/* =========================================================
   FLEXIBLE BUSINESS SYSTEMS, INC.
   Design System — Core Tokens, Base, Typography, Components
   ========================================================= */

/* -----------------------------
   1. DESIGN TOKENS
   ----------------------------- */
:root {
  /* Color — deep navy / near-black technical palette */
  --c-navy-950: #060a13;
  --c-navy-900: #0b1120;
  --c-navy-800: #10182c;
  --c-navy-700: #17233d;
  --c-navy-600: #223257;
  --c-blue-500: #2e6ff2;   /* primary electric blue accent */
  --c-blue-400: #5b8bff;
  --c-cyan-400: #4fd6e8;   /* secondary accent — data/flow */
  --c-white: #ffffff;
  --c-gray-100: #f3f5f9;
  --c-gray-200: #e4e8f0;
  --c-gray-400: #9aa5b8;
  --c-gray-500: #6b7690;
  --c-gray-700: #3b4560;
  --c-success: #29c58a;
  --c-warn: #e8a94f;

  /* Surfaces */
  --surface-page: var(--c-white);
  --surface-dark: var(--c-navy-950);
  --surface-dark-alt: var(--c-navy-900);
  --surface-card: var(--c-white);
  --surface-line: var(--c-gray-200);
  --surface-line-dark: rgba(255, 255, 255, 0.12);

  /* Text */
  --text-primary: var(--c-navy-950);
  --text-secondary: var(--c-gray-500);
  --text-on-dark: var(--c-white);
  --text-on-dark-secondary: #aab4cc;
  --text-accent: var(--c-blue-500);

  /* Typography */
  --font-display: 'Space Grotesk', 'Arial Narrow', Arial, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'IBM Plex Mono', 'SFMono-Regular', Consolas, monospace;

  --fs-2xl: clamp(2.5rem, 4.5vw + 1rem, 5rem);
  --fs-xl: clamp(2rem, 3vw + 1rem, 3.25rem);
  --fs-lg: clamp(1.5rem, 1.6vw + 1rem, 2.25rem);
  --fs-md: clamp(1.15rem, 0.6vw + 1rem, 1.4rem);
  --fs-base: 1.0625rem;
  --fs-sm: 0.9375rem;
  --fs-xs: 0.8125rem;
  --fs-mono: 0.8125rem;

  --lh-tight: 1.08;
  --lh-snug: 1.3;
  --lh-body: 1.65;

  /* Spacing scale */
  --sp-1: 0.25rem;
  --sp-2: 0.5rem;
  --sp-3: 0.75rem;
  --sp-4: 1rem;
  --sp-5: 1.5rem;
  --sp-6: 2rem;
  --sp-7: 3rem;
  --sp-8: 4.5rem;
  --sp-9: 6.5rem;
  --sp-10: 9rem;

  /* Layout */
  --container-max: 1280px;
  --container-pad: clamp(1.25rem, 4vw, 3rem);
  --radius-sm: 2px;
  --radius-md: 4px;
  --border-w: 1px;

  /* Motion */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --dur-fast: 160ms;
  --dur-med: 420ms;
  --dur-slow: 900ms;
}

/* -----------------------------
   2. RESET / BASE
   ----------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

body, h1, h2, h3, h4, p, figure, blockquote, dl, dd, ul, ol {
  margin: 0;
}

body {
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: var(--lh-body);
  color: var(--text-primary);
  background: var(--surface-page);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul[class], ol[class] { list-style: none; padding: 0; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
input, select, textarea { font: inherit; color: inherit; }

:focus-visible {
  outline: 2px solid var(--c-blue-400);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--c-navy-950);
  color: var(--c-white);
  padding: var(--sp-3) var(--sp-4);
  z-index: 1000;
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
}
.skip-link:focus {
  left: var(--sp-4);
  top: var(--sp-4);
}

/* -----------------------------
   3. TYPOGRAPHY
   ----------------------------- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: var(--lh-tight);
  letter-spacing: -0.01em;
  color: var(--text-primary);
}
h1 { font-size: var(--fs-2xl); }
h2 { font-size: var(--fs-xl); }
h3 { font-size: var(--fs-lg); }
h4 { font-size: var(--fs-md); font-weight: 600; }

p { color: var(--text-secondary); }
p.lead { font-size: var(--fs-md); color: var(--text-secondary); line-height: var(--lh-snug); }

