/**
 * FutureLearn AIVerse — GLOBAL THEME TOKENS
 * Seafoam light theme.
 *
 *   --seafoam-1 … --seafoam-5  the supplied palette (light → saturated)
 *   --pine-1 … --pine-3        darker extensions of the same hue family,
 *                              needed so text/CTAs clear WCAG AA on white.
 *
 * The historical --brand-purple / --brand-blue names are kept as aliases so
 * the 15k-line component sheet keeps working; they now carry seafoam values.
 * To retheme the whole site, edit the scale below and nothing else.
 *
 * @version 3.0
 */

/* ============================================================
   ROOT DESIGN TOKENS  ← Single source of truth
   ============================================================ */
:root {
  /* ---- Seafoam scale (supplied) ---- */
  --seafoam-1: #d8f3dc;
  --seafoam-2: #b7e4c7;
  --seafoam-3: #95d5b2;
  --seafoam-4: #74c69d;
  --seafoam-5: #52b788;

  /* ---- Pine extensions (for contrast on light surfaces) ---- */
  --pine-1: #40916c;
  --pine-2: #2d6a4f;
  --pine-3: #1b4332;
  --pine-4: #10241a;

  /* ---- Canvas ---- */
  --canvas:       #f6fbf8;   /* page background */
  --canvas-tint:  #eef8f1;   /* alternating band */
  --canvas-deep:  #0f2a20;   /* pine anchor band (footer) */

  /* ---- Elevation (green-tinted, never grey) ---- */
  --ring:      0 0 0 1px rgba(45, 106, 79, 0.08);
  --lift-sm:   0 2px 8px rgba(16, 36, 26, 0.05);
  --lift-md:   0 10px 30px -12px rgba(16, 36, 26, 0.16);
  --lift-lg:   0 28px 60px -28px rgba(16, 36, 26, 0.28);
  --glow:      0 12px 32px -10px rgba(45, 106, 79, 0.45);

  /* ---- Rhythm ---- */
  --band:      clamp(72px, 9vw, 128px);  /* vertical section padding */
  --gutter:    clamp(20px, 4vw, 40px);   /* horizontal page gutter */

  /* ---- Brand Core (aliases → seafoam) ---- */
  --brand-purple:        #2d6a4f;
  --brand-purple-dark:   #1b4332;   /* darker shade for hover */
  --brand-purple-light:  #95d5b2;   /* lighter tint */
  --brand-purple-wash:   rgba(82, 183, 136, 0.10);  /* subtle bg tint */
  --brand-purple-glow:   rgba(82, 183, 136, 0.35);  /* shadow/glow */

  --brand-blue:          #52b788;
  --brand-blue-dark:     #40916c;   /* darker shade for hover */
  --brand-blue-light:    #b7e4c7;   /* lighter tint */
  --brand-blue-wash:     rgba(116, 198, 157, 0.10);
  --brand-blue-glow:     rgba(116, 198, 157, 0.30);

  --brand-black:         #0f2a20;
  --brand-black-soft:    #0b2018;   /* near-black surface */
  --brand-black-card:    #0f2a20;   /* card surface on dark bg */
  --brand-black-border:  #1b4332;   /* subtle dark border */

  /* ---- Semantic Color Aliases (mapped to brand palette) ---- */

  /* Text & Ink */
  --color-ink:           #10241a;   /* main body text (dark, readable) */
  --color-pencil:        #3d5a4b;   /* secondary text */
  --color-graphite:      #6e8b7c;   /* muted / placeholder */
  --color-charcoal:      #1b4332;

  /* Surfaces & Paper */
  --color-paper:         #ffffff;
  --color-cream:         #eef8f1;   /* light purple wash (was warm cream) */
  --color-stone:         #cbe8d7;   /* borders, dividers */

  /* Brand Accents — primary = purple, secondary = blue */
  --color-ember-red:     var(--brand-purple);      /* was #ffc107 / red */
  --color-deep-ember:    var(--brand-purple-dark);  /* hover state */
  --color-cobalt-link:   var(--brand-blue);         /* was #0f66ae */
  --color-teal-dusk:     var(--brand-blue-dark);

