/* ============================================================
   Mission Control Math — Global Stylesheet
   missioncontrolmath.com
   ============================================================ */

/* ------------------------------------------------------------
   1. Design Tokens
   ------------------------------------------------------------ */
:root {
  /* Colors */
  --color-navy:       #0a0f2e;
  --color-navy-mid:   #141a45;
  --color-navy-light: #1e2660;
  --color-gold:       #f0c060;
  --color-gold-dark:  #c99a30;
  --color-cream:      #faf8f2;
  --color-cream-dark: #f0ece0;
  --color-indigo:     #3d52c4;
  --color-indigo-dark:#2f3f9e;
  --color-white:      #ffffff;
  --color-text-dark:  #0a0f2e;
  --color-text-muted: #6b7280;
  --color-text-light: #c8d6e5;
  --color-star:       rgba(255, 255, 255, 0.8);

  /* Typography */
  --font-display: 'DM Serif Display', Georgia, serif;
  --font-body:    'DM Sans', system-ui, sans-serif;

  /* Type Scale */
  --text-xs:   0.75rem;   /* 12px */
  --text-sm:   0.875rem;  /* 14px */
  --text-base: 1rem;      /* 16px */
  --text-lg:   1.125rem;  /* 18px */
  --text-xl:   1.375rem;  /* 22px */
  --text-2xl:  1.75rem;   /* 28px */
  --text-3xl:  2.25rem;   /* 36px */
  --text-4xl:  3rem;      /* 48px */
  --text-5xl:  3.5rem;    /* 56px */

  /* Spacing (8px base) */
  --space-1:  0.25rem;  /* 4px */
  --space-2:  0.5rem;   /* 8px */
  --space-3:  0.75rem;  /* 12px */
  --space-4:  1rem;     /* 16px */
  --space-5:  1.25rem;  /* 20px */
  --space-6:  1.5rem;   /* 24px */
  --space-8:  2rem;     /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */
  --space-16: 4rem;     /* 64px */
  --space-20: 5rem;     /* 80px */
  --space-24: 6rem;     /* 96px */

  /* Borders & Radii */
  --radius-sm:  6px;
  --radius-md:  12px;
  --radius-lg:  20px;
  --radius-xl:  32px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm:  0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.08);
  --shadow-md:  0 4px 12px rgba(0,0,0,0.15);
  --shadow-lg:  0 8px 32px rgba(0,0,0,0.2);
  --shadow-gold: 0 4px 20px rgba(240,192,96,0.25);
  --shadow-glow: 0 0 40px rgba(61,82,196,0.3);

  /* Transitions */
  --transition-fast: 150ms ease-out;
  --transition-base: 200ms ease-out;

  /* Layout */
  --max-width: 1200px;
  --nav-height: 72px;
}

/* ------------------------------------------------------------
   2. Reset & Base
   ------------------------------------------------------------ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text-dark);
  background-color: var(--color-navy);
  overflow-x: hidden;
}

img, svg {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

ul, ol {
  list-style: none;
}

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

/* Skip to main content (accessibility) */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  background: var(--color-gold);
  color: var(--color-navy);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-sm);
  font-weight: 700;
  z-index: 9999;
  transition: top var(--transition-fast);
}
.skip-link:focus {
  top: var(--space-4);
}

/* ------------------------------------------------------------
   3. Typography
   ------------------------------------------------------------ */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  line-height: 1.2;
  font-weight: 400;
}

h1 { font-size: var(--text-5xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }

p {
  line-height: 1.7;
  max-width: 65ch;
}

strong { font-weight: 700; }

/* ------------------------------------------------------------
   4. Layout Utilities
   ------------------------------------------------------------ */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

.section {
  padding-block: var(--space-20);
}

.section--dark {
  background-color: var(--color-navy);
  color: var(--color-white);
}

.section--mid {
  background-color: var(--color-navy-mid);
  color: var(--color-white);
}

.section--light {
  background-color: var(--color-cream);
  color: var(--color-text-dark);
}

