/*
 * igcse-frontend/css/igcse.css — page styles for igcsemathrevision.com's own
 * pages (landing, hub, teachers, account, notes, legal). The nav, footer and
 * waitlist panel are styled by js/igcse-chrome.js so the shared engine pages
 * (/igcse-unit.html etc.) get them without this file.
 *
 * Brand: the family design system. Pages load /ibmath.css, which imports
 * /css/tokens.css (THE brand source for every site); the aliases below only
 * name those tokens for these layouts. No IGCSE-specific colours or fonts —
 * the sister sites differ only by name and logo.
 */
:root {
  --ig: var(--ibm-primary, #0d3d8f);
  --ig-dark: var(--ibm-primary-hover, #062559);
  --ig-deep: var(--ibm-dark, #062559);
  --ig-soft: var(--ibm-primary-soft, #e8eef9);
  --ig-mint: var(--ibm-accent, #5ec8ff);
  --ink: var(--ibm-ink, #0f1f3d);
  --ink-2: var(--ibm-ink-2, #3a4a68);
  --muted: var(--ibm-muted, #6b7a99);
  --line: var(--ibm-line, #dfe6f1);
  --bg: var(--ibm-bg, #f5f7fb);
  --card: var(--ibm-surface, #ffffff);
  --radius: var(--ibm-r-card, 12px);
  --shadow: var(--ibm-shadow-lift, 0 4px 16px rgba(6,37,89,0.12));
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font-family: var(--ibm-font, Inter, -apple-system, "Segoe UI", Roboto, sans-serif);
  line-height: 1.6; -webkit-font-smoothing: antialiased;
}
a { color: var(--ig); }
img { max-width: 100%; }
.skip-link { position: absolute; left: -9999px; }
.skip-link:focus { left: 12px; top: 12px; z-index: 2000; background: var(--ig-deep); color: #fff; padding: 10px 14px; border-radius: 8px; }
:focus-visible { outline: 3px solid var(--ig-mint); outline-offset: 2px; }

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 20px; }
.narrow { max-width: 780px; }
main { display: block; }
section { scroll-margin-top: 80px; }

h1, h2, h3 { color: var(--ig-deep); letter-spacing: -0.4px; line-height: 1.2; }
h1 { font-size: clamp(1.9rem, 4.6vw, 3rem); margin: 0 0 14px; }
h2 { font-size: clamp(1.4rem, 3vw, 2rem); margin: 0 0 10px; }
h3 { font-size: 1.08rem; margin: 0 0 6px; }
.lede { font-size: 1.1rem; color: var(--ink-2); max-width: 680px; margin: 0 0 22px; }
.eyebrow { display: inline-block; font-size: 0.76rem; font-weight: 800; letter-spacing: 1.2px; text-transform: uppercase; color: var(--ig); margin-bottom: 10px; }
.muted { color: var(--muted); }

.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 12px 22px; border-radius: 999px; font-weight: 800; font-size: 0.97rem; text-decoration: none; border: 0; cursor: pointer; font-family: inherit; }
.btn-primary { background: var(--ig); color: #fff; }
.btn-primary:hover { background: var(--ig-dark); }
.btn-ghost { background: #fff; color: var(--ig); border: 1px solid var(--ibm-line-strong, #c5d1e4); }
.btn-ghost:hover { border-color: var(--ig); color: var(--ig); }
.btn-row { display: flex; gap: 10px; flex-wrap: wrap; }

.pill { display: inline-flex; align-items: center; gap: 6px; padding: 4px 11px; border-radius: 999px; font-size: 0.74rem; font-weight: 800; letter-spacing: 0.4px; }
.pill-soon { background: var(--ig-soft); color: var(--ig-deep); border: 1px solid var(--line); }
.pill-live { background: var(--ig); color: #fff; border: 1px solid var(--ig); }

