/* ============================================================
   LUKAPH AGRO-CARBON PROSPERO — Design System
   style.css | Global tokens, typography, layout, base styles
   ============================================================ */

/* ------------------------------------------------------------
   1. DESIGN TOKENS
   ------------------------------------------------------------ */
:root {

  /* Colour Palette
     Deep blue-greens — environmental authority, corporate trust */
  --color-forest:      #0D3B2E;   /* primary dark green — hero bg, headings */
  --color-pine:        #1A5C45;   /* secondary green — accents, borders */
  --color-sage:        #2E8B63;   /* mid green — buttons, highlights */
  --color-mist:        #B7D9CC;   /* light green — subtle tints, dividers */
  --color-ocean:       #0B3D5E;   /* deep blue — nav, footer bg */
  --color-sky:         #1A6B9A;   /* mid blue — links, secondary buttons */
  --color-ice:         #D6EBF5;   /* light blue — section backgrounds */

  --color-white:       #FFFFFF;
  --color-offwhite:    #F5F8F6;   /* warm off-white — page background */
  --color-charcoal:    #1C2B24;   /* near-black — body text */
  --color-slate:       #4A6558;   /* muted text — captions, meta */
  --color-rule:        #D0DDD9;   /* dividers and borders */

  /* Gold accent — used sparingly for prestige moments */
  --color-gold:        #C8963E;
  --color-gold-light:  #F0D9A8;

  /* Semantic roles */
  --bg-page:           var(--color-offwhite);
  --bg-dark:           var(--color-forest);
  --bg-dark-alt:       var(--color-ocean);
  --bg-subtle:         var(--color-ice);
  --text-primary:      var(--color-charcoal);
  --text-secondary:    var(--color-slate);
  --text-on-dark:      #E8F2EE;
  --text-on-dark-muted:#9BBFB0;
  --accent:            var(--color-sage);
  --accent-dark:       var(--color-pine);
  --border:            var(--color-rule);

  /* Typography */
  --font-display:      'Playfair Display', Georgia, serif;
  --font-body:         'Inter', system-ui, -apple-system, sans-serif;
  --font-mono:         'IBM Plex Mono', monospace;

  /* Type Scale */
  --text-xs:    0.75rem;    /*  12px */
  --text-sm:    0.875rem;   /*  14px */
  --text-base:  1rem;       /*  16px */
  --text-md:    1.125rem;   /*  18px */
  --text-lg:    1.375rem;   /*  22px */
  --text-xl:    1.75rem;    /*  28px */
  --text-2xl:   2.25rem;    /*  36px */
  --text-3xl:   3rem;       /*  48px */
  --text-4xl:   3.75rem;    /*  60px */

  /* Spacing Scale (base 8px) */
  --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 */
  --space-32:   8rem;       /* 128px */

  /* Layout */
  --container-max:  1200px;
  --container-wide: 1400px;
  --container-text:  720px;

  /* Radii */
  --radius-sm:   4px;
  --radius-md:   8px;
  --radius-lg:  16px;
  --radius-xl:  24px;
  --radius-pill: 999px;

  /* Shadows */
  --shadow-sm:  0 1px 3px rgba(13, 59, 46, 0.08);
  --shadow-md:  0 4px 16px rgba(13, 59, 46, 0.12);
  --shadow-lg:  0 12px 40px rgba(13, 59, 46, 0.16);

  /* Transitions */
  --transition-fast:   150ms ease;
  --transition-base:   250ms ease;
  --transition-slow:   400ms ease;

  /* Nav height — used for scroll offset */
  --nav-height: 72px;
}


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

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

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.7;
  color: var(--text-primary);
  background-color: var(--bg-page);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-sky);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-sage);
}

a:focus-visible {
  outline: 2px solid var(--color-sage);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

ul, ol {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  line-height: 1.2;
  color: var(--color-forest);
  font-weight: 700;
}


