius:5px;padding:0 4px;font-weight:600}
.bubbles{list-style:none;margin:0;padding:0;display:grid;gap:8px}
.bub{width:100%;display:flex;align-items:center;gap:14px;text-align:left;background:transparent;color:var(--ink);
  border:1px solid var(--rule);border-radius:12px;padding:10px 14px;font:500 1.06rem/1.35 var(--text);cursor:pointer;
  transition:border-color .15s,background-color .15s}
.bub:hover:not(:disabled){border-color:var(--ink)}
.bub .b{flex:none;display:inline-grid;place-items:center;width:30px;height:30px;border-radius:50%;
  border:2px solid var(--ink-2);font:700 .95rem var(--display);color:var(--ink-2);transition:all .15s}
.bub:disabled{cursor:default}
.bub.pick .b{background:var(--navy);border-color:var(--navy);color:#fff}
.bub.right{border-color:var(--ok);background:var(--ok-bg)}
.bub.right .b{background:var(--ok);border-color:var(--ok);color:#fff}
.bub.wrong{border-color:var(--bad);background:var(--bad-bg)}
.bub.wrong .b{background:var(--bad);border-color:var(--bad);color:#fff}
.sheet-fb{min-height:0}
.correction{margin-top:14px;border-left:4px solid var(--ok);background:var(--sheet-2);border-radius:0 10px 10px 0;padding:12px 16px}
.correction.bad{border-left-color:var(--bad)}
.correction p{margin:0}
.correction p+p{margin-top:4px;color:var(--ink-2)}
.sheet-foot{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px;margin-top:16px}
.sheet-foot .progress{display:flex;gap:6px}
.sheet-foot .progress i{width:10px;height:10px;border-radius:50%;border:2px solid var(--ink-2)}
.sheet-foot .progress i.done-ok{background:var(--ok);border-color:var(--ok)}
.sheet-foot .progress i.done-bad{background:var(--bad);border-color:var(--bad)}
@media (max-width:560px){.sheet{padding:18px 16px 18px 40px}.sheet::before{left:12px;width:9px}}

/* ------------------------------- sections ------------------------------- */
.band{padding:72px 0}
.band-tight{padding:48px 0}
.band h2{max-width:24ch}
.section-intro{color:var(--ink-2);max-width:var(--measure);margin-bottom:28px}
.alt{background:var(--sheet);border-top:1px solid var(--rule-2);border-bottom:1px solid var(--rule-2)}

/* subject index: one row per area, count on the right */
.index{list-style:none;margin:0;padding:0;border-top:2px solid var(--ink)}
.index li{display:grid;grid-template-columns:minmax(0,1fr) auto auto;gap:8px 28px;align-items:center;
  padding:20px 4px;border-bottom:1px solid var(--rule)}
.index h3{margin:0 0 2px;font-size:1.35rem}
.index p{margin:0;color:var(--ink-2)}
.index .count{font:700 2.1rem/1 var(--display);font-variant-numeric:tabular-nums;color:var(--ink);text-align:right}
.index .count small{display:block;font:500 .8rem var(--text);color:var(--ink-2)}
@media (max-width:640px){.index li{grid-template-columns:minmax(0,1fr) auto}.index li .btn{grid-column:1/-1;justify-self:start}}

/* sequence (it is one: a practice session) */
.steps{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:36px;counter-reset:s}
.steps li{counter-increment:s;position:relative;padding-top:56px}
.steps li::before{content:counter(s);position:absolute;top:0;left:0;width:40px;height:40px;border-radius:50%;
  border:2px solid var(--ink);display:grid;place-items:center;font:700 1.15rem var(--display)}
.steps li:not(:last-child)::after{content:"";position:absolute;top:20px;left:52px;right:-24px;border-top:2px dotted var(--rule)}
.steps h3{margin-bottom:6px}
.steps p{color:var(--ink-2);margin:0}
@media (max-width:820px){.steps{grid-template-columns:1fr;gap:28px}.steps li:not(:last-child)::after{display:none}}

/* app band: the one dark band on the page */
.appband{background:var(--navy);color:var(--on-navy)}
.appband .wrap{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(0,.9fr);gap:48px;align-items:center}
.appband h2{color:#fff}
.appband p,.appband li{color:var(--navy-mut)}
.appband ul{padding-left:1.1em;margin:0 0 24px}
.appband li{margin:6px 0}
.appband li b{color:#fff;font-weight:600}
.qr-card{background:#fff;color:#14243D;border-radius:16px;padding:22px;display:grid;justify-items:center;gap:10px;max-width:300px;margin-left:auto}
.qr-card svg{width:200px;height:200px}
.qr-card p{margin:0;color:#4F5F77;font-size:.92rem;text-align:center}
.android-only{font-size:.9rem;color:var(--navy-mut)}
@media (max-width:860px){.appband .wrap{grid-template-columns:1fr}.qr-card{margin:0}}

