/* ===================================================================
   GenZ Maths — Design System
   Palette derived from brand assets: deep navy + electric cyan (avatar
   glow), indigo (wordmark), teal + ember (banner illustration accents).
   Signature motif: the "function line" — every section divider and
   card corner traces a linear / parabolic / exponential curve, since
   Functions is literally the subject being taught.
=================================================================== */

:root{
  /* --- core palette --- */
  --ink:        #0B1220;   /* deep navy — hero / dark sections */
  --ink-2:      #121B31;   /* elevated panel on dark */
  --ink-3:      #1B2745;   /* border / hairline on dark */
  --paper:      #F7F4EC;   /* warm light section background */
  --paper-2:    #FFFFFF;   /* card surface on light */
  --line-light: #E4DFD0;   /* hairline on light */

  --indigo:     #4F46E5;   /* primary brand / CTAs */
  --indigo-700: #3730A3;
  --cyan:       #22D3EE;   /* glow accent / links / graphs */
  --teal:       #12B886;   /* availability, success, badges */
  --ember:      #FB7A3E;   /* scarcity / highlight, used sparingly */

  --text-on-dark: #E9EDF7;
  --text-on-dark-dim: #9AA6C2;
  --text-on-light: #16203A;
  --text-on-light-dim: #5B6478;

  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'IBM Plex Sans', sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;

  --radius: 14px;
  --radius-sm: 8px;
  --container: 1160px;
}

*{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }
body{
  margin: 0;
  font-family: var(--font-body);
  background: var(--paper);
  color: var(--text-on-light);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
img{ max-width: 100%; display:block; }
a{ color: inherit; text-decoration: none; }
h1,h2,h3,h4{ font-family: var(--font-display); margin: 0 0 .5em; line-height: 1.12; letter-spacing: -0.01em; }
p{ margin: 0 0 1em; }
.container{ max-width: var(--container); margin: 0 auto; padding: 0 24px; }
section{ padding: 88px 0; }
@media (max-width: 720px){ section{ padding: 56px 0; } }

/* focus visibility (accessibility floor) */
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible{
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}
@media (prefers-reduced-motion: reduce){
  *{ animation: none !important; transition: none !important; }
}

/* ---------- eyebrow / kicker ---------- */
.eyebrow{
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--cyan);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
}
.eyebrow::before{
  content:'';
  width: 18px; height: 1px;
  background: var(--cyan);
}
.on-light .eyebrow{ color: var(--indigo); }
.on-light .eyebrow::before{ background: var(--indigo); }

/* ---------- buttons ---------- */
.btn{
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 15px;
  padding: 13px 24px;
  border-radius: 999px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .15s ease, background .15s ease, border-color .15s ease;
}
.btn:hover{ transform: translateY(-1px); }
.btn-primary{ background: var(--indigo); color: #fff; }
.btn-primary:hover{ background: var(--indigo-700); }
.btn-ghost-dark{ background: transparent; border-color: var(--ink-3); color: var(--text-on-dark); }
.btn-ghost-dark:hover{ border-color: var(--cyan); color: var(--cyan); }
.btn-ghost-light{ background: transparent; border-color: var(--line-light); color: var(--text-on-light); }
.btn-ghost-light:hover{ border-color: var(--indigo); color: var(--indigo); }
.btn-block{ width: 100%; justify-content: center; }

/* ---------- nav ---------- */
header.site-nav{
  position: sticky; top: 0; z-index: 50;
  background: rgba(11,18,32,.86);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--ink-3);
}
.nav-row{
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 24px;
  max-width: var(--container); margin: 0 auto;
}
.brand{ display:flex; align-items:center; gap: 10px; }
.brand img{ width: 36px; height: 36px; border-radius: 50%; object-fit: cover; border: 1px solid var(--ink-3); }
.brand-name{ font-family: var(--font-display); font-weight: 700; color: var(--text-on-dark); font-size: 17px; }
.brand-name span{ color: var(--cyan); }
.nav-links{ display:flex; align-items:center; gap: 28px; }
.nav-links a{ font-size: 14.5px; color: var(--text-on-dark-dim); font-weight: 500; }
.nav-links a:hover, .nav-links a.active{ color: var(--text-on-dark); }
.nav-cta{ display:flex; gap:10px; }
.nav-toggle{ display:none; }
@media (max-width: 840px){
  .nav-links{ display:none; }
  .nav-toggle{ display:inline-flex; background:none; border:1px solid var(--ink-3); color:var(--text-on-dark); border-radius:8px; padding:8px 10px; }
}