/* ---------- hero ---------- */
.hero { padding: 56px 0 44px; background: radial-gradient(1200px 400px at 85% -10%, rgba(94,200,255,0.18), transparent 60%), linear-gradient(180deg, #ffffff 0%, var(--bg) 100%); border-bottom: 1px solid var(--line); }
.hero-grid { display: grid; grid-template-columns: 1.25fr 1fr; gap: 40px; align-items: center; }
.hero-card { background: var(--card); border: 1px solid var(--line); border-radius: 20px; padding: 22px; box-shadow: var(--shadow); }
.hero-card .q { font-weight: 700; color: var(--ig-deep); margin: 6px 0 12px; }
.hero-card .steps { margin: 0; padding: 0; list-style: none; font-size: 0.92rem; color: var(--ink-2); }
.hero-card .steps li { padding: 8px 0; border-top: 1px dashed var(--line); display: flex; justify-content: space-between; gap: 12px; }
.hero-card .mk { font-weight: 800; color: var(--ig); white-space: nowrap; }
.hero-card .tag { font-size: 0.72rem; font-weight: 800; letter-spacing: 1px; text-transform: uppercase; color: var(--muted); }
.trust { display: flex; gap: 18px; flex-wrap: wrap; margin-top: 20px; font-size: 0.88rem; color: var(--muted); }
.trust span::before { content: "✓ "; color: var(--ig); font-weight: 800; }

/* ---------- sections ---------- */
.band { padding: 56px 0; }
.band-alt { background: #fff; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-head { margin-bottom: 26px; }
.grid { display: grid; gap: 16px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 22px; box-shadow: 0 2px 0 rgba(4,47,35,0.02); }
.card p { margin: 0; color: var(--ink-2); font-size: 0.94rem; }
.card .ico { width: 40px; height: 40px; border-radius: 10px; display: grid; place-items: center; background: var(--ig-soft); color: var(--ig); font-size: 1.2rem; margin-bottom: 12px; }
a.card { text-decoration: none; color: inherit; transition: border-color .15s ease, transform .15s ease, box-shadow .15s ease; display: block; }
a.card:hover { border-color: var(--ig); transform: translateY(-2px); box-shadow: var(--shadow); }
a.card .go { display: inline-block; margin-top: 10px; font-weight: 800; color: var(--ig); font-size: 0.9rem; }

.units { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.unit { display: flex; gap: 12px; align-items: center; background: #fff; border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; text-decoration: none; color: var(--ink); }
.unit b { flex-shrink: 0; width: 34px; height: 34px; border-radius: 9px; display: grid; place-items: center; background: var(--ig); color: #fff; font-size: 0.95rem; }
.unit span { font-weight: 650; font-size: 0.95rem; line-height: 1.3; }
.unit small { display: block; color: var(--muted); font-weight: 500; font-size: 0.8rem; }
a.unit:hover { border-color: var(--ig); background: var(--ig-soft); }

/* ---------- plans ---------- */
.plans { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.plan { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; position: relative; }
.plan h3 { font-size: 1.15rem; }
.plan .price { font-size: 1.05rem; font-weight: 800; color: var(--muted); margin: 6px 0 12px; }
.plan ul { margin: 0; padding-left: 18px; color: var(--ink-2); font-size: 0.92rem; }
.plan li { margin: 5px 0; }
.plan.feature { border: 2px solid var(--ig); }
.plan .pill { position: absolute; top: 18px; right: 18px; }

.waitlist-band { background: linear-gradient(135deg, var(--ig-deep) 0%, var(--ig) 100%); color: #d6e4f7; }
.waitlist-band h2 { color: #fff; }
.waitlist-band .lede { color: #c7d6ef; }
.waitlist-grid { display: grid; grid-template-columns: 1fr 1.1fr; gap: 32px; align-items: center; }

.faq details { background: #fff; border: 1px solid var(--line); border-radius: 12px; padding: 14px 18px; margin-bottom: 10px; }
.faq summary { cursor: pointer; font-weight: 700; color: var(--ig-deep); }
.faq details p { margin: 10px 0 0; color: var(--ink-2); }

