/* Rivermark Coating — Styles */
/* Colors: white #ffffff, text #000000, accent #64b4fa, surface #1a1a1a, muted #5a5a5a, border #dbdbdb */

:root {
  --color-white: #ffffff;
  --color-text: #000000;
  --color-accent: #64b4fa;
  --color-surface: #1a1a1a;
  --color-muted: #5a5a5a;
  --color-border: #dbdbdb;
  --color-gray: #505050;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --max-width: 1120px;
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --spacing-3xl: 64px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --transition: 0.2s ease;
}

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

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

body {
  font-family: var(--font-family);
  color: var(--color-text);
  background: var(--color-white);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  font-weight: 600;
  font-size: 0.9375rem;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-md);
  transition: all var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--color-surface);
  color: var(--color-white);
  border: 2px solid var(--color-surface);
}

.btn-primary:hover,
.btn-primary:focus {
  background: #000000;
  border-color: #000000;
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--color-white);
  color: var(--color-surface);
  border: 2px solid var(--color-surface);
}

.btn-secondary:hover,
.btn-secondary:focus {
  background: var(--color-surface);
  color: var(--color-white);
}

.btn-outline {
  background: transparent;
  color: var(--color-surface);
  border: 2px solid var(--color-border);
}

.btn-outline:hover,
.btn-outline:focus {
  border-color: var(--color-surface);
  color: var(--color-surface);
}

.btn-lg {
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: 1rem;
}

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

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  text-decoration: none;
}

.logo-mark {
  width: 36px;
  height: 36px;
  color: var(--color-surface);
  flex-shrink: 0;
}

.logo-text {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.logo-river {
  color: var(--color-surface);
}

.logo-mark-text {
  color: var(--color-accent);
}

.logo-suffix {
  font-size: 0.625rem;
  font-weight: 600;
  color: var(--color-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-top: 2px;
}

.nav-cta {
  display: none;
}

/* Hero */
.hero {
  padding: var(--spacing-3xl) 0 var(--spacing-2xl);
  text-align: center;
}

.hero-badge {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: var(--spacing-md);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.hero h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: var(--spacing-lg);
  color: var(--color-surface);
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--color-muted);
  max-width: 680px;
  margin: 0 auto var(--spacing-2xl);
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  justify-content: center;
}

/* Sections */
.section-kicker {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--spacing-sm);
}

section h2 {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--color-surface);
  margin-bottom: var(--spacing-2xl);
}

/* Services */
.services {
  padding: var(--spacing-3xl) 0;
  background: #fafafa;
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
}

.service-card {
  background: var(--color-white);
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: all var(--transition);
}

.service-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.08);
}

.service-icon {
  width: 48px;
  height: 48px;
  color: var(--color-accent);
  margin-bottom: var(--spacing-md);
}

.service-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-surface);
  margin-bottom: var(--spacing-sm);
}

.service-card p {
  font-size: 0.9375rem;
  color: var(--color-muted);
  line-height: 1.6;
}

/* Why */
.why {
  padding: var(--spacing-3xl) 0;
}

.why-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
}

.why-card {
  text-align: center;
  padding: var(--spacing-xl);
}

.why-icon {
  width: 56px;
  height: 56px;
  color: var(--color-accent);
  margin: 0 auto var(--spacing-md);
}

.why-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-surface);
  margin-bottom: var(--spacing-sm);
}

.why-card p {
  font-size: 0.9375rem;
  color: var(--color-muted);
  line-height: 1.6;
}

/* CTA */
.cta {
  padding: var(--spacing-3xl) 0;
  background: var(--color-surface);
  color: var(--color-white);
  text-align: center;
}

.cta .section-kicker {
  color: var(--color-accent);
}

.cta h2 {
  color: var(--color-white);
}

.cta-text {
  font-size: 1.125rem;
  color: rgba(255, 255, 255, 0.7);
  max-width: 560px;
  margin: 0 auto var(--spacing-2xl);
  line-height: 1.7;
}

.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  justify-content: center;
}

.cta .btn-primary {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-surface);
}

.cta .btn-primary:hover,
.cta .btn-primary:focus {
  background: #4aa3f0;
  border-color: #4aa3f0;
}

.cta .btn-secondary {
  background: transparent;
  border-color: var(--color-white);
  color: var(--color-white);
}

.cta .btn-secondary:hover,
.cta .btn-secondary:focus {
  background: var(--color-white);
  color: var(--color-surface);
}

.cta .btn-outline {
  border-color: rgba(255, 255, 255, 0.3);
  color: var(--color-white);
}

.cta .btn-outline:hover,
.cta .btn-outline:focus {
  border-color: var(--color-white);
  background: rgba(255, 255, 255, 0.1);
}

/* Footer */
.site-footer {
  padding: var(--spacing-2xl) 0;
  border-top: 1px solid var(--color-border);
  background: var(--color-white);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--color-surface);
  margin-bottom: var(--spacing-lg);
}

.footer-brand .logo-mark {
  width: 28px;
  height: 28px;
}

.footer-contact {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-lg);
  font-size: 0.9375rem;
}

.footer-contact a {
  color: var(--color-text);
  transition: color var(--transition);
}

.footer-contact a:hover {
  color: var(--color-accent);
}

.footer-copyright {
  font-size: 0.8125rem;
  color: var(--color-muted);
}

/* Modal */
.modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-lg);
}

.modal[hidden] {
  display: none;
}

.modal-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
}

.modal-content {
  position: relative;
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--spacing-2xl);
  max-width: 400px;
  width: 100%;
  box-shadow: 0 24px 48px rgba(0, 0, 0, 0.15);
  animation: modalIn 0.2s ease;
}

@keyframes modalIn {
  from {
    opacity: 0;
    transform: scale(0.95) translateY(10px);
  }
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

.modal-close {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--color-muted);
  border-radius: 50%;
  transition: all var(--transition);
}

.modal-close:hover {
  background: #f5f5f5;
  color: var(--color-surface);
}

.modal-content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-surface);
  margin-bottom: var(--spacing-xs);
  text-align: center;
}

.modal-subtitle {
  color: var(--color-muted);
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.modal-options {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xl);
}

.modal-option {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-md) var(--spacing-lg);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition);
  text-align: left;
}

.modal-option:hover,
.modal-option:focus-within {
  border-color: var(--color-accent);
  background: #fafafa;
}

.modal-option[aria-checked="true"] {
  border-color: var(--color-accent);
  background: rgba(100, 180, 250, 0.1);
}

.option-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
}

.option-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.option-text strong {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-surface);
}

.option-text span {
  font-size: 0.8125rem;
  color: var(--color-muted);
}

.modal-actions {
  display: flex;
  gap: var(--spacing-md);
}

.modal-actions .btn {
  flex: 1;
}

.modal-back:disabled,
.modal-continue:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Responsive */
@media (max-width: 768px) {
  :root {
    --spacing-2xl: 32px;
    --spacing-3xl: 48px;
  }

  .nav-cta {
    display: inline-flex;
  }

  .hero {
    padding: var(--spacing-2xl) 0;
  }

  .services-grid,
  .why-grid {
    grid-template-columns: 1fr;
  }

  .footer-contact {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
}

@media (max-width: 480px) {
  .btn-lg {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.875rem;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .cta-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .cta-actions .btn {
    width: 100%;
  }
}

/* Focus visible for accessibility */
:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-surface);
  color: var(--color-white);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  z-index: 10000;
  font-weight: 600;
}

.skip-link:focus {
  top: var(--spacing-md);
}