/* ExamLuck — one stylesheet, no build step.
   Light and dark are both first-class; the child can also force a theme,
   bump the text size, or switch on a dyslexia-friendly face. */

:root{
  --bg:#f6f7fb; --surface:#ffffff; --surface-2:#eef1f8; --line:#dde3ee;
  --ink:#141b2d; --ink-2:#5a6478; --ink-3:#8a93a6;
  --brand:#2f6fed; --brand-ink:#ffffff; --brand-soft:#e6efff;
  --ok:#0f9d58; --ok-soft:#e3f6ea; --bad:#d93838; --bad-soft:#fdeaea;
  --warn:#e8a317; --gold:#f2b705;
  --maths:#2f6fed; --vr:#8a4fdd; --nvr:#0d9488; --spatial:#d97706; --english:#db2777;
  --r:16px; --r-sm:10px; --shadow:0 1px 2px rgba(16,24,40,.06),0 8px 24px rgba(16,24,40,.06);
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  --maxw:760px;
}
:root:not([data-theme="light"]){
  @media (prefers-color-scheme: dark){
    --bg:#0d1117; --surface:#161b25; --surface-2:#1e2533; --line:#2a3240;
    --ink:#e9edf5; --ink-2:#a4adbe; --ink-3:#78829a;
    --brand:#5b8dff; --brand-soft:#17233d; --ok:#3fbe7a; --ok-soft:#12281c;
    --bad:#ef6b6b; --bad-soft:#2c1618; --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.35);
  }
}
:root[data-theme="dark"]{
  --bg:#0d1117; --surface:#161b25; --surface-2:#1e2533; --line:#2a3240;
  --ink:#e9edf5; --ink-2:#a4adbe; --ink-3:#78829a;
  --brand:#5b8dff; --brand-soft:#17233d; --ok:#3fbe7a; --ok-soft:#12281c;
  --bad:#ef6b6b; --bad-soft:#2c1618; --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.35);
}
:root[data-contrast="high"]{ --line:#000; --ink-2:#000; --shadow:none; --bg:#fff; --surface:#fff; }
:root[data-font="dys"]{ --font:"Comic Sans MS","Trebuchet MS",Verdana,sans-serif; letter-spacing:.02em; }

*{box-sizing:border-box}
/* `hidden` must beat the display rules below, or hidden chrome still shows. */
[hidden]{display:none!important}
html{
  -webkit-text-size-adjust:100%;
  /* `clip` rather than `hidden`: it contains a stray wide element without
     creating a scroll container, so the sticky header keeps working. A page
     that scrolls sideways makes every centred margin look uneven. */
  overflow-x:clip;
}
body{
  margin:0; background:var(--bg); color:var(--ink); font-family:var(--font);
  font-size:calc(1rem * var(--scale,1)); line-height:1.55;
  padding-bottom:calc(72px + env(safe-area-inset-bottom));
}
@media (prefers-reduced-motion: reduce){ *{animation:none!important; transition:none!important} }
:root[data-motion="off"] *{animation:none!important; transition:none!important}

.skip{position:absolute;left:-999px}
.skip:focus{left:8px;top:8px;z-index:99;background:var(--brand);color:#fff;padding:.6rem 1rem;border-radius:8px}
button{font:inherit;color:inherit}
:focus-visible{outline:3px solid var(--brand);outline-offset:2px;border-radius:6px}