/* ---------- hero / function-curve signature ---------- */
.hero{
  background: var(--ink);
  color: var(--text-on-dark);
  position: relative;
  overflow: hidden;
  padding: 100px 0 80px;
}
.hero-grid{
  display:grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items:center;
  position: relative; z-index: 2;
}
@media (max-width: 900px){ .hero-grid{ grid-template-columns: 1fr; } }
.hero h1{ font-size: clamp(34px, 5vw, 54px); }
.hero .lede{ color: var(--text-on-dark-dim); font-size: 18px; max-width: 46ch; }
.hero-actions{ display:flex; gap:14px; margin-top: 28px; flex-wrap: wrap; }
.hero-curve-field{ position:absolute; inset:0; opacity:.55; z-index:1; pointer-events:none; }

.hero-stats{ display:flex; gap:28px; margin-top:40px; flex-wrap:wrap; }
.hero-stat b{ font-family: var(--font-display); font-size: 26px; display:block; color:#fff; }
.hero-stat span{ font-size: 12.5px; color: var(--text-on-dark-dim); font-family: var(--font-mono); }

/* function-curve divider used between sections */
.curve-divider{ width:100%; height:56px; display:block; }
.curve-divider path{ fill:none; stroke-width:2; }

/* ---------- section headers ---------- */
.section-head{ max-width: 640px; margin-bottom: 44px; }
.section-head h2{ font-size: clamp(26px,3.4vw,38px); }
.on-dark .section-head p, .on-dark p.dim{ color: var(--text-on-dark-dim); }
.on-light p.dim{ color: var(--text-on-light-dim); }

/* ---------- cards ---------- */
.grid{ display:grid; gap: 22px; }
.grid-3{ grid-template-columns: repeat(3, 1fr); }
.grid-4{ grid-template-columns: repeat(4, 1fr); }
.grid-5{ grid-template-columns: repeat(5, 1fr); }
.grid-2{ grid-template-columns: repeat(2, 1fr); }
@media (max-width: 1080px){ .grid-5{ grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 900px){ .grid-3, .grid-4, .grid-2{ grid-template-columns: 1fr 1fr; } }
@media (max-width: 620px){ .grid-3, .grid-4, .grid-2, .grid-5{ grid-template-columns: 1fr; } }

.card{
  background: var(--paper-2);
  border: 1px solid var(--line-light);
  border-radius: var(--radius);
  padding: 26px;
  position: relative;
}
.card-dark{
  background: var(--ink-2);
  border: 1px solid var(--ink-3);
  color: var(--text-on-dark);
}

/* course card specific */
.course-card{ display:flex; flex-direction:column; gap:14px; }
.course-code{ font-family: var(--font-mono); font-size: 12px; color: var(--indigo); letter-spacing:.04em; }
.course-card h3{ font-size: 21px; margin:0; }
.course-meta{ display:flex; flex-wrap:wrap; gap:8px; margin: 4px 0 6px; }
.pill{
  font-family: var(--font-mono); font-size: 11.5px; letter-spacing:.03em;
  padding: 5px 10px; border-radius: 999px; background: #F0EEFB; color: var(--indigo-700);
}
.pill-teal{ background: #E4F7F0; color: #067A55; }
.pill-ember{ background: #FFEDE2; color: #C2530F; }
.course-price{ font-family: var(--font-display); font-size: 24px; margin-top: 6px; }
.course-price small{ font-family: var(--font-body); font-size: 13px; color: var(--text-on-light-dim); font-weight: 400; }
.seats-row{ display:flex; align-items:center; gap:8px; font-size: 13px; color: var(--text-on-light-dim); }
.seats-dot{ width:8px; height:8px; border-radius:50%; background: var(--teal); }

/* ---------- footer ---------- */
footer.site-footer{
  background: var(--ink);
  color: var(--text-on-dark-dim);
  padding: 56px 0 28px;
}
.footer-grid{ display:grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; }
@media (max-width: 720px){ .footer-grid{ grid-template-columns: 1fr; } }
.footer-grid h4{ color: var(--text-on-dark); font-size: 14px; font-family: var(--font-mono); letter-spacing:.06em; text-transform:uppercase; margin-bottom: 14px;}
.footer-grid ul{ list-style:none; padding:0; margin:0; display:flex; flex-direction:column; gap:10px; }
.footer-grid a:hover{ color: var(--cyan); }
.footer-bottom{ border-top:1px solid var(--ink-3); margin-top:40px; padding-top:22px; display:flex; justify-content:space-between; flex-wrap:wrap; gap:10px; font-size:13px; }

/* ---------- misc content sections ---------- */
.on-dark{ background: var(--ink); color: var(--text-on-dark); }
.on-light{ background: var(--paper); color: var(--text-on-light); }
.on-white{ background: var(--paper-2); }

.badge-inline{
  display:inline-flex; align-items:center; gap:6px; font-family: var(--font-mono);
  font-size: 12px; color: var(--teal); background:#E4F7F0; padding:4px 10px; border-radius:999px;
}

