/* ============================================================
   Reset
   ============================================================ */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
html {
  scroll-behavior: smooth;
}

/* ============================================================
   Custom Properties
   ============================================================ */
:root {
  --color-bg: #f9f8f6;
  --color-surface: #ffffff;
  --color-border: #e8e6e1;
  --color-text-primary: #1a1a1a;
  --color-text-secondary: #5a5a5a;
  --color-accent: #2563eb;
  --color-accent-light: #eff6ff;
  --color-code-bg: #f3f4f6;

  --font-sans:
    "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial,
    sans-serif;
  --font-mono:
    "JetBrains Mono", "Fira Code", "Cascadia Code", ui-monospace, "Courier New",
    monospace;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.563rem;
  --text-3xl: 1.953rem;
  --text-4xl: 2.441rem;
  --text-5xl: 3.052rem;

  --radius-sm: 6px;
  --radius-md: 12px;
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.07), 0 4px 12px rgba(0, 0, 0, 0.04);
  --shadow-card-hover:
    0 2px 8px rgba(0, 0, 0, 0.1), 0 8px 24px rgba(0, 0, 0, 0.08);
  --transition: 150ms ease;
}

/* ============================================================
   Base
   ============================================================ */
body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

a:hover {
  text-decoration: underline;
}

/* ============================================================
   Layout
   ============================================================ */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 96px 0;
}

section.section-tinted {
  background: var(--color-accent-light);
}

/* ============================================================
   Fade-in Animation
   ============================================================ */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 0.5s ease,
    transform 0.5s ease;
}

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

/* ============================================================
   Navigation
   ============================================================ */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(249, 248, 246, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.nav-wordmark {
  font-weight: 600;
  font-size: var(--text-base);
  color: var(--color-text-primary);
  letter-spacing: -0.01em;
}

/* ============================================================
   Buttons
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: 500;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  border: 1px solid transparent;
  line-height: 1;
}

.btn-primary {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}

.btn-primary:hover {
  background: #1d4ed8;
  border-color: #1d4ed8;
  text-decoration: none;
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-primary);
  border-color: var(--color-border);
}

.btn-ghost:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  text-decoration: none;
}

/* ============================================================
   Hero
   ============================================================ */
.section-hero {
  padding: 120px 0 96px;
  position: relative;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse 80% 60% at 70% 0%,
    rgba(37, 99, 235, 0.06) 0%,
    transparent 70%
  );
  pointer-events: none;
  z-index: 0;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 720px;
}

.hero-label {
  display: inline-block;
  padding: 4px 12px;
  background: var(--color-accent-light);
  color: var(--color-accent);
  border: 1px solid rgba(37, 99, 235, 0.2);
  border-radius: 100px;
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 20px;
}

.hero-title {
  font-size: var(--text-5xl);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--color-text-primary);
  margin-bottom: 20px;
}

.hero-sub {
  font-size: var(--text-xl);
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 36px;
  max-width: 600px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* ============================================================
   Section Headings
   ============================================================ */
.section-heading {
  font-size: var(--text-3xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text-primary);
  margin-bottom: 12px;
}

.section-sub {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  margin-bottom: 48px;
  max-width: 560px;
}

/* ============================================================
   Grids
   ============================================================ */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.grid-5-wrap {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 20px;
}

.grid-2-asymmetric {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 64px;
  align-items: start;
}

/* ============================================================
   Callout Cards (What This Demonstrates)
   ============================================================ */
.callout-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  box-shadow: var(--shadow-card);
}

.callout-icon {
  width: 40px;
  height: 40px;
  color: var(--color-accent);
  margin-bottom: 16px;
}

.callout-icon svg {
  width: 100%;
  height: 100%;
}

.callout-card h3 {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.callout-card p {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ============================================================
   Domain Cards
   ============================================================ */
.domain-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  box-shadow: var(--shadow-card);
  transition:
    box-shadow var(--transition),
    border-left var(--transition);
  border-left: 3px solid transparent;
}

.domain-card:hover {
  box-shadow: var(--shadow-card-hover);
  border-left-color: var(--color-accent);
}

.domain-icon {
  width: 32px;
  height: 32px;
  color: var(--color-accent);
  margin-bottom: 14px;
}

.domain-icon svg {
  width: 100%;
  height: 100%;
}

.domain-name {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.domain-desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.5;
  margin-bottom: 16px;
}

.domain-tech {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.domain-tech li {
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
  font-family: var(--font-mono);
  padding: 2px 0;
  border-top: 1px solid var(--color-border);
  padding-top: 4px;
}

.domain-tech li:first-child {
  border-top: none;
  padding-top: 0;
}

/* ============================================================
   Architecture Section
   ============================================================ */
.arch-text {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.arch-text p {
  font-size: var(--text-base);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.arch-diagram {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-card);
}