/* ------------------------------------------------------------
   3. TYPOGRAPHY
   ------------------------------------------------------------ */
.display-xl {
  font-family: var(--font-display);
  font-size: clamp(var(--text-3xl), 6vw, var(--text-4xl));
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.display-lg {
  font-family: var(--font-display);
  font-size: clamp(var(--text-2xl), 4vw, var(--text-3xl));
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.01em;
}

.display-md {
  font-family: var(--font-display);
  font-size: clamp(var(--text-xl), 3vw, var(--text-2xl));
  font-weight: 600;
  line-height: 1.2;
}

.text-lg    { font-size: var(--text-lg); }
.text-md    { font-size: var(--text-md); }
.text-base  { font-size: var(--text-base); }
.text-sm    { font-size: var(--text-sm); }
.text-xs    { font-size: var(--text-xs); }

.text-muted       { color: var(--text-secondary); }
.text-on-dark     { color: var(--text-on-dark); }
.text-on-dark-muted { color: var(--text-on-dark-muted); }
.text-accent      { color: var(--accent); }
.text-gold        { color: var(--color-gold); }

.eyebrow {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-sage);
}

.eyebrow--gold {
  color: var(--color-gold);
}

.eyebrow--light {
  color: var(--text-on-dark-muted);
}


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

.container--wide {
  max-width: var(--container-wide);
}

.container--text {
  max-width: var(--container-text);
}

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

.section--lg {
  padding-block: var(--space-32);
}

.section--sm {
  padding-block: var(--space-12);
}

.section--dark {
  background-color: var(--bg-dark);
  color: var(--text-on-dark);
}

.section--dark h1,
.section--dark h2,
.section--dark h3,
.section--dark h4 {
  color: var(--text-on-dark);
}

.section--dark-alt {
  background-color: var(--bg-dark-alt);
  color: var(--text-on-dark);
}

.section--dark-alt h1,
.section--dark-alt h2,
.section--dark-alt h3 {
  color: var(--text-on-dark);
}

.section--subtle {
  background-color: var(--bg-subtle);
}

.grid {
  display: grid;
  gap: var(--space-8);
}

.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }

.flex { display: flex; }
.flex--center { align-items: center; justify-content: center; }
.flex--between { align-items: center; justify-content: space-between; }
.flex--gap-4 { gap: var(--space-4); }
.flex--gap-6 { gap: var(--space-6); }
.flex--gap-8 { gap: var(--space-8); }

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

.mt-2  { margin-top: var(--space-2); }
.mt-4  { margin-top: var(--space-4); }
.mt-6  { margin-top: var(--space-6); }
.mt-8  { margin-top: var(--space-8); }
.mt-12 { margin-top: var(--space-12); }

.mb-2  { margin-bottom: var(--space-2); }
.mb-4  { margin-bottom: var(--space-4); }
.mb-6  { margin-bottom: var(--space-6); }
.mb-8  { margin-bottom: var(--space-8); }
.mb-12 { margin-bottom: var(--space-12); }


/* ------------------------------------------------------------
   5. BUTTONS
   ------------------------------------------------------------ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.02em;
  border-radius: var(--radius-pill);
  border: 2px solid transparent;
  cursor: pointer;
  transition: background var(--transition-base),
              color var(--transition-base),
              border-color var(--transition-base),
              transform var(--transition-fast),
              box-shadow var(--transition-base);
  text-decoration: none;
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

/* Primary — solid green */
.btn--primary {
  background-color: var(--color-sage);
  color: var(--color-white);
  border-color: var(--color-sage);
}

.btn--primary:hover {
  background-color: var(--color-pine);
  border-color: var(--color-pine);
  color: var(--color-white);
  box-shadow: var(--shadow-md);
}

/* Secondary — outlined green */
.btn--secondary {
  background-color: transparent;
  color: var(--color-sage);
  border-color: var(--color-sage);
}

.btn--secondary:hover {
  background-color: var(--color-sage);
  color: var(--color-white);
}

/* Ghost — for dark backgrounds */
.btn--ghost {
  background-color: rgba(255,255,255,0.1);
  color: var(--color-white);
  border-color: rgba(255,255,255,0.35);
}