  /* Background Washes */
  --color-mint-wash:     var(--brand-purple-wash);
  --color-sky-wash:      var(--brand-blue-wash);
  --color-forest:        var(--brand-purple-dark);

  /* Surface Layers */
  --surface-paper-canvas:  #ffffff;
  --surface-cream-wash:    var(--color-cream);
  --surface-tinted-wave:   var(--color-cream);
  --surface-card-surface:  #ffffff;

  /* ---- Typography ---- */
  --font-graphik:    'Graphik', 'Inter', ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-inter:      'Inter', ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-caecilia:   'Caecilia', 'Lora', 'Source Serif Pro', serif;
  --font-shantell-sans: 'Shantell Sans', 'Caveat', 'Kalam', cursive;

  /* Typography Scale */
  --text-caption:       12px;  --leading-caption:   1.5;  --tracking-caption:  0.14px;
  --text-body-sm:       14px;  --leading-body-sm:   1.5;  --tracking-body-sm:  0.07px;
  --text-body:          16px;  --leading-body:      1.5;  --tracking-body:     0.16px;
  --text-body-lg:       18px;  --leading-body-lg:   1.5;  --tracking-body-lg:  0.18px;
  --text-subheading:    21px;  --leading-subheading:1.5;  --tracking-subheading:0.21px;
  --text-heading:       38px;  --leading-heading:   1.28; --tracking-heading:  -0.19px;
  --text-heading-lg:    44px;  --leading-heading-lg:1.15; --tracking-heading-lg:-0.22px;
  --text-display:       55px;  --leading-display:   1;    --tracking-display:  -0.55px;

  /* Font Weights */
  --font-weight-regular:  400;
  --font-weight-w475:     475;
  --font-weight-medium:   500;
  --font-weight-semibold: 600;
  --font-weight-w625:     625;
  --font-weight-bold:     700;

  /* ---- Spacing Scale (4px unit) ---- */
  --spacing-unit: 4px;
  --spacing-4:    4px;   --spacing-8:   8px;   --spacing-10:  10px;
  --spacing-12:  12px;   --spacing-16: 16px;   --spacing-20:  20px;
  --spacing-24:  24px;   --spacing-32: 32px;   --spacing-48:  48px;
  --spacing-64:  64px;   --spacing-80: 80px;   --spacing-128:128px;
  --spacing-192:192px;

  /* ---- Border Radius ---- */
  --radius-sm:      2.5px;
  --radius-lg:      8px;
  --radius-xl:      15px;
  --radius-nav:     8px;
  --radius-cards:   8px;
  --radius-badges:  8px;
  --radius-images:  15px;
  --radius-inputs:  8px;
  --radius-buttons: 8px;

  /* ---- Shadows — updated to use brand purple glow ---- */
  --shadow-subtle: rgba(82, 183, 136, 0.06) 0px 1px 0px 0px;
  --shadow-lg:     rgba(82, 183, 136, 0.12) 0px 14px 19px -9px, rgba(82, 183, 136, 0.22) 0px 10px 48px 0px;

  /* ---- Layout ---- */
  --page-max-width: 1200px;
  --section-gap:    48px;
  --card-padding:   16px;
  --element-gap:    16px;

  /* ---- Transitions ---- */
  --transition-fast:   150ms ease-out;
  --transition-normal: 250ms ease-out;
  --transition-slow:   350ms ease-out;

  /* ---- Gradient Presets (use anywhere via var()) ---- */
  --gradient-primary:    linear-gradient(135deg, var(--brand-purple) 0%, var(--brand-blue) 100%);
  --gradient-primary-r:  linear-gradient(135deg, var(--brand-blue)   0%, var(--brand-purple) 100%);
  --gradient-dark:       linear-gradient(135deg, var(--brand-black-soft) 0%, #0b2018 100%);
  --gradient-hero-overlay: linear-gradient(100deg, rgba(0,0,0,0.82) 0%, rgba(0,0,0,0.55) 45%, rgba(0,0,0,0.10) 100%);
}