.section-eyebrow {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-gold);
  margin-bottom: var(--space-3);
  display: block;
}

.section-title {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  margin-bottom: var(--space-4);
}

.section-subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 52ch;
}

.section-title--light + .section-subtitle,
.section--dark .section-subtitle {
  color: var(--color-text-light);
}

.text-center {
  text-align: center;
}
.text-center p {
  margin-inline: auto;
}

/* ------------------------------------------------------------
   5. Buttons
   ------------------------------------------------------------ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-8);
  border-radius: var(--radius-full);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 700;
  line-height: 1;
  min-height: 48px;
  min-width: 44px;
  cursor: pointer;
  transition: transform var(--transition-fast),
              box-shadow var(--transition-fast),
              background-color var(--transition-base);
  text-decoration: none;
  white-space: nowrap;
  border: 2px solid transparent;
}

.btn:focus-visible {
  outline: 3px solid var(--color-gold);
  outline-offset: 3px;
}

/* Primary: gold on navy */
.btn--primary {
  background-color: var(--color-gold);
  color: var(--color-navy);
  box-shadow: var(--shadow-gold);
}
.btn--primary:hover {
  background-color: #f8d080;
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(240,192,96,0.4);
}
.btn--primary:active {
  transform: translateY(0);
}

/* Secondary: outline gold */
.btn--secondary {
  background-color: transparent;
  color: var(--color-gold);
  border-color: var(--color-gold);
}
.btn--secondary:hover {
  background-color: rgba(240,192,96,0.1);
  transform: translateY(-2px);
}

/* Indigo: for light sections */
.btn--indigo {
  background-color: var(--color-indigo);
  color: var(--color-white);
  box-shadow: 0 4px 16px rgba(61,82,196,0.3);
}
.btn--indigo:hover {
  background-color: var(--color-indigo-dark);
  transform: translateY(-2px);
}

/* Ghost light: for nav */
.btn--ghost {
  background-color: transparent;
  color: var(--color-gold);
  border-color: var(--color-gold);
  padding: var(--space-2) var(--space-5);
  font-size: var(--text-sm);
  min-height: 40px;
}
.btn--ghost:hover {
  background-color: rgba(240,192,96,0.12);
}

/* Small */
.btn--sm {
  padding: var(--space-2) var(--space-5);
  font-size: var(--text-sm);
  min-height: 40px;
}

/* ------------------------------------------------------------
   6. Navigation
   ------------------------------------------------------------ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  transition: background-color var(--transition-base),
              box-shadow var(--transition-base);
}

.nav.scrolled {
  background-color: rgba(10, 15, 46, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 rgba(255,255,255,0.06);
}

.nav__inner {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-8);
}

.nav__logo {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-white);
  white-space: nowrap;
  flex-shrink: 0;
  text-decoration: none;
}

.nav__logo span {
  color: var(--color-gold);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.nav__link {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-light);
  text-decoration: none;
  transition: color var(--transition-fast);
  padding: var(--space-2) 0;
  min-height: 44px;
  display: flex;
  align-items: center;
}

.nav__link:hover {
  color: var(--color-white);
}

.nav__link:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 4px;
  border-radius: 2px;
}

/* Hamburger */
.nav__hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: var(--space-2);
  cursor: pointer;
  background: none;
  border: none;
}

.nav__hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-white);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.nav__hamburger[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav__hamburger[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}
.nav__hamburger[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile nav drawer */
.nav__mobile {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  background-color: var(--color-navy-mid);
  border-top: 1px solid rgba(255,255,255,0.08);
  padding: var(--space-6);
  flex-direction: column;
  gap: var(--space-2);
  z-index: 99;
}

.nav__mobile.open {
  display: flex;
}

.nav__mobile .nav__link {
  font-size: var(--text-base);
  padding: var(--space-3) 0;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.nav__mobile .btn {
  margin-top: var(--space-4);
  width: 100%;
}

/* ------------------------------------------------------------
   7. Hero Section
   ------------------------------------------------------------ */
.hero {
  position: relative;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  background-color: #04060f;
  overflow: hidden;
  padding-top: var(--nav-height);
}

