:root {
  --navy-900: #0a1a33;
  --navy-800: #0b1f3a;
  --navy-700: #142b50;
  --navy-600: #1d3a6b;
  --navy-500: #2c4f8c;
  --gold-600: #b8862f;
  --gold-500: #d4a24a;
  --gold-400: #e3b96d;
  --gold-100: #f5e6c5;
  --cream-50: #faf6ee;
  --cream-100: #f4ecd9;
  --paper: #fdfaf3;
  --ink: #1a1a1a;
  --muted: #5b6470;
  --border: #e2dccd;
  --success: #2f7d4f;
  --error: #b14242;
  --shadow-sm: 0 1px 2px rgba(11, 31, 58, 0.06), 0 1px 1px rgba(11, 31, 58, 0.04);
  --shadow-md: 0 6px 16px -8px rgba(11, 31, 58, 0.18), 0 2px 4px rgba(11, 31, 58, 0.06);
  --shadow-lg: 0 24px 48px -16px rgba(11, 31, 58, 0.20);
  --radius: 6px;
  --radius-lg: 12px;
  --maxw: 1200px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5 {
  font-family: 'Playfair Display', Georgia, serif;
  font-weight: 700;
  color: var(--navy-800);
  line-height: 1.2;
  margin: 0 0 0.5em;
  letter-spacing: -0.01em;
}
h1 { font-size: clamp(2rem, 4vw, 2.75rem); }
h2 { font-size: clamp(1.5rem, 2.6vw, 2rem); }
h3 { font-size: 1.35rem; }
h4 { font-size: 1.1rem; }

p { margin: 0 0 1em; }
a { color: var(--navy-700); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--gold-600); }

img { max-width: 100%; height: auto; display: block; }
hr { border: 0; border-top: 1px solid var(--border); margin: 2rem 0; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 1.25rem; }

/* Top bar */
.topbar {
  background: var(--navy-900);
  color: var(--cream-100);
  font-size: 0.78rem;
  padding: 0.4rem 0;
}
.topbar .container { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
.topbar a { color: var(--gold-400); text-decoration: none; }
.topbar a:hover { color: var(--gold-100); }

/* Header */
.site-header {
  background: linear-gradient(180deg, var(--navy-800), var(--navy-700));
  color: white;
  border-bottom: 3px solid var(--gold-500);
}
.site-header .container { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding-top: 1.1rem; padding-bottom: 1.1rem; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 0.7rem; text-decoration: none; color: white; }
.brand-mark {
  width: 42px; height: 42px;
  background: var(--gold-500);
  color: var(--navy-900);
  display: grid; place-items: center;
  font-family: 'Playfair Display', serif;
  font-weight: 800; font-size: 1.4rem;
  border-radius: 6px;
  box-shadow: inset 0 -3px 0 rgba(0,0,0,0.15);
}
.brand-name { font-family: 'Playfair Display', serif; font-weight: 700; font-size: 1.55rem; letter-spacing: 0.02em; }
.brand-tag { font-size: 0.72rem; color: var(--gold-300, var(--gold-400)); letter-spacing: 0.18em; text-transform: uppercase; }

.nav { display: flex; gap: 0.25rem; flex-wrap: wrap; align-items: center; }
.nav a {
  color: var(--cream-50);
  text-decoration: none;
  padding: 0.5rem 0.9rem;
  font-weight: 500;
  font-size: 0.95rem;
  border-radius: 4px;
  transition: background 0.15s, color 0.15s;
}
.nav a:hover, .nav a.is-active { background: rgba(212, 162, 74, 0.18); color: var(--gold-400); }
.nav .cta {
  background: var(--gold-500);
  color: var(--navy-900);
  font-weight: 700;
  margin-left: 0.5rem;
}
.nav .cta:hover { background: var(--gold-400); color: var(--navy-900); }