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

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-accent);
  margin-bottom: var(--sp-3);
}
.eyebrow::before {
  content: '';
  width: 18px;
  height: var(--border-w);
  background: currentColor;
}
.on-dark .eyebrow { color: var(--c-cyan-400); }

/* -----------------------------
   4. LAYOUT PRIMITIVES
   ----------------------------- */
.container {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-pad);
}

.section {
  padding-block: var(--sp-9);
}
.section--tight { padding-block: var(--sp-8); }
.section--dark {
  background: var(--surface-dark);
  color: var(--text-on-dark);
}
.section--alt {
  background: var(--c-gray-100);
}
.section-head {
  max-width: 62ch;
  margin-bottom: var(--sp-7);
}
.section-head--center { margin-inline: auto; text-align: center; }

.grid {
  display: grid;
  gap: var(--sp-6);
}
.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }
.grid--12 { grid-template-columns: repeat(12, 1fr); }

.divider {
  border: 0;
  border-top: var(--border-w) solid var(--surface-line);
}
.on-dark .divider, .divider--dark { border-top-color: var(--surface-line-dark); }

/* -----------------------------
   5. BUTTONS
   ----------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  letter-spacing: 0.02em;
  padding: var(--sp-3) var(--sp-5);
  border: var(--border-w) solid transparent;
  border-radius: var(--radius-sm);
  transition: background var(--dur-fast) var(--ease-out), border-color var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out), transform var(--dur-fast) var(--ease-out);
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }

.btn--primary {
  background: var(--c-blue-500);
  color: var(--c-white);
  border-color: var(--c-blue-500);
}
.btn--primary:hover { background: var(--c-blue-400); border-color: var(--c-blue-400); }

.btn--outline {
  background: transparent;
  color: var(--text-on-dark);
  border-color: var(--surface-line-dark);
}
.btn--outline:hover { border-color: var(--c-cyan-400); color: var(--c-cyan-400); }

.btn--outline-light {
  background: transparent;
  color: var(--text-primary);
  border-color: var(--surface-line);
}
.btn--outline-light:hover { border-color: var(--c-blue-500); color: var(--c-blue-500); }

.btn--ghost {
  color: var(--text-accent);
  padding-inline: 0;
}
.btn--ghost::after { content: '→'; transition: transform var(--dur-fast) var(--ease-out); }
.btn--ghost:hover::after { transform: translateX(3px); }

/* -----------------------------
   6. HEADER / NAV
   ----------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 500;
  background: rgba(6, 10, 19, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: var(--border-w) solid var(--surface-line-dark);
}
.header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-5);
  padding-block: var(--sp-4);
}
.brand {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--c-white);
  letter-spacing: -0.01em;
}
.brand .brand-mark { color: var(--c-blue-400); }
.brand small {
  display: block;
  font-family: var(--font-mono);
  font-weight: 400;
  font-size: 0.62rem;
  letter-spacing: 0.14em;
  color: var(--text-on-dark-secondary);
  text-transform: uppercase;
}

.primary-nav { display: flex; }
.primary-nav ul { display: flex; align-items: center; gap: var(--sp-6); }
.primary-nav a {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  color: var(--text-on-dark-secondary);
  padding-block: var(--sp-2);
  position: relative;
}
.primary-nav a:hover, .primary-nav a[aria-current="page"] { color: var(--c-white); }
.primary-nav a[aria-current="page"]::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: -3px;
  height: 2px;
  background: var(--c-blue-400);
}
.has-submenu { position: relative; }
.submenu {
  position: absolute;
  top: calc(100% + var(--sp-4));
  left: -1.25rem;
  min-width: 240px;
  background: var(--c-navy-900);
  border: var(--border-w) solid var(--surface-line-dark);
  border-radius: var(--radius-md);
  padding: var(--sp-3);
  display: grid;
  gap: var(--sp-1);
  opacity: 0;
  visibility: hidden;
  transform: translateY(4px);
  transition: opacity var(--dur-fast) var(--ease-out), transform var(--dur-fast) var(--ease-out), visibility var(--dur-fast);
}
.has-submenu:hover .submenu,
.has-submenu:focus-within .submenu {
  opacity: 1; visibility: visible; transform: translateY(0);
}
.submenu a {
  padding: var(--sp-2) var(--sp-3);
  border-radius: var(--radius-sm);
  display: block;
}
.submenu a:hover { background: rgba(255,255,255,0.06); }

