/**
 * Practical Super Intelligence — Core Stylesheet (main.css)
 * 
 * Aesthetic: Restrained, modern B2B software platform.
 * Palette: Deep evergreen accents, slate neutrals, warm off-white surfaces.
 * Standard: WCAG 2.2 AA target compliance, zero external fonts/CDNs.
 */

/* ==========================================================================
   1. CSS RESET & ACCESSIBLE FOUNDATION
   ========================================================================== */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  line-height: 1.5;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--color-slate-900);
  background-color: var(--color-slate-50);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ==========================================================================
   2. DESIGN TOKENS (CSS CUSTOM PROPERTIES)
   ========================================================================== */

:root {
  /* Brand / Evergreen Primary */
  --color-brand-950: #022c22;
  --color-brand-900: #064e3b; /* Contrast > 7:1 against white */
  --color-brand-800: #065f46;
  --color-brand-700: #047857; /* Primary CTA */
  --color-brand-600: #059669; /* Interactive hover / focus */
  --color-brand-500: #10b981;
  --color-brand-200: #a7f3d0;
  --color-brand-100: #d1fae5; /* Light tint border */
  --color-brand-50:  #ecfdf5; /* Surface badge background */

  /* Neutral Slate Foundation */
  --color-slate-950: #090d16; /* Primary dark heading text */
  --color-slate-900: #0f172a; /* Body text (Contrast > 12:1 against white) */
  --color-slate-800: #1e293b;
  --color-slate-700: #334155; /* Secondary text (Contrast > 7:1) */
  --color-slate-600: #475569; /* Supporting metadata */
  --color-slate-400: #94a3b8; /* Muted placeholder */
  --color-slate-300: #cbd5e1; /* Borders & input outlines */
  --color-slate-200: #e2e8f0; /* Card borders & dividers */
  --color-slate-100: #f1f5f9; /* Surface tint */
  --color-slate-50:  #f8fafc; /* Base page background */
  --color-white:     #ffffff;

  /* Feedback & Safety Overrides */
  --color-status-success:        #047857;
  --color-status-success-bg:     #ecfdf5;
  --color-status-success-border: #a7f3d0;

  --color-status-warning:        #b45309;
  --color-status-warning-bg:     #fffbeb;
  --color-status-warning-border: #fde68a;

  --color-status-danger:         #b91c1c;
  --color-status-danger-bg:      #fef2f2;
  --color-status-danger-border:  #fecaca;

  /* Typography Stacks */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;

  /* Spacing Scale (4px / 8px baseline) */
  --space-1: 0.25rem;  /* 4px */
  --space-2: 0.5rem;   /* 8px */
  --space-3: 0.75rem;  /* 12px */
  --space-4: 1.0rem;   /* 16px */
  --space-5: 1.25rem;  /* 20px */
  --space-6: 1.5rem;   /* 24px */
  --space-8: 2.0rem;   /* 32px */
  --space-10: 2.5rem;  /* 40px */
  --space-12: 3.0rem;  /* 48px */
  --space-16: 4.0rem;  /* 64px */
  --space-20: 5.0rem;  /* 80px */

  /* Border Radii */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Elevation Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);

  /* Accessible Focus Rings */
  --focus-ring: 0 0 0 3px rgba(5, 150, 105, 0.4);
  --focus-ring-danger: 0 0 0 3px rgba(220, 38, 38, 0.4);

  /* Layout */
  --container-max: 1120px;
  --container-narrow: 800px;
}

/* ==========================================================================
   3. TYPOGRAPHY
   ========================================================================== */

h1, h2, h3, h4, h5, h6 {
  color: var(--color-slate-950);
  font-family: var(--font-sans);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(2.0rem, 4vw, 2.75rem); margin-bottom: var(--space-4); }
h2 { font-size: clamp(1.5rem, 3vw, 2.0rem); margin-bottom: var(--space-4); }
h3 { font-size: clamp(1.2rem, 2vw, 1.4rem); margin-bottom: var(--space-3); }
h4 { font-size: 1.125rem; font-weight: 600; margin-bottom: var(--space-2); }

