/* ============================================
   BVille Budgeting — Design System & Styles
   Single source of truth: DESIGN-SYSTEM.md
   ============================================ */

/* --- Design Tokens --- */
:root {
  /* Brand */
  --color-primary: #1E56A0;
  --color-primary-dark: #163D72;
  --color-primary-light: #E8F1FB;
  --color-accent: #0EA5A1;
  --color-accent-dark: #0B8783;
  --color-accent-light: #E0F7F6;

  /* Categories */
  --color-needs: #1E56A0;
  --color-needs-light: #E8F1FB;
  --color-wants: #D64550;
  --color-wants-light: #FCEAEC;
  --color-goals: #16864D;
  --color-goals-light: #E2F5EA;

  /* Neutrals */
  --color-dark: #111827;
  --color-gray-800: #1F2937;
  --color-gray-600: #4B5563;
  --color-gray-400: #9CA3AF;
  --color-gray-200: #E5E7EB;
  --color-gray-100: #F3F4F6;
  --color-white: #FFFFFF;

  /* Semantic overlays */
  --color-overlay-white: rgba(255, 255, 255, 0.97);
  --color-overlay-accent: rgba(14, 165, 161, 0.08);
  --color-cta-orb: rgba(14, 165, 161, 0.15);
  --color-footer-border: rgba(255, 255, 255, 0.1);
  --color-cta-text: rgba(255, 255, 255, 0.85);

  /* Typography */
  --font-heading: 'Inter', system-ui, -apple-system, sans-serif;
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 5rem;

  /* Sizing */
  --max-width: 1200px;
  --radius-sm: 0.5rem;
  --radius-md: 1rem;
  --radius-lg: 1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 20px 50px rgba(0, 0, 0, 0.15);

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-body);
  color: var(--color-gray-800);
  line-height: 1.7;
  background: var(--color-white);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

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

/* --- Typography --- */
h1, h2, h3, h4 {
  font-family: var(--font-heading);
  color: var(--color-dark);
  line-height: 1.2;
}
h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); font-weight: 800; }
h2 { font-size: clamp(1.8rem, 3.5vw, 2.5rem); font-weight: 700; }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); font-weight: 600; }
p  { font-size: 1.05rem; color: var(--color-gray-600); }

.section-label {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}

.section-title { margin-bottom: var(--space-md); }
.section-subtitle { max-width: 600px; margin: 0 auto var(--space-xl); }

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 0.85rem 2rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--transition-base);
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-white);
}
.btn-primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}
.btn-secondary:hover {
  background: var(--color-primary);
  color: var(--color-white);
  transform: translateY(-2px);
}

.btn-accent {
  background: var(--color-accent);
  color: var(--color-white);
}
.btn-accent:hover {
  background: var(--color-accent-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* --- Navigation --- */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  padding: var(--space-md) 0;
  transition: all var(--transition-base);
  background: transparent;
}

.navbar.scrolled {
  background: var(--color-overlay-white);
  box-shadow: var(--shadow-sm);
  padding: var(--space-sm) 0;
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--color-primary);
}
.nav-logo span { color: var(--color-accent); }

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

.nav-links a {
  font-weight: 500;
  color: var(--color-gray-600);
  transition: color var(--transition-fast);
  font-size: 0.95rem;
}
.nav-links a:hover { color: var(--color-primary); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: var(--space-sm);
}
.nav-toggle span {
  width: 24px;
  height: 2.5px;
  background: var(--color-dark);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

/* --- Hero Section --- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(
    135deg,
    var(--color-primary-light) 0%,
    var(--color-white) 50%,
    var(--color-accent-light) 100%
  );
  padding: calc(var(--space-2xl) + 60px) 0 var(--space-2xl);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 800px;
  height: 800px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--color-overlay-accent) 0%, transparent 70%);
  pointer-events: none;
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: center;
}

.hero-content h1 { margin-bottom: var(--space-md); }
.hero-content h1 .highlight {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-content p {
  font-size: 1.2rem;
  margin-bottom: var(--space-lg);
  max-width: 520px;
}

.hero-cta { display: flex; gap: var(--space-md); flex-wrap: wrap; }

.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

/* --- Budget Card Mockup --- */
.budget-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-xl);
  width: 100%;
  max-width: 380px;
  position: relative;
}

.budget-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-lg);
}
.budget-card-header h4 { font-size: 1rem; color: var(--color-gray-600); }
.budget-card-header .amount { font-size: 1.8rem; font-weight: 800; color: var(--color-dark); }

.budget-bar {
  display: flex;
  height: 12px;
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: var(--space-lg);
  background: var(--color-gray-200);
}
.budget-bar .needs { width: 45%; background: var(--color-needs); }
.budget-bar .wants { width: 30%; background: var(--color-wants); }
.budget-bar .goals { width: 25%; background: var(--color-goals); }

.budget-legend { display: flex; gap: var(--space-md); }
.legend-item {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 0.85rem;
  font-weight: 500;
}

.legend-dot { width: 10px; height: 10px; border-radius: 50%; }
.legend-dot.needs { background: var(--color-needs); }
.legend-dot.wants { background: var(--color-wants); }
.legend-dot.goals { background: var(--color-goals); }