.header-cta { display: flex; align-items: center; gap: var(--sp-4); }
.header-phone {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-on-dark-secondary);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: var(--sp-2);
}
.nav-toggle span {
  width: 22px; height: 2px; background: var(--c-white);
  transition: transform var(--dur-fast) var(--ease-out), opacity var(--dur-fast) var(--ease-out);
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* -----------------------------
   7. HERO
   ----------------------------- */
.hero {
  background: var(--surface-dark);
  color: var(--text-on-dark);
  position: relative;
  overflow: hidden;
  border-bottom: var(--border-w) solid var(--surface-line-dark);
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--surface-line-dark) 1px, transparent 1px),
    linear-gradient(90deg, var(--surface-line-dark) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse at 70% 30%, black 0%, transparent 70%);
  opacity: 0.5;
  pointer-events: none;
}
.hero-inner {
  position: relative;
  padding-block: var(--sp-10) var(--sp-9);
  display: grid;
  gap: var(--sp-7);
}
.hero h1 { max-width: 16ch; }
.hero .lead { max-width: 52ch; margin-top: var(--sp-5); }
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-4);
  margin-top: var(--sp-6);
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-7);
  margin-top: var(--sp-8);
  padding-top: var(--sp-6);
  border-top: var(--border-w) solid var(--surface-line-dark);
  font-family: var(--font-mono);
}
.hero-meta dt { font-size: var(--fs-xs); color: var(--text-on-dark-secondary); text-transform: uppercase; letter-spacing: 0.08em; }
.hero-meta dd { font-size: 0.95rem; color: var(--c-white); margin-top: var(--sp-1); }

/* Page header for interior pages */
.page-header {
  background: var(--surface-dark);
  color: var(--text-on-dark);
  padding-block: var(--sp-8) var(--sp-7);
  border-bottom: var(--border-w) solid var(--surface-line-dark);
}
.page-header h1 { max-width: 22ch; }
.page-header .lead { max-width: 60ch; margin-top: var(--sp-4); }
.breadcrumb {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--text-on-dark-secondary);
  display: flex;
  gap: var(--sp-2);
  margin-bottom: var(--sp-5);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.breadcrumb a:hover { color: var(--c-white); }

/* -----------------------------
   8. CARDS
   ----------------------------- */
.card {
  background: var(--surface-card);
  border: var(--border-w) solid var(--surface-line);
  border-radius: var(--radius-md);
  padding: var(--sp-6);
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  transition: border-color var(--dur-fast) var(--ease-out), transform var(--dur-fast) var(--ease-out);
}
.card:hover { border-color: var(--c-blue-500); }
.card .card-index {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--text-accent);
}
.card h3 { font-size: 1.25rem; }
.card p { font-size: var(--fs-sm); }
.card-link {
  margin-top: auto;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--text-accent);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.card--dark {
  background: var(--c-navy-900);
  border-color: var(--surface-line-dark);
  color: var(--text-on-dark);
}
.card--dark p { color: var(--text-on-dark-secondary); }
.card--dark:hover { border-color: var(--c-cyan-400); }

/* Solution / Industry index cards */
.solution-grid { grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }

/* -----------------------------
   9. FLOW / PROCESS LIST (used for stage sequences)
   ----------------------------- */
.flow-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-3);
  align-items: center;
  font-family: var(--font-mono);
}
.flow-list li {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
}
.flow-node {
  border: var(--border-w) solid var(--surface-line);
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
  background: var(--surface-page);
}
.on-dark .flow-node { border-color: var(--surface-line-dark); color: var(--text-on-dark); background: transparent; }
.flow-arrow { color: var(--text-accent); font-size: 1rem; }