/* ------------------------------------------------------------------ chrome */
.topbar{
  position:sticky;top:0;z-index:20;display:flex;align-items:center;gap:.75rem;
  padding:.6rem max(.9rem,env(safe-area-inset-right)) .6rem max(.9rem,env(safe-area-inset-left));
  background:color-mix(in srgb,var(--surface) 86%,transparent);
  backdrop-filter:blur(12px);border-bottom:1px solid var(--line);
}
.brand{display:flex;align-items:center;gap:.45rem;background:none;border:0;cursor:pointer;padding:.2rem;font-weight:800;font-size:1.05rem}
.logo{font-size:1.3rem}
.stats{margin-left:auto;display:flex;gap:.35rem;align-items:center;font-weight:700;font-size:.82rem;min-width:0}
.chip{display:inline-flex;align-items:center;gap:.25rem;background:var(--surface-2);border:1px solid var(--line);
  padding:.28rem .55rem;border-radius:999px;white-space:nowrap}
.chip.flame{background:linear-gradient(135deg,#fff1e0,#ffe1c2);border-color:#f5c98a;color:#8a4b06}
:root[data-theme="dark"] .chip.flame,:root:not([data-theme="light"]) .chip.flame{background:#2e2010;border-color:#5b3d13;color:#f0b464}
.icon-btn{flex:0 0 auto;background:var(--surface-2);border:1px solid var(--line);border-radius:10px;width:38px;height:38px;cursor:pointer;font-size:1.05rem}
/* On narrow phones the wordmark gives way to the chips and buttons. */
@media (max-width:430px){ .brandname{display:none} .chip{padding:.24rem .45rem;font-size:.78rem} }

main{max-width:var(--maxw);margin:0 auto;
  padding:1rem max(.9rem,env(safe-area-inset-right)) 1.5rem max(.9rem,env(safe-area-inset-left))}
.tabbar{
  position:fixed;left:0;right:0;bottom:0;z-index:20;display:grid;grid-template-columns:repeat(5,1fr);
  gap:.15rem;padding:.4rem .4rem calc(.4rem + env(safe-area-inset-bottom));
  background:color-mix(in srgb,var(--surface) 92%,transparent);backdrop-filter:blur(12px);border-top:1px solid var(--line);
}
.tab{display:flex;flex-direction:column;align-items:center;gap:.1rem;background:none;border:0;cursor:pointer;
  font-size:.68rem;font-weight:700;color:var(--ink-3);padding:.35rem .1rem;border-radius:12px}
.tab span{font-size:1.25rem;line-height:1}
.tab[aria-current="page"]{color:var(--brand);background:var(--brand-soft)}
.tab.primary span{background:var(--brand);color:#fff;border-radius:12px;padding:.15rem .5rem}

/* ------------------------------------------------------------------ blocks */
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:1rem;box-shadow:var(--shadow);margin-bottom:.9rem}
.card.tight{padding:.75rem}
h1{font-size:1.5rem;margin:.2rem 0 .8rem;letter-spacing:-.02em}
h2{font-size:1.12rem;margin:1.4rem 0 .6rem;letter-spacing:-.01em}
h3{font-size:.95rem;margin:0 0 .4rem}
p{margin:.5rem 0}
.dim{color:var(--ink-2);font-weight:400}
.tiny{font-size:.8rem;color:var(--ink-2)}
.center{text-align:center}
.row{display:flex;gap:.6rem;align-items:center;flex-wrap:wrap}
.spread{display:flex;justify-content:space-between;align-items:center;gap:.6rem}
.grid{display:grid;gap:.7rem}
.grid.two{grid-template-columns:repeat(auto-fit,minmax(150px,1fr))}
.grid.three{grid-template-columns:repeat(auto-fit,minmax(110px,1fr))}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:.45rem;
  background:var(--brand);color:var(--brand-ink);border:0;border-radius:12px;
  padding:.8rem 1.15rem;font-weight:750;cursor:pointer;font-size:1rem;transition:transform .08s,filter .15s;min-height:48px}
.btn:active{transform:scale(.98)}
.btn:hover{filter:brightness(1.06)}
.btn.big{width:100%;font-size:1.1rem;padding:1.05rem;border-radius:14px}
.btn.ghost{background:var(--surface-2);color:var(--ink);border:1px solid var(--line)}
.btn.quiet{background:none;border:1px solid var(--line);color:var(--ink-2);padding:.55rem .8rem;min-height:40px;font-size:.88rem}
.btn.danger{background:var(--bad)}
.btn[disabled]{opacity:.5;pointer-events:none}

