/* ============================================
   MORPHEUS LINK BOT — MODERN UI DESIGN SYSTEM
   Version: 3.0 | Mobile-First, Accessible
   ============================================ */

/* --- CSS Custom Properties (Design Tokens) --- */
:root {
  /* Colors — Dark Theme Primary */
  --color-bg: #0f1419;
  --color-bg-elevated: #1a1f26;
  --color-bg-card: #232a35;
  --color-bg-hover: #2d3642;
  --color-fg: #e7e9ea;
  --color-fg-muted: #8b98a5;
  --color-fg-subtle: #536471;
  --color-border: #2f3944;
  --color-link: #4fa3e0;
  --color-link-hover: #71b9f4;
  --color-accent: #1d9bf0;
  --color-accent-hover: #1a8cd8;
  --color-success: #00ba7c;
  --color-warning: #ffd400;
  --color-error: #f4212e;

  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 2rem;
  --text-4xl: 2.5rem;
  --text-5xl: 3rem;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 1rem;
  --space-4: 1.5rem;
  --space-5: 2rem;
  --space-6: 3rem;
  --space-8: 4rem;
  --space-10: 5rem;

  /* Layout */
  --max-width: 1200px;
  --content-width: 780px;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 40px rgba(29, 155, 240, 0.15);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-primary);
  font-size: var(--text-base);
  line-height: 1.7;
  color: var(--color-fg);
  background-color: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Accessibility --- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-3);
  background: var(--color-accent);
  color: var(--color-bg);
  padding: var(--space-2) var(--space-4);
  z-index: 1000;
  text-decoration: none;
  font-weight: 700;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 0;
}

:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-4);
}

.content-container {
  max-width: var(--content-width);
  margin: 0 auto;
}

main {
  flex: 1;
  padding: var(--space-6) 0;
}

/* --- Header --- */
.site-header {
  background: var(--color-bg-elevated);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-3) 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-fg);
  font-weight: 700;
  font-size: var(--text-lg);
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--color-accent) 0%, #7c3aed 100%);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-lg);
}

.lang-switch {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
}

.lang-link {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  color: var(--color-fg-muted);
  text-decoration: none;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.lang-link:hover {
  color: var(--color-fg);
  background: var(--color-bg-card);
  border-color: var(--color-border);
}

.lang-link.active {
  color: var(--color-accent);
  background: rgba(29, 155, 240, 0.1);
  border-color: rgba(29, 155, 240, 0.3);
}

.lang-flag {
  font-size: var(--text-lg);
}

.lang-sep {
  color: var(--color-fg-subtle);
  user-select: none;
}

/* --- Breadcrumb Navigation --- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-5);
  font-size: var(--text-sm);
}

.breadcrumb-link {
  color: var(--color-fg-muted);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: var(--space-1);
  transition: color var(--transition-fast);
}

.breadcrumb-link:hover {
  color: var(--color-link);
}

.breadcrumb-sep {
  color: var(--color-fg-subtle);
}

.breadcrumb-current {
  color: var(--color-fg);
  font-weight: 500;
}

/* --- Language Indicator Badge --- */
.lang-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-2);
  background: rgba(29, 155, 240, 0.1);
  border: 1px solid rgba(29, 155, 240, 0.2);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: var(--space-3);
}

/* --- Hero Section (Landing Page) --- */
.hero {
  text-align: center;
  padding: var(--space-10) 0;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(29, 155, 240, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 50px;
  font-size: var(--text-sm);
  color: var(--color-fg-muted);
  margin-bottom: var(--space-4);
}

.hero-badge-icon {
  color: var(--color-success);
}

.hero h1 {
  font-size: clamp(var(--text-3xl), 6vw, var(--text-5xl));
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: var(--space-4);
  letter-spacing: -0.02em;
}

.hero h1 span {
  background: linear-gradient(135deg, var(--color-accent) 0%, #a855f7 50%, var(--color-link) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-description {
  max-width: 55ch;
  margin: 0 auto var(--space-5);
  color: var(--color-fg-muted);
  font-size: var(--text-lg);
  line-height: 1.6;
}

/* --- Language Selection Cards --- */
.lang-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-6);
}

.lang-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-5);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.lang-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), #a855f7);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.lang-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.lang-card:hover::before {
  opacity: 1;
}

.lang-card-icon {
  font-size: 3rem;
  margin-bottom: var(--space-3);
}

.lang-card-title {
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-fg);
  margin-bottom: var(--space-2);
}

.lang-card-desc {
  color: var(--color-fg-muted);
  font-size: var(--text-sm);
  text-align: center;
}

.lang-card-arrow {
  margin-top: var(--space-4);
  color: var(--color-accent);
  font-size: var(--text-xl);
  transition: transform var(--transition-fast);
}

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

/* --- Content Page Typography --- */
.page-header {
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-5);
  border-bottom: 1px solid var(--color-border);
}

.page-title {
  font-size: var(--text-4xl);
  font-weight: 800;
  margin-bottom: var(--space-3);
  letter-spacing: -0.01em;
}