/* guide list */
.guide-list{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 48px}
.guide-list li{padding:18px 0;border-bottom:1px solid var(--rule)}
.guide-list a{font:600 1.25rem/1.25 var(--display);text-decoration:none;color:var(--ink)}
.guide-list a:hover{color:var(--link)}
.guide-list p{margin:4px 0 0;color:var(--ink-2)}
@media (max-width:760px){.guide-list{grid-template-columns:1fr}}

/* FAQ */
.faq{max-width:48rem}
.faq details{border-bottom:1px solid var(--rule)}
.faq summary{list-style:none;cursor:pointer;padding:18px 40px 18px 0;position:relative;font:600 1.2rem/1.3 var(--display)}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"";position:absolute;right:6px;top:50%;width:12px;height:12px;margin-top:-8px;
  border-right:2px solid var(--ink);border-bottom:2px solid var(--ink);transform:rotate(45deg);transition:transform .2s}
.faq details[open] summary::after{transform:rotate(225deg);margin-top:-2px}
.faq details>div{padding:0 0 18px;color:var(--ink-2)}

/* -------------------------------- footer -------------------------------- */
.site-footer{background:var(--navy-deep);color:#C9D4E5;padding:56px 0 36px;font-size:.95rem}
.site-footer a{color:#fff;text-decoration:none}
.site-footer a:hover{text-decoration:underline}
.foot-grid{display:grid;grid-template-columns:1.4fr repeat(3,1fr);gap:32px}
.foot-grid h2{font:600 1rem var(--display);color:#fff;margin:0 0 10px;letter-spacing:.02em}
.foot-grid ul{list-style:none;margin:0;padding:0}
.foot-grid li{margin:6px 0}
.foot-brand{display:flex;gap:12px;align-items:flex-start}
.foot-brand img{width:44px;height:44px;border-radius:11px}
.foot-brand b{display:block;color:#fff;font:700 1.15rem var(--display)}
.disclaimer{border-top:1px solid rgba(255,255,255,.14);margin-top:36px;padding-top:20px;color:#9FB0C6;font-size:.88rem;max-width:62rem}
.linkbtn{background:none;border:0;padding:0;color:#fff;font:inherit;cursor:pointer}
.linkbtn:hover{text-decoration:underline}
@media (max-width:820px){.foot-grid{grid-template-columns:1fr 1fr}.foot-grid>div:first-child{grid-column:1/-1}}

/* ------------------------------- articles ------------------------------- */
.page-head{padding-top:40px;padding-bottom:8px}
.crumbs{font-size:.92rem;color:var(--ink-2);margin-bottom:14px}
.crumbs a{color:var(--ink-2)}
.dek{font-size:1.18rem;color:var(--ink-2);max-width:var(--measure)}
.layout{display:grid;grid-template-columns:minmax(0,var(--measure)) 300px;gap:64px;align-items:start;padding:20px 24px 72px}
.layout.single{grid-template-columns:minmax(0,var(--measure))}
.prose h2{margin-top:1.8em;font-size:1.75rem}
.prose h3{margin-top:1.4em}
.prose ul,.prose ol{padding-left:1.3em}
.prose li{margin:.35em 0}
.prose table{border-collapse:collapse;width:100%;margin:1em 0 1.5em;font-size:.98rem}
.prose th,.prose td{text-align:left;border-bottom:1px solid var(--rule);padding:10px 12px 10px 0;vertical-align:top}
.prose th{font:600 1rem var(--display)}
.prose blockquote{margin:1.2em 0;padding:4px 0 4px 18px;border-left:4px solid var(--brass);color:var(--ink-2)}
.note-box{background:var(--sheet);border:1px solid var(--rule);border-left:4px solid var(--brass);border-radius:0 12px 12px 0;padding:16px 20px;margin:1.5em 0}
.note-box p:last-child{margin:0}
.sources{font-size:.92rem;color:var(--ink-2);border-top:1px solid var(--rule);margin-top:2.5em;padding-top:1em}
.sources ul{padding-left:1.2em}
.updated{font-size:.9rem;color:var(--ink-2)}
.aside{align-self:stretch;display:flex;flex-direction:column;gap:20px}
.aside-card{background:var(--sheet);border:1px solid var(--rule-2);border-radius:14px;padding:20px;box-shadow:var(--shadow)}
.aside-card h2{font-size:1.25rem;margin-bottom:6px}
.aside-card p{font-size:.95rem;color:var(--ink-2)}
.aside-card .btn{width:100%}
.aside-card.app{display:grid;gap:10px;justify-items:center;text-align:center}
.aside-card.app svg.qr{width:150px;height:150px;background:#fff;border-radius:8px;padding:6px}
@media (max-width:980px){.layout{grid-template-columns:1fr;gap:32px}.aside{align-self:auto}}