.bar{height:10px;background:var(--surface-2);border-radius:999px;overflow:hidden}
.bar>i{display:block;height:100%;background:var(--brand);border-radius:999px;transition:width .4s}
.bar.thin{height:6px}

/* ---------------------------------------------------------------- home */
.hero{display:flex;gap:1rem;align-items:center}
.avatar{position:relative;width:76px;height:76px;flex:0 0 auto;display:grid;place-items:center;
  background:var(--brand-soft);border-radius:22px;font-size:2.4rem}
.avatar .hat{position:absolute;top:-10px;left:50%;transform:translateX(-50%);font-size:1.4rem}
.avatar .pet{position:absolute;bottom:-6px;right:-8px;font-size:1.2rem}
.lvl{font-weight:800;font-size:1.15rem}

.quest{display:flex;gap:.7rem;align-items:center;background:linear-gradient(120deg,var(--brand-soft),transparent);
  border:1px solid var(--line);border-radius:var(--r);padding:.8rem;margin-bottom:.9rem}
.quest .q-icon{font-size:1.5rem}
.quest.done{background:var(--ok-soft);border-color:color-mix(in srgb,var(--ok) 40%,transparent)}

.strand-tile{display:flex;align-items:center;gap:.7rem;background:var(--surface);border:1px solid var(--line);
  border-radius:var(--r);padding:.8rem;cursor:pointer;text-align:left;width:100%;box-shadow:var(--shadow)}
.ring{--p:0;flex:0 0 auto;width:46px;height:46px;border-radius:50%;display:grid;place-items:center;font-size:1.25rem;
  background:conic-gradient(var(--c,var(--brand)) calc(var(--p)*1%), var(--surface-2) 0)}
.ring i{width:36px;height:36px;border-radius:50%;background:var(--surface);display:grid;place-items:center;font-style:normal}
.pct{margin-left:auto;font-weight:800;font-size:.95rem}

/* -------------------------------------------------------------- question */
.qwrap{max-width:640px;margin:0 auto}
.qhead{display:flex;align-items:center;gap:.6rem;margin-bottom:.6rem;font-size:.8rem;color:var(--ink-2);font-weight:700}
.pill{background:var(--surface-2);border:1px solid var(--line);border-radius:999px;padding:.2rem .55rem;font-size:.74rem}
.stem{font-size:1.12rem;line-height:1.6;margin:.2rem 0 1rem}
.stem b{font-weight:800}
.opts{display:grid;gap:.55rem}
.opt{display:flex;align-items:center;gap:.7rem;background:var(--surface);border:2px solid var(--line);
  border-radius:14px;padding:.85rem .9rem;cursor:pointer;text-align:left;width:100%;font-size:1.02rem;
  transition:border-color .12s,background .12s,transform .08s;min-height:52px}
.opt:hover{border-color:var(--brand)}
.opt:active{transform:scale(.995)}
.opt .key{flex:0 0 auto;width:28px;height:28px;border-radius:8px;background:var(--surface-2);display:grid;place-items:center;
  font-weight:800;font-size:.85rem;color:var(--ink-2)}
.opt.right{border-color:var(--ok);background:var(--ok-soft)}
.opt.right .key{background:var(--ok);color:#fff}
.opt.wrong{border-color:var(--bad);background:var(--bad-soft)}
.opt.wrong .key{background:var(--bad);color:#fff}
.opt.muted{opacity:.55}
.opts.figures{grid-template-columns:repeat(auto-fit,minmax(96px,1fr))}
.opts.figures .opt{flex-direction:column;gap:.35rem;padding:.5rem .3rem;justify-content:center}
.opts.figures .q-svg{max-width:100%}
.opts.figures .key{width:22px;height:22px;font-size:.72rem}