.arch-ascii {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1.5;
  color: var(--color-text-primary);
  overflow-x: auto;
  white-space: pre;
}

.link-arrow {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-accent);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  text-decoration: none;
}

.link-arrow:hover {
  text-decoration: underline;
}

/* ============================================================
   Scenario List
   ============================================================ */
.scenario-list {
  list-style: none;
  counter-reset: scenario;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.scenario-item {
  counter-increment: scenario;
  display: flex;
  gap: 32px;
  align-items: flex-start;
  padding: 32px 0;
  border-bottom: 1px solid var(--color-border);
}

.scenario-item:last-child {
  border-bottom: none;
}

.scenario-number {
  font-size: 3rem;
  font-weight: 700;
  color: var(--color-accent);
  opacity: 0.15;
  line-height: 1;
  min-width: 64px;
  font-family: var(--font-sans);
  letter-spacing: -0.04em;
  flex-shrink: 0;
}

.scenario-body h3 {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.scenario-body p {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 12px;
}

.scenario-cmd {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  background: var(--color-code-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 4px 10px;
  color: var(--color-text-primary);
}

/* ============================================================
   Quick Start / Code Block
   ============================================================ */
.quick-start-inner {
  max-width: 680px;
}

.code-block-wrapper {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  margin-bottom: 20px;
}

.code-block-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
  background: var(--color-code-bg);
  border-bottom: 1px solid var(--color-border);
}

.code-lang {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
  font-weight: 500;
}

.copy-btn {
  font-family: var(--font-sans);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-secondary);
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 3px 10px;
  cursor: pointer;
  transition: all var(--transition);
}

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

.code-block {
  padding: 20px 24px;
  overflow-x: auto;
}

.code-block code {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-text-primary);
  line-height: 1.7;
  white-space: pre;
}

.quick-start-note {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-bottom: 16px;
}

/* ============================================================
   Badge Pills (Tech Stack)
   ============================================================ */
.badge-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.badge {
  display: inline-block;
  padding: 5px 12px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 100px;
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  font-weight: 500;
  white-space: nowrap;
  transition: all var(--transition);
  cursor: default;
}

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

/* ============================================================
   Footer
   ============================================================ */
.site-footer {
  background: var(--color-text-primary);
  color: var(--color-bg);
  padding: 32px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-copy {
  font-size: var(--text-sm);
  color: rgba(249, 248, 246, 0.5);
}

.footer-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: var(--text-sm);
  color: rgba(249, 248, 246, 0.7);
  text-decoration: none;
  transition: color var(--transition);
}

.footer-links a:hover {
  color: var(--color-bg);
  text-decoration: none;
}

/* ============================================================
   Responsive — 768px
   ============================================================ */
@media (max-width: 768px) {
  section {
    padding: 64px 0;
  }

  .section-hero {
    padding: 80px 0 64px;
  }

  .hero-title {
    font-size: var(--text-4xl);
  }

  .hero-sub {
    font-size: var(--text-base);
  }

  .section-heading {
    font-size: var(--text-2xl);
  }

  .grid-3 {
    grid-template-columns: 1fr;
  }

  .grid-5-wrap {
    grid-template-columns: repeat(2, 1fr);
  }

  .grid-2-asymmetric {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .scenario-item {
    gap: 20px;
  }

  .scenario-number {
    font-size: 2rem;
    min-width: 44px;
  }
}

/* ============================================================
   Responsive — 480px
   ============================================================ */
@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .hero-title {
    font-size: var(--text-3xl);
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn {
    justify-content: center;
  }

  .grid-5-wrap {
    grid-template-columns: 1fr;
  }

  .scenario-item {
    flex-direction: column;
    gap: 8px;
  }

  .scenario-number {
    font-size: 1.5rem;
    min-width: auto;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-links {
    gap: 16px;
  }
}

/* ── Live Platform Screenshot Grid ──────────────────────── */
.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 40px;
}

@media (max-width: 900px) {
  .screenshot-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 560px) {
  .screenshot-grid {
    grid-template-columns: 1fr;
  }
}

.screenshot-card {
  margin: 0;
  border: 1px solid var(--border, #e2e8f0);
  border-radius: 8px;
  overflow: hidden;
  background: var(--surface, #fff);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
  transition: box-shadow 0.2s;
}

.screenshot-card:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
}

.screenshot-card img {
  display: block;
  width: 100%;
  height: 200px;
  object-fit: cover;
  object-position: top;
}

.screenshot-card figcaption {
  padding: 10px 14px;
  font-size: 0.8rem;
  color: var(--text-muted, #64748b);
  font-weight: 500;
  border-top: 1px solid var(--border, #e2e8f0);
}