/* IELTS study pages — the fixed session format.
   Colour is ENCODING, not decoration: one hue per role, used nowhere else.
   Four hues plus neutral. A fifth hue would mean a fifth slot, and there isn't one.
   Contrast ratios are measured, not assumed — all pass WCAG AA at body size. */
:root{
  --bg:#151535; --panel:#1a1a42; --line:#2a2a5c;
  --text:#e0e0f0;        /* 13.51:1 on --bg */
  --muted:#939ec2;       /*  6.64:1 — was #7a7a9a at 4.27:1, an AA failure at 11px */
  --analogy:#a78bfa;  --analogy-bg:#171233;   /* violet  6.59:1 */
  --example:#7dd3fc;  --example-bg:#0d1f2e;   /* cyan   10.06:1 — moved off green,
                                                 which collided with "correct" */
  --rule:#8b96b8;     --rule-bg:#151535;      /* neutral 6.01:1 */
  --trap:#fbbf24;     --trap-bg:#2a1d09;      /* amber   9.84:1 */
  --ok:#10b981;       --ok-bg:#0e2a1c;        /* green = correct. ONE meaning. */
  --wrong:#f87171;
}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);
  font:16px/1.65 -apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif}
a{color:var(--example)}
.bar{position:sticky;top:0;z-index:20;background:#151535ee;backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line);display:flex;gap:2px;padding:9px 18px;flex-wrap:wrap;align-items:center}
.bar a{color:var(--muted);text-decoration:none;padding:6px 11px;border-radius:7px;font-size:13.5px}
.bar a:hover{color:var(--text);background:#22224e}
.bar a.on{color:var(--example);background:#7dd3fc1a}
.bar .brand{font-weight:700;color:var(--text);margin-right:10px}
main{max-width:860px;margin:0 auto;padding:30px 22px 90px}
h1{font-size:30px;line-height:1.25;margin:0 0 6px}
.eyebrow{color:var(--muted);font-size:12px;letter-spacing:.9px;text-transform:uppercase;margin:0 0 8px}

/* 1 — GOAL. If anything sits at the top it is the goal, never the compression. */
.goal{border-left:3px solid var(--ok);background:var(--ok-bg);padding:14px 18px;border-radius:0 9px 9px 0;margin:22px 0}
.goal b{color:var(--ok);display:block;font-size:11.5px;letter-spacing:.9px;text-transform:uppercase;margin-bottom:4px}

/* 2 — session map: structure only, never the content */
.map{background:var(--panel);border:1px solid var(--line);border-radius:11px;padding:16px;margin:22px 0}
.map .cap{color:var(--muted);font-size:12px;margin-bottom:8px}

/* 3 — analogy */
.analogy{border-left:3px solid var(--analogy);background:var(--analogy-bg);padding:14px 18px;border-radius:0 9px 9px 0;margin:22px 0}
.analogy b{color:var(--analogy);display:block;font-size:11.5px;letter-spacing:.9px;text-transform:uppercase;margin-bottom:4px}

/* 4 — per idea: example → rule → trap, in that order */
.idea{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:20px;margin:24px 0}
.idea > h3{margin:0 0 14px;font-size:18px}
.ex{border-left:3px solid var(--example);background:var(--example-bg);padding:13px 16px;border-radius:0 8px 8px 0;margin-bottom:13px}
.ex b{color:var(--example);display:block;font-size:11.5px;letter-spacing:.9px;text-transform:uppercase;margin-bottom:4px}
.rule{border-left:3px solid var(--rule);background:#1d1d47;padding:13px 16px;border-radius:0 8px 8px 0;margin-bottom:13px}
.rule b{color:var(--rule);display:block;font-size:11.5px;letter-spacing:.9px;text-transform:uppercase;margin-bottom:4px}
.trap{border-left:3px solid var(--trap);background:var(--trap-bg);padding:13px 16px;border-radius:0 8px 8px 0}
.trap b{color:var(--trap);display:block;font-size:11.5px;letter-spacing:.9px;text-transform:uppercase;margin-bottom:4px}
.idea .inline-map{margin-top:14px}

/* 5 — situation, 6 — teach-back */
.situation,.teach{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:18px;margin:24px 0}
.situation h4,.teach h4{margin:0 0 8px;font-size:13px;letter-spacing:.9px;text-transform:uppercase;color:var(--muted)}
.decide{margin-top:10px;color:var(--ok)}

/* 7 — the compression. LAST. Putting the most abstract line first, loudest,
   undoes the concrete-first ordering of everything above it. */
.compression{border-left:3px solid var(--example);background:var(--example-bg);
  padding:18px 20px;border-radius:0 11px 11px 0;margin:30px 0 10px;font-size:17px}
.compression b{color:var(--example);display:block;font-size:11.5px;letter-spacing:.9px;
  text-transform:uppercase;margin-bottom:6px}

/* quiz — answer, then find out immediately */
.quiz{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:20px;margin:30px 0}
.quiz h4{margin:0 0 4px;font-size:13px;letter-spacing:.9px;text-transform:uppercase;color:var(--muted)}
.q{border-top:1px solid var(--line);padding:16px 0}
.q:first-of-type{border-top:none}
.q .stem{margin-bottom:11px}
.opt{display:block;width:100%;text-align:left;background:#1d1d47;color:var(--text);
  border:1px solid var(--line);border-radius:8px;padding:10px 13px;margin-bottom:7px;cursor:pointer;font:inherit;font-size:14.5px}
.opt:hover:not(.done){border-color:var(--example)}
.opt.correct{border-color:var(--ok);background:var(--ok-bg);color:var(--ok)}
.opt.wrong{border-color:var(--wrong);background:#2a1114;color:var(--wrong)}
.opt.done{cursor:default}
.why{display:none;margin-top:9px;padding:11px 14px;border-radius:8px;background:#1d1d47;
  border-left:3px solid var(--rule);font-size:14.5px;color:var(--text)}
.why.show{display:block}
.score{margin-top:14px;color:var(--muted);font-size:14px}
.nav{display:flex;justify-content:space-between;gap:12px;margin-top:40px;padding-top:22px;border-top:1px solid var(--line)}
.nav a{background:var(--panel);border:1px solid var(--line);padding:11px 16px;border-radius:9px;
  text-decoration:none;color:var(--text);font-size:14px}
.nav a:hover{border-color:var(--example)}
.cards{display:grid;gap:13px;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));margin:24px 0}
.card{display:block;background:var(--panel);border:1px solid var(--line);border-radius:12px;
  padding:17px;text-decoration:none;color:inherit}
.card:hover{border-color:var(--example)}
.card .t{font-weight:650;margin-bottom:5px}
.card .m{color:var(--muted);font-size:13px}
pre.mermaid{background:transparent;text-align:center}

/* ── Mobile ─────────────────────────────────────────────────────────── */
input, select, textarea { font-size: 16px; }   /* stop iOS zoom-on-focus */

@media (max-width: 760px) {
  main { padding: 18px 14px 80px }
  h1 { font-size: 23px; line-height: 1.3 }
  .bar { padding: 6px 10px; flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none }
  .bar::-webkit-scrollbar { display: none }
  .bar a { padding: 10px 12px; white-space: nowrap }
  .idea, .quiz, .situation, .teach { padding: 15px 13px }
  .opt { padding: 13px 15px }                  /* ≥44px touch target */
  .compression { padding: 15px 16px; font-size: 16px }
  .cards { grid-template-columns: 1fr }
  .nav { flex-direction: column }
  .nav a { text-align: center; padding: 13px }
  pre.mermaid svg { max-width: 100% }
}