*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --ink:#15171b;--ink-soft:#63666d;--accent:#11845b;--accent-2:#b45309;
  --dark:#191b1f;--rule:#e7e8ea;--sol-bg:#eef8f2;--band:#f5f6f7;--bg:#fff;
  --serif:Georgia,'Times New Roman',serif;
  --sans:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif;
}
html{scroll-behavior:smooth}
body{font-family:var(--sans);font-size:1.02rem;line-height:1.6;color:var(--ink);background:var(--bg);overflow-x:hidden}
.wrap{max-width:820px;margin:0 auto;padding:0 20px}
a{color:var(--accent)}
h1,h2,h3{letter-spacing:-.02em}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.skip{position:fixed;left:14px;top:-60px;z-index:100;background:var(--dark);color:#fff;padding:10px 15px;border-radius:8px;text-decoration:none}
.skip:focus{top:10px}

/* header — white, minimal, 1px rule */
.top{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.92);backdrop-filter:blur(8px);
  border-bottom:1px solid var(--rule)}
.top nav{display:flex;align-items:center;justify-content:space-between;height:56px}
.brand{font-family:var(--sans);font-weight:800;font-size:1.08rem;color:var(--ink);text-decoration:none;letter-spacing:-.01em}
.brand-pi{display:inline-block;background:var(--dark);color:#fff;border-radius:8px;width:28px;height:28px;text-align:center;line-height:28px;margin-right:3px}
.navlinks{display:flex;gap:14px;align-items:center}
.subjnav{display:flex;gap:2px;margin-left:14px;background:var(--band);border-radius:999px;padding:3px}
.subjlink{font-family:var(--sans);font-size:.85rem;font-weight:700;color:var(--ink-soft);text-decoration:none;padding:6px 15px;border-radius:999px;white-space:nowrap}
.subjlink:hover{color:var(--ink)}
.subjlink.on{background:var(--dark);color:#fff}
@media (max-width:560px){.subjnav{margin-left:6px}.subjlink{padding:6px 11px;font-size:.8rem}}
.navlink{font-family:var(--sans);font-size:.85rem;font-weight:600;color:var(--ink-soft);text-decoration:none}
.navlink:hover{color:var(--ink)}
.navlink.hot{background:var(--accent);color:#fff;padding:8px 16px;border-radius:999px;white-space:nowrap}
.navlink.hot:hover{background:#0d6b4a;color:#fff}

/* ── Test Maker banner (home): soft tinted card, dark text ── */
.tool-banner{display:flex;align-items:center;gap:16px;text-decoration:none;
  background:#edf9f2;border:1px solid #cfe9db;
  border-radius:16px;padding:18px 20px;margin:20px 0 8px;color:var(--ink);
  transition:border-color .15s,transform .12s}
.tool-banner:hover{border-color:var(--accent);transform:translateY(-2px);color:var(--ink)}
.tb-icon{font-size:1.9rem;flex-shrink:0;background:#fff;border:1px solid #cfe9db;border-radius:14px;
  width:56px;height:56px;display:flex;align-items:center;justify-content:center}
.tb-txt{flex:1;min-width:0}
.tb-h{display:block;font-family:var(--sans);font-weight:800;font-size:1.12rem;line-height:1.25;letter-spacing:-.01em}
.tb-s{display:block;font-family:var(--sans);font-size:.84rem;color:var(--ink-soft);margin-top:4px;line-height:1.45}
.tb-btn{font-family:var(--sans);font-weight:700;font-size:.9rem;background:var(--accent);color:#fff;
  border-radius:999px;padding:11px 22px;white-space:nowrap}
@media (max-width:560px){
  .tool-banner{flex-wrap:wrap;padding:16px}
  .tb-btn{width:100%;text-align:center}
}