/* ============================================================
   GLOBAL RESETS & DEFAULTS
   ============================================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  background-color: var(--surface-paper-canvas);
  color: var(--color-ink);
  font-family: var(--font-inter);
  font-size: var(--text-body);
  line-height: var(--leading-body);
  letter-spacing: var(--tracking-body);
  font-weight: var(--font-weight-regular);
}

/* ============================================================
   TYPOGRAPHY COMPONENTS
   ============================================================ */

/* Display Heading (55px) */
h1, .display {
  font-family: var(--font-graphik);
  font-size: var(--text-display);
  font-weight: var(--font-weight-bold);
  line-height: var(--leading-display);
  letter-spacing: var(--tracking-display);
  color: var(--color-ink);
  margin-bottom: var(--spacing-16);
}

/* Large Heading (44px) */
h2, .heading-lg {
  font-family: var(--font-graphik);
  font-size: var(--text-heading-lg);
  font-weight: var(--font-weight-bold);
  line-height: var(--leading-heading-lg);
  letter-spacing: var(--tracking-heading-lg);
  color: var(--color-ink);
  margin-bottom: var(--spacing-16);
}

/* Heading (38px) */
h3, .heading {
  font-family: var(--font-graphik);
  font-size: var(--text-heading);
  font-weight: var(--font-weight-bold);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  margin-bottom: var(--spacing-12);
}

/* Subheading (21px) */
h4, .subheading {
  font-family: var(--font-graphik);
  font-size: var(--text-subheading);
  font-weight: var(--font-weight-semibold);
  line-height: var(--leading-subheading);
  letter-spacing: var(--tracking-subheading);
  color: var(--color-ink);
  margin-bottom: var(--spacing-12);
}

/* Body Large (18px) */
.body-lg, h5 {
  font-family: var(--font-inter);
  font-size: var(--text-body-lg);
  font-weight: var(--font-weight-regular);
  line-height: var(--leading-body-lg);
  letter-spacing: var(--tracking-body-lg);
  color: var(--color-ink);
}

/* Body (16px) */
p, .body {
  font-family: var(--font-inter);
  font-size: var(--text-body);
  font-weight: var(--font-weight-regular);
  line-height: var(--leading-body);
  letter-spacing: var(--tracking-body);
  color: var(--color-ink);
  margin-bottom: var(--spacing-16);
}

/* Body Small (14px) */
.body-sm, h6 {
  font-family: var(--font-inter);
  font-size: var(--text-body-sm);
  font-weight: var(--font-weight-regular);
  line-height: var(--leading-body-sm);
  letter-spacing: var(--tracking-body-sm);
  color: var(--color-ink);
}

/* Caption (12px) */
.caption {
  font-family: var(--font-inter);
  font-size: var(--text-caption);
  font-weight: var(--font-weight-medium);
  line-height: var(--leading-caption);
  letter-spacing: var(--tracking-caption);
  color: var(--color-graphite);
}

/* Secondary Text */
.text-secondary {
  color: var(--color-pencil);
  font-size: var(--text-body-sm);
}

/* Muted Text */
.text-muted {
  color: var(--color-graphite);
}

/* ============================================================
   BUTTONS & ACTIONS
   ============================================================ */

/* Primary Button - Single CTA per view */
.btn-primary,
button[type="submit"],
input[type="submit"] {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-8);

  background-color: var(--color-ember-red);
  color: var(--color-paper);

  font-family: var(--font-inter);
  font-size: var(--text-body);
  font-weight: var(--font-weight-semibold);
  line-height: var(--leading-body);
  letter-spacing: var(--tracking-body);

  padding: var(--spacing-12) var(--spacing-24);
  border: none;
  border-radius: var(--radius-buttons);

  cursor: pointer;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-lg);
  text-decoration: none;
}

.btn-primary:hover,
button[type="submit"]:hover,
input[type="submit"]:hover {
  background-color: var(--color-deep-ember);
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}

.btn-primary:active,
button[type="submit"]:active,
input[type="submit"]:active {
  background-color: var(--color-charcoal);
  transform: translateY(0);
}