.hero__canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

/* Subtle nebula glow */
.hero::after {
  content: '';
  position: absolute;
  top: 20%;
  right: 10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(ellipse at center,
    rgba(61,82,196,0.15) 0%,
    rgba(10,15,46,0) 70%);
  pointer-events: none;
}

.hero__inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--space-6);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-16);
  align-items: center;
  padding-block: var(--space-20);
}

.hero__content {}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background-color: rgba(240,192,96,0.1);
  border: 1px solid rgba(240,192,96,0.3);
  border-radius: var(--radius-full);
  padding: var(--space-1) var(--space-4);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-gold);
  margin-bottom: var(--space-6);
  letter-spacing: 0.04em;
}

.hero__badge svg {
  display: inline;
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

.hero__title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 5vw, 3.75rem);
  color: var(--color-white);
  line-height: 1.1;
  margin-bottom: var(--space-6);
}

.hero__title .highlight {
  color: var(--color-gold);
  text-shadow: 0 0 40px rgba(240,192,96,0.3);
}

.hero__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-light);
  max-width: 48ch;
  margin-bottom: var(--space-8);
  line-height: 1.7;
}

.hero__ctas {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  align-items: center;
}

.hero__social-proof {
  margin-top: var(--space-8);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text-light);
  font-size: var(--text-sm);
}

.hero__stars {
  display: flex;
  gap: 2px;
  color: var(--color-gold);
}

.hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.hero__book-wrapper {
  position: relative;
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50%       { transform: translateY(-16px); }
}

@media (prefers-reduced-motion: reduce) {
  .hero__book-wrapper { animation: none; }
}

.hero__book {
  width: 280px;
  height: 360px;
  background: linear-gradient(145deg, var(--color-navy-light), var(--color-navy-mid));
  border-radius: var(--radius-md);
  box-shadow:
    0 20px 60px rgba(0,0,0,0.5),
    0 0 0 1px rgba(255,255,255,0.06),
    inset 0 1px 0 rgba(255,255,255,0.1);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  padding: var(--space-8);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero__book::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-gold), var(--color-indigo), var(--color-gold));
}

.hero__book-icon {
  font-size: 3.5rem;
  line-height: 1;
}

.hero__book-title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-white);
  line-height: 1.3;
}

.hero__book-sub {
  font-size: var(--text-sm);
  color: var(--color-gold);
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.hero__book-orbit {
  position: absolute;
  width: 320px;
  height: 320px;
  border: 1px dashed rgba(240,192,96,0.15);
  border-radius: 50%;
  animation: orbit-spin 30s linear infinite;
}

.hero__book-orbit::after {
  content: '⭐';
  position: absolute;
  top: -8px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 14px;
}

@keyframes orbit-spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

@media (prefers-reduced-motion: reduce) {
  .hero__book-orbit { animation: none; }
}

/* ------------------------------------------------------------
   8. How It Works Section
   ------------------------------------------------------------ */
.how-it-works {
  background-color: var(--color-navy-mid);
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
  margin-top: var(--space-12);
}

.step {
  background-color: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  position: relative;
  transition: transform var(--transition-base),
              box-shadow var(--transition-base);
}

.step:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

.step__number {
  font-family: var(--font-display);
  font-size: 4rem;
  color: rgba(240,192,96,0.15);
  line-height: 1;
  margin-bottom: var(--space-4);
  font-weight: 400;
}

.step__icon {
  font-size: 2rem;
  margin-bottom: var(--space-4);
  line-height: 1;
}

.step__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-white);
  margin-bottom: var(--space-3);
}

.step__desc {
  font-size: var(--text-base);
  color: var(--color-text-light);
  max-width: none;
  line-height: 1.7;
}

/* ------------------------------------------------------------
   9. What's Inside Section
   ------------------------------------------------------------ */
.whats-inside {
  background-color: var(--color-cream);
}