/* hero / home */
.hero{padding:44px 0 12px}
.hero h1{font-size:2.15rem;line-height:1.14;font-weight:800}
.hero p.lead{font-family:var(--sans);color:var(--ink-soft);margin-top:14px;font-size:1.04rem;max-width:60ch}
.stats{display:flex;gap:8px;flex-wrap:wrap;margin:20px 0 6px}
.stat{font-family:var(--sans);font-size:.8rem;font-weight:600;background:var(--band);color:var(--ink);
  border-radius:999px;padding:7px 15px}
.subject-picker{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:14px 0 20px}
.subject-picker a{display:flex;align-items:center;justify-content:center;min-height:76px;border-radius:14px;
  color:#fff;text-decoration:none;font-size:1.05rem;font-weight:800;transition:transform .12s,filter .15s}
.subject-picker a:hover{transform:translateY(-2px);filter:brightness(.96)}
.subject-picker .maths{background:#11845b}.subject-picker .science{background:#2563a7}
.chgrid{list-style:none;display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:12px;margin:18px 0 30px}
.chgrid a{display:block;border:1px solid var(--rule);border-radius:14px;padding:16px 18px;background:#fff;
  text-decoration:none;transition:border-color .15s,transform .12s}
.chgrid a:hover{border-color:#b9bcc2;transform:translateY(-2px)}
.chgrid .ch-name{font-family:var(--sans);font-weight:700;color:var(--ink);font-size:.95rem;letter-spacing:-.01em}
.chgrid .ch-count{font-family:var(--sans);font-size:.78rem;color:var(--ink-soft);margin-top:4px}
.howto{border:1px solid var(--rule);background:var(--band);border-radius:14px;
  padding:15px 18px;margin:6px 0 34px;font-family:var(--sans);font-size:.9rem;color:var(--ink-soft)}

/* breadcrumbs / hints */
.crumbs{font-family:var(--sans);font-size:.9rem;color:var(--ink-soft);margin:14px 0 14px;
  display:flex;align-items:center;gap:7px;overflow-x:auto;-webkit-overflow-scrolling:touch;white-space:nowrap}
.crumbs a,.crumbs .current{display:inline-flex;align-items:center;min-height:38px;padding:0 10px;border-radius:8px}
.crumbs a{color:var(--ink);background:#f5f6f8;border:1px solid var(--rule);text-decoration:none;font-weight:700}
.crumbs a:hover{border-color:#b9bcc2;background:#fff}
.crumbs .current{color:var(--ink-soft);font-weight:700}
.crumbs .sep{color:#9aa0aa;font-size:1.05rem;flex:0 0 auto}
.hint{font-family:var(--sans);font-size:.82rem;color:var(--ink-soft);margin:8px 0 18px}
kbd{font-family:var(--sans);font-size:.75em;border:1px solid var(--rule);border-bottom-width:2px;border-radius:5px;
  padding:1px 6px;background:#fff;color:var(--ink)}

/* chapter page */
h1.pgtitle{font-size:1.7rem;line-height:1.2;margin:2px 0 6px;font-weight:800}
.pgsub{font-family:var(--sans);color:var(--ink-soft);font-size:.92rem;margin-bottom:14px}
.filter{width:100%;font-family:var(--sans);font-size:.95rem;padding:11px 16px;border:1.5px solid var(--rule);
  border-radius:12px;margin:4px 0 20px;background:#fff}
.filter:focus{outline:none;border-color:var(--dark)}
.topic-h{font-family:var(--sans);font-size:1.05rem;font-weight:800;letter-spacing:-.01em;margin:30px 0 6px}
.mark-band{font-family:var(--sans);font-size:.72rem;font-weight:700;letter-spacing:.1em;text-transform:uppercase;
  color:var(--ink-soft);margin:16px 0 8px}