.verdict{margin-top:.9rem;border-radius:14px;padding:.85rem;border:1px solid var(--line);background:var(--surface-2)}
.verdict.right{background:var(--ok-soft);border-color:color-mix(in srgb,var(--ok) 40%,transparent)}
.verdict.wrong{background:var(--bad-soft);border-color:color-mix(in srgb,var(--bad) 40%,transparent)}
.verdict h3{display:flex;align-items:center;gap:.4rem;font-size:1rem}
.why{font-size:.95rem;line-height:1.65;color:var(--ink)}
.why b{font-weight:800}
.why i{color:var(--ink-2)}

/* question-internal markup produced by the generators */
.q-svg{width:100%;max-width:190px;height:auto;display:block;margin:.7rem auto;color:var(--ink)}
/* A series has to read left-to-right on one line, so it scrolls rather than
   wraps — wrapping breaks the logic of the question. */
.fig-row{display:flex;gap:.4rem;align-items:center;justify-content:center;flex-wrap:nowrap;
  margin:.8rem 0;overflow-x:auto;padding-bottom:.2rem;scrollbar-width:thin}
.fig-row.analogy{flex-wrap:wrap}
.fig{background:var(--surface-2);border:1px solid var(--line);border-radius:12px;padding:.3rem;display:grid;place-items:center}
.fig-row>.fig{flex:1 1 0;min-width:0;max-width:78px}
.fig .q-svg{width:100%;max-width:72px;margin:0}
.fig.fig-q{aspect-ratio:1;display:grid;place-items:center;font-size:1.5rem;font-weight:800;color:var(--ink-3);border-style:dashed}
.fig.labelled{position:relative;padding-bottom:1.2rem}
.fig.labelled b{position:absolute;bottom:.1rem;left:0;right:0;text-align:center;font-size:.78rem}
.fig-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:.35rem;max-width:280px;margin:.8rem auto}
.fig-grid .fig{padding:.2rem}
.rel{font-size:.8rem;color:var(--ink-2);font-weight:700}
.frac{display:inline-flex;flex-direction:column;vertical-align:middle;text-align:center;margin:0 .18em;line-height:1.05;font-size:.82em}
.frac b{border-bottom:2px solid currentColor;padding:0 .18em;font-weight:700}
.frac i{padding:0 .18em;font-style:normal;font-weight:700}
.seq,.eq{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:1.05em;letter-spacing:.02em;
  overflow-wrap:anywhere}
.sentence{background:var(--surface-2);border-left:3px solid var(--brand);border-radius:0 10px 10px 0;
  padding:.7rem .8rem;margin:.7rem 0;font-size:1.05rem}
.sentence mark{background:var(--gold);color:#231a00;border-radius:4px;padding:0 .1em}
.gap{background:var(--brand-soft);border-radius:6px;padding:0 .3em;letter-spacing:.05em}
.big-word{font-size:1.5rem;font-weight:800;text-align:center;margin:.8rem 0;letter-spacing:-.01em}
.il{display:flex;flex-direction:column;gap:.4rem;margin:.8rem 0;align-items:center}
.il-pair{font-size:1.15rem;font-weight:700;letter-spacing:.03em;background:var(--surface-2);padding:.5rem .9rem;border-radius:10px}
.groups{display:flex;gap:.6rem;justify-content:center;flex-wrap:wrap;margin:.8rem 0}
.grp{background:var(--surface-2);border:1px solid var(--line);border-radius:10px;padding:.5rem .8rem;font-weight:700}
.jumble{display:flex;gap:.4rem;flex-wrap:wrap;margin:.8rem 0;justify-content:center}
.jumble span{background:var(--surface-2);border:1px solid var(--line);border-radius:8px;padding:.35rem .6rem;font-weight:700}
.clues{margin:.6rem 0;padding-left:1.2rem}
.clues li{margin:.25rem 0}
.analogy-text{font-size:1.15rem;text-align:center;margin:.8rem 0;line-height:1.9}
.analogy .rel{margin:0 .1rem}
table.tt{border-collapse:collapse;width:100%;margin:.6rem 0;font-size:.86rem;table-layout:fixed}
table.tt th,table.tt td{border:1px solid var(--line);padding:.3rem .25rem;text-align:center;
  /* Wrap rather than truncate: an ellipsis would hide the station name the
     question is actually asking about. */
  white-space:normal;overflow-wrap:anywhere;hyphens:auto}
table.tt td:first-child,table.tt th:first-child{text-align:left;font-weight:700;width:32%}
.passage{background:var(--surface-2);border-radius:12px;padding:.9rem;margin-bottom:.9rem;max-height:44vh;overflow:auto;font-size:.98rem}
.passage p{margin:.6rem 0}
.passage .poem{font-family:Georgia,'Times New Roman',serif;line-height:1.7}
.passage h3{position:sticky;top:0;background:var(--surface-2);padding:.2rem 0;margin:0 0 .3rem}