.whats-inside__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-16);
  align-items: center;
  margin-top: var(--space-12);
}

.features-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
}

.feature-item__icon {
  width: 44px;
  height: 44px;
  background-color: var(--color-navy);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.feature-item__icon svg {
  width: 20px;
  height: 20px;
  color: var(--color-gold);
}

.feature-item__text {}

.feature-item__title {
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text-dark);
  margin-bottom: var(--space-1);
}

.feature-item__desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  max-width: none;
}

/* Worksheet preview panel */
.preview-panel {
  background-color: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  border: 1px solid var(--color-cream-dark);
}

.preview-panel__header {
  background-color: var(--color-navy);
  padding: var(--space-4) var(--space-6);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.preview-panel__dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.preview-panel__dot:nth-child(1) { background: #ff5f57; }
.preview-panel__dot:nth-child(2) { background: #febc2e; }
.preview-panel__dot:nth-child(3) { background: #28c840; }

.preview-panel__title {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  color: rgba(255,255,255,0.5);
  margin-left: var(--space-3);
  letter-spacing: 0.04em;
}

.preview-panel__body {
  padding: var(--space-8);
}

.worksheet-sample {
  font-family: var(--font-body);
}

.worksheet-sample__heading {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-navy);
  margin-bottom: var(--space-2);
}

.worksheet-sample__sub {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
}

.worksheet-problems {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
  margin-bottom: var(--space-6);
}

.problem-box {
  border: 1.5px solid var(--color-cream-dark);
  border-radius: var(--radius-sm);
  padding: var(--space-3);
  text-align: center;
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text-dark);
  background: var(--color-cream);
}

.problem-box .answer-line {
  display: block;
  margin-top: var(--space-2);
  border-bottom: 2px solid var(--color-navy);
  width: 60%;
  margin-inline: auto;
}

.cryptogram-preview {
  background-color: var(--color-navy);
  border-radius: var(--radius-sm);
  padding: var(--space-4);
  text-align: center;
}

.cryptogram-preview__label {
  font-size: 0.8rem;
  color: var(--color-text-light);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--space-2);
}

.cryptogram-preview__code {
  font-family: 'Space Mono', monospace;
  font-size: var(--text-lg);
  color: var(--color-gold);
  letter-spacing: 0.2em;
}

.cryptogram-preview__key {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.6);
  letter-spacing: 0.04em;
  margin-bottom: var(--space-2);
}

/* Worksheet carousel */
.carousel {
  display: grid;
}

.carousel__slide {
  grid-row: 1;
  grid-column: 1;
  opacity: 0;
  transition: opacity 400ms ease-in-out;
  pointer-events: none;
}

.carousel__slide.active {
  opacity: 1;
  pointer-events: auto;
}

@keyframes handwrite {
  from   { opacity: 0; transform: scale(0.6) rotate(-4deg); }
  60%    { opacity: 1; transform: scale(1.08) rotate(1deg); }
  to     { opacity: 1; transform: scale(1) rotate(-1deg); }
}

.handwrite-answer {
  display: block;
  font-family: 'Caveat', cursive;
  font-size: 1.3rem;
  font-weight: 700;
  color: #1e3a8a;
  margin-top: 0.25rem;
  opacity: 0;
}

.handwrite-answer--inline {
  display: inline;
}

.handwrite-answer.animated {
  animation: handwrite 350ms ease-out forwards;
}

.worksheet-problems--wide {
  grid-template-columns: repeat(2, 1fr);
}

.worksheet-problems--mult {
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-2);
}

.problem-box--mult {
  border: 1.5px solid var(--color-cream-dark);
  border-radius: var(--radius-sm);
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text-dark);
  background: var(--color-cream);
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.carousel__nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 0;
  background: var(--color-white);
  border-top: 1px solid var(--color-cream-dark);
}

.carousel__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-cream-dark);
  border: none;
  cursor: pointer;
  transition: background 200ms ease-out, transform 200ms ease-out;
  padding: 0;
}

.carousel__dot.active {
  background: var(--color-navy);
  transform: scale(1.4);
}