/* question card */
.qcard{background:#fff;border:1px solid var(--rule);border-radius:14px;padding:16px 18px;margin-bottom:14px;
  scroll-margin-top:76px}
.q-head{display:flex;align-items:center;gap:8px;margin-bottom:6px}
.q-n{font-family:var(--sans);font-weight:700;font-size:.8rem;color:#fff;background:var(--dark);
  min-width:24px;height:23px;padding:0 8px;display:inline-flex;align-items:center;justify-content:center;border-radius:7px}
.q-meta{font-family:var(--sans);font-size:.74rem;color:var(--ink-soft)}
.plink{font-family:var(--sans);font-size:.72rem;font-weight:600;margin-left:auto;text-decoration:none;
  color:var(--ink-soft);border:1px solid var(--rule);border-radius:999px;padding:3px 10px}
.plink:hover{color:var(--ink);border-color:#b9bcc2}
.q-text{overflow-wrap:anywhere}
.opts{list-style:none;margin:8px 0 0;display:grid;grid-template-columns:1fr 1fr;gap:4px 20px}
.opts.one-col{grid-template-columns:1fr}
.opts li{display:flex;gap:6px;align-items:baseline}
.opt-l{font-family:var(--sans);font-weight:700;color:var(--ink-soft);min-width:22px;font-size:.9rem}
.fig{margin:10px 0}
.fig img{max-width:min(420px,100%);height:auto;display:block;border:1px solid var(--rule);border-radius:10px;padding:4px;background:#fff}
/* per-question figure size, chosen in the Review Studio */
.fig-s img{max-width:min(230px,70%)}
.fig-m img{max-width:min(420px,100%)}
.fig-l img{max-width:min(680px,100%)}

/* solution reveal */
details.sol{margin-top:12px}
details.sol summary{list-style:none;cursor:pointer;display:inline-flex;align-items:center;gap:8px;
  font-family:var(--sans);font-size:.85rem;font-weight:700;color:#fff;background:var(--dark);
  border-radius:999px;padding:9px 18px;user-select:none}
details.sol summary::-webkit-details-marker{display:none}
details.sol summary:hover{background:#000}
details.sol .s-hide{display:none}
details.sol[open] .s-show{display:none}
details.sol[open] .s-hide{display:inline}
details.sol summary kbd{background:rgba(255,255,255,.92);border-color:transparent}
.sol-inner{margin-top:12px;background:var(--sol-bg);border-radius:12px;padding:14px 16px}
.sol-body{line-height:1.6;overflow-wrap:anywhere}
/* wide equations scroll inside their own box instead of stretching the page */
mjx-container{line-height:0;max-width:100%;overflow-x:auto;overflow-y:hidden;padding-bottom:2px}

/* repeated-question badge */
.rep{color:var(--accent-2);font-style:normal;font-weight:600}

/* year / marks / level filter bar */
.fbar{display:flex;gap:16px;flex-wrap:wrap;align-items:center;margin:6px 0 14px;
  font-family:var(--sans);font-size:.82rem}
.fgrp{display:inline-flex;gap:6px;align-items:center;flex-wrap:wrap}
.fgrp>b{color:var(--ink-soft);font-weight:600;margin-right:2px}
.fchip{font-family:var(--sans);font-size:.78rem;font-weight:600;border:none;
  border-radius:999px;padding:6px 14px;background:var(--band);color:var(--ink-soft);cursor:pointer}
.fchip:hover{color:var(--ink)}
.fchip.on{background:var(--dark);color:#fff}
.fnote{font-size:.72rem;color:var(--ink-soft);flex-basis:100%}

/* sticky filter block on chapter pages — only questions scroll */
.stickyfilters{position:sticky;top:56px;z-index:40;background:var(--bg);
  padding:8px 4px 6px;margin:0 -4px;border-bottom:1px solid var(--rule)}
.stickyfilters .fbar{margin:0 0 8px}
.stickyfilters .filter{margin:0}

/* repeated-question chip — the unique insight, made to stand out */
.fchip.rep-chip{background:#fdf1e0;color:var(--accent-2)}
.fchip.rep-chip.on{background:var(--accent-2);color:#fff}

