/* ============================================
   DARROW GROUP - Investor Demand Infrastructure
   Madison Avenue meets Wall Street
   Premium Visual Design
   ============================================ */

/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@400;500;600;700&family=Inter:wght@400;500;600;700&display=swap');

/* CSS Variables */
:root {
  /* Backgrounds - Deep Navy instead of Black */
  --bg-primary: #0d1b2a;
  --bg-secondary: #1b2838;
  --bg-tertiary: #243447;
  --bg-card: #162232;
  --bg-card-hover: #1d2d40;

  /* Text */
  --text-primary: #ffffff;
  --text-secondary: #e8eaed;
  --text-muted: #8899a6;
  --text-dim: #5c6f7e;

  /* Accents - Muted steel blue */
  --accent: #4a7c8a;
  --accent-hover: #5a8fa0;
  --accent-dim: rgba(74, 124, 138, 0.15);

  /* Gold - use sparingly for premium touches */
  --gold: #b8a04a;
  --gold-dim: rgba(184, 160, 74, 0.15);

  /* Legacy mappings for compatibility */
  --accent-primary: var(--accent);
  --accent-primary-dim: var(--accent-dim);
  --accent-primary-glow: rgba(74, 124, 138, 0.3);
  --accent-secondary: var(--gold);
  --accent-secondary-dim: var(--gold-dim);

  /* Borders */
  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-light: rgba(255, 255, 255, 0.1);
  --border-accent: rgba(74, 124, 138, 0.3);

  /* Typography */
  --font-heading: 'Playfair Display', 'Georgia', serif;
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

  /* Spacing */
  --container-max: 1200px;
  --section-padding: 120px;
  --section-padding-mobile: 60px;

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

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-primary);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-secondary);
  background-color: var(--bg-primary);
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.015) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.015) 1px, transparent 1px);
  background-size: 60px 60px;
  min-height: 100vh;
  padding-top: 90px;
}

/* Typography */
h1, h2, h3 {
  font-family: var(--font-heading);
  color: var(--text-primary);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

h4, h5, h6 {
  color: var(--text-primary);
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: 0;
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
}

h2 {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  margin-bottom: 1.5rem;
}

h3 {
  font-size: clamp(1.25rem, 2vw, 1.5rem);
  margin-bottom: 1rem;
}

p {
  margin-bottom: 1.25rem;
}

p:last-child {
  margin-bottom: 0;
}

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

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

strong, .highlight {
  color: var(--text-primary);
  font-weight: 600;
}

.accent {
  color: var(--gold);
}

.mono {
  font-family: var(--font-primary);
  font-size: 0.85em;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* Layout */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

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

@media (max-width: 768px) {
  section {
    padding: var(--section-padding-mobile) 0;
  }
}

/* ============================================
   NAVIGATION
   ============================================ */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 1rem 0;
  background: rgba(13, 27, 42, 0.97);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-subtle);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 70px;
}

.nav-logo {
  display: flex;
  align-items: center;
}

.nav-logo img {
  height: 45px !important;
  width: auto !important;
  display: block;
  transition: opacity var(--transition-fast);
}

@media (max-width: 768px) {
  .nav-logo img {
    height: 36px !important;
  }
}

.nav-logo:hover img {
  opacity: 0.8;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 40px;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  padding: 8px 0;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--gold);
  transition: width var(--transition-medium);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text-primary);
}

.nav-links a.active::after,
.nav-links a:hover::after {
  width: 100%;
}

/* Mobile Navigation */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: var(--transition-fast);
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: rgba(13, 27, 42, 0.98);
    flex-direction: column;
    gap: 0;
    padding: 20px 0;
    border-bottom: 1px solid var(--border-subtle);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-medium);
  }

  .nav-links.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-links a {
    padding: 16px 24px;
    width: 100%;
    text-align: center;
  }

  .nav-links a::after {
    display: none;
  }
}

/* ============================================
   HERO SECTIONS
   ============================================ */

.hero {
  padding: 6rem 0 3rem 0;
  min-height: auto;
  background: radial-gradient(ellipse at center, var(--bg-secondary) 0%, var(--bg-primary) 70%);
}

/* Home page hero - slightly more presence */
.hero-home {
  padding: 7rem 0 4rem 0;
}

.hero-content {
  max-width: 800px;
}

.hero h1 {
  margin-bottom: 1.5rem;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.5);
}