.carousel__dot:hover:not(.active) {
  background: var(--color-indigo);
}

.slide-badge {
  display: inline-block;
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.2rem 0.6rem;
  border-radius: 9999px;
  margin-bottom: var(--space-3);
  background: rgba(61,82,196,0.1);
  color: var(--color-indigo);
}

.slide-badge--grade {
  background: rgba(16,124,68,0.1);
  color: #0d6b3a;
}

.slide-badge--gold {
  background: rgba(240,192,96,0.2);
  color: #8a6a00;
}

.slide-badge--book {
  background: rgba(61,82,196,0.18);
  color: #2d4db5;
}

.star-marker {
  font-size: 0.65em;
  margin-left: 0.2rem;
  line-height: 1;
}

/* Cryptogram message display */
.crypto-message {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.15rem;
  margin-top: 0.4rem;
}

.crypto-message + .crypto-message {
  margin-top: 0.3rem;
}.crypto-word {
  display: inline-flex;
  align-items: center;
  gap: 0.15rem;
  white-space: nowrap;
}

.crypto-char {
  width: 1.5rem;
  height: 1.7rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: 'Space Mono', monospace;
  font-size: 0.82rem;
  font-weight: 700;
  color: rgba(255,255,255,0.75);
  opacity: 0;
}

.crypto-char--coded {
  background: rgba(240,192,96,0.2);
  border: 1px solid rgba(240,192,96,0.55);
  border-radius: 2px;
  color: transparent; /* letter hidden until JS fills it in */
}

.crypto-space {
  width: 0.4rem;
}

@keyframes cryptoBoxReveal {
  from { opacity: 0; transform: scale(0.7) translateY(3px); }
  to   { opacity: 1; transform: scale(1)   translateY(0); }
}

@keyframes cryptoLetterFill {
  from { color: transparent; }
  to   { color: var(--color-gold); }
}

/* Plain chars: just appear */
.crypto-char.box-revealed {
  animation: cryptoBoxReveal 200ms ease-out forwards;
}

/* Coded chars: box appears first, letter fills in later via second animation.
   animation-delay is set as "box-delay, letter-delay" inline by JS. */
.crypto-char--coded.box-revealed {
  animation-name: cryptoBoxReveal, cryptoLetterFill;
  animation-duration: 200ms, 280ms;
  animation-timing-function: ease-out, ease-in-out;
  animation-fill-mode: forwards, forwards;
}

/* ------------------------------------------------------------
   10. Meet the Team Section
   ------------------------------------------------------------ */
.meet-the-team {
  background-color: var(--color-navy);
}

.team-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-6);
  margin-top: var(--space-12);
}

.team-card {
  flex: 0 0 calc(25% - var(--space-6) * 0.75);
  min-width: 200px;
  background-color: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  text-align: center;
  transition: transform var(--transition-base),
              box-shadow var(--transition-base),
              border-color var(--transition-base);
}

.team-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
  border-color: rgba(240,192,96,0.2);
}

.team-card__avatar {
  width: calc(100% + 2 * var(--space-6));
  height: 220px;
  margin: calc(-1 * var(--space-6)) calc(-1 * var(--space-6)) var(--space-5);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-indigo), var(--color-navy-light));
}

.team-card__avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
}

.team-card__avatar--split {
  display: flex;
}

.team-card__avatar--split img {
  width: 50%;
  flex-shrink: 0;
}

.team-card__avatar--split img:first-child {
  border-right: 2px solid var(--color-navy);
}

.team-card__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-white);
  margin-bottom: var(--space-1);
}

.team-card__role {
  font-size: var(--text-sm);
  color: var(--color-gold);
  font-weight: 600;
  letter-spacing: 0.04em;
  margin-bottom: var(--space-3);
}

.team-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  line-height: 1.6;
  max-width: none;
}

/* ------------------------------------------------------------
   11. The Series Section
   ------------------------------------------------------------ */
.the-series {
  background-color: var(--color-cream);
}