/* Hero */
.hero {
  background:
    linear-gradient(135deg, rgba(11,31,58,0.92), rgba(20,43,80,0.85)),
    radial-gradient(circle at 80% 20%, rgba(212,162,74,0.18), transparent 60%);
  background-color: var(--navy-800);
  color: white;
  padding: 4rem 0 4.5rem;
  position: relative;
  overflow: hidden;
}
.hero h1 { color: white; max-width: 22ch; }
.hero .lede { font-size: 1.15rem; max-width: 56ch; color: var(--cream-100); }
.hero-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 3rem; align-items: center; }
.hero-art { background: rgba(255,255,255,0.04); border: 1px solid rgba(212,162,74,0.25); border-radius: var(--radius-lg); padding: 0.5rem; box-shadow: var(--shadow-lg); }
.hero-art img { border-radius: 8px; }
.hero-stats { display: flex; gap: 1.5rem; margin-top: 1.5rem; flex-wrap: wrap; }
.hero-stat { border-left: 2px solid var(--gold-500); padding-left: 0.9rem; }
.hero-stat strong { display: block; font-family: 'Playfair Display', serif; font-size: 1.7rem; color: var(--gold-400); }
.hero-stat span { font-size: 0.82rem; color: var(--cream-100); text-transform: uppercase; letter-spacing: 0.12em; }
.hero-cta { display: flex; gap: 0.75rem; margin-top: 1.75rem; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 0.85rem 1.4rem;
  background: var(--gold-500); color: var(--navy-900);
  font-weight: 700; font-size: 0.95rem;
  text-decoration: none; border-radius: var(--radius);
  border: 1px solid var(--gold-600);
  transition: transform 0.1s, background 0.15s;
  box-shadow: var(--shadow-sm);
}
.btn:hover { background: var(--gold-400); color: var(--navy-900); transform: translateY(-1px); }
.btn-ghost { background: transparent; color: white; border: 1px solid rgba(255,255,255,0.3); }
.btn-ghost:hover { background: rgba(255,255,255,0.08); color: white; }
.btn-secondary { background: white; color: var(--navy-800); border-color: var(--border); }
.btn-secondary:hover { background: var(--cream-50); color: var(--navy-800); }

@media (max-width: 800px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero { padding: 3rem 0 3.5rem; }
}

/* Sections */
.section { padding: 3.5rem 0; }
.section-tight { padding: 2rem 0; }
.section-cream { background: var(--cream-50); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-head { display: flex; justify-content: space-between; align-items: end; gap: 1rem; flex-wrap: wrap; margin-bottom: 1.75rem; }
.section-head h2 { margin: 0; }
.eyebrow {
  display: inline-block;
  font-size: 0.78rem; letter-spacing: 0.18em;
  color: var(--gold-600);
  text-transform: uppercase; font-weight: 700;
  margin-bottom: 0.5rem;
}

/* Subject grid */
.subject-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1.5rem; }
.subject-card {
  display: block;
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  text-decoration: none;
  color: var(--ink);
  transition: transform 0.18s, box-shadow 0.18s, border-color 0.18s;
  box-shadow: var(--shadow-sm);
}
.subject-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--gold-500); color: var(--ink); }
.subject-card .img { aspect-ratio: 4/3; background: var(--navy-800); }
.subject-card .img img { width: 100%; height: 100%; object-fit: cover; }
.subject-card .body { padding: 1.25rem 1.4rem 1.5rem; }
.subject-card h3 { color: var(--navy-800); margin-bottom: 0.4rem; }
.subject-card .meta { font-size: 0.78rem; color: var(--gold-600); letter-spacing: 0.12em; text-transform: uppercase; font-weight: 700; }
.subject-card .desc { color: var(--muted); font-size: 0.95rem; margin: 0.5rem 0 0; }
.subject-card .arrow { display: inline-block; margin-top: 0.85rem; color: var(--navy-700); font-weight: 600; font-size: 0.9rem; }

/* Layout grid: main + sidebar */
.layout-2col { display: grid; grid-template-columns: minmax(0, 1fr) 320px; gap: 2.5rem; }
@media (max-width: 900px) { .layout-2col { grid-template-columns: 1fr; } }

.prose { max-width: 70ch; }
.prose p, .prose li { font-size: 1rem; }
.prose h2 { margin-top: 2rem; }
.prose h3 { margin-top: 1.5rem; }
.prose ul, .prose ol { padding-left: 1.4rem; }
.prose blockquote { border-left: 3px solid var(--gold-500); padding-left: 1rem; color: var(--muted); font-style: italic; margin: 1.5rem 0; }
.prose code { background: var(--cream-100); padding: 0.1em 0.3em; border-radius: 3px; font-size: 0.9em; }