.hero-subhead {
  font-size: 1.25rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
  line-height: 1.6;
}

.hero-subhead-secondary {
  font-size: 1.125rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

@media (max-width: 768px) {
  .hero {
    padding: 5rem 0 2rem 0;
  }

  .hero-home {
    padding: 6rem 0 3rem 0;
  }
}

/* ============================================
   BUTTONS
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 1rem 2rem;
  font-family: var(--font-primary);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  transition: all var(--transition-medium);
  text-decoration: none;
}

.btn-primary {
  background: #3d5a73;
  color: #ffffff;
}

.btn-primary:hover {
  background: #4a6d8a;
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(61, 90, 115, 0.3);
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-light);
}

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-arrow {
  transition: transform var(--transition-fast);
}

.btn:hover .btn-arrow {
  transform: translateX(4px);
}

/* ============================================
   SECTIONS
   ============================================ */

.section-header {
  margin-bottom: 3rem;
}

.section-label {
  display: inline-block;
  font-family: var(--font-primary);
  font-size: 11px;
  font-weight: 600;
  color: var(--gold);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: 1rem;
}

.section-divider {
  height: 1px;
  background: var(--border-subtle);
  margin: 0;
  border: none;
}

/* Content Sections */
.content-section {
  padding: 4rem 0;
  border-top: none;
}

/* Alternating section backgrounds */
.content-section:nth-child(odd) {
  background-color: var(--bg-primary);
}

.content-section:nth-child(even) {
  background-color: var(--bg-secondary);
}

/* Subtle gradient transition line between sections */
.content-section:nth-child(even)::before {
  content: '';
  display: block;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(184, 160, 74, 0.2), transparent);
  margin-bottom: 3rem;
}

.content-section .content-text {
  max-width: 700px;
}

.content-section p {
  font-size: 1.0625rem;
  color: var(--text-muted);
}

/* ============================================
   CARDS & GRIDS
   ============================================ */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 3rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 32px;
  transition: all var(--transition-medium);
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(184, 160, 74, 0.4);
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

.card-label {
  font-family: var(--font-primary);
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--gold);
  margin-bottom: 12px;
  display: block;
}

.card h3 {
  font-size: 1.125rem;
  margin-bottom: 0.75rem;
}

.card p {
  color: var(--text-muted);
  font-size: 0.9375rem;
  margin-bottom: 0;
}

/* Numbered Cards */
.numbered-card {
  position: relative;
  padding-left: 0;
}

.numbered-card .card-number {
  font-family: var(--font-heading);
  font-size: 48px;
  font-weight: 700;
  color: var(--gold);
  opacity: 0.5;
  position: absolute;
  top: 24px;
  right: 24px;
  line-height: 1;
}

/* Feature Items */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 3rem;
}

@media (max-width: 768px) {
  .feature-grid {
    grid-template-columns: 1fr;
  }
}

.feature-item {
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  transition: all var(--transition-medium);
}

.feature-item:hover {
  background: var(--bg-card-hover);
  border-color: rgba(184, 160, 74, 0.4);
  border-left-color: var(--gold);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

.feature-item h4 {
  font-size: 1rem;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.feature-item p {
  font-size: 0.9375rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* ============================================
   CREDIBILITY BAR
   ============================================ */

.credibility-bar {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
  padding: 2rem 0;
}

.credibility-inner {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 60px;
  flex-wrap: wrap;
}

.credibility-item {
  font-family: var(--font-primary);
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  position: relative;
}

.credibility-item:not(:last-child)::after {
  content: '';
  display: inline-block;
  width: 4px;
  height: 4px;
  background: var(--gold);
  border-radius: 50%;
  position: absolute;
  right: -32px;
  top: 50%;
  transform: translateY(-50%);
}

@media (max-width: 768px) {
  .credibility-inner {
    flex-direction: column;
    gap: 20px;
  }

  .credibility-item::after {
    display: none;
  }
}

/* ============================================
   COMPARISON TABLE
   ============================================ */

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
}

.comparison-table th {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-family: var(--font-primary);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 1rem 1.5rem;
  text-align: left;
  border-bottom: 2px solid var(--gold);
}

.comparison-table th:last-child {
  color: var(--gold);
}

.comparison-table td {
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

.comparison-table td:last-child {
  color: var(--text-primary);
  font-weight: 500;
}