.series-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
  margin-top: var(--space-12);
}

.book-card {
  background-color: var(--color-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-cream-dark);
  transition: transform var(--transition-base),
              box-shadow var(--transition-base);
  display: flex;
  flex-direction: column;
}

.book-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.book-card--available .book-card__cover {
  background: linear-gradient(155deg, var(--color-navy), var(--color-navy-light));
}

.book-card--coming-soon {
  opacity: 0.75;
}

.book-card--coming-soon .book-card__cover {
  background: linear-gradient(155deg, #1a1a2e, #2d2d44);
}

.book-card__cover {
  height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-6);
  position: relative;
  overflow: hidden;
}

.book-card__cover::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Ccircle cx='30' cy='30' r='1'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.book-card__cover-icon {
  font-size: 3rem;
  position: relative;
  z-index: 1;
}

.book-card__cover-title {
  position: relative;
  z-index: 1;
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-white);
  text-align: center;
  line-height: 1.3;
}

.book-card__badge {
  display: inline-block;
  background-color: var(--color-gold);
  color: var(--color-navy);
  font-size: var(--text-xs);
  font-weight: 700;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
}

.book-card__body {
  padding: var(--space-6);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.book-card__grade {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-indigo);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: var(--space-2);
}

.book-card__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-text-dark);
  margin-bottom: var(--space-3);
  line-height: 1.3;
}

.book-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  flex: 1;
  margin-bottom: var(--space-5);
  max-width: none;
}

.book-card__cta {
  margin-top: auto;
}

/* ------------------------------------------------------------
   12. Blog Preview Section
   ------------------------------------------------------------ */
.blog-preview {
  background-color: var(--color-navy-mid);
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
  margin-top: var(--space-12);
}

.blog-card {
  background-color: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform var(--transition-base),
              box-shadow var(--transition-base),
              border-color var(--transition-base);
  display: flex;
  flex-direction: column;
  text-decoration: none;
}

.blog-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
  border-color: rgba(240,192,96,0.15);
}

.blog-card:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 2px;
}

.blog-card__img {
  height: 160px;
  background: linear-gradient(135deg, var(--color-navy-light), var(--color-indigo));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  position: relative;
  overflow: hidden;
}

.blog-card__img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.blog-card__body {
  padding: var(--space-6);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.blog-card__tag {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-gold);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--space-3);
}

.blog-card__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-white);
  margin-bottom: var(--space-3);
  line-height: 1.3;
  flex: 1;
}

.blog-card__excerpt {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  line-height: 1.6;
  margin-bottom: var(--space-4);
  max-width: none;
}

.blog-card__read-more {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-gold);
  display: flex;
  align-items: center;
  gap: var(--space-1);
  transition: gap var(--transition-fast);
}

.blog-card:hover .blog-card__read-more {
  gap: var(--space-2);
}

/* ------------------------------------------------------------
   13. CTA Section (Final)
   ------------------------------------------------------------ */
.cta-section {
  background-color: var(--color-navy);
  position: relative;
  overflow: hidden;
  text-align: center;
}

.cta-section::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 800px;
  height: 400px;
  background: radial-gradient(ellipse at center,
    rgba(61,82,196,0.2) 0%,
    rgba(10,15,46,0) 70%);
  pointer-events: none;
}

.cta-section__inner {
  position: relative;
  z-index: 1;
  max-width: 640px;
  margin-inline: auto;
}

.cta-section__title {
  font-family: var(--font-display);
  font-size: var(--text-4xl);
  color: var(--color-white);
  margin-bottom: var(--space-5);
}

.cta-section__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-light);
  margin-bottom: var(--space-8);
  max-width: none;
}

.cta-section__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  justify-content: center;
}

/* ------------------------------------------------------------
   14. Footer
   ------------------------------------------------------------ */
.footer {
  background-color: var(--color-navy-mid);
  border-top: 1px solid rgba(255,255,255,0.06);
  padding-block: var(--space-12);
}

.footer__inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-12);
}

.footer__brand {}

.footer__logo {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-white);
  margin-bottom: var(--space-4);
}