/* -----------------------------
   10. TABLE
   ----------------------------- */
.data-table { width: 100%; border-collapse: collapse; font-size: var(--fs-sm); }
.data-table th, .data-table td {
  text-align: left;
  padding: var(--sp-3) var(--sp-4);
  border-bottom: var(--border-w) solid var(--surface-line);
}
.data-table th {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
}
.table-scroll { overflow-x: auto; }

/* -----------------------------
   11. FORMS
   ----------------------------- */
.form-grid { display: grid; gap: var(--sp-5); grid-template-columns: repeat(2, 1fr); }
.field { display: flex; flex-direction: column; gap: var(--sp-2); }
.field--full { grid-column: 1 / -1; }
.field label {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
}
.field input, .field select, .field textarea {
  border: var(--border-w) solid var(--surface-line);
  border-radius: var(--radius-sm);
  padding: var(--sp-3) var(--sp-4);
  font-size: var(--fs-base);
  background: var(--surface-page);
  color: var(--text-primary);
  transition: border-color var(--dur-fast) var(--ease-out);
}
.field input:focus, .field select:focus, .field textarea:focus {
  border-color: var(--c-blue-500);
}
.field textarea { resize: vertical; min-height: 140px; }
.field.has-error input, .field.has-error select, .field.has-error textarea {
  border-color: #d64545;
}
.field-error {
  font-size: var(--fs-xs);
  color: #d64545;
  display: none;
}
.field.has-error .field-error { display: block; }
.form-status {
  margin-top: var(--sp-5);
  padding: var(--sp-4) var(--sp-5);
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
  display: none;
}
.form-status.is-visible { display: block; }
.form-status.is-success { background: rgba(41, 197, 138, 0.12); color: #0f7a53; border: var(--border-w) solid rgba(41,197,138,0.4); }
.form-status.is-error { background: rgba(214, 69, 69, 0.1); color: #b23a3a; border: var(--border-w) solid rgba(214,69,69,0.35); }

/* -----------------------------
   12. FOOTER
   ----------------------------- */
.site-footer {
  background: var(--surface-dark);
  color: var(--text-on-dark-secondary);
  padding-block: var(--sp-8) var(--sp-6);
  font-size: var(--fs-sm);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: var(--sp-7);
  padding-bottom: var(--sp-7);
}
.footer-grid h4 {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--c-white);
  margin-bottom: var(--sp-4);
}
.footer-grid ul { display: grid; gap: var(--sp-2); }
.footer-grid a:hover { color: var(--c-white); }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--sp-3);
  padding-top: var(--sp-6);
  border-top: var(--border-w) solid var(--surface-line-dark);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
}
.footer-bottom ul { display: flex; gap: var(--sp-5); }

/* -----------------------------
   13. UTILITIES
   ----------------------------- */
.mt-0 { margin-top: 0; }
.text-center { text-align: center; }
.visually-hidden {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}
.stat {
  font-family: var(--font-display);
  font-size: 2.25rem;
  color: var(--c-blue-500);
}
.on-dark .stat { color: var(--c-cyan-400); }
.stat-label {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.on-dark .stat-label { color: var(--text-on-dark-secondary); }

/* Accordion (Support / FAQ) */
.accordion-item p { display: none; }
.accordion-item.is-open p { display: block; }
.accordion-trigger { cursor: pointer; text-align: left; }
.accordion-trigger[aria-expanded="true"] span[aria-hidden] { transform: rotate(45deg); display: inline-block; }
.accordion-trigger span[aria-hidden] { transition: transform var(--dur-fast) var(--ease-out); display: inline-block; color: var(--text-accent); }

.tag-list { display: flex; flex-wrap: wrap; gap: var(--sp-2); }
.tag {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  padding: var(--sp-1) var(--sp-3);
  border: var(--border-w) solid var(--surface-line);
  border-radius: 999px;
  color: var(--text-secondary);
}
.on-dark .tag { border-color: var(--surface-line-dark); color: var(--text-on-dark-secondary); }