/* ==========================================================================
   Agentic SEO — Shared Stylesheet
   Dark theme, mobile-first, vanilla CSS, WCAG 2.1 AA
   ========================================================================== */

/* --- Custom Properties --- */
:root {
  --color-bg: #0a0e17;
  --color-bg-alt: #111827;
  --color-bg-card: #1a2235;
  --color-bg-card-hover: #1f2a40;
  --color-surface: #232d42;
  --color-text: #e2e8f0;
  --color-text-muted: #94a3b8;
  --color-text-dim: #64748b;
  --color-accent: #00e5a0;
  --color-accent-dim: #00c48a;
  --color-accent-glow: rgba(0, 229, 160, 0.15);
  --color-accent-border: rgba(0, 229, 160, 0.3);
  --color-border: #1e293b;
  --color-white: #f8fafc;
  --color-red: #f87171;
  --color-green: #4ade80;
  --color-yellow: #fbbf24;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", monospace;

  --max-width: 1120px;
  --radius: 8px;
  --radius-lg: 12px;
  --transition: 200ms ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

ul, ol { list-style: none; }

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-white);
  line-height: 1.2;
  font-weight: 700;
}

h1 { font-size: clamp(2rem, 5vw, 3.25rem); }
h2 { font-size: clamp(1.5rem, 3.5vw, 2.25rem); }
h3 { font-size: clamp(1.15rem, 2.5vw, 1.5rem); }
h4 { font-size: 1.125rem; }

p + p { margin-top: 1rem; }

.text-accent { color: var(--color-accent); }
.text-muted  { color: var(--color-text-muted); }
.text-dim    { color: var(--color-text-dim); }

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

section {
  padding: 4rem 0;
}

@media (min-width: 768px) {
  section {
    padding: 6rem 0;
  }
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 0.75rem;
}

.section-title {
  margin-bottom: 1rem;
}

.section-subtitle {
  color: var(--color-text-muted);
  font-size: 1.125rem;
  max-width: 640px;
  margin-bottom: 2.5rem;
}

/* --- Navigation --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 14, 23, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-white);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

.nav-links {
  display: none;
  align-items: baseline;
  gap: 2rem;
}

.nav-links a:not(.btn) {
  font-size: 0.875rem;
  line-height: 1;
  color: var(--color-text-muted);
  font-weight: 500;
  transition: color var(--transition);
}

.nav-links a:not(.btn):hover {
  color: var(--color-white);
}

@media (min-width: 768px) {
  .nav-links {
    display: flex;
    align-items: baseline;
  }
}

/* Mobile menu toggle */
.nav-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  color: var(--color-text);
  cursor: pointer;
  width: 40px;
  height: 40px;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: currentColor;
  position: relative;
  transition: background var(--transition);
}

.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  display: block;
  width: 20px;
  height: 2px;
  background: currentColor;
  position: absolute;
  left: 0;
  transition: transform var(--transition);
}

.nav-toggle span::before { top: -6px; }
.nav-toggle span::after  { top: 6px; }

@media (min-width: 768px) {
  .nav-toggle { display: none; }
}

/* Mobile menu */
.mobile-nav {
  display: none;
  flex-direction: column;
  gap: 0.5rem;
  padding: 1rem 1.25rem 1.5rem;
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
}

.mobile-nav.open {
  display: flex;
}

.mobile-nav a {
  padding: 0.5rem 0;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  font-family: var(--font-sans);
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-bg);
}

.btn-primary:hover {
  background: var(--color-accent-dim);
  color: var(--color-bg);
  transform: translateY(-1px);
  box-shadow: 0 4px 20px var(--color-accent-glow);
}

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

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

.btn-sm {
  padding: 0.5rem 1.25rem;
  font-size: 0.85rem;
}

/* --- Hero --- */
.hero {
  padding-top: 8rem;
  padding-bottom: 4rem;
  text-align: center;
}

@media (min-width: 768px) {
  .hero {
    padding-top: 10rem;
    padding-bottom: 6rem;
  }
}

.hero h1 {
  max-width: 800px;
  margin: 0 auto 1.25rem;
}

.hero .subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto 2.5rem;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
}

