/* ==========================================================================
   learn - Cybernetic Dark Design System & Landingpage Tokens
   Strikt nach ISO/IEC 25010, WCAG AAA und Jeremy Benz Ökosystem-Standard
   ========================================================================== */

:root {
  /* Basisschichten (Cybernetic Dark) */
  --bg-page: #080a0f;
  --bg-surface: #0e121b;
  --bg-card: #141a26;
  --bg-card-hover: #1a2232;
  --bg-input: #101420;

  /* Typografische Farben (Kontrast >= 7:1) */
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  /* Akzentfarben */
  --accent-cyan: #38bdf8;
  --accent-cyan-glow: rgba(56, 189, 248, 0.25);
  --accent-violet: #a855f7;
  --accent-violet-glow: rgba(168, 85, 247, 0.25);
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-rose: #f43f5e;

  /* Konturen */
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);
  --border-focus: #38bdf8;

  /* 8-Punkt-Raster & Spacing */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-12: 48px;
  --space-16: 64px;
  --space-24: 96px;

  /* Typografie */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  /* Schatten & Radien */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 24px var(--accent-cyan-glow);

  --header-bg: rgba(14, 18, 27, 0.85);
}

/* Light Theme Anpassung */
[data-theme="light"] {
  --bg-page: #f8fafc;
  --bg-surface: #ffffff;
  --bg-card: #f1f5f9;
  --bg-card-hover: #e2e8f0;
  --bg-input: #ffffff;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --border-subtle: rgba(0, 0, 0, 0.08);
  --border-strong: rgba(0, 0, 0, 0.16);
  --header-bg: rgba(255, 255, 255, 0.88);
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.06);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background-color: var(--bg-page);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  transition: background-color 0.25s ease, color 0.25s ease;
}

a {
  color: inherit;
  text-decoration: none;
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-4);
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  height: 64px;
  display: flex;
  align-items: center;
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.brand-area {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.ecosystem-back {
  display: inline-flex;
  align-items: center;
  font-size: 0.8125rem;
  color: var(--text-muted);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
  transition: color 0.15s, background-color 0.15s;
}

.ecosystem-back:hover {
  color: var(--accent-cyan);
  background-color: rgba(56, 189, 248, 0.1);
}

.brand-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.brand-logo {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-md);
  object-fit: cover;
  box-shadow: 0 0 10px var(--accent-cyan-glow);
}

.brand-info {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.brand-name {
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: -0.02em;
}

.brand-ver {
  font-size: 0.6875rem;
  font-family: var(--font-mono);
  background: rgba(56, 189, 248, 0.12);
  color: var(--accent-cyan);
  border: 1px solid rgba(56, 189, 248, 0.3);
  padding: 2px 6px;
  border-radius: var(--radius-full);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.main-nav a {
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-weight: 500;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  transition: color 0.15s, background-color 0.15s;
}

.main-nav a:hover {
  color: var(--text-primary);
  background: var(--bg-card);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.lang-switch {
  display: inline-flex;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 2px;
}

.lang-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.15s;
}

.lang-btn.active {
  background: var(--accent-cyan);
  color: #080a0f;
}

.theme-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1rem;
  transition: all 0.15s;
}

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

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  position: relative;
  padding: var(--space-16) 0 var(--space-12);
  text-align: center;
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 700px;
  height: 350px;
  background: radial-gradient(ellipse at center, rgba(56, 189, 248, 0.15), rgba(168, 85, 247, 0.08) 60%, transparent 80%);
  filter: blur(60px);
  pointer-events: none;
  z-index: 0;
}

.hero-container {
  position: relative;
  z-index: 1;
  max-width: 860px;
  margin: 0 auto;
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-subtle);
  background: var(--bg-surface);
  color: var(--text-secondary);
}

.badge-cyan {
  border-color: rgba(56, 189, 248, 0.35);
  color: var(--accent-cyan);
  background: rgba(56, 189, 248, 0.08);
}

.badge-violet {
  border-color: rgba(168, 85, 247, 0.35);
  color: var(--accent-violet);
  background: rgba(168, 85, 247, 0.08);
}

