/*
 * epidebug.help — Dark Tech Blog Theme (Standalone GUI)
 * Design system: .stitch/DESIGN.md
 */

/* ===== Fonts ===== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700;800&family=JetBrains+Mono:wght@400;500&display=swap');

/* ===== Custom Properties ===== */
:root {
  /* Base */
  --color-void: #0D1117;
  --color-surface: #161B22;
  --color-elevated: #21262D;
  --color-border: #30363D;

  /* Text */
  --color-snow: #E6EDF3;
  --color-fog: #8B949E;
  --color-ash: #484F58;

  /* Syntax Accents */
  --color-blue: #58A6FF;
  --color-green: #3FB950;
  --color-amber: #D29922;
  --color-red: #F85149;
  --color-violet: #BC8CFF;
  --color-cyan: #79C0FF;
  --color-sage: #7EE787;

  /* Gradients */
  --gradient-hero: linear-gradient(135deg, #58A6FF 0%, #BC8CFF 100%);
  --gradient-card: linear-gradient(180deg, #161B22 0%, #0D1117 100%);
  --gradient-cta: linear-gradient(90deg, #58A6FF 0%, #3FB950 100%);

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 40px;
  --space-2xl: 64px;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
}

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

html {
  scroll-behavior: smooth;
}

body {
  background-color: var(--color-void);
  background-image: linear-gradient(rgba(13, 17, 23, 0.85), rgba(13, 17, 23, 0.95)), url('./assets/nano_banana_bg.png');
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
  color: var(--color-snow);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* ===== Links ===== */
a {
  color: var(--color-blue);
  text-decoration: none;
  transition: color 200ms ease;
}
a:hover,
a:focus {
  color: var(--color-cyan);
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sans);
  color: var(--color-snow);
  letter-spacing: -0.01em;
}
h1 { font-size: 2.25rem; font-weight: 700; line-height: 1.2; }
h2 { font-size: 1.75rem; font-weight: 700; line-height: 1.3; }
h3 { font-size: 1.375rem; font-weight: 600; line-height: 1.4; }
h4 { font-size: 1.125rem; font-weight: 600; line-height: 1.4; }

p {
  color: var(--color-snow);
  line-height: 1.7;
  margin-bottom: var(--space-md);
}

/* ===== Header / Navigation ===== */
.site-header {
  background-color: rgba(13, 17, 23, 0.85);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: var(--space-md) var(--space-lg);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-family: var(--font-sans);
  font-weight: 700;
  color: var(--color-snow);
  font-size: 1.2rem;
}

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

.main-nav {
  display: flex;
  gap: var(--space-lg);
}

.nav-link {
  color: var(--color-fog);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color 200ms ease;
}
.nav-link:hover {
  color: var(--color-blue);
}
.blog-link {
    background: var(--color-surface);
    padding: 2px 8px;
    border-radius: 4px;
    border: 1px solid var(--color-border);
}
.blog-link:hover {
    background: var(--color-elevated);
    border-color: var(--color-blue);
}

.mobile-menu-toggle {
  display: none;
  background: transparent;
  border: none;
  color: var(--color-fog);
  cursor: pointer;
}

/* ===== Hero Section ===== */
.hero-section {
  padding: calc(var(--space-2xl) * 2) var(--space-lg) calc(var(--space-2xl) * 1.5);
  text-align: center;
  background-color: transparent;
}

.hero-content {
  max-width: 800px;
  margin: 0 auto;
}

.hero-title {
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--space-md);
  display: inline-block;
}

.terminal-cursor {
  color: var(--color-blue);
  animation: blink 1s step-end infinite;
  display: inline-block;
  -webkit-text-fill-color: var(--color-blue);
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--color-fog);
  font-weight: 400;
  max-width: 600px;
  margin: 0 auto var(--space-lg);
}

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

/* ===== Main Content Area ===== */
.primary-content {
  background-color: transparent;
  padding: 0 var(--space-lg) var(--space-2xl);
}

.article-layout {
  max-width: 840px;
  margin: 0 auto;
}

/* ===== Post Cards / Feature Cards ===== */
.feature-card {
  background: var(--gradient-card);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: var(--space-lg);
  margin-bottom: var(--space-xl);
  transition: transform 300ms cubic-bezier(0.4, 0, 0.2, 1),
              box-shadow 300ms cubic-bezier(0.4, 0, 0.2, 1),
              background-color 300ms cubic-bezier(0.4, 0, 0.2, 1);
  scroll-margin-top: 100px;
}
.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
  background-color: var(--color-elevated);
}

/* ===== Headings — Gradient Accent Bar ===== */
.feature-header h2 {
  position: relative;
  padding-left: var(--space-md);
  color: var(--color-snow);
  margin-bottom: var(--space-sm);
}
.feature-header h2::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--gradient-hero);
  border-radius: 2px;
}

/* ===== Tags ===== */
.feature-header .tags {
  margin-bottom: var(--space-md);
  margin-left: var(--space-md);
}

.tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-blue);
  background: var(--color-surface);
  padding: 2px 8px;
  border-radius: 4px;
  display: inline-block;
  margin: 0 4px 4px 0;
  transition: background 200ms ease;
  border: 1px solid var(--color-border);
}

/* ===== Code Blocks ===== */
code {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  background: var(--color-surface);
  color: var(--color-snow);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--color-border);
}

/* ===== Images ===== */
.image-wrapper {
  margin-top: var(--space-lg);
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
}

.image-wrapper img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 12px;
  transition: transform 300ms ease;
}

/* ===== Buttons ===== */
.btn {
  display: inline-block;
  border-radius: 8px;
  font-family: var(--font-sans);
  font-weight: 600;
  padding: 10px 24px;
  cursor: pointer;
  transition: filter 150ms ease-out, transform 150ms ease-out, box-shadow 150ms ease;
  text-align: center;
}

.btn-primary {
  background: var(--gradient-cta);
  color: var(--color-snow);
  border: none;
}
.btn-primary:hover {
  filter: brightness(1.1);
  transform: scale(1.02);
  color: var(--color-snow);
}

.btn-secondary {
  background: transparent;
  border: 1px solid var(--color-blue);
  color: var(--color-blue);
}
.btn-secondary:hover {
  background: rgba(88, 166, 255, 0.1);
  color: var(--color-blue);
  transform: scale(1.02);
}
.btn-secondary:focus {
  outline: none;
  box-shadow: 0 0 20px rgba(88,166,255,0.15), 0 0 0 2px var(--color-blue);
}

/* ===== Footer ===== */
.site-footer {
  background-color: transparent;
  border-top: 1px solid var(--color-border);
  color: var(--color-ash);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  padding: var(--space-xl) var(--space-lg);
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer-links {
  display: flex;
  gap: var(--space-md);
}

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

/* ===== Intersection Observer Fade In ===== */
.fade-in {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 600ms ease-out, transform 600ms ease-out;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .hero-title { font-size: 2.25rem; }
  h2 { font-size: 1.375rem; }
  h3 { font-size: 1.125rem; }

  .hero-section {
    padding: var(--space-2xl) var(--space-md) var(--space-lg);
  }

  .main-nav {
    display: none;
  }
  .main-nav.active {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-surface);
    flex-direction: column;
    padding: var(--space-md);
    border-bottom: 1px solid var(--color-border);
  }

  .mobile-menu-toggle {
    display: block;
  }

  .footer-content {
    flex-direction: column;
    text-align: center;
  }
  
  .feature-card {
    padding: var(--space-md);
  }
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .fade-in {
    opacity: 1;
    transform: none;
  }
}