.footer__logo span {
  color: var(--color-gold);
}

.footer__tagline {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  line-height: 1.7;
  max-width: 28ch;
}

.footer__col-title {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-white);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-4);
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer__link {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-gold);
}

.footer__link:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 2px;
  border-radius: 2px;
}

.footer__bottom {
  margin-top: var(--space-12);
  padding-top: var(--space-8);
  border-top: 1px solid rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.footer__copyright {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* ------------------------------------------------------------
   15. Email Capture / Kit embed
   ------------------------------------------------------------ */
.email-capture {
  background-color: rgba(240,192,96,0.06);
  border: 1px solid rgba(240,192,96,0.2);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  text-align: center;
  max-width: 580px;
  margin-inline: auto;
}

.email-capture__title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  color: var(--color-white);
  margin-bottom: var(--space-2);
}

.email-capture__desc {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  margin-bottom: var(--space-6);
  max-width: none;
}

/* Kit custom form */
.kit-form__row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
}

.kit-form__group {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  text-align: left;
}

.kit-form__label {
  font-size: var(--text-xs);
  font-weight: 600;
  color: rgba(200,214,229,0.8);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.kit-form__input {
  width: 100%;
  padding: 0.65rem 0.9rem;
  background: rgba(255,255,255,0.07);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius-sm);
  color: var(--color-white);
  font-family: var(--font-body);
  font-size: var(--text-base);
  transition: border-color 150ms ease-out, background 150ms ease-out;
}

.kit-form__input::placeholder {
  color: rgba(200,214,229,0.35);
}

.kit-form__input:focus {
  outline: none;
  border-color: var(--color-gold);
  background: rgba(255,255,255,0.1);
}

.kit-form__input:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 2px;
}

.kit-form__btn {
  width: 100%;
  margin-top: var(--space-1);
}

.kit-form__error {
  margin-top: var(--space-3);
  font-size: var(--text-sm);
  color: #fca5a5;
  text-align: center;
  max-width: none;
}

.kit-form__meta {
  margin-top: var(--space-4);
  font-size: 0.72rem;
  color: rgba(200,214,229,0.45);
  text-align: center;
  max-width: none;
}

/* Kit success state */
.kit-success {
  text-align: center;
  padding: var(--space-4) 0;
}

.kit-success__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: rgba(16,185,129,0.15);
  border: 2px solid rgba(16,185,129,0.4);
  color: #34d399;
  margin-bottom: var(--space-4);
}

.kit-success__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-white);
  margin-bottom: var(--space-2);
}

.kit-success__desc {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  max-width: none;
}

.kit-success__desc strong {
  color: var(--color-gold);
}

@media (max-width: 480px) {
  .kit-form__row {
    grid-template-columns: 1fr;
  }
}

/* ------------------------------------------------------------
   16. Badges & Tags
   ------------------------------------------------------------ */
.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.badge--gold {
  background-color: rgba(240,192,96,0.15);
  color: var(--color-gold);
  border: 1px solid rgba(240,192,96,0.3);
}

.badge--indigo {
  background-color: rgba(61,82,196,0.15);
  color: #7b92e8;
  border: 1px solid rgba(61,82,196,0.3);
}

.badge--coming-soon {
  background-color: rgba(255,255,255,0.06);
  color: var(--color-text-muted);
  border: 1px solid rgba(255,255,255,0.1);
}

/* ------------------------------------------------------------
   17. Stars (ratings)
   ------------------------------------------------------------ */
.stars {
  display: flex;
  gap: 2px;
  color: var(--color-gold);
}

.stars svg {
  width: 16px;
  height: 16px;
}

/* ------------------------------------------------------------
   18. Divider
   ------------------------------------------------------------ */
.divider {
  width: 48px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-gold), var(--color-indigo));
  border-radius: 2px;
  margin-block: var(--space-6);
}