.hero-title {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-4);
}

.gradient-text {
  background: linear-gradient(135deg, var(--accent-cyan) 0%, var(--accent-violet) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: var(--space-8);
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
}

/* Call to Action Buttons */
.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  margin-bottom: var(--space-8);
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  background: linear-gradient(135deg, var(--accent-cyan) 0%, #2563eb 100%);
  color: #ffffff;
  font-weight: 600;
  font-size: 1rem;
  padding: 14px 28px;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 16px rgba(56, 189, 248, 0.35);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(56, 189, 248, 0.5);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  background: var(--bg-surface);
  color: var(--text-primary);
  font-weight: 600;
  font-size: 1rem;
  padding: 14px 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-strong);
  cursor: pointer;
  transition: all 0.15s ease;
}

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

/* Quick Command */
.hero-quick-cmd {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-4);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--text-secondary);
  box-shadow: var(--shadow-card);
}

.hero-quick-cmd code {
  color: var(--accent-cyan);
}

.copy-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  font-size: 0.875rem;
  transition: color 0.15s;
}

.copy-btn:hover {
  color: var(--text-primary);
}

/* ==========================================================================
   Feature Grid Section
   ========================================================================== */
.features-section {
  padding: var(--space-12) 0;
  border-top: 1px solid var(--border-subtle);
}

.section-header {
  text-align: center;
  max-width: 650px;
  margin: 0 auto var(--space-8);
}

.section-tag {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-cyan);
  margin-bottom: var(--space-2);
}

.section-title {
  font-size: clamp(1.5rem, 3.5vw, 2.25rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-3);
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-6);
}

.feature-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.feature-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.4);
}

.f-card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: var(--space-4);
}

.f-card-icon.cyan { background: rgba(56, 189, 248, 0.12); color: var(--accent-cyan); }
.f-card-icon.violet { background: rgba(168, 85, 247, 0.12); color: var(--accent-violet); }
.f-card-icon.emerald { background: rgba(16, 185, 129, 0.12); color: var(--accent-emerald); }
.f-card-icon.amber { background: rgba(245, 158, 11, 0.12); color: var(--accent-amber); }
.f-card-icon.rose { background: rgba(244, 63, 94, 0.12); color: var(--accent-rose); }

.feature-card h3 {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.feature-card p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ==========================================================================
   Downloads & Installation Grid
   ========================================================================== */
.download-section {
  padding: var(--space-12) 0;
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-surface);
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-6);
}

.download-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.download-card h3 {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 1.125rem;
}

.download-card p {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.btn-card {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  background: var(--bg-surface);
  border: 1px solid var(--border-strong);
  color: var(--text-primary);
  padding: 10px 16px;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  transition: all 0.15s;
}

.btn-card:hover {
  border-color: var(--accent-cyan);
  background: var(--bg-card-hover);
}

.btn-card.highlight {
  background: var(--accent-cyan);
  color: #080a0f;
  border-color: var(--accent-cyan);
}

.btn-card.highlight:hover {
  box-shadow: 0 4px 16px var(--accent-cyan-glow);
}

/* ==========================================================================
   About & Contributors Section
   ========================================================================== */
.about-section {
  padding: var(--space-12) 0;
  border-top: 1px solid var(--border-subtle);
}

.about-layout-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-6);
}

@media (max-width: 768px) {
  .about-layout-grid { grid-template-columns: 1fr; }
  .main-nav { display: none; }
}

.about-box {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
}

.about-box h3 {
  font-size: 1.125rem;
  margin-bottom: var(--space-3);
}

.author-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 6px 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-full);
  margin-right: var(--space-2);
  margin-bottom: var(--space-2);
  font-size: 0.8125rem;
}

.author-avatar {
  width: 24px;
  height: 24px;
  border-radius: var(--radius-full);
  background: var(--accent-cyan);
  color: #080a0f;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.6875rem;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  margin-top: auto;
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-surface);
  padding: var(--space-8) 0;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

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

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
}

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