/* ==========================================================================
   Bnm — design system
   Editorial serif display + clean sans body. Warm paper ground, forest ink.
   No external font/CDN requests: nothing leaves the visitor's browser.
   (Deliberate — a UK education product handling under-18 audiences should not
   leak visitor IPs to a third-party font host. See CONTENT-TODO.md.)
   ========================================================================== */

/* ---------- tokens: light (default, defined on bare :root) ---------- */
:root {
  --paper:        #FBFAF7;
  --paper-2:      #F4F2EC;
  --paper-3:      #EAE7DE;
  --ink:          #12211C;
  --ink-2:        #2C3B34;
  --muted:        #5D6B64;
  --line:         #DFDBD0;

  --forest:       #0E5C43;
  --forest-deep:  #0A4433;
  --forest-soft:  #E4EFE9;
  --coral:        #D9553C;
  --coral-soft:   #FBEAE5;
  --amber:        #E0A83C;
  --amber-soft:   #FBF1DC;

  --card:         #FFFFFF;
  --card-line:    #E6E2D8;
  --shadow-sm:    0 1px 2px rgba(18,33,28,.06), 0 2px 6px rgba(18,33,28,.04);
  --shadow-md:    0 2px 6px rgba(18,33,28,.06), 0 12px 28px rgba(18,33,28,.08);
  --shadow-lg:    0 4px 12px rgba(18,33,28,.07), 0 24px 60px rgba(18,33,28,.11);

  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --serif: ui-serif, Georgia, Cambria, "Times New Roman", Times, serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --r-sm: 8px;
  --r-md: 14px;
  --r-lg: 22px;
  --r-xl: 32px;

  --wrap: 1180px;
  --gut: clamp(20px, 5vw, 48px);
}

/* ---------- tokens: dark (system pref, unless user forced light) ---------- */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper:       #0B1512;
    --paper-2:     #101E19;
    --paper-3:     #16281F;
    --ink:         #EDF3EF;
    --ink-2:       #C8D6CE;
    --muted:       #93A69C;
    --line:        #22362C;

    --forest:      #4FBF91;
    --forest-deep: #7FD9B2;
    --forest-soft: #12291F;
    --coral:       #F1836C;
    --coral-soft:  #2B1712;
    --amber:       #EBBA5E;
    --amber-soft:  #2A2113;

    --card:        #101E19;
    --card-line:   #22362C;
    --shadow-sm:   0 1px 2px rgba(0,0,0,.4);
    --shadow-md:   0 2px 6px rgba(0,0,0,.4), 0 12px 28px rgba(0,0,0,.32);
    --shadow-lg:   0 4px 12px rgba(0,0,0,.45), 0 24px 60px rgba(0,0,0,.4);
  }
}

/* ---------- tokens: dark forced by toggle ---------- */
:root[data-theme="dark"] {
  --paper:       #0B1512;
  --paper-2:     #101E19;
  --paper-3:     #16281F;
  --ink:         #EDF3EF;
  --ink-2:       #C8D6CE;
  --muted:       #93A69C;
  --line:        #22362C;

  --forest:      #4FBF91;
  --forest-deep: #7FD9B2;
  --forest-soft: #12291F;
  --coral:       #F1836C;
  --coral-soft:  #2B1712;
  --amber:       #EBBA5E;
  --amber-soft:  #2A2113;

  --card:        #101E19;
  --card-line:   #22362C;
  --shadow-sm:   0 1px 2px rgba(0,0,0,.4);
  --shadow-md:   0 2px 6px rgba(0,0,0,.4), 0 12px 28px rgba(0,0,0,.32);
  --shadow-lg:   0 4px 12px rgba(0,0,0,.45), 0 24px 60px rgba(0,0,0,.4);
}

/* ---------- reset / base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img, svg, video { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
button { font: inherit; color: inherit; }

h1, h2, h3, h4 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.14;
  letter-spacing: -.018em;
  margin: 0 0 .5em;
  text-wrap: balance;
}
h1 { font-size: clamp(2.6rem, 6.2vw, 4.4rem); }
h2 { font-size: clamp(1.95rem, 4vw, 2.9rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.45rem); }
p  { margin: 0 0 1.1em; text-wrap: pretty; }

:focus-visible {
  outline: 3px solid var(--forest);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip {
  position: absolute; left: -9999px; top: 0;
  background: var(--forest); color: #fff;
  padding: 12px 20px; z-index: 999; border-radius: 0 0 var(--r-sm) 0;
}
.skip:focus { left: 0; }