.hero-stat-bar {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 2rem;
  margin-top: 3.5rem;
  padding-top: 2.5rem;
  border-top: 1px solid var(--color-border);
}

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

.hero-stat .number {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
}

.hero-stat .label {
  font-size: 0.8rem;
  color: var(--color-text-dim);
  margin-top: 0.35rem;
}

/* --- Cards --- */
.card-grid {
  display: grid;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .card-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .card-grid.two-col {
    grid-template-columns: repeat(2, 1fr);
  }
}

.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: all var(--transition);
}

.card:hover {
  border-color: var(--color-accent-border);
  background: var(--color-bg-card-hover);
  transform: translateY(-2px);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius);
  background: var(--color-accent-glow);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  color: var(--color-accent);
  font-size: 1.25rem;
}

.card h3 {
  margin-bottom: 0.5rem;
}

.card p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* --- Pricing Cards --- */
.pricing-card {
  position: relative;
  overflow: hidden;
}

.pricing-card.featured {
  border-color: var(--color-accent-border);
  box-shadow: 0 0 40px var(--color-accent-glow);
}

.pricing-badge {
  position: absolute;
  top: 2rem;
  right: -2rem;
  background: var(--color-accent);
  color: var(--color-bg);
  font-size: 0.7rem;
  line-height: 1;
  font-weight: 700;
  padding: 0.55rem 2.1rem 0.45rem;
  transform: rotate(45deg);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.pricing-card .tier-name {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
}

.pricing-card h3 {
  margin-bottom: 0.75rem;
}

.pricing-card .price {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 0.25rem;
}

.pricing-card .price-sub {
  font-size: 0.85rem;
  color: var(--color-text-dim);
  margin-bottom: 1.5rem;
}

.pricing-card ul {
  margin-bottom: 1.5rem;
}

.pricing-card li {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  padding: 0.35rem 0;
  padding-left: 1.5rem;
  position: relative;
}

.pricing-card li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-weight: 700;
}

/* --- Steps / How It Works --- */
.steps {
  counter-reset: step-counter;
}

.step {
  display: flex;
  gap: 1.5rem;
  padding: 1.5rem 0;
  position: relative;
}

.step + .step {
  border-top: 1px solid var(--color-border);
}

.step-number {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-accent-glow);
  border: 2px solid var(--color-accent-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-accent);
}

.step h3 {
  margin-bottom: 0.35rem;
}

.step p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

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

.comparison-table th,
.comparison-table td {
  text-align: left;
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.95rem;
}

.comparison-table th {
  color: var(--color-text-dim);
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.comparison-table .before {
  color: var(--color-red);
}

.comparison-table .after {
  color: var(--color-green);
}

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

/* --- Proof / Before-After --- */
.proof-grid {
  display: grid;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .proof-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.proof-item {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}

.proof-item .metric-label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-dim);
  margin-bottom: 0.75rem;
}

.proof-item .metric-row {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 0.5rem;
}

.proof-item .metric-before {
  color: var(--color-red);
  font-size: 0.9rem;
  text-decoration: line-through;
  opacity: 0.7;
}

.proof-item .metric-after {
  color: var(--color-green);
  font-size: 1.5rem;
  font-weight: 700;
}

.proof-item .metric-change {
  font-size: 0.8rem;
  color: var(--color-accent);
  background: var(--color-accent-glow);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
}

/* --- Company Logos / Tags --- */
.company-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.company-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.5rem 1rem;
  font-size: 0.85rem;
  color: var(--color-text-muted);
  font-weight: 500;
}

.company-tag .tag-label {
  font-size: 0.7rem;
  color: var(--color-text-dim);
}

/* --- FAQ --- */
.faq-item {
  border-bottom: 1px solid var(--color-border);
}

.faq-question {
  width: 100%;
  background: none;
  border: none;
  color: var(--color-white);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  text-align: left;
  padding: 1.25rem 0;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  transition: color var(--transition);
}

.faq-question:hover {
  color: var(--color-accent);
}

.faq-question::after {
  content: "+";
  font-size: 1.25rem;
  font-weight: 400;
  color: var(--color-text-dim);
  flex-shrink: 0;
  transition: transform var(--transition);
}