/* Sidebar */
.sidebar > * + * { margin-top: 1.5rem; }
.sidebar-card {
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.4rem;
  box-shadow: var(--shadow-sm);
}
.sidebar-card h4 {
  margin: 0 0 0.85rem;
  padding-bottom: 0.6rem;
  border-bottom: 2px solid var(--gold-500);
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--navy-800);
}
.sidebar-list { list-style: none; padding: 0; margin: 0; }
.sidebar-list li { border-bottom: 1px dashed var(--border); }
.sidebar-list li:last-child { border-bottom: 0; }
.sidebar-list a { display: block; padding: 0.55rem 0; color: var(--navy-700); text-decoration: none; font-size: 0.93rem; }
.sidebar-list a:hover { color: var(--gold-600); }

.sidebar-tip { background: var(--navy-800); color: var(--cream-100); border-radius: var(--radius-lg); padding: 1.25rem 1.4rem; }
.sidebar-tip h4 { color: var(--gold-400); border-color: var(--gold-500); }
.sidebar-tip p { font-size: 0.92rem; margin: 0; }

/* Question card / drill list */
.q-list { list-style: none; padding: 0; margin: 0; }
.q-row {
  display: grid;
  grid-template-columns: 36px 1fr auto;
  gap: 0.9rem;
  align-items: center;
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.8rem 1rem;
  margin-bottom: 0.55rem;
  box-shadow: var(--shadow-sm);
  text-decoration: none;
  color: var(--ink);
  transition: border-color 0.15s, transform 0.1s;
}
.q-row:hover { border-color: var(--gold-500); color: var(--ink); transform: translateX(2px); }
.q-num {
  display: grid; place-items: center;
  background: var(--cream-100);
  color: var(--navy-700);
  font-weight: 700; font-size: 0.85rem;
  width: 36px; height: 36px;
  border-radius: 6px;
}
.q-title { font-weight: 600; color: var(--navy-800); font-size: 0.98rem; }
.q-meta { color: var(--muted); font-size: 0.82rem; margin-top: 0.15rem; }

/* Badges */
.badge {
  display: inline-block;
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.badge-easy   { background: #e1f1e6; color: #1f6c3a; border: 1px solid #b6dcc1; }
.badge-medium { background: #fcf0d9; color: #8a6014; border: 1px solid #f1d9a3; }
.badge-hard   { background: #f7dede; color: #8b2e2e; border: 1px solid #f0bcbc; }
.badge-navy   { background: var(--navy-800); color: var(--gold-400); }

/* Question detail */
.q-stem {
  background: white; border: 1px solid var(--border);
  border-left: 4px solid var(--gold-500);
  border-radius: var(--radius-lg);
  padding: 1.5rem 1.75rem; margin: 1rem 0 1.5rem;
  font-size: 1.05rem; line-height: 1.65;
  box-shadow: var(--shadow-sm);
}
.q-passage {
  background: var(--cream-50); border: 1px solid var(--border);
  padding: 1.25rem 1.5rem; border-radius: var(--radius);
  font-family: Georgia, serif; font-size: 1rem; line-height: 1.7;
  margin: 1rem 0 1.5rem;
}
.q-passage h5 { font-family: 'Playfair Display', serif; font-size: 1rem; margin: 0 0 0.5rem; color: var(--navy-700); text-transform: uppercase; letter-spacing: 0.1em; }
.q-choices { list-style: none; padding: 0; margin: 0 0 2rem; counter-reset: c; }
.q-choices li {
  background: white; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 0.85rem 1rem 0.85rem 3rem;
  margin-bottom: 0.5rem; position: relative;
  font-size: 1rem;
  transition: border-color 0.15s, background 0.15s;
}
.q-choices li::before {
  counter-increment: c;
  content: counter(c, upper-alpha);
  position: absolute; left: 0.85rem; top: 50%; transform: translateY(-50%);
  width: 28px; height: 28px;
  background: var(--cream-100); color: var(--navy-700);
  border: 1px solid var(--border);
  border-radius: 50%;
  display: grid; place-items: center;
  font-weight: 700; font-size: 0.85rem;
}
.q-choices li.is-correct {
  border-color: var(--success); background: #f1faf3;
}
.q-choices li.is-correct::before {
  background: var(--success); color: white; border-color: var(--success);
}

