/* ============================================
   AI Business Trust Score — Design System
   Light/Clean Theme (Stripe/Linear inspired)

   Created:  2026-02-26
   Author:   AI Business Trust Score / jbrenttuttle
   Purpose:  Single source of truth for all public-facing
             pages on aibusinessscore.com. Defines colors,
             typography, spacing, and reusable components
             (navbar, buttons, cards, forms, footer, etc.).
   Usage:    <link rel="stylesheet" href="/css/theme.css">
   Notes:    Dashboard/member area uses its own styles.
             This file covers the public site only.
   ============================================ */

/* --- Tokens --- */
:root {
  /* Colors */
  --color-white: #ffffff;
  --color-bg: #ffffff;
  --color-bg-subtle: #f8fafc;
  --color-bg-muted: #f1f5f9;
  --color-border: #e2e8f0;
  --color-border-strong: #cbd5e1;

  --color-text: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #94a3b8;

  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-primary-light: #eff6ff;
  --color-primary-border: #bfdbfe;

  --color-accent: #0ea5e9;
  --color-success: #16a34a;
  --color-warning: #f59e0b;
  --color-danger: #dc2626;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-display: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;

  --leading-tight: 1.2;
  --leading-snug: 1.35;
  --leading-normal: 1.6;

  --tracking-tight: -0.025em;
  --tracking-normal: 0;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Radius */
  --radius-sm: 6px;
  --radius: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition: 200ms ease;
  --transition-slow: 300ms ease;

  /* Layout */
  --container-max: 1140px;
  --container-narrow: 800px;
}

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

/* --- Base --- */
html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text);
  background: var(--color-bg);
}

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

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

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

ul, ol {
  list-style: none;
}

/* --- Layout --- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.container-narrow {
  max-width: var(--container-narrow);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* --- Navbar --- */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.navbar-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.navbar-brand {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: var(--tracking-tight);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.navbar-brand:hover {
  color: var(--color-text);
}

.navbar-brand .brand-mark {
  width: 28px;
  height: 28px;
  background: var(--color-primary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
  font-size: var(--text-sm);
}

.navbar-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.navbar-nav a {
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: var(--radius);
  transition: all var(--transition-fast);
}

.navbar-nav a:hover {
  color: var(--color-text);
  background: var(--color-bg-subtle);
}

.navbar-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--color-text);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
}

.text-5xl { font-size: var(--text-5xl); }
.text-4xl { font-size: var(--text-4xl); }
.text-3xl { font-size: var(--text-3xl); }
.text-2xl { font-size: var(--text-2xl); }
.text-xl  { font-size: var(--text-xl); }
.text-lg  { font-size: var(--text-lg); }
.text-base { font-size: var(--text-base); }
.text-sm  { font-size: var(--text-sm); }
.text-xs  { font-size: var(--text-xs); }

.text-secondary { color: var(--color-text-secondary); }
.text-muted { color: var(--color-text-muted); }
.text-primary { color: var(--color-primary); }

.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

.leading-snug { line-height: var(--leading-snug); }
.leading-normal { line-height: var(--leading-normal); }

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

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}

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

.btn-secondary {
  background: var(--color-white);
  color: var(--color-text);
  border-color: var(--color-border-strong);
}

.btn-secondary:hover {
  background: var(--color-bg-subtle);
  border-color: var(--color-border-strong);
  color: var(--color-text);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-secondary);
  border-color: transparent;
}

.btn-ghost:hover {
  background: var(--color-bg-subtle);
  color: var(--color-text);
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
  border-radius: var(--radius);
}

.btn-sm {
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-xs);
}

.btn-full {
  width: 100%;
}

/* --- Cards --- */
.card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  box-shadow: var(--shadow-xs);
}

.card-elevated {
  box-shadow: var(--shadow-md);
  border-color: transparent;
}

.card-interactive {
  transition: all var(--transition);
}

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

/* --- Section --- */
.section {
  padding: var(--space-20) 0;
}

.section-alt {
  background: var(--color-bg-subtle);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.section-label {
  display: inline-block;
  padding: var(--space-1) var(--space-3);
  background: var(--color-primary-light);
  color: var(--color-primary);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-4);
}

/* --- Forms --- */
.form-group {
  margin-bottom: var(--space-5);
}

.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.form-input {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  color: var(--color-text);
  background: var(--color-white);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius);
  transition: all var(--transition-fast);
}

.form-input::placeholder {
  color: var(--color-text-muted);
}

.form-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-input-lg {
  padding: var(--space-4) var(--space-5);
  font-size: var(--text-lg);
}

.form-hint {
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: var(--leading-normal);
}

select.form-input {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%2394a3b8' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-4) center;
  padding-right: var(--space-10);
}

textarea.form-input {
  resize: vertical;
  min-height: 100px;
}

/* --- Badges --- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-full);
  line-height: 1.4;
}