p {
  color: var(--color-slate-700);
  font-size: 1.0rem;
  line-height: 1.65;
  margin-bottom: var(--space-4);
}

p.lead {
  font-size: 1.1875rem;
  line-height: 1.6;
  color: var(--color-slate-800);
}

a {
  color: var(--color-brand-700);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--color-brand-800);
}

a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
  border-radius: var(--radius-sm);
}

code, pre {
  font-family: var(--font-mono);
  font-size: 0.9em;
}

code {
  background-color: var(--color-slate-100);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
  color: var(--color-brand-900);
  border: 1px solid var(--color-slate-200);
}

/* ==========================================================================
   4. LAYOUT & CONTAINERS
   ========================================================================== */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-4);
  padding-right: var(--space-4);
}

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

.section {
  padding-top: var(--space-12);
  padding-bottom: var(--space-12);
}

.section-muted {
  background-color: var(--color-slate-100);
  border-top: 1px solid var(--color-slate-200);
  border-bottom: 1px solid var(--color-slate-200);
}

.grid {
  display: grid;
  gap: var(--space-6);
}

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

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

@media (min-width: 768px) {
  .grid-2 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
}

/* ==========================================================================
   5. BUTTONS & INTERACTIVE ELEMENTS
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-sans);
  font-size: 1.0rem;
  font-weight: 600;
  line-height: 1.25;
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.15s ease-in-out;
  text-align: center;
}

.btn-primary {
  background-color: var(--color-brand-700);
  color: var(--color-white) !important;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background-color: var(--color-brand-800);
  color: var(--color-white) !important;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: var(--color-white);
  color: var(--color-slate-800) !important;
  border-color: var(--color-slate-300);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background-color: var(--color-slate-50);
  border-color: var(--color-slate-400);
  color: var(--color-slate-900) !important;
}

.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: 0.875rem;
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: 1.125rem;
}

/* ==========================================================================
   6. CARDS, BADGES & PANELS
   ========================================================================== */

.card {
  background-color: var(--color-white);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
}

.card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-slate-300);
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.badge-emerald {
  background-color: var(--color-status-success-bg);
  color: var(--color-status-success);
  border: 1px solid var(--color-status-success-border);
}

.badge-amber {
  background-color: var(--color-status-warning-bg);
  color: var(--color-status-warning);
  border: 1px solid var(--color-status-warning-border);
}

.badge-red {
  background-color: var(--color-status-danger-bg);
  color: var(--color-status-danger);
  border: 1px solid var(--color-status-danger-border);
}

/* ==========================================================================
   7. FORM CONTROLS & RADIO TILES
   ========================================================================== */

.form-group {
  margin-bottom: var(--space-6);
}

.form-label {
  display: block;
  font-size: 1.0rem;
  font-weight: 600;
  color: var(--color-slate-900);
  margin-bottom: var(--space-2);
}

.form-helper {
  font-size: 0.875rem;
  color: var(--color-slate-600);
  margin-bottom: var(--space-3);
}

.form-control {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: 1.0rem;
  font-family: var(--font-sans);
  color: var(--color-slate-900);
  background-color: var(--color-white);
  border: 1px solid var(--color-slate-300);
  border-radius: var(--radius-md);
  transition: border-color 0.15s ease;
}

.form-control:focus {
  border-color: var(--color-brand-600);
  box-shadow: var(--focus-ring);
  outline: none;
}

/* Radio Selection Tiles */
.radio-tile-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.radio-tile {
  display: flex;
  align-items: flex-start;
  padding: var(--space-4);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-md);
  background-color: var(--color-white);
  cursor: pointer;
  transition: all 0.15s ease;
}

.radio-tile:hover {
  border-color: var(--color-brand-600);
  background-color: var(--color-brand-50);
}

.radio-tile input[type="radio"] {
  margin-top: 0.25rem;
  margin-right: var(--space-3);
  accent-color: var(--color-brand-700);
  width: 1.125rem;
  height: 1.125rem;
}