.page-subtitle {
  font-size: var(--text-xl);
  color: var(--color-fg-muted);
  max-width: 60ch;
}

/* --- Content Sections --- */
.content-section {
  margin-bottom: var(--space-8);
}

.section-title {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-2xl);
  font-weight: 700;
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-border);
}

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

.section-content {
  color: var(--color-fg-muted);
  line-height: 1.8;
}

/* --- Feature List --- */
.feature-list {
  list-style: none;
  display: grid;
  gap: var(--space-3);
}

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.feature-item:hover {
  border-color: var(--color-accent);
  background: var(--color-bg-hover);
}

.feature-icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  background: rgba(29, 155, 240, 0.1);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xl);
}

.feature-text {
  flex: 1;
}

.feature-title {
  font-weight: 600;
  color: var(--color-fg);
  margin-bottom: var(--space-1);
}

.feature-desc {
  font-size: var(--text-sm);
  color: var(--color-fg-muted);
}

/* --- FAQ / Definition List --- */
.faq-list {
  display: grid;
  gap: var(--space-4);
}

.faq-item {
  padding: var(--space-4);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.faq-question {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-fg);
  margin-bottom: var(--space-2);
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
}

.faq-question::before {
  content: '?';
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  background: var(--color-accent);
  color: var(--color-bg);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-sm);
  font-weight: 700;
}

.faq-answer {
  color: var(--color-fg-muted);
  margin-left: 32px;
  line-height: 1.7;
}

/* --- Info / Note Boxes --- */
.info-box {
  padding: var(--space-4);
  border-radius: var(--radius-md);
  margin: var(--space-4) 0;
  display: flex;
  gap: var(--space-3);
}

.info-box.tip {
  background: rgba(0, 186, 124, 0.1);
  border: 1px solid rgba(0, 186, 124, 0.3);
}

.info-box.warning {
  background: rgba(255, 212, 0, 0.1);
  border: 1px solid rgba(255, 212, 0, 0.3);
}

.info-box-icon {
  font-size: var(--text-xl);
}

.info-box-content {
  flex: 1;
}

.info-box-title {
  font-weight: 600;
  margin-bottom: var(--space-1);
}

.info-box.tip .info-box-title {
  color: var(--color-success);
}

.info-box.warning .info-box-title {
  color: var(--color-warning);
}

/* --- Code Blocks --- */
pre, code {
  font-family: var(--font-mono);
}

code {
  font-size: 0.9em;
  background: var(--color-bg-card);
  padding: 0.2em 0.5em;
  border-radius: var(--radius-sm);
  color: var(--color-link);
}

pre {
  background: var(--color-bg-elevated);
  padding: var(--space-4);
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin: var(--space-4) 0;
  border: 1px solid var(--color-border);
}

pre code {
  background: none;
  padding: 0;
  color: var(--color-fg);
  font-size: var(--text-sm);
  line-height: 1.6;
}

/* --- Keywords / Badges --- */
.keyword-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.keyword {
  display: inline-block;
  padding: var(--space-1) var(--space-2);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  color: var(--color-fg-muted);
  font-weight: 500;
}

/* --- Footer --- */
.footer {
  text-align: center;
  padding: var(--space-6) 0;
  color: var(--color-fg-subtle);
  font-size: var(--text-sm);
  border-top: 1px solid var(--color-border);
  margin-top: var(--space-8);
}

.footer a {
  color: var(--color-fg-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* --- Mobile Navigation Toggle --- */
.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-fg);
  font-size: var(--text-xl);
  cursor: pointer;
  padding: var(--space-2);
}

/* --- Responsive Design --- */
@media (max-width: 768px) {
  :root {
    --text-4xl: 2rem;
    --text-3xl: 1.75rem;
    --text-2xl: 1.35rem;
  }

  .container {
    padding: 0 var(--space-3);
  }

  .hero {
    padding: var(--space-6) 0;
  }

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

  .lang-cards {
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }

  .lang-card {
    padding: var(--space-4);
  }

  .header-inner {
    flex-wrap: wrap;
    gap: var(--space-2);
  }

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

  .lang-switch {
    display: none;
    width: 100%;
    justify-content: center;
    padding-top: var(--space-3);
    border-top: 1px solid var(--color-border);
    margin-top: var(--space-3);
  }

  .lang-switch.open {
    display: flex;
  }

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

  .breadcrumb {
    font-size: var(--text-xs);
    flex-wrap: wrap;
  }
}

@media (max-width: 480px) {
  .feature-item {
    flex-direction: column;
    align-items: flex-start;
  }

  .feature-icon {
    width: 32px;
    height: 32px;
    font-size: var(--text-lg);
  }

  .faq-answer {
    margin-left: 0;
    margin-top: var(--space-2);
  }
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }
}

/* --- High Contrast Mode --- */
@media (prefers-contrast: high) {
  :root {
    --color-border: #ffffff;
    --color-fg-muted: #cccccc;
  }

  .lang-card, .feature-item, .faq-item {
    border-width: 2px;
  }
}