/* ad slots: collapse while empty or unfilled */
.ad-slot{margin:36px 0;min-height:0}
.ad-slot:empty{display:none}
.ad-slot .ad-label{display:block;font-size:.75rem;color:var(--ink-2);margin-bottom:4px}
ins.adsbygoogle[data-ad-status="unfilled"]{display:none!important}
.ad-slot:has(ins[data-ad-status="unfilled"]){display:none}

/* ----------------------------- topic pages ------------------------------ */
.qlist,.prose .qlist{list-style:none;margin:1.2em 0 0;padding:0;counter-reset:q}
.qlist>li{counter-increment:q;border-top:1px solid var(--rule);padding:20px 0 18px 44px;position:relative}
.qlist>li::before{content:counter(q);position:absolute;left:0;top:20px;width:30px;height:30px;border-radius:50%;
  border:2px solid var(--ink-2);display:grid;place-items:center;font:700 .9rem var(--display);color:var(--ink-2)}
.qlist .q{font-weight:500;font-size:1.08rem;margin:0 0 8px}
.qlist .opts{list-style:none;margin:0 0 8px;padding:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 24px}
.qlist .opts li{color:var(--ink-2)}
.qlist .opts b{font-family:var(--display);color:var(--ink);margin-right:6px}
.qlist details summary{cursor:pointer;color:var(--link);font-weight:600;width:max-content}
.qlist details p{margin:8px 0 0}
.qlist .ans{color:var(--ok);font-weight:600}
@media (max-width:560px){.qlist .opts{grid-template-columns:1fr}}
.cta-box{background:var(--navy);color:#fff;border-radius:16px;padding:24px 26px;margin:2em 0;display:flex;flex-wrap:wrap;
  align-items:center;justify-content:space-between;gap:16px}
.cta-box p{margin:0;color:var(--navy-mut)}
.cta-box b{color:#fff;font:700 1.3rem var(--display);display:block}
.filter{display:flex;gap:10px;align-items:center;margin:1em 0}
.filter input{flex:1;min-height:46px;border-radius:10px;border:1px solid var(--rule);background:var(--sheet);color:var(--ink);
  padding:0 14px;font:inherit}
.letters{display:flex;flex-wrap:wrap;gap:6px;margin:1em 0}
.letters a{display:inline-grid;place-items:center;min-width:34px;height:34px;border-radius:8px;border:1px solid var(--rule);
  text-decoration:none;font:600 1rem var(--display);color:var(--ink)}
.idioms dt{font:600 1.2rem var(--display);margin-top:18px}
.idioms dd{margin:2px 0 0}
.idioms dd.ex{color:var(--ink-2);font-style:italic}
.idioms h2{border-bottom:2px solid var(--ink);padding-bottom:4px;margin-top:1.6em}
.verbs{font-variant-numeric:tabular-nums}
.verbs thead th{position:sticky;top:68px;background:var(--paper)}
.topic-grid{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 48px}
.topic-grid li{display:flex;justify-content:space-between;gap:16px;padding:14px 0;border-bottom:1px solid var(--rule)}
.topic-grid a{font:600 1.15rem var(--display);text-decoration:none;color:var(--ink)}
.topic-grid a:hover{color:var(--link)}
.topic-grid span{color:var(--ink-2);white-space:nowrap}
@media (max-width:700px){.topic-grid{grid-template-columns:1fr}}