/* repeated-questions banner: soft amber card */
.rep-banner{display:flex;align-items:center;gap:16px;text-decoration:none;
  background:#fff7e8;border:1px solid #f1dfb8;
  border-radius:16px;padding:18px 20px;margin:14px 0 8px;color:var(--ink);
  transition:border-color .15s,transform .12s}
.rep-banner:hover{border-color:var(--accent-2);transform:translateY(-2px);color:var(--ink)}
.rb-icon{font-size:1.9rem;flex-shrink:0;background:#fff;border:1px solid #f1dfb8;border-radius:14px;
  width:56px;height:56px;display:flex;align-items:center;justify-content:center}
.rb-txt{flex:1;min-width:0}
.rb-h{display:block;font-family:var(--sans);font-weight:800;font-size:1.12rem;line-height:1.25;letter-spacing:-.01em}
.rb-s{display:block;font-family:var(--sans);font-size:.84rem;color:var(--ink-soft);margin-top:4px;line-height:1.45}
.rb-btn{font-family:var(--sans);font-weight:700;font-size:.9rem;background:var(--accent-2);color:#fff;
  border-radius:999px;padding:11px 22px;white-space:nowrap}
@media (max-width:560px){.rep-banner{flex-wrap:wrap;padding:16px}.rb-btn{width:100%;text-align:center}}
.rep-times{font-family:var(--sans);font-size:.72rem;font-weight:700;background:#fdf1e0;color:#92400e;
  border-radius:999px;padding:4px 11px;white-space:nowrap;margin-left:6px}

/* data tables (frequency distributions etc.) */
.qtbl{border-collapse:collapse;margin:8px 0;font-size:.92em;max-width:100%}
.qtbl th,.qtbl td{border:1px solid #d6d8db;padding:4px 10px;text-align:center}
.qtbl th{background:var(--band);font-weight:600;font-family:var(--sans);font-size:.9em}

/* question page nav */
.qnav{display:flex;gap:10px;margin:22px 0;font-family:var(--sans);font-size:.85rem;font-weight:600}
.qnav a{flex:1;border:1px solid var(--rule);border-radius:12px;padding:11px 16px;text-decoration:none;background:#fff;color:var(--ink)}
.qnav a:hover{border-color:#b9bcc2}
.qnav .nxt{text-align:right}
.related{margin:26px 0}
.related h2{font-family:var(--sans);font-size:1rem;margin-bottom:8px}
.related ul{list-style:none}
.related li{margin:6px 0;font-family:var(--sans);font-size:.9rem}