/* ---------- layout ---------- */
.wrap { width: 100%; max-width: var(--wrap); margin-inline: auto; padding-inline: var(--gut); }
.section { padding-block: clamp(64px, 9vw, 120px); }
.section--tight { padding-block: clamp(48px, 6vw, 80px); }
.section--paper2 { background: var(--paper-2); }
.center { text-align: center; }
.mx-narrow { max-width: 720px; margin-inline: auto; }

.grid { display: grid; gap: clamp(20px, 3vw, 32px); }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 270px), 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 210px), 1fr)); }

/* ---------- eyebrow / kicker ---------- */
.eyebrow {
  display: inline-flex; align-items: center; gap: 9px;
  font-size: .77rem; font-weight: 650; letter-spacing: .13em;
  text-transform: uppercase; color: var(--forest);
  margin-bottom: 18px;
}
.eyebrow::before {
  content: ""; width: 26px; height: 2px; border-radius: 2px;
  background: currentColor; opacity: .55;
}
.eyebrow--center { justify-content: center; }

.lede { font-size: clamp(1.06rem, 1.7vw, 1.22rem); color: var(--muted); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  padding: 14px 26px; border-radius: 100px;
  font-size: .97rem; font-weight: 620; letter-spacing: -.005em;
  text-decoration: none; cursor: pointer;
  border: 1.5px solid transparent;
  transition: transform .18s cubic-bezier(.2,.7,.3,1), box-shadow .18s, background .18s, border-color .18s, color .18s;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.btn--primary { background: var(--forest); color: #fff; box-shadow: var(--shadow-sm); }
.btn--primary:hover { background: var(--forest-deep); box-shadow: var(--shadow-md); }
:root[data-theme="dark"] .btn--primary,
:root:not([data-theme="light"]) .btn--primary { color: #06120D; }
@media (prefers-color-scheme: light) { :root:not([data-theme="dark"]) .btn--primary { color: #fff; } }

.btn--ghost { border-color: var(--line); background: transparent; color: var(--ink); }
.btn--ghost:hover { border-color: var(--forest); color: var(--forest); background: var(--forest-soft); }

.btn--light { background: var(--paper); color: var(--ink); }
.btn--light:hover { background: #fff; box-shadow: var(--shadow-md); }

.btn-row { display: flex; flex-wrap: wrap; gap: 14px; }
.btn-row--center { justify-content: center; }

/* ---------- header ---------- */
.site-head {
  position: sticky; top: 0; z-index: 60;
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  backdrop-filter: saturate(1.5) blur(14px);
  -webkit-backdrop-filter: saturate(1.5) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s, background .25s;
}
.site-head.is-stuck { border-bottom-color: var(--line); }
.head-in {
  display: flex; align-items: center; gap: 20px;
  min-height: 74px;
}

.brand { display: inline-flex; align-items: center; gap: 11px; text-decoration: none; margin-right: auto; }
.brand__mark { width: 36px; height: 36px; flex: none; }
.brand__name {
  font-family: var(--serif); font-size: 1.42rem; font-weight: 640;
  letter-spacing: -.03em; color: var(--ink);
}
.brand__dot { color: var(--coral); }

.nav { display: flex; align-items: center; gap: 4px; }
.nav a {
  padding: 9px 14px; border-radius: 100px; text-decoration: none;
  font-size: .945rem; font-weight: 520; color: var(--ink-2);
  transition: background .18s, color .18s;
}
.nav a:hover { background: var(--paper-3); color: var(--ink); }
.nav a[aria-current="page"] { color: var(--forest); font-weight: 620; }

.head-actions { display: flex; align-items: center; gap: 10px; }

.theme-btn {
  width: 38px; height: 38px; flex: none; display: grid; place-items: center;
  border-radius: 100px; border: 1px solid var(--line);
  background: transparent; cursor: pointer; color: var(--ink-2);
  transition: background .18s, color .18s, border-color .18s;
}
.theme-btn:hover { background: var(--paper-3); color: var(--ink); }
.theme-btn .moon { display: none; }
:root[data-theme="dark"] .theme-btn .moon { display: block; }
:root[data-theme="dark"] .theme-btn .sun { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-btn .moon { display: block; }
  :root:not([data-theme="light"]) .theme-btn .sun { display: none; }
}