/* ============================ study material ============================ */
:root{
  --c1:#2F6FDE;--c1-ink:#1D4FA8;--c1-soft:#E9F0FD;  --c2:#1E8657;--c2-ink:#166B45;--c2-soft:#E3F3EA;
  --c3:#C98A12;--c3-ink:#87590A;--c3-soft:#FBF0D9;  --c4:#C0392B;--c4-ink:#9D2C20;--c4-soft:#FBE9E7;
  --c5:#7B4FA2;--c5-ink:#62398A;--c5-soft:#F2EAF9;  --c6:#1D7A70;--c6-ink:#14625A;--c6-soft:#E0F2EF;
  --c7:#C2571A;--c7-ink:#99410F;--c7-soft:#FCEBDD;  --on-th:#FFFFFF;
}
.c1{--c:var(--c1);--c-ink:var(--c1-ink);--c-soft:var(--c1-soft)}
.c2{--c:var(--c2);--c-ink:var(--c2-ink);--c-soft:var(--c2-soft)}
.c3{--c:var(--c3);--c-ink:var(--c3-ink);--c-soft:var(--c3-soft)}
.c4{--c:var(--c4);--c-ink:var(--c4-ink);--c-soft:var(--c4-soft)}
.c5{--c:var(--c5);--c-ink:var(--c5-ink);--c-soft:var(--c5-soft)}
.c6{--c:var(--c6);--c-ink:var(--c6-ink);--c-soft:var(--c6-soft)}
.th-grammar{--th:var(--c1);--th-ink:var(--c1-ink);--th-soft:var(--c1-soft)}
.th-vocab{--th:var(--c6);--th-ink:var(--c6-ink);--th-soft:var(--c6-soft)}
.th-phrasal{--th:var(--c7);--th-ink:var(--c7-ink);--th-soft:var(--c7-soft)}
.th-idioms{--th:var(--c5);--th-ink:var(--c5-ink);--th-soft:var(--c5-soft)}

.btn-th{background:var(--th);color:var(--on-th)}
.btn-th:hover{filter:brightness(.93);color:var(--on-th)}
.btn[aria-pressed="true"]{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.lbadge{flex:none;display:inline-grid;place-items:center;min-width:64px;height:64px;padding:0 10px;border-radius:16px;
  background:var(--c);color:var(--on-th);font:700 1.45rem/1 var(--display);letter-spacing:.01em;
  box-shadow:0 6px 16px color-mix(in srgb,var(--c) 32%,transparent)}