.radio-tile-content strong {
  display: block;
  color: var(--color-slate-900);
  font-size: 0.9375rem;
  margin-bottom: 0.15rem;
}

.radio-tile-content span {
  font-size: 0.875rem;
  color: var(--color-slate-600);
  line-height: 1.4;
}

/* ==========================================================================
   8. SITE HEADER & NAVIGATION
   ========================================================================== */

.site-header {
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-slate-200);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.5rem;
}

.brand-link {
  display: flex;
  flex-direction: column;
  text-decoration: none;
}

.brand-name {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-slate-950);
  letter-spacing: -0.01em;
}

.brand-tagline {
  font-size: 0.75rem;
  color: var(--color-slate-500);
  font-weight: 500;
}

.site-nav ul {
  display: flex;
  list-style: none;
  gap: var(--space-6);
  align-items: center;
}

.site-nav a {
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-slate-700);
}

.site-nav a:hover, .site-nav a.active {
  color: var(--color-brand-700);
}

/* ==========================================================================
   9. SITE FOOTER
   ========================================================================== */

.site-footer {
  margin-top: auto;
  background-color: var(--color-white);
  border-top: 1px solid var(--color-slate-200);
  padding-top: var(--space-12);
  padding-bottom: var(--space-8);
  font-size: 0.875rem;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

@media (min-width: 768px) {
  .footer-inner {
    flex-direction: row;
    justify-content: space-between;
  }
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-6);
  list-style: none;
}

.footer-nav a {
  color: var(--color-slate-600);
  text-decoration: none;
}

.footer-nav a:hover {
  color: var(--color-slate-900);
  text-decoration: underline;
}

.footer-disclaimer {
  font-size: 0.8125rem;
  color: var(--color-slate-500);
  line-height: 1.5;
  border-top: 1px solid var(--color-slate-200);
  padding-top: var(--space-6);
}

/* ==========================================================================
   10. ACCESSIBILITY UTILITIES
   ========================================================================== */

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

.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-brand-800);
  color: var(--color-white);
  padding: var(--space-2) var(--space-4);
  z-index: 1000;
  text-decoration: none;
}

.skip-link:focus {
  top: 0;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ==========================================================================
   11. EXTENDED COMPONENTS (HERO, STAGES, PREVIEWS, TABLES)
   ========================================================================== */

/* Hero Section */
.hero {
  padding-top: var(--space-16);
  padding-bottom: var(--space-12);
  text-align: center;
}

.hero .lead {
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
  margin-bottom: var(--space-8);
  font-size: 1.25rem;
  color: var(--color-slate-700);
}

.hero-actions {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  justify-content: center;
  align-items: center;
  margin-bottom: var(--space-8);
}

@media (min-width: 640px) {
  .hero-actions {
    flex-direction: row;
  }
}

.trust-bar {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-6);
  padding-top: var(--space-4);
  font-size: 0.875rem;
  color: var(--color-slate-600);
}

.trust-item {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.trust-item svg {
  color: var(--color-brand-700);
  flex-shrink: 0;
}

/* Stage Progress Bar (for Assessment) */
.stage-progress {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-2);
  margin-bottom: var(--space-8);
}

.stage-step {
  text-align: center;
  padding: var(--space-3) var(--space-2);
  background-color: var(--color-white);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-md);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-slate-600);
  transition: all 0.2s ease;
}

.stage-step.active {
  background-color: var(--color-brand-50);
  border-color: var(--color-brand-600);
  color: var(--color-brand-900);
  box-shadow: 0 0 0 1px var(--color-brand-600);
}

.stage-step.completed {
  background-color: var(--color-slate-100);
  border-color: var(--color-slate-300);
  color: var(--color-slate-800);
}

.stage-step .step-num {
  display: block;
  font-size: 0.75rem;
  color: var(--color-slate-500);
  text-transform: uppercase;
  margin-bottom: 0.2rem;
}