.btn--ghost:hover {
  background-color: rgba(255,255,255,0.2);
  border-color: rgba(255,255,255,0.6);
  color: var(--color-white);
}

/* Gold — prestige/CTA moments */
.btn--gold {
  background-color: var(--color-gold);
  color: var(--color-forest);
  border-color: var(--color-gold);
}

.btn--gold:hover {
  background-color: #b5832e;
  border-color: #b5832e;
  color: var(--color-white);
  box-shadow: var(--shadow-md);
}

/* Sizes */
.btn--lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
}

.btn--sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
}


/* ------------------------------------------------------------
   6. DIVIDERS & DECORATIVE ELEMENTS
   ------------------------------------------------------------ */
.rule {
  border: none;
  border-top: 1px solid var(--border);
  margin-block: var(--space-8);
}

.rule--dark {
  border-color: rgba(255,255,255,0.12);
}

/* Accent line — used under section headings */
.accent-line {
  display: block;
  width: 48px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-sage), var(--color-sky));
  border-radius: var(--radius-pill);
  margin-block: var(--space-4);
}

.accent-line--center {
  margin-inline: auto;
}

.accent-line--gold {
  background: linear-gradient(90deg, var(--color-gold), var(--color-gold-light));
}


/* ------------------------------------------------------------
   7. SECTION HEADING PATTERN
   ------------------------------------------------------------ */
.section-header {
  margin-bottom: var(--space-12);
}

.section-header--center {
  text-align: center;
}

.section-header .eyebrow {
  margin-bottom: var(--space-3);
}

.section-header h2 {
  margin-bottom: 0;
}

.section-header p {
  margin-top: var(--space-4);
  font-size: var(--text-md);
  color: var(--text-secondary);
  max-width: 600px;
}

.section-header--center p {
  margin-inline: auto;
}

.section-header--dark h2 {
  color: var(--text-on-dark);
}

.section-header--dark p {
  color: var(--text-on-dark-muted);
}


/* ------------------------------------------------------------
   8. CARDS (base — extended in components.css)
   ------------------------------------------------------------ */
.card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  overflow: hidden;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

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


/* ------------------------------------------------------------
   9. FORM BASE STYLES (extended in contact.js handling)
   ------------------------------------------------------------ */
.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.form-label {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: 0.01em;
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--color-white);
  color: var(--text-primary);
  font-size: var(--text-base);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  outline: none;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  border-color: var(--color-sage);
  box-shadow: 0 0 0 3px rgba(46, 139, 99, 0.15);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--text-secondary);
  opacity: 0.7;
}

.form-textarea {
  resize: vertical;
  min-height: 140px;
}

.form-error {
  font-size: var(--text-xs);
  color: #C0392B;
  display: none;
}

.form-error.visible {
  display: block;
}

.form-input.error,
.form-textarea.error {
  border-color: #C0392B;
  box-shadow: 0 0 0 3px rgba(192, 57, 43, 0.12);
}


/* ------------------------------------------------------------
   10. SCROLL REVEAL UTILITY
   ------------------------------------------------------------ */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal--delay-1 { transition-delay: 100ms; }
.reveal--delay-2 { transition-delay: 200ms; }
.reveal--delay-3 { transition-delay: 300ms; }
.reveal--delay-4 { transition-delay: 400ms; }

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}


/* ------------------------------------------------------------
   11. RESPONSIVE BREAKPOINTS
   ------------------------------------------------------------ */
@media (max-width: 1024px) {
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  :root {
    --nav-height: 64px;
  }

  .section        { padding-block: var(--space-12); }
  .section--lg    { padding-block: var(--space-20); }
  .section--sm    { padding-block: var(--space-8); }

  .container      { padding-inline: var(--space-4); }

  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: 1fr; }

  .section-header { margin-bottom: var(--space-8); }
}

@media (max-width: 480px) {
  .btn--lg {
    padding: var(--space-3) var(--space-6);
    font-size: var(--text-sm);
  }
}