/* Ghost Button - Secondary action */
.btn-ghost,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-8);

  background-color: transparent;
  color: var(--color-ink);

  font-family: var(--font-inter);
  font-size: var(--text-body);
  font-weight: var(--font-weight-medium);
  line-height: var(--leading-body);
  letter-spacing: var(--tracking-body);

  padding: var(--spacing-8) var(--spacing-16);
  border: 1px solid transparent;
  border-radius: var(--radius-buttons);

  cursor: pointer;
  transition: all var(--transition-normal);
  text-decoration: none;
}

.btn-ghost:hover,
.btn-secondary:hover {
  color: var(--color-deep-ember);
  background-color: var(--brand-purple-wash);
}

.btn-ghost:focus,
.btn-secondary:focus {
  border-color: var(--color-deep-ember);
  outline: none;
}

/* Text Link */
a, .link {
  color: var(--color-cobalt-link);
  text-decoration: none;
  transition: color var(--transition-normal);
  font-weight: var(--font-weight-medium);
}

a:hover, .link:hover {
  color: var(--color-deep-ember);
  /* text-decoration: underline; */
}

a:focus, .link:focus {
  outline: 2px solid var(--color-cobalt-link);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ============================================================
   CARDS & CONTAINERS
   ============================================================ */

.card {
  background-color: var(--surface-card-surface);
  border-radius: var(--radius-cards);
  padding: var(--card-padding);
  box-shadow: var(--shadow-subtle);
  transition: box-shadow var(--transition-normal);
  border: 1px solid var(--color-stone);
}

.card:hover {
  box-shadow: 0px 4px 12px var(--brand-purple-wash);
}

/* ============================================================
   FORMS & INPUTS
   ============================================================ */

input[type="text"],
input[type="email"],
input[type="password"],
input[type="search"],
input[type="number"],
input[type="tel"],
input[type="date"],
textarea,
select {
  width: 100%;
  padding: var(--spacing-12) var(--spacing-16);
  font-family: var(--font-inter);
  font-size: var(--text-body);
  line-height: var(--leading-body);

  background-color: var(--surface-paper-canvas);
  color: var(--color-ink);
  border: 1px solid var(--color-stone);
  border-radius: var(--radius-inputs);

  transition: border-color var(--transition-normal);
}

input::placeholder,
textarea::placeholder {
  color: var(--color-graphite);
}

input:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--color-deep-ember);
  background-color: #fff;
  box-shadow: 0 0 0 3px var(--brand-purple-wash);
}

input:disabled,
textarea:disabled,
select:disabled {
  background-color: var(--color-grey2);
  color: var(--color-graphite);
  cursor: not-allowed;
}

/* ============================================================
   BADGES & LABELS
   ============================================================ */

.badge {
  display: inline-block;
  font-family: var(--font-inter);
  font-size: var(--text-caption);
  font-weight: var(--font-weight-semibold);
  line-height: var(--leading-caption);
  letter-spacing: var(--tracking-caption);

  padding: var(--spacing-4) var(--spacing-10);
  border-radius: var(--radius-badges);

  white-space: nowrap;
}

/* Badge Variants */
.badge-success {
  background-color: var(--color-mint-wash);
  color: var(--color-forest);
}

.badge-info {
  background-color: var(--color-sky-wash);
  color: var(--color-cobalt-link);
}

.badge-warning {
  background-color: var(--brand-purple-wash);
  color: var(--color-deep-ember);
}

/* ============================================================
   EYEBROW LABEL
   ============================================================ */

.eyebrow {
  font-family: var(--font-inter);
  font-size: var(--text-caption);
  font-weight: var(--font-weight-semibold);
  line-height: var(--leading-caption);
  letter-spacing: var(--tracking-caption);
  color: var(--color-deep-ember);
  text-transform: uppercase;
  margin-bottom: var(--spacing-8);
  display: block;
}