/* lesson page */
.lesson-head .lh{display:flex;gap:18px;align-items:center;margin-bottom:10px}
.kicker{margin:0 0 6px;font:600 .8rem/1.2 var(--text);letter-spacing:.07em;text-transform:uppercase;color:var(--th-ink)}
.lesson-head h1{margin:0;font-size:clamp(1.9rem,1.4rem + 1.8vw,2.8rem)}
.lesson-head .dek{max-width:48rem}
.ltools{display:flex;flex-wrap:wrap;gap:10px;margin:18px 0 14px}
.chips{display:flex;flex-wrap:wrap;gap:8px;margin:4px 0 0}
.chips a{display:inline-flex;align-items:center;min-height:34px;padding:0 13px;border-radius:999px;border:1px solid var(--rule);
  background:var(--sheet);color:var(--ink);font:600 .95rem var(--display);text-decoration:none;transition:all .15s}
.chips a:hover{border-color:var(--th);color:var(--th-ink)}
.chips a[aria-current="true"]{background:var(--th);border-color:var(--th);color:var(--on-th)}
.chips a.chip-q{border-color:var(--brass);color:var(--brass-ink)}
.lesson .lsec{scroll-margin-top:88px}
.lesson .lsec>h2{display:flex;align-items:center;gap:12px}
.lesson .lsec>h2::before{content:"";flex:none;width:6px;height:1.05em;border-radius:3px;background:var(--th)}
.rule{background:var(--sheet);border:1px solid var(--rule-2);border-top:5px solid var(--c);border-radius:14px;
  padding:16px 18px 12px;margin:1.3em 0;box-shadow:var(--shadow)}
.prose .rule-name{margin:0 0 8px;font:700 1.25rem/1.15 var(--display);color:var(--c-ink)}
.rule-form{display:inline-block;margin:0 0 8px;padding:6px 12px;border-radius:9px;background:var(--c-soft);color:var(--c-ink);
  font:600 1.02rem/1.4 var(--display)}
.rule-use{margin:0 0 4px;color:var(--ink-2)}
.rule .kw{color:var(--c-ink);background:var(--c-soft)}
.rule .sig{margin:8px 0 2px;font-size:.95rem;color:var(--ink-2)}
.exs,.prose .exs{list-style:none;margin:10px 0 4px;padding:0}
.prose .exs li,.exs li{display:flex;align-items:flex-start;gap:10px;margin:0;padding:7px 0;border-top:1px dashed var(--rule)}
.exs li:first-child{border-top:0}
.say{flex:none;display:inline-grid;place-items:center;width:32px;height:32px;margin-top:-2px;border-radius:50%;border:1px solid var(--rule);
  background:var(--sheet-2);color:var(--th,var(--link));cursor:pointer;transition:background-color .15s,color .15s,border-color .15s}
.say svg{width:16px;height:16px}
.say:hover{border-color:var(--th,var(--link))}
.say[aria-pressed="true"]{background:var(--th,var(--link));color:var(--on-th);border-color:transparent}
html.no-voice .say{display:none}
.ltable-wrap{margin:1.1em 0 1.4em;border:1px solid var(--rule-2);border-radius:12px;overflow:hidden;background:var(--sheet)}
.prose .ltable{margin:0;font-size:.97rem}
.prose .ltable thead th{background:var(--th-soft);color:var(--th-ink);font:700 .98rem/1.25 var(--display);padding:10px 12px;border-bottom:2px solid var(--th)}
.prose .ltable td{padding:10px 12px;border-bottom:1px solid var(--rule-2)}
.prose .ltable tbody tr:last-child td{border-bottom:0}
.prose .ltable tbody tr:nth-child(even) td{background:var(--sheet-2)}
.prose .ltable td:first-child{font-weight:600}
@media (max-width:640px){
  .prose .ltable thead{display:none}
  .prose .ltable,.prose .ltable tbody,.prose .ltable tr,.prose .ltable td{display:block;width:100%}
  .prose .ltable tr{padding:10px 14px;border-bottom:1px solid var(--rule-2)}
  .prose .ltable tbody tr:last-child{border-bottom:0}
  .prose .ltable tbody tr:nth-child(even) td{background:none}
  .prose .ltable tbody tr:nth-child(even){background:var(--sheet-2)}
  .prose .ltable td{border:0;padding:3px 0}
  .prose .ltable td::before{content:attr(data-th);display:block;font:700 .72rem/1.4 var(--text);letter-spacing:.06em;text-transform:uppercase;color:var(--th-ink)}
  .prose .ltable td.empty{display:none}
}
.mistakes{margin:1.3em 0}
.m-label{margin:0 0 8px;font:700 .78rem/1.2 var(--text);letter-spacing:.07em;text-transform:uppercase;color:var(--bad)}
.mistakes ul,.prose .mistakes ul{list-style:none;margin:0;padding:0;display:grid;gap:8px}
.prose .mistakes li{margin:0;display:grid;grid-template-columns:1fr 1fr;border-radius:12px;overflow:hidden;border:1px solid var(--rule-2)}
.mistakes .no,.mistakes .yes{display:flex;gap:8px;align-items:flex-start;padding:10px 14px;font-size:.98rem}
.mistakes .no{background:var(--bad-bg)}
.mistakes .no>b{color:var(--bad)}
.mistakes .yes{background:var(--ok-bg)}
.mistakes .yes>b{color:var(--ok)}
@media (max-width:640px){.prose .mistakes li{grid-template-columns:1fr}}
.tip,.note{margin:1.3em 0;padding:14px 18px;border-radius:12px}
.tip{background:var(--brass-soft);border-left:5px solid var(--brass)}
.tip-l{display:inline-block;margin-right:8px;padding:2px 8px;border-radius:6px;background:var(--brass);color:var(--on-brass);
  font:700 .74rem/1.4 var(--text);letter-spacing:.06em;text-transform:uppercase;vertical-align:2px}
.note{background:var(--th-soft,var(--sheet));border-left:5px solid var(--th,var(--brass))}
.tip p,.note p{margin:0}
.bul li::marker{color:var(--th)}
.qc{scroll-margin-top:88px;margin-top:2.6em}
.qc-sheet{padding:6px 26px 16px 54px}
.qc-list,.prose .qc-list{list-style:none;margin:0;padding:0}
.prose .qc-item{margin:0;padding:16px 0;border-bottom:1px solid var(--rule-2)}
.qc-q{display:flex;gap:10px;margin:0 0 10px;font-weight:500;font-size:1.1rem}
.qc-n{flex:none;display:inline-grid;place-items:center;width:26px;height:26px;margin-top:1px;border-radius:50%;background:var(--navy);
  color:#fff;font:700 .85rem var(--display)}
.prose .qc .bubbles{padding:0;gap:6px}
.prose .qc .bubbles li{margin:0}
.qc .bub{font-size:1rem;padding:8px 12px}
.qc-end{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:12px;padding-top:14px}
.qc-score{margin:0;font:700 1.15rem var(--display)}
@media (max-width:560px){.qc-sheet{padding:4px 14px 16px 34px}}
.pager{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:2.2em 0 0}
.pager a{display:block;padding:14px 16px;border:1px solid var(--rule);border-radius:12px;background:var(--sheet);text-decoration:none;
  color:var(--ink);font:700 1.12rem/1.25 var(--display)}
.pager a:hover{border-color:var(--th,var(--ink))}
.pager small{display:block;margin-bottom:2px;font:500 .8rem var(--text);color:var(--ink-2)}
.pager .pg-next{text-align:right}
@media (max-width:560px){.pager{grid-template-columns:1fr}.pager .pg-next{text-align:left}}
.lesson-link{padding:12px 16px;border-radius:12px;background:var(--sheet);border:1px solid var(--rule-2)}