/* footer */
.foot{border-top:1px solid var(--rule);margin-top:48px;padding:24px 0 36px;background:var(--band)}
.foot p{font-family:var(--sans);font-size:.78rem;color:var(--ink-soft);margin-top:12px;line-height:1.6}
.foot-chaps{font-family:var(--sans);font-size:.78rem;color:var(--ink-soft);line-height:1.9}
.foot-chaps a{margin-right:10px;white-space:nowrap}
.foot-subjects{font-size:.82rem;margin-bottom:10px}.foot-subjects a,.foot-subjects span{margin-right:14px}
.trust-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin:22px 0 34px}
.trust-card{border:1px solid var(--rule);background:#fff;border-radius:16px;padding:20px}
.trust-card h2,.trust-card h3{font-size:1rem;margin-bottom:6px}
.trust-card p{font-size:.9rem;color:var(--ink-soft)}
.prose{max-width:72ch;padding-top:24px}.prose h1{font-size:2rem;line-height:1.15;margin:12px 0}.prose h2{font-size:1.2rem;margin:30px 0 8px}.prose p,.prose li{margin:8px 0}.prose ul{padding-left:22px}
.hub-hero{padding:38px 0 20px}.hub-hero .eyebrow,.eyebrow{display:block;color:var(--accent);font-size:.74rem;font-weight:800;letter-spacing:.1em;text-transform:uppercase;margin-bottom:8px}
.hub-hero h1{font-size:2rem;line-height:1.2;max-width:none}.hub-hero .lead{font-size:1rem;color:var(--ink-soft);max-width:62ch;margin-top:10px}
.continue-card{display:none;align-items:center;gap:14px;margin:8px 0 24px;padding:16px 18px;background:var(--dark);color:#fff;border-radius:16px;text-decoration:none}.continue-card.show{display:flex}.continue-card strong{display:block}.continue-card small{color:#cbd6d0}.continue-card .go{margin-left:auto;font-weight:800}
.subject-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px;margin:18px 0 42px}.subject-card{display:flex;align-items:center;justify-content:center;min-height:130px;border:1px solid var(--rule);background:#fff;border-radius:20px;padding:24px;text-decoration:none;color:var(--ink);transition:.16s}.subject-card:hover{transform:translateY(-3px);box-shadow:0 14px 34px rgba(20,33,27,.08)}
.subject-card h2{font-size:1.45rem}.subject-card.coming{opacity:.7;cursor:default}.subject-card.maths{border-top:4px solid #087a55}.subject-card.science{border-top:4px solid #2563a7}.subject-card.social{border-top:4px solid #b76a09}.subject-card.english{border-top:4px solid #7652a7}
.seo-copy{border-top:1px solid var(--rule);padding:28px 0 8px;margin-top:16px}.seo-copy h2{font-size:1.2rem;margin-bottom:8px}.seo-copy p{color:var(--ink-soft);font-size:.92rem;max-width:72ch}
.subject-head{padding:34px 0 18px}.subject-head h1{font-size:2rem;line-height:1.2}.subject-head p{color:var(--ink-soft);font-size:1rem;margin-top:10px;max-width:68ch}.subject-actions{display:flex;gap:10px;flex-wrap:wrap;margin:0 0 24px}.subject-actions a{font-size:.82rem;font-weight:700;text-decoration:none;border:1px solid var(--rule);border-radius:999px;padding:7px 13px;background:#fff}
.path-panel{margin:22px 0 30px}.path-intro{display:flex;align-items:end;justify-content:space-between;gap:15px;margin-bottom:13px}.path-intro h2{font-size:1.35rem}.path-intro>span{font-size:.78rem;color:var(--ink-soft)}.path-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.path-card{display:flex;flex-direction:column;min-height:145px;border:1px solid var(--rule);border-radius:16px;padding:18px;text-decoration:none;color:var(--ink);background:#fff}.path-card:hover{border-color:#a8c9b9;transform:translateY(-2px)}.path-card.primary{background:var(--dark);color:#fff}.path-card .path-icon{font-size:1.2rem;margin-bottom:auto}.path-card strong{font-size:1rem}.path-card small{color:var(--ink-soft);margin-top:3px}.path-card.primary small{color:#cbd6d0}
.archive{margin:12px 0 30px}.archive>summary{cursor:pointer;border:1px solid var(--rule);background:var(--band);border-radius:12px;padding:13px 16px;font-size:.88rem;font-weight:750}.archive[open]>summary{margin-bottom:16px}.checkin{border-top:1px solid var(--rule);margin-top:18px;padding-top:16px}.checkin p{font-size:.85rem;font-weight:700;margin-bottom:8px}.checkin-actions{display:flex;gap:8px;flex-wrap:wrap}.checkin button{border:1px solid var(--rule);background:#fff;border-radius:999px;padding:8px 13px;font-weight:700;cursor:pointer}.checkin button:hover{border-color:var(--accent);color:var(--accent)}.checkin button.on{background:var(--accent);border-color:var(--accent);color:#fff}

@media (max-width:560px){
  body{font-size:.98rem}
  .wrap{padding:0 16px}
  .hero{padding-top:30px}
  .hero h1{font-size:2rem}
  h1.pgtitle{font-size:1.32rem}
  .navlinks .navlink:not(.hot){display:none}
  .navlink.hot{padding:7px 11px;font-size:.78rem}
  .qcard{padding:18px 16px;border-radius:15px}
  .subject-grid,.path-grid{grid-template-columns:1fr 1fr}
  .subject-card{min-height:100px;padding:16px}.subject-card h2{font-size:1.05rem}
  .hub-hero h1,.subject-head h1{font-size:1.625rem}
  .path-grid{grid-template-columns:1fr}
  .path-intro{align-items:start;flex-direction:column}.path-card{min-height:120px}
  .opts{grid-template-columns:1fr}
  .qnav{flex-direction:column}
  .qnav .nxt{text-align:left}
}