/* ---------------------------------------------------------------- learn */
.unit{margin-bottom:1rem}
.skill-row{display:flex;align-items:center;gap:.6rem;padding:.65rem .75rem;border:1px solid var(--line);
  border-radius:12px;background:var(--surface);cursor:pointer;width:100%;text-align:left;margin-bottom:.4rem}
.skill-row .nm{font-weight:700;font-size:.95rem}
.dots{margin-left:auto;display:flex;gap:2px;flex:0 0 auto}
.dots i{width:7px;height:7px;border-radius:50%;background:var(--surface-2);border:1px solid var(--line)}
.dots i.on{background:var(--gold);border-color:var(--gold)}
.lesson ul{padding-left:1.1rem;margin:.5rem 0}
.lesson li{margin:.35rem 0}
.tipbox{background:var(--brand-soft);border-radius:10px;padding:.65rem .8rem;margin-top:.6rem;font-size:.92rem}

/* --------------------------------------------------------------- papers */
.timer{font-variant-numeric:tabular-nums;font-weight:800}
.timer.low{color:var(--bad)}
.qnav{display:flex;flex-wrap:wrap;gap:.3rem;margin:.7rem 0}
.qnav button{width:32px;height:32px;border-radius:8px;border:1px solid var(--line);background:var(--surface);
  font-size:.78rem;font-weight:700;cursor:pointer}
.qnav button.done{background:var(--brand);color:#fff;border-color:var(--brand)}
.qnav button.here{outline:2px solid var(--brand);outline-offset:1px}

/* -------------------------------------------------------------- progress */
.heat{display:grid;grid-template-columns:repeat(auto-fill,minmax(58px,1fr));gap:.3rem}
.heat b{display:block;border-radius:8px;padding:.4rem .2rem;font-size:.62rem;text-align:center;font-weight:700;
  border:1px solid var(--line);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.badge{display:flex;flex-direction:column;align-items:center;gap:.2rem;padding:.6rem .3rem;border-radius:12px;
  background:var(--surface-2);border:1px solid var(--line);text-align:center;font-size:.68rem;font-weight:700}
.badge.locked{opacity:.35}
.badge span{font-size:1.5rem}
.spark{display:flex;align-items:flex-end;gap:2px;height:48px}
.spark i{flex:1;background:var(--brand);border-radius:2px 2px 0 0;min-height:2px}