/* word lists: phrasal verbs, vocabulary, idioms */
.study-bar{display:flex;flex-wrap:wrap;gap:10px;margin:0 0 6px}
.legend,.prose .legend{list-style:none;margin:12px 0;padding:12px 16px;border-radius:12px;background:var(--sheet);border:1px solid var(--rule-2);
  font-size:.95rem;color:var(--ink-2)}
.prose .legend li{margin:4px 0}
.legend .ty{min-width:96px;text-align:center;margin-right:6px}
.wl-mrow{display:flex;align-items:baseline;flex-wrap:wrap;gap:4px 10px}
.ty{display:inline-block;padding:1px 8px;border-radius:999px;font:700 .7rem/1.6 var(--text);letter-spacing:.05em;text-transform:uppercase;
  vertical-align:1px;white-space:nowrap}
.ty-sep{background:var(--c1-soft);color:var(--c1-ink)}
.ty-ins{background:var(--c5-soft);color:var(--c5-ink)}
.ty-nob{background:var(--c2-soft);color:var(--c2-ink)}
.prose .wl-letter{margin:1.4em 0 0;padding-bottom:4px;border-bottom:2px solid var(--th);color:var(--th-ink)}
.wl{display:grid;gap:12px;margin:12px 0}
.wl-item{background:var(--sheet);border:1px solid var(--rule-2);border-left:4px solid var(--th);border-radius:12px;padding:12px 16px}
.wl-head{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.prose .wl-term{margin:0;font:700 1.3rem/1.2 var(--display);color:var(--ink)}
.pos{font-style:italic;color:var(--ink-2);font-size:.92rem}
.wl-head .say{margin-left:auto}
.wl-senses,.prose .wl-senses{list-style:none;margin:8px 0 0;padding:0;display:grid;gap:10px}
.prose .wl-senses li{margin:0;display:grid;justify-items:start;gap:3px}
.wl-m{font-weight:600;color:var(--th-ink)}
.wl-x{display:flex;gap:10px;align-items:flex-start;margin:2px 0 0;color:var(--ink-2);font-style:italic}
.wl-x .say,.idioms .say{width:28px;height:28px;margin-top:0}
.wl-x .say svg,.idioms .say svg{width:14px;height:14px}
.wl-v{grid-template-columns:repeat(2,minmax(0,1fr))}
@media (max-width:700px){.wl-v{grid-template-columns:1fr}}
.wl-v .wl-m{margin:6px 0 0;font-weight:500;color:var(--ink)}
.wl-v .wl-x{margin-top:6px}
.idioms dt{display:flex;align-items:center;gap:10px}
.idioms dt .say{margin-left:auto}
.idioms dd.wl-m{font-weight:500;color:var(--th-ink)}
.idioms dd.ex{display:flex;gap:10px;align-items:flex-start}
.hide-m .wl-m,.hide-m .wl-x,.hide-m .idioms dd{filter:blur(6px);transition:filter .2s;-webkit-user-select:none;user-select:none;cursor:pointer}
.hide-m .wl-item:hover .wl-m,.hide-m .wl-item:hover .wl-x,.hide-m .wl-item.show .wl-m,.hide-m .wl-item.show .wl-x,
.hide-m .idioms>div:hover dd,.hide-m .idioms>div.show dd{filter:none}
.vchips{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.vchip{display:inline-flex;align-items:center;gap:8px;min-height:36px;padding:0 5px 0 14px;border-radius:999px;background:var(--c-soft);
  color:var(--c-ink);font:600 .98rem var(--display);text-decoration:none;border:1px solid transparent}
.vchip span{display:inline-grid;place-items:center;min-width:26px;height:26px;padding:0 6px;border-radius:999px;background:var(--c);color:var(--on-th);font-size:.8rem}
.vchip:hover{border-color:var(--c)}
.vt{scroll-margin-top:88px;margin-top:2em}
.vt-head{display:grid;grid-template-columns:1fr auto;gap:4px 16px;align-items:center;padding:14px 18px;border-radius:14px;
  background:var(--c-soft);border-left:6px solid var(--c)}
.prose .vt-head h2{margin:0;color:var(--c-ink);font-size:1.5rem}
.vt-head p{margin:0;grid-column:1;color:var(--ink-2)}
.vt-tools{grid-column:2;grid-row:1/3;display:flex;gap:8px}
.tool{display:inline-flex;align-items:center;min-height:36px;padding:0 12px;border-radius:9px;border:1px solid var(--c,var(--th));
  background:var(--sheet);color:var(--c-ink,var(--th-ink));font:600 .95rem var(--display);cursor:pointer}
.tool:hover{background:var(--c,var(--th));color:var(--on-th)}
.vt .wl-item{border-left-color:var(--c)}
@media (max-width:560px){.vt-head{grid-template-columns:1fr}.vt-tools{grid-column:1;grid-row:auto}}