.stage-step.active .step-num {
  color: var(--color-brand-700);
}

.stage-step .step-label {
  display: block;
}

@media (max-width: 480px) {
  .stage-progress {
    gap: var(--space-1);
  }
  .stage-step {
    padding: var(--space-2) 2px;
  }
  .stage-step .step-num {
    margin-bottom: 0;
    font-size: 0.75rem;
    font-weight: 700;
  }
  .stage-step .step-label {
    display: none;
  }
}

/* Preset Pills */
.preset-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.preset-pill {
  background: var(--color-slate-100);
  border: 1px solid var(--color-slate-300);
  border-radius: var(--radius-full);
  padding: 0.35rem 0.85rem;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-slate-700);
  cursor: pointer;
  transition: all 0.15s ease;
}

.preset-pill:hover {
  background: var(--color-brand-50);
  border-color: var(--color-brand-600);
  color: var(--color-brand-900);
}

/* Pre-Functionality Status Notice (for Assessment) */
.status-callout {
  padding: var(--space-4);
  background-color: var(--color-slate-100);
  border: 1px solid var(--color-slate-300);
  border-left: 4px solid var(--color-brand-700);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-8);
  font-size: 0.9375rem;
  color: var(--color-slate-800);
}

.status-callout strong {
  display: block;
  margin-bottom: 0.25rem;
  color: var(--color-slate-950);
}

/* Diagnostic Result Banners */
.result-banner {
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  border: 2px solid;
  margin-bottom: var(--space-8);
}

.result-banner-success {
  background-color: var(--color-status-success-bg);
  border-color: var(--color-status-success-border);
}

.result-banner-warning {
  background-color: var(--color-status-warning-bg);
  border-color: var(--color-status-warning-border);
}

.result-banner-danger {
  background-color: var(--color-status-danger-bg);
  border-color: var(--color-status-danger-border);
}

/* Interface Preview Windows */
.preview-window {
  background: var(--color-white);
  border: 1px solid var(--color-slate-300);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  margin-top: var(--space-6);
  margin-bottom: var(--space-8);
}

.preview-bar {
  background: var(--color-slate-100);
  border-bottom: 1px solid var(--color-slate-200);
  padding: var(--space-2) var(--space-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8125rem;
  font-family: var(--font-mono);
  color: var(--color-slate-600);
}

.preview-dots {
  display: flex;
  gap: 6px;
}

.preview-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-slate-300);
}

.preview-body {
  padding: var(--space-6);
  overflow-x: auto;
}

/* Data Tables */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
  text-align: left;
}

.data-table th, .data-table td {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-slate-200);
}

.data-table th {
  background: var(--color-slate-50);
  font-weight: 600;
  color: var(--color-slate-900);
  border-top: 1px solid var(--color-slate-200);
}

.data-table tbody tr:hover {
  background-color: var(--color-slate-50);
}

/* Deliverable Item Cards */
.deliverable-card {
  background: var(--color-white);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-md);
  padding: var(--space-5);
  display: flex;
  gap: var(--space-4);
  align-items: flex-start;
  transition: all 0.2s ease;
}

.deliverable-card:hover {
  border-color: var(--color-brand-600);
  box-shadow: var(--shadow-sm);
}

.deliverable-icon {
  width: 2.5rem;
  height: 2.5rem;
  background: var(--color-brand-50);
  color: var(--color-brand-800);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.deliverable-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-brand-700);
}

/* Mobile Nav Toggle */
.mobile-nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--color-slate-300);
  border-radius: var(--radius-md);
  padding: var(--space-2);
  color: var(--color-slate-800);
  cursor: pointer;
}

@media (min-width: 768px) {
  .mobile-nav-toggle {
    display: none;
  }
}

@media (max-width: 767px) {
  .site-nav {
    display: none;
    position: absolute;
    top: 4.5rem;
    left: 0;
    right: 0;
    background: var(--color-white);
    border-bottom: 1px solid var(--color-slate-200);
    padding: var(--space-4);
    box-shadow: var(--shadow-lg);
  }

  .site-nav.is-open {
    display: block;
  }

  .site-nav ul {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-4);
  }
}