/* =========================================
   CSS Variables & Reset
   ========================================= */
:root {
  --bg-color: #FAFAFA;
  --text-main: #1A1A1A;
  --text-muted: #5A5A5A;
  --text-light: #888888;
  --border-light: #E0E0E0;
  
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  
  --container-width: 900px;
  --space-sm: 1rem;
  --space-md: 2.5rem;
  --space-lg: 5rem;
  --space-xl: 8rem;
}

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

body {
  background-color: var(--bg-color);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.65;
  font-size: 1.125rem;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--text-main);
  text-decoration: none;
  transition: opacity 0.2s ease, color 0.2s ease;
}

a:hover {
  opacity: 0.6;
}

/* =========================================
   Typography
   ========================================= */
h1, h2, h3, h4 {
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-sm);
  color: var(--text-main);
}

h1 {
  font-size: 3rem;
  margin-bottom: 1.5rem;
}

h2 {
  font-size: 2rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 0.75rem;
}

h3 {
  font-size: 1.35rem;
}

p {
  margin-bottom: 1.5rem;
  color: var(--text-muted);
}

.intro-text {
  font-size: 1.25rem;
  color: var(--text-main);
  max-width: 750px;
}

/* =========================================
   Layout & Components
   ========================================= */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

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

.hero {
  padding: var(--space-xl) 0 3rem;
}

.hero-sub {
  font-size: 1.5rem;
  color: var(--text-muted);
  max-width: 800px;
  line-height: 1.4;
}

/* Credibility Bridge */
.credibility-bridge {
  padding: 1.5rem 0;
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
  margin-bottom: var(--space-lg);
}

.credibility-bridge p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-light);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Header & Nav */
header {
  padding: 2rem 0;
  border-bottom: 1px solid var(--border-light);
}

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

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.01em;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  font-size: 0.95rem;
  font-weight: 500;
  opacity: 0.7;
  position: relative;
  padding-bottom: 4px;
}

.nav-links a:hover {
  opacity: 1;
}

/* Active Nav State */
.nav-links a.active {
  opacity: 1;
  color: var(--text-main);
}

.nav-links a.active::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  background-color: var(--text-main);
}

/* Mobile Menu Button */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1rem;
  cursor: pointer;
  font-family: var(--font-sans);
  font-weight: 500;
  color: var(--text-main);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.8rem 1.5rem;
  background-color: var(--text-main);
  color: var(--bg-color);
  font-weight: 500;
  font-size: 1rem;
  border-radius: 4px;
  margin-top: 1rem;
  transition: background-color 0.2s ease, opacity 0.2s ease;
}

.btn:hover {
  background-color: var(--text-muted);
  color: var(--bg-color);
  opacity: 1;
}

.btn-outline {
  background-color: transparent;
  color: var(--text-main);
  border: 1px solid var(--text-main);
}

.btn-outline:hover {
  background-color: var(--text-main);
  color: var(--bg-color);
}

/* Grids & Cards */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.card {
  padding: 2.5rem;
  border: 1px solid var(--border-light);
  background: #FFFFFF;
  display: flex;
  flex-direction: column;
}

.card h3 {
  margin-bottom: 1rem;
}

.card p {
  margin-bottom: 0;
  font-size: 1rem;
}

/* Trust Section */
.trust-block {
  background-color: #FFFFFF;
  border: 1px solid var(--border-light);
  padding: 3rem;
  margin-top: 2rem;
}

.trust-block h3 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
}

/* Footer */
footer {
  padding: 3rem 0;
  margin-top: var(--space-lg);
  border-top: 1px solid var(--border-light);
  text-align: left;
  font-size: 0.9rem;
  color: var(--text-muted);
}

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

/* =========================================
   Responsive Design
   ========================================= */
@media (max-width: 768px) {
  h1 { font-size: 2.25rem; }
  h2 { font-size: 1.75rem; }
  .hero-sub { font-size: 1.25rem; }
  
  .menu-toggle {
    display: block;
  }
  
  .nav-links {
    display: none;
    flex-direction: column;
    width: 100%;
    position: absolute;
    top: 80px;
    left: 0;
    background-color: var(--bg-color);
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-light);
    gap: 1.5rem;
    z-index: 100;
  }
  
  .nav-links.active {
    display: flex;
  }

  .nav-links a.active::after {
    display: none;
  }
  
  .footer-content {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }
  
  .trust-block {
    padding: 2rem;
  }
}