/* lessons hub and home page */
.hub-nav{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin:24px 0 6px}
.hn{display:flex;flex-direction:column;gap:2px;padding:16px 18px;border-radius:14px;background:var(--th);color:var(--on-th);text-decoration:none;
  box-shadow:0 8px 20px color-mix(in srgb,var(--th) 28%,transparent);transition:transform .15s}
.hn b{font:700 1.35rem/1.1 var(--display)}
.hn span{font-size:.92rem;opacity:.92}
.hn:hover{transform:translateY(-2px)}
@media (max-width:760px){.hub-nav{grid-template-columns:1fr 1fr}}
.hub-sec{padding-top:40px;padding-bottom:16px}
.hub-sec:last-child{padding-bottom:72px}
.hub-h{display:flex;align-items:baseline;flex-wrap:wrap;gap:6px 20px;margin-bottom:18px}
.hub-h h2{margin:0}
.hub-h p{margin:0;color:var(--ink-2)}
.lgrid{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}
@media (max-width:980px){.lgrid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:620px){.lgrid{grid-template-columns:1fr}}
.lcard{display:flex;flex-direction:column;background:var(--sheet);border:1px solid var(--rule-2);border-radius:16px;box-shadow:var(--shadow)}
.lcard-main{flex:1;display:grid;grid-template-columns:auto 1fr;column-gap:14px;align-content:start;padding:18px 18px 10px;color:var(--ink);text-decoration:none}
.lcard-main .lbadge{grid-row:1/3;min-width:54px;height:54px;font-size:1.15rem;border-radius:14px}
.lcard-n{align-self:end;font:600 .74rem/1.4 var(--text);letter-spacing:.07em;text-transform:uppercase;color:var(--ink-2)}
.lcard h3{margin:0;font-size:1.3rem}
.lcard p{grid-column:1/-1;margin:12px 0 0;color:var(--ink-2);font-size:.96rem}
.lcard-main:hover h3{color:var(--link)}
.lcard-foot{display:flex;flex-wrap:wrap;gap:8px;padding:0 18px 16px}
.tgrid,.study-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px}
@media (max-width:1000px){.tgrid,.study-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:560px){.tgrid,.study-grid{grid-template-columns:1fr}}
.tcard,.scard{display:flex;flex-direction:column;align-items:flex-start;gap:6px;padding:18px;border-radius:16px;background:var(--sheet);
  border:1px solid var(--rule-2);border-top:5px solid var(--th);box-shadow:var(--shadow);color:var(--ink);text-decoration:none;transition:transform .15s}
.tcard:hover,.scard:hover{transform:translateY(-2px)}
.tcard .lbadge,.scard .lbadge{min-width:50px;height:50px;font-size:1.1rem;border-radius:13px;margin-bottom:6px}
.tcard b,.scard b{font:700 1.3rem/1.15 var(--display)}
.tcard>span:not(.lbadge),.scard>span:not(.lbadge){color:var(--ink-2);font-size:.96rem}
.tcard em,.scard em{margin-top:auto;padding-top:8px;font:600 1rem var(--display);font-style:normal;color:var(--th-ink)}
.study-band{background:var(--paper-2);border-top:1px solid var(--rule-2);border-bottom:1px solid var(--rule-2)}
.pill-row{list-style:none;margin:24px 0 0;padding:0;display:flex;flex-wrap:wrap;gap:8px}
.pill-row a{display:inline-flex;align-items:center;gap:8px;min-height:38px;padding:0 14px 0 5px;border-radius:999px;background:var(--sheet);
  border:1px solid var(--rule);color:var(--ink);font:600 .98rem var(--display);text-decoration:none}
.pill-row a:hover{border-color:var(--ink)}
.pb{display:inline-grid;place-items:center;min-width:30px;height:30px;padding:0 7px;border-radius:999px;background:var(--c);color:var(--on-th);font:700 .78rem var(--display)}
.prose .note-box,.hub .note-box{max-width:48rem}