/* ============================================================
   NAVIGATION
   ============================================================ */

nav {
  font-family: var(--font-inter);
  font-size: var(--text-body);
  font-weight: var(--font-weight-medium);
}

nav a {
  display: inline-block;
  padding: var(--spacing-8) var(--spacing-16);
  color: var(--color-ink);
  transition: color var(--transition-normal);
  position: relative;
}

nav a:hover {
  color: var(--color-deep-ember);
}

nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: var(--spacing-16);
  right: var(--spacing-16);
  height: 2px;
  background-color: var(--color-deep-ember);
  transform: scaleX(0);
  transition: transform var(--transition-normal);
}

nav a:hover::after,
nav a.active::after {
  transform: scaleX(1);
}

/* ============================================================
   SECTIONS & SPACING
   ============================================================ */

section {
  padding: var(--spacing-64) var(--spacing-20);
}

section:nth-child(even) {
  background-color: transparent;
}

section:nth-child(3n) {
  background-color: transparent;
}

.container {
  width: 100%;
  max-width: var(--page-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-20);
}

/* ============================================================
   UTILITIES
   ============================================================ */

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: var(--spacing-4); }
.mt-2 { margin-top: var(--spacing-8); }
.mt-3 { margin-top: var(--spacing-12); }
.mt-4 { margin-top: var(--spacing-16); }
.mt-5 { margin-top: var(--spacing-24); }
.mt-6 { margin-top: var(--spacing-32); }

.mb-1 { margin-bottom: var(--spacing-4); }
.mb-2 { margin-bottom: var(--spacing-8); }
.mb-3 { margin-bottom: var(--spacing-12); }
.mb-4 { margin-bottom: var(--spacing-16); }
.mb-5 { margin-bottom: var(--spacing-24); }
.mb-6 { margin-bottom: var(--spacing-32); }

.p-1 { padding: var(--spacing-4); }
.p-2 { padding: var(--spacing-8); }
.p-3 { padding: var(--spacing-12); }
.p-4 { padding: var(--spacing-16); }
.p-5 { padding: var(--spacing-24); }
.p-6 { padding: var(--spacing-32); }

.gap-1 { gap: var(--spacing-4); }
.gap-2 { gap: var(--spacing-8); }
.gap-3 { gap: var(--spacing-12); }
.gap-4 { gap: var(--spacing-16); }
.gap-5 { gap: var(--spacing-24); }

/* ============================================================
   RESPONSIVE HELPERS
   ============================================================ */

.hide-mobile {
  display: none;
}

@media (min-width: 768px) {
  .hide-mobile {
    display: block;
  }

  .hide-desktop {
    display: none;
  }

  section {
    padding: var(--spacing-80) var(--spacing-32);
  }
}

/* ============================================================
   ACCESSIBILITY
   ============================================================ */

/* Skip link */
.skip-to-content {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-deep-ember);
  color: var(--color-paper);
  padding: var(--spacing-8) var(--spacing-16);
  text-decoration: none;
  border-radius: var(--radius-sm);
}

.skip-to-content:focus {
  top: 0;
}

/* Focus visible for keyboard navigation */
*:focus-visible {
  outline: 2px solid var(--color-cobalt-link);
  outline-offset: 2px;
}

button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: 2px solid var(--color-deep-ember);
  outline-offset: 2px;
}

/* ============================================================
   HOMEPAGE HERO — warm theme background + effects (global)
   ============================================================ */
/* Hero (.af-hero*) styles moved to app.css, scoped under .page-index */

/* ============================================================
   MODERN BADGE (NEW THEME GLOBAL OVERRIDE)
   ============================================================ */
.modern-badge {
  display: inline-flex !important;
  align-items: center !important;
  font-family: var(--font-inter) !important;
  font-size: 11px !important;
  font-weight: var(--font-weight-semibold) !important;
  letter-spacing: 0.08em !important;
  padding: 6px 12px !important;
  border-radius: var(--radius-badges, 8px) !important;
  background-color: var(--color-cream) !important;
  color: var(--color-deep-ember) !important;
  border: 1px solid var(--color-stone) !important;
  text-transform: uppercase !important;
  box-shadow: var(--shadow-subtle) !important;
}