.badge-primary {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

.badge-success {
  background: #f0fdf4;
  color: var(--color-success);
}

.badge-warning {
  background: #fffbeb;
  color: var(--color-warning);
}

.badge-danger {
  background: #fef2f2;
  color: var(--color-danger);
}

.badge-neutral {
  background: var(--color-bg-muted);
  color: var(--color-text-secondary);
}

/* --- Divider --- */
.divider {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: var(--space-8) 0;
}

/* --- Feature Grid --- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(1, 1fr);
  gap: var(--space-6);
}

@media (min-width: 640px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 960px) {
  .feature-grid { grid-template-columns: repeat(3, 1fr); }
}

.feature-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-light);
  color: var(--color-primary);
  border-radius: var(--radius);
  font-size: var(--text-lg);
  margin-bottom: var(--space-4);
}

/* --- Footer --- */
.site-footer {
  background: var(--color-text);
  color: rgba(255, 255, 255, 0.7);
  padding: var(--space-16) 0 var(--space-8);
}

.footer-grid {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: var(--space-12);
}

.footer-col h4 {
  color: var(--color-white);
  font-size: var(--text-sm);
  font-weight: 600;
  margin-bottom: var(--space-4);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-col p,
.footer-col a {
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
  color: rgba(255, 255, 255, 0.6);
  text-decoration: none;
}

.footer-col a:hover {
  color: var(--color-white);
}

.footer-links a {
  display: block;
  margin-bottom: var(--space-2);
}

.footer-bottom {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: var(--space-8) var(--space-6) 0;
  margin-top: var(--space-12);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  font-size: var(--text-xs);
  color: rgba(255, 255, 255, 0.4);
}

.footer-bottom a {
  color: rgba(255, 255, 255, 0.4);
  margin: 0 var(--space-2);
}

.footer-bottom a:hover {
  color: rgba(255, 255, 255, 0.7);
}

/* --- Contact toggle (footer) --- */
.contact-toggle {
  cursor: pointer;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.6);
  font-size: var(--text-sm);
}

.contact-toggle::before {
  content: "\25B8  ";
}

.contact-toggle.active::before {
  content: "\25BE  ";
}

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

.contact-form-wrapper {
  display: none;
  margin-top: var(--space-4);
}

.contact-form {
  background: rgba(255, 255, 255, 0.06);
  padding: var(--space-5);
  border-radius: var(--radius);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.contact-form label {
  display: block;
  font-size: var(--text-xs);
  margin-top: var(--space-3);
  margin-bottom: var(--space-1);
  color: rgba(255, 255, 255, 0.7);
}

.contact-form input,
.contact-form select,
.contact-form textarea {
  width: 100%;
  padding: var(--space-2);
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.15);
  background: rgba(255, 255, 255, 0.08);
  color: var(--color-white);
  font-size: var(--text-sm);
  font-family: var(--font-sans);
}

.contact-form select option {
  background: #1e293b;
  color: #fff;
}

.contact-form input:focus,
.contact-form select:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--color-primary);
}

.contact-form textarea {
  resize: vertical;
  min-height: 70px;
}

.contact-form button {
  margin-top: var(--space-4);
  padding: var(--space-3) var(--space-4);
  background: var(--color-primary);
  color: var(--color-white);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: var(--text-sm);
  font-weight: 600;
  font-family: var(--font-sans);
  transition: background var(--transition-fast);
}

.contact-form button:hover {
  background: var(--color-primary-hover);
}

/* --- Utility --- */
.mx-auto { margin-left: auto; margin-right: auto; }
.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); }
.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); }

.max-w-narrow { max-width: var(--container-narrow); }
.max-w-lg { max-width: 640px; }
.max-w-md { max-width: 480px; }

/* --- Mobile Menu --- */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.mobile-menu-btn span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

.nav-open .mobile-menu-btn span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.nav-open .mobile-menu-btn span:nth-child(2) {
  opacity: 0;
}
.nav-open .mobile-menu-btn span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .container,
  .container-narrow {
    padding: 0 var(--space-4);
  }

  .section {
    padding: var(--space-12) 0;
  }

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

  .navbar-inner {
    flex-wrap: wrap;
  }

  .navbar-nav,
  .navbar-actions {
    display: none;
  }

  .nav-open .navbar-nav,
  .nav-open .navbar-actions {
    display: flex;
    flex-direction: column;
    width: 100%;
    padding-top: var(--space-3);
    gap: 0;
  }

  .nav-open .navbar-nav {
    border-top: 1px solid var(--color-border);
    padding-top: var(--space-2);
  }

  .nav-open .navbar-nav a {
    padding: var(--space-3) 0;
    border-bottom: 1px solid var(--color-border);
    border-radius: 0;
  }

  .nav-open .navbar-actions {
    padding-bottom: var(--space-3);
  }

  .nav-open .navbar-actions .btn {
    width: 100%;
    justify-content: center;
  }

  .nav-open .navbar-inner {
    height: auto;
    padding-bottom: 0;
  }

  .mobile-menu-btn {
    display: flex;
  }
}

@media (min-width: 769px) {
  .mobile-menu-btn {
    display: none;
  }
}