/* flashcards and quiz */
.fc-dlg,.fq-dlg{border:0;padding:0;border-radius:20px;width:min(560px,calc(100% - 24px));max-height:calc(100% - 24px);background:var(--paper);
  color:var(--ink);box-shadow:0 30px 70px rgba(0,0,0,.4)}
.fc-dlg::backdrop,.fq-dlg::backdrop{background:rgba(6,16,31,.62)}
.dlg-in{padding:18px 20px 20px}
.dlg-top{display:flex;align-items:center;gap:12px;margin-bottom:14px}
.dlg-top h2{margin:0;font-size:1.35rem}
.dlg-n{margin-left:auto;color:var(--ink-2);font:600 .95rem var(--display)}
.dlg-x{flex:none;width:40px;height:40px;border-radius:10px;border:1px solid var(--rule);background:var(--sheet);color:var(--ink);font-size:24px;line-height:1;cursor:pointer}
.fc-stage{perspective:1200px}
.fc-card{position:relative;display:block;width:100%;height:270px;border:0;padding:0;background:none;color:var(--ink);font:inherit;cursor:pointer;
  transform-style:preserve-3d;transition:transform .45s}
.fc-card.flip{transform:rotateY(180deg)}
.fc-face{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:12px;padding:20px 24px;
  border-radius:16px;background:var(--sheet);border:1px solid var(--rule-2);box-shadow:var(--shadow);text-align:center;
  -webkit-backface-visibility:hidden;backface-visibility:hidden}
.fc-front{border-top:6px solid var(--th,var(--brass))}
.fc-back{transform:rotateY(180deg);border-top:6px solid var(--ok)}
.fc-term{font:700 2.1rem/1.15 var(--display)}
.fc-hint{color:var(--ink-2);font-size:.9rem}
.fc-mean{font:600 1.35rem/1.3 var(--display);color:var(--th-ink,var(--ink))}
.fc-t2{font:700 .8rem/1.2 var(--text);letter-spacing:.06em;text-transform:uppercase;color:var(--ink-2)}
.fc-ex{color:var(--ink-2);font-style:italic;font-size:1.02rem}
.dlg-row{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.dlg-row .btn{flex:1;min-width:104px}
.fq-q{margin:0 0 8px;font:500 1.15rem/1.45 var(--text)}
.fq-ctx{margin:0 0 14px;padding:10px 14px;border-left:4px solid var(--th,var(--brass));background:var(--sheet);border-radius:0 10px 10px 0;
  font-style:italic;color:var(--ink-2)}
.fq-end{text-align:center;padding:12px 0 4px}
.fq-score{margin:4px 0 14px;font:700 2.2rem var(--display)}
@media (prefers-reduced-motion:reduce){.fc-card{transition:none}}

@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --c1:#7FA8F5;--c1-ink:#A9C5FA;--c1-soft:rgba(127,168,245,.14);  --c2:#4FC08A;--c2-ink:#86DDB0;--c2-soft:rgba(79,192,138,.14);
    --c3:#E2B04A;--c3-ink:#F0CB7C;--c3-soft:rgba(226,176,74,.14);  --c4:#E77B6F;--c4-ink:#F3A79E;--c4-soft:rgba(231,123,111,.15);
    --c5:#B994E0;--c5-ink:#D2B9EF;--c5-soft:rgba(185,148,224,.15);  --c6:#56C1B3;--c6-ink:#8EDCD1;--c6-soft:rgba(86,193,179,.14);
    --c7:#F08A4B;--c7-ink:#F7B289;--c7-soft:rgba(240,138,75,.15);  --on-th:#0A1830;
  }
}
:root[data-theme="dark"]{
  --c1:#7FA8F5;--c1-ink:#A9C5FA;--c1-soft:rgba(127,168,245,.14);  --c2:#4FC08A;--c2-ink:#86DDB0;--c2-soft:rgba(79,192,138,.14);
  --c3:#E2B04A;--c3-ink:#F0CB7C;--c3-soft:rgba(226,176,74,.14);  --c4:#E77B6F;--c4-ink:#F3A79E;--c4-soft:rgba(231,123,111,.15);
  --c5:#B994E0;--c5-ink:#D2B9EF;--c5-soft:rgba(185,148,224,.15);  --c6:#56C1B3;--c6-ink:#8EDCD1;--c6-soft:rgba(86,193,179,.14);
  --c7:#F08A4B;--c7-ink:#F7B289;--c7-soft:rgba(240,138,75,.15);  --on-th:#0A1830;
}

/* small screens: the app link opens Google Play directly, QR codes are for desktop */
.only-desktop{display:block}
.only-phone{display:none}
html.is-phone .only-desktop{display:none}
html.is-phone .only-phone{display:block}
html.is-ios .android-cta{display:none}

@media (prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important;scroll-behavior:auto!important}}
@media print{.site-header,.site-footer,.aside,.ad-slot,.cta-box,.ltools,.chips,.study-bar,.say,.pager{display:none}.hide-m .wl-m,.hide-m .wl-x{filter:none}}