.comparison-table tr:hover td {
  background: var(--bg-card);
}

@media (max-width: 768px) {
  .comparison-table th,
  .comparison-table td {
    padding: 1rem;
    font-size: 14px;
  }
}

/* ============================================
   CASE STUDY / IN ACTION
   ============================================ */

.case-study {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 2.5rem;
  margin-top: 2rem;
}

.case-study-intro {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border-subtle);
}

.case-study-item {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
  border-left: 2px solid var(--border-light);
}

.case-study-item:last-of-type {
  margin-bottom: 2rem;
}

.case-study-label {
  font-family: var(--font-primary);
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--gold);
  margin-bottom: 4px;
}

.case-study-text {
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

.case-study-conclusion {
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-subtle);
  font-style: italic;
  color: var(--text-primary);
  font-weight: 500;
}

@media (max-width: 768px) {
  .case-study {
    padding: 2rem 1.5rem;
  }
}

/* ============================================
   CTA SECTIONS
   ============================================ */

.cta-section {
  padding: 5rem 0;
  text-align: center;
  border-top: 1px solid var(--border-subtle);
  background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.cta-section h2 {
  margin-bottom: 1rem;
}

.cta-section p {
  max-width: 600px;
  margin: 0 auto 2rem auto;
  color: var(--text-secondary);
}

/* ============================================
   CALLOUT / BLOCKQUOTE
   ============================================ */

.callout {
  background: var(--bg-secondary);
  border-left: 3px solid var(--gold);
  padding: 24px 32px;
  margin: 2rem 0;
  font-size: 1.125rem;
  color: var(--text-secondary);
  font-style: italic;
  border-radius: 0 8px 8px 0;
}

/* ============================================
   CONTACT FORM
   ============================================ */

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 60px;
  margin-top: 3rem;
}

@media (max-width: 900px) {
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
}

.contact-info h3 {
  margin-bottom: 1.5rem;
}

.contact-info-item {
  margin-bottom: 1.5rem;
}

.contact-info-label {
  font-family: var(--font-primary);
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: 8px;
}

.contact-info-value {
  font-size: 1.0625rem;
}

.contact-info-value a {
  color: var(--accent);
}

.contact-form h3 {
  margin-bottom: 1.5rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.form-input,
.form-textarea {
  width: 100%;
  padding: 1rem;
  font-family: var(--font-primary);
  font-size: 1rem;
  color: var(--text-primary);
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: 4px;
  transition: all var(--transition-medium);
}

.form-input:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-dim);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--text-dim);
}

.form-textarea {
  min-height: 150px;
  resize: vertical;
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
  padding: 3rem 0;
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-secondary);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
}

.footer-copy {
  font-size: 0.875rem;
  color: var(--text-dim);
}

.footer-links {
  display: flex;
  gap: 32px;
  list-style: none;
}

.footer-links a {
  font-size: 14px;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

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

@media (max-width: 768px) {
  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}

/* ============================================
   STEP CARDS (ENGINE PAGE)
   ============================================ */

.step-cards {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-top: 3rem;
}

.step-card {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 32px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 40px;
  transition: all var(--transition-medium);
}

.step-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(184, 160, 74, 0.4);
  border-left-color: var(--gold);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

.step-number {
  font-family: var(--font-heading);
  font-size: 56px;
  font-weight: 700;
  color: var(--gold);
  opacity: 0.5;
  line-height: 1;
}

.step-content h3 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
}

.step-content p {
  color: var(--text-muted);
  margin-bottom: 0;
}

@media (max-width: 768px) {
  .step-card {
    grid-template-columns: 1fr;
    gap: 16px;
    padding: 28px;
  }

  .step-number {
    font-size: 40px;
  }
}

/* ============================================
   UTILITIES
   ============================================ */

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

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mt-5 { margin-top: 3rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.mb-5 { margin-bottom: 3rem; }

/* ============================================
   ANIMATIONS
   ============================================ */

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  animation: fadeIn 0.6s ease forwards;
}

.fade-in-delay-1 { animation-delay: 0.1s; opacity: 0; }
.fade-in-delay-2 { animation-delay: 0.2s; opacity: 0; }
.fade-in-delay-3 { animation-delay: 0.3s; opacity: 0; }
.fade-in-delay-4 { animation-delay: 0.4s; opacity: 0; }