.answer-box {
  background: var(--cream-50);
  border: 1px solid var(--border); border-left: 4px solid var(--success);
  padding: 1.25rem 1.5rem; border-radius: var(--radius);
  margin: 1.5rem 0;
}
.answer-box h3 { margin-top: 0; color: var(--navy-800); display: flex; align-items: center; gap: 0.5rem; font-size: 1.1rem; }
.answer-box .key {
  display: inline-grid; place-items: center;
  width: 28px; height: 28px;
  background: var(--success); color: white;
  border-radius: 50%; font-weight: 700; font-size: 0.85rem;
}

/* Stat bars / progress meters */
.meter { display: grid; grid-template-columns: 80px 1fr 56px; gap: 0.75rem; align-items: center; padding: 0.4rem 0; }
.meter-label { font-size: 0.85rem; color: var(--muted); }
.meter-track { height: 8px; background: var(--cream-100); border-radius: 999px; overflow: hidden; }
.meter-fill { height: 100%; background: linear-gradient(90deg, var(--gold-500), var(--gold-600)); }
.meter-val { font-weight: 700; font-size: 0.9rem; color: var(--navy-800); text-align: right; }

/* Test card */
.test-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.25rem; }
.test-card {
  display: block; background: white;
  border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.4rem; text-decoration: none; color: var(--ink);
  box-shadow: var(--shadow-sm); transition: border-color 0.15s, transform 0.15s;
}
.test-card:hover { border-color: var(--gold-500); transform: translateY(-2px); color: var(--ink); }
.test-card .num { font-family: 'Playfair Display', serif; font-size: 2rem; color: var(--gold-500); line-height: 1; }
.test-card h3 { margin: 0.4rem 0 0.5rem; }
.test-card .test-meta { font-size: 0.85rem; color: var(--muted); }
.test-card .test-tags { margin-top: 0.85rem; display: flex; gap: 0.4rem; flex-wrap: wrap; }
.test-tags .badge { background: var(--cream-100); color: var(--navy-700); }

/* AdSense placeholders rendered as quiet boxes */
.ad-slot {
  margin: 1.75rem 0;
  border: 1px dashed var(--border);
  background: var(--cream-50);
  color: var(--muted);
  text-align: center;
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  padding: 1.4rem 1rem;
  border-radius: var(--radius);
}
.ad-slot.ad-sidebar { padding: 2rem 1rem; }

/* Recommended block */
.recommended {
  background: white; border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 1.4rem 1.5rem; margin-top: 2rem;
}
.recommended h4 { margin: 0 0 0.85rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--gold-500); font-size: 0.92rem; text-transform: uppercase; letter-spacing: 0.1em; color: var(--navy-800); }
.recommended ul { list-style: none; padding: 0; margin: 0; }
.recommended li { border-bottom: 1px dashed var(--border); padding: 0.65rem 0; }
.recommended li:last-child { border-bottom: 0; }
.recommended a { color: var(--navy-700); text-decoration: none; font-weight: 500; font-size: 0.95rem; }
.recommended a:hover { color: var(--gold-600); }
.recommended .src { display: block; color: var(--muted); font-size: 0.78rem; margin-top: 0.15rem; }

/* Breadcrumb */
.breadcrumb { font-size: 0.85rem; color: var(--muted); padding: 1rem 0 0.25rem; }
.breadcrumb a { color: var(--navy-700); text-decoration: none; }
.breadcrumb a:hover { color: var(--gold-600); }
.breadcrumb .sep { margin: 0 0.4rem; color: var(--border); }

/* Page header */
.page-head { padding: 2rem 0 1rem; }
.page-head h1 { margin: 0.3rem 0 0.5rem; }
.page-head .lede { color: var(--muted); max-width: 70ch; font-size: 1.05rem; }

/* Subject hero (for subject landing pages) */
.subject-hero { background: var(--navy-800); color: white; padding: 3rem 0 3.5rem; border-bottom: 3px solid var(--gold-500); }
.subject-hero .container { display: grid; grid-template-columns: 1.4fr 1fr; gap: 2.5rem; align-items: center; }
.subject-hero h1 { color: white; }
.subject-hero p { color: var(--cream-100); max-width: 56ch; }
.subject-hero img { border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); }
.subject-hero .meters { margin-top: 1.5rem; }
.subject-hero .meters .meter-label { color: var(--cream-100); }
.subject-hero .meters .meter-val { color: var(--gold-400); }
.subject-hero .meters .meter-track { background: rgba(255,255,255,0.1); }
@media (max-width: 800px) { .subject-hero .container { grid-template-columns: 1fr; } }