/* ---------- app pages (hub / teach / account / notes) ---------- */
.page-head { padding: 34px 0 10px; }
.page-head h1 { font-size: clamp(1.7rem, 3.6vw, 2.3rem); }
.panel { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 24px; margin-bottom: 18px; }
.panel h2 { font-size: 1.2rem; margin-bottom: 6px; }
.status-strip { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; background: var(--ig-soft); border: 1px solid var(--line); color: var(--ig-deep); padding: 10px 14px; border-radius: 12px; font-size: 0.9rem; font-weight: 600; margin: 0 0 18px; }
.kv { display: grid; grid-template-columns: 160px 1fr; gap: 8px 16px; margin: 0; }
.kv dt { color: var(--muted); font-weight: 600; }
.kv dd { margin: 0; font-weight: 600; word-break: break-word; }

/* ---------- prose (legal / about) ---------- */
.prose { padding: 34px 0 10px; }
.prose h1 { font-size: clamp(1.7rem, 3.6vw, 2.3rem); }
.prose h2 { font-size: 1.25rem; margin-top: 30px; }
.prose p, .prose li { color: var(--ink-2); }
.prose table { width: 100%; border-collapse: collapse; font-size: 0.92rem; background: #fff; }
.prose th, .prose td { text-align: left; border: 1px solid var(--line); padding: 8px 10px; vertical-align: top; }
.prose th { background: var(--ig-soft); color: var(--ig-deep); }
.table-scroll { overflow-x: auto; }
.tldr { background: var(--ig-soft); border-left: 4px solid var(--ig); padding: 14px 18px; border-radius: 0 12px 12px 0; color: var(--ink); }

/* ---------- notes ---------- */
.note-unit { margin-bottom: 26px; }
.note-unit > h2 { font-size: 1.25rem; display: flex; gap: 10px; align-items: baseline; flex-wrap: wrap; }
.note-unit > h2 small { color: var(--muted); font-weight: 600; font-size: 0.85rem; }
.note { background: #fff; border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; margin-bottom: 10px; }
.note h3 { font-size: 1rem; }
.note .desc { color: var(--muted); font-size: 0.88rem; margin: 0 0 8px; }
.note .primer { margin: 0 0 8px; }
.note .ex { background: var(--bg); border-left: 3px solid var(--ig); border-radius: 0 8px 8px 0; padding: 10px 12px; font-size: 0.92rem; }
.note .ex b { color: var(--ig-deep); }

@media (max-width: 900px) {
  .hero-grid, .waitlist-grid { grid-template-columns: 1fr; }
  .grid-3, .plans { grid-template-columns: 1fr 1fr; }
  .units { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 600px) {
  .hero { padding: 36px 0 30px; }
  .band { padding: 40px 0; }
  .grid-3, .grid-2, .plans, .units { grid-template-columns: 1fr; }
  .kv { grid-template-columns: 1fr; gap: 2px; }
  .kv dd { margin-bottom: 8px; }
  .btn-row .btn { flex: 1 1 100%; }
}

/* Exam-board switch (Edexcel 4MA1 | Cambridge 0580), igcse-frontend/js/board-memory.js.
   Same strip as the A Level site's UK / IAL switch. */
.board-switcher { display: flex; justify-content: center; flex-wrap: wrap; gap: 4px; padding: 6px 16px; background: var(--ig-deep); font-size: .82rem; }
.board-switcher a { display: inline-flex; align-items: center; min-height: 32px; padding: 4px 14px; color: #c9d6ee; text-decoration: none; font-weight: 600; border-radius: 999px; }
.board-switcher a:hover { color: #fff; }
.board-switcher a[aria-current] { background: rgba(255,255,255,.14); color: #fff; }
@media (pointer: coarse) { .board-switcher a { min-height: 44px; } }