/* ------------------------------------------------------------
   19. Responsive — Tablet (768px)
   ------------------------------------------------------------ */
@media (max-width: 1024px) {
  .team-card {
    flex-basis: calc(50% - var(--space-6) * 0.5);
  }

  .footer__inner {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }
}

@media (max-width: 768px) {
  :root {
    --text-5xl: 2.5rem;
    --text-4xl: 2.25rem;
    --text-3xl: 1.875rem;
  }

  .nav__links {
    display: none;
  }

  .nav__hamburger {
    display: flex;
  }

  .hero__inner {
    grid-template-columns: 1fr;
    text-align: center;
    padding-block: var(--space-16);
    gap: var(--space-12);
  }

  .hero__subtitle {
    margin-inline: auto;
  }

  .hero__ctas {
    justify-content: center;
  }

  .hero__social-proof {
    justify-content: center;
  }

  .steps {
    grid-template-columns: 1fr;
  }

  .whats-inside__grid {
    grid-template-columns: 1fr;
  }

  .series-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
    margin-inline: auto;
  }
  .series-grid.margin-top-fix { margin-top: var(--space-12); }

  .blog-grid {
    grid-template-columns: 1fr;
  }

  .footer__inner {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }

  .footer__bottom {
    flex-direction: column;
    text-align: center;
  }
}

/* ------------------------------------------------------------
   20. Responsive — Mobile (375px)
   ------------------------------------------------------------ */
@media (max-width: 480px) {
  .container {
    padding-inline: var(--space-4);
  }

  .section {
    padding-block: var(--space-16);
  }

  .hero__book {
    width: 220px;
    height: 280px;
  }

  .team-card {
    flex-basis: 100%;
  }

  .btn {
    padding: var(--space-3) var(--space-6);
  }

  .hero__ctas {
    flex-direction: column;
    align-items: center;
  }

  .hero__ctas .btn {
    width: 100%;
    max-width: 320px;
  }

  .worksheet-problems {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ------------------------------------------------------------
   21. Blog & Interior Pages
   ------------------------------------------------------------ */
.page-hero {
  background-color: var(--color-navy);
  padding-top: calc(var(--nav-height) + var(--space-16));
  padding-bottom: var(--space-16);
  position: relative;
  overflow: hidden;
}

.page-hero__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-12);
  align-items: center;
}

.page-hero__image {
  border-radius: var(--radius-lg);
  overflow: hidden;
  aspect-ratio: 4 / 3;
}

.page-hero__image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

@media (max-width: 768px) {
  .page-hero__inner {
    grid-template-columns: 1fr;
  }

  .page-hero__image {
    order: -1;
    aspect-ratio: 16 / 9;
  }
}

.article-body {
  background-color: var(--color-cream);
  padding-block: var(--space-16);
}

.article-content {
  max-width: 720px;
  margin-inline: auto;
}

.article-content h2 {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  color: var(--color-text-dark);
  margin-top: var(--space-10);
  margin-bottom: var(--space-4);
}

.article-content h3 {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-text-dark);
  margin-top: var(--space-8);
  margin-bottom: var(--space-3);
}

.article-content p {
  font-size: var(--text-base);
  color: var(--color-text-dark);
  line-height: 1.75;
  margin-bottom: var(--space-5);
  max-width: none;
}

.article-content ul,
.article-content ol {
  margin-bottom: var(--space-5);
  padding-left: var(--space-6);
}

.article-content ul { list-style: disc; }
.article-content ol { list-style: decimal; }

.article-content li {
  font-size: var(--text-base);
  color: var(--color-text-dark);
  line-height: 1.75;
  margin-bottom: var(--space-2);
}

.article-content blockquote {
  border-left: 4px solid var(--color-gold);
  padding: var(--space-4) var(--space-6);
  margin-block: var(--space-8);
  background-color: rgba(240,192,96,0.06);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-style: italic;
  color: var(--color-text-dark);
}

/* ------------------------------------------------------------
   22. Utility classes
   ------------------------------------------------------------ */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border-width: 0;
}

.mt-auto { margin-top: auto; }
.mb-0    { margin-bottom: 0; }