.faq-item.open .faq-question::after {
  content: "\2212";
  color: var(--color-accent);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 300ms ease, padding 300ms ease;
}

.faq-item.open .faq-answer {
  max-height: 500px;
  padding-bottom: 1.25rem;
}

.faq-answer p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* --- CTA Section --- */
.cta-section {
  text-align: center;
  background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-alt) 100%);
}

.cta-box {
  background: var(--color-bg-card);
  border: 1px solid var(--color-accent-border);
  border-radius: var(--radius-lg);
  padding: 3rem 2rem;
  max-width: 640px;
  margin: 0 auto;
}

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

.cta-box p {
  color: var(--color-text-muted);
  margin-bottom: 2rem;
}

/* --- Contact Form --- */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-width: 480px;
  margin: 0 auto;
}

.form-row {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

@media (min-width: 480px) {
  .form-row {
    flex-direction: row;
  }
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 0.95rem;
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: border-color var(--transition);
}

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

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

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

/* --- Footer --- */
.site-footer {
  padding: 2rem 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.site-footer p {
  font-size: 0.85rem;
  color: var(--color-text-dim);
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 1rem;
}

.footer-links a {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* --- Case Study Specific --- */
.case-hero {
  padding-top: 8rem;
  padding-bottom: 3rem;
}

@media (min-width: 768px) {
  .case-hero { padding-top: 10rem; }
}

.case-hero .breadcrumb {
  font-size: 0.85rem;
  color: var(--color-text-dim);
  margin-bottom: 1.5rem;
}

.case-hero .breadcrumb a {
  color: var(--color-text-muted);
}

.case-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.case-meta-item {
  font-size: 0.85rem;
}

.case-meta-item .meta-label {
  color: var(--color-text-dim);
}

.case-meta-item .meta-value {
  color: var(--color-text);
  font-weight: 600;
}

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

.case-content h2 {
  margin-top: 3rem;
  margin-bottom: 1rem;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border);
}

.case-content h2:first-of-type {
  border-top: none;
  padding-top: 0;
}

.case-content p {
  margin-bottom: 1rem;
}

.case-content ul {
  margin: 1rem 0;
  padding-left: 1.5rem;
}

.case-content li {
  padding: 0.25rem 0;
  color: var(--color-text-muted);
  position: relative;
}

.case-content li::before {
  content: "\2022";
  color: var(--color-accent);
  position: absolute;
  left: -1rem;
}

/* Timeline */
.timeline {
  margin: 2rem 0;
  padding-left: 1.5rem;
  border-left: 2px solid var(--color-border);
}

.timeline-item {
  position: relative;
  padding: 0 0 2rem 1.5rem;
}

.timeline-item:last-child { padding-bottom: 0; }

.timeline-item::before {
  content: "";
  position: absolute;
  left: -1.6rem;
  top: 0.35rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 2px solid var(--color-bg);
}

.timeline-item h4 {
  color: var(--color-accent);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.25rem;
}

.timeline-item h3 {
  font-size: 1.1rem;
  margin-bottom: 0.35rem;
}

.timeline-item p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* Results highlights */
.results-grid {
  display: grid;
  gap: 1rem;
  margin: 2rem 0;
}

@media (min-width: 480px) {
  .results-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 768px) {
  .results-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.result-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem;
  text-align: center;
}

.result-card .result-value {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
}

.result-card .result-label {
  font-size: 0.8rem;
  color: var(--color-text-dim);
  margin-top: 0.35rem;
}

/* Code block style */
.code-block {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin: 1rem 0;
  line-height: 1.6;
}

/* --- Utility --- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.divider {
  border: 0;
  border-top: 1px solid var(--color-border);
  margin: 0;
}

/* --- Animations --- */
@media (prefers-reduced-motion: no-preference) {
  .fade-in {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 500ms ease, transform 500ms ease;
  }

  .fade-in.visible {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .fade-in {
    opacity: 1;
    transform: none;
  }
}

/* Subtle glow effect on accent borders */
@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 20px var(--color-accent-glow); }
  50% { box-shadow: 0 0 40px var(--color-accent-glow); }
}

.glow {
  animation: pulse-glow 4s ease-in-out infinite;
}