.burger {
  display: none; width: 40px; height: 40px; border-radius: 10px;
  border: 1px solid var(--line); background: transparent; cursor: pointer;
  place-items: center; color: var(--ink);
}

@media (max-width: 900px) {
  .burger { display: grid; }
  .nav {
    position: fixed; inset: 74px 0 auto; flex-direction: column; align-items: stretch;
    gap: 2px; padding: 16px var(--gut) 28px;
    background: var(--paper); border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-lg);
    transform: translateY(-12px); opacity: 0; pointer-events: none;
    transition: opacity .2s, transform .2s;
  }
  .nav.is-open { transform: translateY(0); opacity: 1; pointer-events: auto; }
  .nav a { padding: 13px 14px; font-size: 1.03rem; }
  .head-actions .btn { display: none; }
}

/* ---------- hero ---------- */
.hero { position: relative; overflow: hidden; padding-block: clamp(56px, 8vw, 104px) clamp(56px, 8vw, 96px); }
.hero__glow {
  position: absolute; pointer-events: none; z-index: 0;
  width: 780px; height: 780px; border-radius: 50%;
  top: -340px; right: -220px;
  background: radial-gradient(circle, color-mix(in srgb, var(--forest) 17%, transparent) 0%, transparent 66%);
}
.hero__glow2 {
  position: absolute; pointer-events: none; z-index: 0;
  width: 560px; height: 560px; border-radius: 50%;
  bottom: -300px; left: -200px;
  background: radial-gradient(circle, color-mix(in srgb, var(--amber) 15%, transparent) 0%, transparent 66%);
}
.hero .wrap { position: relative; z-index: 1; }
.hero__grid { display: grid; grid-template-columns: 1.08fr .92fr; gap: clamp(32px, 5vw, 64px); align-items: center; }
@media (max-width: 940px) { .hero__grid { grid-template-columns: 1fr; } }

.hero h1 .accent {
  color: var(--forest);
  font-style: italic;
}
.hero__lede { font-size: clamp(1.1rem, 1.9vw, 1.3rem); color: var(--muted); max-width: 44ch; }

.trust { margin-top: 34px; padding-top: 26px; border-top: 1px solid var(--line); }
.trust__label { font-size: .76rem; letter-spacing: .12em; text-transform: uppercase; color: var(--muted); margin-bottom: 14px; font-weight: 600; }
.trust__row { display: flex; flex-wrap: wrap; gap: 12px 28px; align-items: center; }
.trust__item { display: inline-flex; align-items: center; gap: 8px; font-size: .9rem; color: var(--ink-2); font-weight: 530; }
.trust__item svg { color: var(--forest); flex: none; }

/* ---------- hero visual ---------- */
.hero-card {
  background: var(--card); border: 1px solid var(--card-line);
  border-radius: var(--r-xl); box-shadow: var(--shadow-lg);
  padding: 24px; position: relative;
}
.hero-card__bar { display: flex; align-items: center; gap: 7px; margin-bottom: 20px; }
.hero-card__bar i { width: 10px; height: 10px; border-radius: 50%; background: var(--line); }
.hero-card__bar span { margin-left: auto; font-size: .74rem; color: var(--muted); font-family: var(--mono); }

.lesson { display: flex; gap: 13px; padding: 13px; border-radius: var(--r-md); transition: background .2s; }
.lesson + .lesson { margin-top: 6px; }
.lesson:hover { background: var(--paper-2); }
.lesson__icon {
  width: 40px; height: 40px; flex: none; border-radius: 11px;
  display: grid; place-items: center; background: var(--forest-soft); color: var(--forest);
}
.lesson__icon--coral { background: var(--coral-soft); color: var(--coral); }
.lesson__icon--amber { background: var(--amber-soft); color: var(--amber); }
.lesson__t { font-weight: 620; font-size: .96rem; margin-bottom: 3px; }
.lesson__m { font-size: .83rem; color: var(--muted); }
.lesson__pct { margin-left: auto; align-self: center; font-size: .82rem; font-weight: 640; color: var(--forest); font-family: var(--mono); }

.bar { height: 6px; border-radius: 100px; background: var(--paper-3); overflow: hidden; margin-top: 7px; }
.bar > i { display: block; height: 100%; border-radius: 100px; background: var(--forest); }
.bar--coral > i { background: var(--coral); }
.bar--amber > i { background: var(--amber); }