/* Footer */
.site-footer {
  background: var(--navy-900); color: var(--cream-100);
  padding: 3rem 0 1.5rem; margin-top: 4rem;
  border-top: 4px solid var(--gold-500);
}
.site-footer .container { display: grid; grid-template-columns: 1.5fr repeat(3, 1fr); gap: 2.5rem; }
@media (max-width: 800px) { .site-footer .container { grid-template-columns: 1fr 1fr; } }
.site-footer h5 {
  color: var(--gold-400); font-family: 'Playfair Display', serif;
  font-size: 0.92rem; text-transform: uppercase; letter-spacing: 0.14em;
  margin: 0 0 1rem;
}
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin: 0.4rem 0; }
.site-footer a { color: var(--cream-100); text-decoration: none; font-size: 0.92rem; }
.site-footer a:hover { color: var(--gold-400); }
.site-footer .legal { grid-column: 1 / -1; padding-top: 1.5rem; border-top: 1px solid rgba(255,255,255,0.08); margin-top: 1.5rem; font-size: 0.8rem; color: rgba(245, 230, 197, 0.6); display: flex; justify-content: space-between; flex-wrap: wrap; gap: 1rem; }

/* Pagination */
.pager { display: flex; gap: 0.5rem; justify-content: center; margin: 2rem 0 0; flex-wrap: wrap; }
.pager a, .pager span {
  display: inline-block; padding: 0.5rem 0.85rem;
  border: 1px solid var(--border); border-radius: var(--radius);
  background: white; color: var(--navy-700); text-decoration: none; font-size: 0.9rem;
}
.pager a:hover { border-color: var(--gold-500); color: var(--gold-600); }
.pager .current { background: var(--navy-800); color: white; border-color: var(--navy-800); }

/* Misc */
.tag-row { display: flex; gap: 0.4rem; flex-wrap: wrap; margin: 0.5rem 0; }
.divider-gold { width: 60px; height: 3px; background: var(--gold-500); margin: 0 0 1.25rem; border-radius: 2px; }

/* Data table for science/score */
.data-table { width: 100%; border-collapse: collapse; margin: 1rem 0; font-size: 0.95rem; }
.data-table th, .data-table td { border: 1px solid var(--border); padding: 0.55rem 0.75rem; text-align: center; }
.data-table th { background: var(--navy-800); color: white; font-weight: 600; letter-spacing: 0.04em; }
.data-table tbody tr:nth-child(odd) { background: var(--cream-50); }

/* Subtopic grid */
.topic-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 1rem; }
.topic-card {
  background: white; border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.2rem 1.4rem; text-decoration: none; color: var(--ink);
  box-shadow: var(--shadow-sm); transition: border-color 0.15s, transform 0.15s;
}
.topic-card:hover { border-color: var(--gold-500); transform: translateY(-2px); color: var(--ink); }
.topic-card h3 { font-size: 1.1rem; margin: 0 0 0.35rem; }
.topic-card .stat { font-size: 0.82rem; color: var(--muted); }
.topic-card .diff-row { margin-top: 0.85rem; display: flex; gap: 0.4rem; }

/* Counter row (questions/topics/tests stats) */
.counter-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 1rem; margin: 1.5rem 0; }
.counter {
  background: white; border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.1rem 1.25rem; text-align: center;
}
.counter strong { display: block; font-family: 'Playfair Display', serif; font-size: 1.85rem; color: var(--gold-600); }
.counter span { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.12em; color: var(--muted); }

/* Section CTA */
.cta-band {
  background: linear-gradient(135deg, var(--navy-800), var(--navy-700));
  color: white; padding: 3rem 0; margin-top: 2rem; text-align: center;
}
.cta-band h2 { color: white; }
.cta-band p { color: var(--cream-100); max-width: 56ch; margin: 0.5rem auto 1.5rem; }

/* Score calc form */
.calc-form { background: white; border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 1.5rem; max-width: 540px; }
.calc-form label { display: block; font-weight: 600; color: var(--navy-800); margin: 0.5rem 0 0.25rem; }
.calc-form input { width: 100%; padding: 0.55rem 0.75rem; border: 1px solid var(--border); border-radius: 6px; font: inherit; }

/* Skip link */
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 1rem; top: 1rem; background: var(--gold-500); padding: 0.5rem 1rem; border-radius: 4px; z-index: 10; color: var(--navy-900); }