.two-col{ display:grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items:center; }
@media (max-width: 860px){ .two-col{ grid-template-columns: 1fr; } }

.quote-card{ border-left: 3px solid var(--cyan); padding-left: 20px; font-size: 17px; color: var(--text-on-dark); }
.quote-card cite{ display:block; margin-top:10px; font-style:normal; font-size:13px; color: var(--text-on-dark-dim); font-family: var(--font-mono); }

table.compare{ width:100%; border-collapse: collapse; }
table.compare th, table.compare td{ text-align:left; padding: 14px 16px; border-bottom: 1px solid var(--line-light); font-size:14.5px; }
table.compare th{ font-family: var(--font-mono); font-size:12px; text-transform:uppercase; letter-spacing:.05em; color: var(--text-on-light-dim); }

.form-field{ display:flex; flex-direction:column; gap:6px; margin-bottom:18px; }
.form-field label{ font-size:13px; font-family: var(--font-mono); color: var(--text-on-light-dim); }
.form-field input, .form-field select, .form-field textarea{
  font-family: var(--font-body); font-size:15px; padding:12px 14px; border-radius: var(--radius-sm);
  border: 1px solid var(--line-light); background: #fff;
}
.form-field textarea{ resize: vertical; min-height: 110px; }

.faq-item{ border-bottom:1px solid var(--line-light); padding: 18px 0; }
.faq-item summary{ cursor:pointer; font-weight:600; font-size:16px; list-style:none; display:flex; justify-content:space-between; align-items:center; }
.faq-item summary::-webkit-details-marker{ display:none; }
.faq-item summary::after{ content:'+'; font-family: var(--font-display); font-size:20px; color: var(--indigo); }
.faq-item[open] summary::after{ content:'\2212'; }
.faq-item p{ margin-top:10px; color: var(--text-on-light-dim); }

.resource-card{ display:flex; flex-direction:column; gap:10px; }
.resource-tag{ font-family: var(--font-mono); font-size:11.5px; color: var(--indigo); text-transform:uppercase; letter-spacing:.05em; }

/* ---------- course pathway diagram (resources page) ---------- */
.pathway{ max-width: 980px; margin: 0 auto; }
.pathway-row{ display:flex; justify-content:center; gap:16px; flex-wrap:wrap; }
.pathway-row.four .pathway-box, .pathway-row.two .pathway-box{ flex: 1 1 200px; max-width: 230px; }
.pathway-arrow{ text-align:center; font-size:22px; color: var(--indigo); font-family: var(--font-mono); margin: 6px 0; }
.pathway-label{ text-align:center; max-width:640px; margin:18px auto 14px; font-size:14px; color: var(--text-on-light-dim); }
.pathway-box{
  border-radius: var(--radius-sm);
  padding: 16px 18px;
  min-width: 190px;
  display:flex; flex-direction:column; gap:4px;
  border: 1px solid var(--line-light);
}
.pathway-box.ours{ background: #F0EEFB; border-color: #C7C2F0; }
.pathway-box.other{ background: var(--paper); color: var(--text-on-light-dim); }
.pathway-box strong{ font-size:15px; }
.pathway-code{ font-family: var(--font-mono); font-size:12px; color: var(--text-on-light-dim); }
.pathway-tag{ font-family: var(--font-mono); font-size:11px; text-transform:uppercase; letter-spacing:.03em; color: var(--indigo-700); margin-top:2px; }
.pathway-pill{
  align-self:flex-start; font-family: var(--font-mono); font-size:10.5px; text-transform:uppercase; letter-spacing:.03em;
  padding:3px 8px; border-radius:999px; margin-bottom:2px;
}
.pathway-pill.compulsory{ background:#E4F7F0; color:#067A55; }
.pathway-pill.elective{ background:#FFEDE2; color:#C2530F; }
.pathway-legend{ display:flex; justify-content:center; gap:28px; margin-top:28px; flex-wrap:wrap; font-size:13.5px; color: var(--text-on-light-dim); }
.pathway-legend .swatch{ display:inline-block; width:12px; height:12px; border-radius:3px; margin-right:6px; vertical-align:middle; }
.pathway-legend .swatch.ours{ background:#4F46E5; }
.pathway-legend .swatch.other{ background:#D8D4C8; }
@media (max-width: 720px){ .pathway-row.four, .pathway-row.two{ flex-direction:column; align-items:stretch; } .pathway-row.four .pathway-box, .pathway-row.two .pathway-box{ max-width:none; } }

.mobile-menu{ display:none; flex-direction:column; gap:14px; padding: 18px 24px 26px; background: var(--ink); border-bottom:1px solid var(--ink-3); }
.mobile-menu.open{ display:flex; }
.mobile-menu a{ color: var(--text-on-dark-dim); font-size:15px; }