.float-chip {
  position: absolute; background: var(--card); border: 1px solid var(--card-line);
  border-radius: 100px; padding: 9px 16px; box-shadow: var(--shadow-md);
  display: inline-flex; align-items: center; gap: 9px;
  font-size: .84rem; font-weight: 600;
}
.float-chip--tl { top: -18px; left: -14px; }
.float-chip--br { bottom: -18px; right: -10px; }
@media (max-width: 940px) { .float-chip { display: none; } }

/* ---------- cards ---------- */
.card {
  background: var(--card); border: 1px solid var(--card-line);
  border-radius: var(--r-lg); padding: clamp(24px, 3vw, 32px);
  box-shadow: var(--shadow-sm);
  transition: transform .22s cubic-bezier(.2,.7,.3,1), box-shadow .22s, border-color .22s;
}
.card--hover:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: color-mix(in srgb, var(--forest) 35%, var(--card-line)); }
.card h3 { margin-bottom: .4em; }
.card p:last-child { margin-bottom: 0; }

.icon-badge {
  width: 50px; height: 50px; border-radius: 14px; display: grid; place-items: center;
  background: var(--forest-soft); color: var(--forest); margin-bottom: 20px;
}
.icon-badge--coral { background: var(--coral-soft); color: var(--coral); }
.icon-badge--amber { background: var(--amber-soft); color: var(--amber); }

/* numbered steps */
.step { position: relative; padding-left: 62px; }
.step__n {
  position: absolute; left: 0; top: 0;
  width: 44px; height: 44px; border-radius: 13px; display: grid; place-items: center;
  background: var(--forest); color: #fff;
  font-family: var(--serif); font-size: 1.2rem; font-weight: 600;
}
:root[data-theme="dark"] .step__n { color: #06120D; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .step__n { color: #06120D; } }

/* ---------- stats ---------- */
.stat { text-align: center; padding: 8px; }
.stat__n {
  font-family: var(--serif); font-size: clamp(2.4rem, 5vw, 3.4rem);
  font-weight: 620; line-height: 1; color: var(--forest); letter-spacing: -.03em;
}
.stat__l { font-size: .93rem; color: var(--muted); margin-top: 10px; }

/* ---------- feature split ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(32px, 5vw, 72px); align-items: center; }
.split--flip .split__media { order: -1; }
@media (max-width: 900px) {
  .split { grid-template-columns: 1fr; }
  .split--flip .split__media { order: 0; }
}

.checklist { list-style: none; padding: 0; margin: 24px 0 0; display: grid; gap: 13px; }
.checklist li { display: flex; gap: 12px; align-items: flex-start; font-size: .98rem; }
.checklist svg { flex: none; margin-top: 3px; color: var(--forest); }

/* ---------- panel (dark band) ---------- */
.panel {
  background: var(--forest-deep); color: #EAF5EF;
  border-radius: var(--r-xl); padding: clamp(36px, 5vw, 68px);
  position: relative; overflow: hidden;
}
:root[data-theme="dark"] .panel { background: var(--paper-3); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .panel { background: var(--paper-3); } }
.panel h2 { color: #fff; }
:root[data-theme="dark"] .panel h2 { color: var(--ink); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .panel h2 { color: var(--ink); } }
.panel p { color: rgba(255,255,255,.8); }
:root[data-theme="dark"] .panel p { color: var(--muted); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .panel p { color: var(--muted); } }
.panel .eyebrow { color: var(--amber); }

/* ---------- quotes ---------- */
.quote {
  background: var(--card); border: 1px solid var(--card-line);
  border-radius: var(--r-lg); padding: clamp(24px, 3vw, 34px);
  display: flex; flex-direction: column;
}
.quote__mark { font-family: var(--serif); font-size: 3.4rem; line-height: .7; color: var(--forest); opacity: .35; margin-bottom: 8px; }
.quote__body { font-size: 1.03rem; margin-bottom: 22px; }
.quote__who { display: flex; align-items: center; gap: 13px; margin-top: auto; }
.quote__av {
  width: 42px; height: 42px; border-radius: 50%; flex: none;
  display: grid; place-items: center; background: var(--forest-soft); color: var(--forest);
  font-weight: 700; font-size: .92rem;
}
.quote__n { font-weight: 630; font-size: .93rem; }
.quote__r { font-size: .84rem; color: var(--muted); }