/* --------------------------------------------------------------- drawer */
.drawer{position:fixed;inset:auto 0 0 0;z-index:40;background:var(--surface);border-top:1px solid var(--line);
  border-radius:20px 20px 0 0;box-shadow:0 -8px 40px rgba(0,0,0,.2);max-height:82vh;display:flex;flex-direction:column;
  padding:.9rem max(.9rem,env(safe-area-inset-right)) calc(.9rem + env(safe-area-inset-bottom)) max(.9rem,env(safe-area-inset-left));
  max-width:var(--maxw);margin:0 auto}
.chatlog{flex:1;overflow:auto;display:flex;flex-direction:column;gap:.55rem;padding:.4rem 0}
.msg{max-width:88%;padding:.6rem .8rem;border-radius:14px;font-size:.95rem;line-height:1.55}
.msg.me{align-self:flex-end;background:var(--brand);color:#fff;border-bottom-right-radius:4px}
.msg.bot{align-self:flex-start;background:var(--surface-2);border-bottom-left-radius:4px}
.msg.sys{align-self:center;background:none;color:var(--ink-3);font-size:.8rem;text-align:center}
.composer{display:flex;gap:.5rem;padding-top:.5rem;border-top:1px solid var(--line)}
.composer input,.composer textarea{flex:1;padding:.7rem .8rem;border:1px solid var(--line);border-radius:12px;
  background:var(--surface-2);color:var(--ink);font:inherit;font-size:1rem}
.quickies{display:flex;gap:.4rem;flex-wrap:wrap;padding-bottom:.5rem}

/* ---------------------------------------------------------------- misc */
.toast-wrap{position:fixed;left:0;right:0;bottom:calc(96px + env(safe-area-inset-bottom));z-index:50;
  display:flex;flex-direction:column;align-items:center;gap:.4rem;pointer-events:none}
.toast{background:var(--ink);color:var(--bg);padding:.6rem 1rem;border-radius:999px;font-weight:700;font-size:.9rem;
  box-shadow:var(--shadow);animation:pop .3s}
@keyframes pop{from{transform:translateY(12px) scale(.94);opacity:0}}
label.field{display:block;margin:.6rem 0}
label.field span{display:block;font-size:.82rem;font-weight:700;color:var(--ink-2);margin-bottom:.25rem}
select,input[type=text],input[type=date],textarea{
  display:block;width:100%;max-width:100%;min-width:0;
  padding:.7rem .8rem;border:1px solid var(--line);
  border-radius:12px;background:var(--surface-2);color:var(--ink);font-family:inherit;
  /* Never below 16px: iOS Safari zooms the whole page when a smaller field is
     focused, which leaves the layout shifted and off-centre afterwards. Text
     scaling still applies above that floor. */
  font-size:max(16px, calc(1rem * var(--scale,1)));
}
/* iOS Safari ignores width on a date input and sizes it from its own internal
   value element, so it spills off a narrow screen. Neutralising the native
   appearance and pinning the inner element is what actually contains it. */
input[type=date]{
  /* Only the date input drops its native appearance — selects keep theirs so
     they still show a dropdown arrow. */
  -webkit-appearance:none; appearance:none;
  min-height:48px; line-height:1.2; background-clip:padding-box;
}
input[type=date]::-webkit-date-and-time-value{
  text-align:left; width:100%; margin:0; min-width:0;
}
input[type=date]::-webkit-datetime-edit{ width:100%; padding:0; }
input[type=date]::-webkit-calendar-picker-indicator{ margin-inline-start:auto; }
textarea{min-height:130px;resize:vertical}
.switch{display:flex;align-items:center;justify-content:space-between;gap:.8rem;padding:.6rem 0;border-bottom:1px solid var(--line)}
.switch:last-child{border-bottom:0}
.seg{display:flex;gap:.25rem;background:var(--surface-2);border-radius:10px;padding:.2rem}
.seg button{border:0;background:none;padding:.35rem .6rem;border-radius:8px;cursor:pointer;font-size:.85rem;font-weight:700;color:var(--ink-2)}
.seg button[aria-pressed=true]{background:var(--surface);color:var(--ink);box-shadow:var(--shadow)}
@media print{ .topbar,.tabbar,.btn{display:none!important} body{padding:0;background:#fff} .card{break-inside:avoid} }