.budget-transactions { margin-top: var(--space-lg); }
.transaction-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--color-gray-200);
}
.transaction-row:last-child { border-bottom: none; }
.transaction-info { display: flex; align-items: center; gap: var(--space-sm); }
.transaction-icon {
  width: 36px; height: 36px;
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  font-size: 1rem;
}
.transaction-icon.needs { background: var(--color-needs-light); }
.transaction-icon.wants { background: var(--color-wants-light); }
.transaction-icon.goals { background: var(--color-goals-light); }
.transaction-name { font-weight: 500; font-size: 0.9rem; }
.transaction-category { font-size: 0.75rem; color: var(--color-gray-400); }
.transaction-amount { font-weight: 600; font-size: 0.95rem; }

/* --- Features Section --- */
.features {
  padding: var(--space-2xl) 0;
  text-align: center;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

.feature-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  padding: var(--space-xl) var(--space-lg);
  text-align: left;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 4px;
}
.feature-card.needs::before { background: var(--color-needs); }
.feature-card.wants::before { background: var(--color-wants); }
.feature-card.goals::before { background: var(--color-goals); }

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.feature-icon {
  width: 56px; height: 56px;
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.6rem;
  margin-bottom: var(--space-md);
}
.feature-card.needs .feature-icon { background: var(--color-needs-light); }
.feature-card.wants .feature-icon { background: var(--color-wants-light); }
.feature-card.goals .feature-icon { background: var(--color-goals-light); }

.feature-card h3 { margin-bottom: var(--space-sm); }
.feature-card p { font-size: 0.95rem; }

/* --- How It Works Section --- */
.how-it-works {
  padding: var(--space-2xl) 0;
  background: var(--color-gray-100);
  text-align: center;
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

.step { padding: var(--space-lg); position: relative; }

.step-number {
  width: 48px; height: 48px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-white);
  display: flex; align-items: center; justify-content: center;
  font-weight: 800;
  font-size: 1.2rem;
  margin: 0 auto var(--space-md);
}

.step h3 { margin-bottom: var(--space-sm); }

/* --- Integrations Section --- */
.integrations {
  padding: var(--space-2xl) 0;
  text-align: center;
}

.integration-logos {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

.integration-logo {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-lg);
  display: flex; align-items: center; gap: var(--space-sm);
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--color-gray-600);
  transition: all var(--transition-base);
}
.integration-logo:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
  color: var(--color-primary);
}
.integration-logo .icon { font-size: 1.5rem; }

/* --- CTA Section --- */
.cta-section {
  padding: var(--space-2xl) 0;
  background: linear-gradient(
    135deg,
    var(--color-primary) 0%,
    var(--color-primary-dark) 100%
  );
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-section::before {
  content: '';
  position: absolute;
  bottom: -40%;
  left: -10%;
  width: 500px; height: 500px;
  border-radius: 50%;
  background: var(--color-cta-orb);
  pointer-events: none;
}
.cta-section h2 { color: var(--color-white); }
.cta-section p {
  color: var(--color-cta-text);
  font-size: 1.15rem;
  margin-bottom: var(--space-lg);
}
.cta-section .section-label { color: var(--color-accent); }

/* --- Footer --- */
.footer {
  padding: var(--space-xl) 0 var(--space-lg);
  background: var(--color-dark);
  color: var(--color-gray-400);
}

.footer .container {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-xl);
}

.footer-brand .nav-logo {
  font-size: 1.3rem;
  margin-bottom: var(--space-md);
  display: inline-block;
}
.footer-brand p { font-size: 0.9rem; line-height: 1.6; }

.footer-col h4 {
  color: var(--color-white);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-md);
}
.footer-col a {
  display: block;
  font-size: 0.9rem;
  padding: var(--space-xs) 0;
  transition: color var(--transition-fast);
}
.footer-col a:hover { color: var(--color-accent); }

.footer-bottom {
  margin-top: var(--space-xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-footer-border);
  text-align: center;
  font-size: 0.85rem;
}

/* ============================================
   Responsive Breakpoints
   ============================================ */

/* Tablet */
@media (max-width: 900px) {
  .hero .container { grid-template-columns: 1fr; text-align: center; }
  .hero-content p { margin: 0 auto var(--space-lg); }
  .hero-cta { justify-content: center; }
  .hero-visual { margin-top: var(--space-lg); }
  .features-grid { grid-template-columns: 1fr 1fr; }
  .steps {
    grid-template-columns: 1fr;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
  }
  .footer .container { grid-template-columns: 1fr 1fr; }
}

/* Mobile */
@media (max-width: 640px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: var(--color-white);
    flex-direction: column;
    padding: var(--space-lg);
    box-shadow: var(--shadow-md);
    gap: var(--space-md);
  }
  .nav-links.active { display: flex; }
  .nav-toggle { display: flex; }
  .features-grid { grid-template-columns: 1fr; }
  .footer .container { grid-template-columns: 1fr; }
  .budget-card { max-width: 320px; }
  .budget-legend { flex-wrap: wrap; }
  .hero-cta .btn { width: 100%; justify-content: center; }
}