/* ---------- accordion ---------- */
.faq { border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  cursor: pointer; list-style: none; padding: 22px 44px 22px 0;
  font-weight: 600; font-size: 1.04rem; position: relative;
  font-family: var(--serif); letter-spacing: -.01em;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: ""; position: absolute; right: 6px; top: 50%;
  width: 11px; height: 11px; margin-top: -7px;
  border-right: 2px solid var(--muted); border-bottom: 2px solid var(--muted);
  transform: rotate(45deg); transition: transform .22s;
}
.faq details[open] summary::after { transform: rotate(-135deg); margin-top: -2px; }
.faq details[open] summary { color: var(--forest); }
.faq__a { padding: 0 44px 24px 0; color: var(--muted); }
.faq__a p:last-child { margin-bottom: 0; }

/* ---------- forms ---------- */
.field { margin-bottom: 20px; }
.field label { display: block; font-size: .89rem; font-weight: 620; margin-bottom: 8px; }
.field .hint { font-weight: 400; color: var(--muted); }
.input, .textarea, .select {
  width: 100%; padding: 13px 16px; font: inherit; font-size: .97rem;
  color: var(--ink); background: var(--paper);
  border: 1.5px solid var(--line); border-radius: var(--r-md);
  transition: border-color .18s, box-shadow .18s;
}
.input:focus, .textarea:focus, .select:focus {
  outline: none; border-color: var(--forest);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--forest) 15%, transparent);
}
.textarea { min-height: 150px; resize: vertical; }
.form-note { font-size: .86rem; color: var(--muted); }

/* ---------- badges / pills ---------- */
.pill {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 6px 14px; border-radius: 100px;
  background: var(--forest-soft); color: var(--forest);
  font-size: .8rem; font-weight: 630;
}
.pill--amber { background: var(--amber-soft); color: var(--amber); }
.pill--coral { background: var(--coral-soft); color: var(--coral); }

/* placeholder marker — visible in-page so nothing fake ships unnoticed */
.tbd {
  border-bottom: 2px dotted var(--coral);
  cursor: help;
}

/* ---------- footer ---------- */
.site-foot { background: var(--paper-2); border-top: 1px solid var(--line); padding-block: clamp(48px, 6vw, 76px) 32px; }
.foot-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: clamp(28px, 4vw, 48px); }
@media (max-width: 820px) { .foot-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 480px) { .foot-grid { grid-template-columns: 1fr; } }
.foot-col h4 {
  font-family: var(--sans); font-size: .78rem; letter-spacing: .12em;
  text-transform: uppercase; color: var(--muted); font-weight: 650; margin-bottom: 16px;
}
.foot-col ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 11px; }
.foot-col a { text-decoration: none; color: var(--ink-2); font-size: .94rem; transition: color .16s; }
.foot-col a:hover { color: var(--forest); }
.foot-blurb { color: var(--muted); font-size: .94rem; max-width: 34ch; margin-top: 16px; }
.foot-bottom {
  margin-top: clamp(36px, 5vw, 56px); padding-top: 26px; border-top: 1px solid var(--line);
  display: flex; flex-wrap: wrap; gap: 14px 24px; align-items: center;
  font-size: .87rem; color: var(--muted);
}
.foot-bottom .spacer { margin-left: auto; }

/* ---------- page header (inner pages) ---------- */
.page-head { padding-block: clamp(52px, 7vw, 88px) clamp(36px, 4vw, 56px); position: relative; overflow: hidden; }
.page-head__glow {
  position: absolute; width: 640px; height: 640px; border-radius: 50%;
  top: -380px; right: -180px; pointer-events: none;
  background: radial-gradient(circle, color-mix(in srgb, var(--forest) 14%, transparent) 0%, transparent 68%);
}
.page-head .wrap { position: relative; z-index: 1; }
.page-head p { max-width: 62ch; }

/* ---------- prose (legal pages) ---------- */
.prose { max-width: 760px; }
.prose h2 { font-size: clamp(1.4rem, 2.4vw, 1.75rem); margin-top: 2.2em; }
.prose h3 { font-size: 1.12rem; margin-top: 1.8em; }
.prose ul, .prose ol { padding-left: 1.3em; margin-bottom: 1.2em; }
.prose li { margin-bottom: .5em; }
.prose a { color: var(--forest); text-underline-offset: 3px; }

/* ---------- reveal on scroll ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s cubic-bezier(.2,.7,.3,1); }
.reveal.is-in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; } }

/* ---------- misc ---------- */
.hr { height: 1px; background: var(--line); border: 0; margin-block: clamp(40px, 6vw, 72px); }
.tag-row { display: flex; flex-wrap: wrap; gap: 10px; }