/* =============================================================================
   GITHUB COPILOT DEV DAYS MADRID — DESIGN SYSTEM
   Inspirado en GitHub Primer Design System y GitHub Copilot branding
   ============================================================================= */

/* =============================================================================
   1. CSS CUSTOM PROPERTIES (DESIGN TOKENS)
   ============================================================================= */
:root {
  /* Brand Colors */
  --copilot-purple:       #8957e5;
  --copilot-purple-light: #a371f7;
  --copilot-purple-dark:  #6639ba;
  --copilot-purple-glow:  rgba(137, 87, 229, 0.35);
  --github-blue:          #58a6ff;
  --github-green:         #3fb950;
  --github-yellow:        #d29922;
  --github-red:           #f85149;
  --github-orange:        #e3b341;

  /* Dark Mode Palette (default) */
  --bg-canvas:     #0d1117;
  --bg-default:    #0d1117;
  --bg-overlay:    #161b22;
  --bg-subtle:     #161b22;
  --bg-muted:      #21262d;
  --bg-elevated:   #1c2128;

  --border-default:  #30363d;
  --border-muted:    #21262d;
  --border-subtle:   rgba(240, 246, 252, 0.1);

  --text-primary:     #e6edf3;
  --text-secondary:   #8b949e;
  --text-tertiary:    #6e7681;
  --text-disabled:    #484f58;
  --text-inverse:     #0d1117;
  --text-link:        #58a6ff;
  --text-link-hover:  #79c0ff;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans",
               Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
               "Liberation Mono", monospace;

  --text-xs:   0.75rem;    /* 12px */
  --text-sm:   0.875rem;   /* 14px */
  --text-base: 1rem;       /* 16px */
  --text-lg:   1.125rem;   /* 18px */
  --text-xl:   1.25rem;    /* 20px */
  --text-2xl:  1.5rem;     /* 24px */
  --text-3xl:  1.875rem;   /* 30px */
  --text-4xl:  2.25rem;    /* 36px */
  --text-5xl:  3rem;       /* 48px */
  --text-6xl:  3.75rem;    /* 60px */

  --leading-tight:  1.25;
  --leading-snug:   1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;

  --weight-normal:    400;
  --weight-medium:    500;
  --weight-semibold:  600;
  --weight-bold:      700;
  --weight-extrabold: 800;

  /* Spacing */
  --space-1:  4px;
  --space-2:  8px;
  --space-3:  12px;
  --space-4:  16px;
  --space-5:  20px;
  --space-6:  24px;
  --space-8:  32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;
  --space-24: 96px;

  /* Border radius */
  --radius-sm:   6px;
  --radius-md:   8px;
  --radius-lg:   12px;
  --radius-xl:   16px;
  --radius-2xl:  24px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm:    0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md:    0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg:    0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow:  0 0 24px var(--copilot-purple-glow);
  --shadow-card:  0 1px 0 var(--border-default);
  --inset-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);

  /* Transitions */
  --transition-fast:   150ms cubic-bezier(0.2, 0, 0, 1);
  --transition-normal: 200ms cubic-bezier(0.2, 0, 0, 1);
  --transition-slow:   350ms cubic-bezier(0.2, 0, 0, 1);

  /* Z-index scale */
  --z-base:    0;
  --z-raised:  10;
  --z-overlay: 100;
  --z-nav:     200;
  --z-modal:   300;
  --z-top:     400;

  /* Layout */
  --nav-height:       64px;
  --container-max:    1280px;
  --container-wide:   1440px;
  --container-narrow: 768px;

  /* Agenda type colors */
  --agenda-logistics: #6e7681;
  --agenda-keynote:   var(--copilot-purple);
  --agenda-session:   var(--github-blue);
  --agenda-workshop:  var(--github-green);
  --agenda-break:     #30363d;
  --agenda-panel:     var(--github-orange);
  --agenda-closing:   var(--github-yellow);
}

/* Light Mode */
[data-theme="light"] {
  --bg-canvas:    #ffffff;
  --bg-default:   #ffffff;
  --bg-overlay:   #f6f8fa;
  --bg-subtle:    #f6f8fa;
  --bg-muted:     #eaeef2;
  --bg-elevated:  #ffffff;

  --border-default: #d0d7de;
  --border-muted:   #d8dee4;
  --border-subtle:  rgba(31, 35, 40, 0.12);

  --text-primary:   #1f2328;
  --text-secondary: #656d76;
  --text-tertiary:  #6e7781;
  --text-disabled:  #8c959f;
  --text-inverse:   #ffffff;
  --text-link:      #0969da;
  --text-link-hover: #0550ae;

  --shadow-sm:  0 1px 2px rgba(31, 35, 40, 0.12);
  --shadow-md:  0 3px 12px rgba(31, 35, 40, 0.15);
  --shadow-lg:  0 8px 32px rgba(31, 35, 40, 0.20);
  --inset-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.8);
}

/* =============================================================================
   2. RESET & BASE
   ============================================================================= */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + var(--space-4));
  -webkit-text-size-adjust: 100%;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: var(--weight-normal);
  line-height: var(--leading-normal);
  color: var(--text-primary);
  background-color: var(--bg-canvas);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

h1, h2, h3, h4, h5, h6 {
  font-weight: var(--weight-bold);
  line-height: var(--leading-tight);
  color: var(--text-primary);
}

p { color: var(--text-secondary); line-height: var(--leading-relaxed); }
a {
  color: var(--text-link);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--text-link-hover); text-decoration: underline; }
a:focus-visible {
  outline: 2px solid var(--copilot-purple);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

img, svg { display: block; max-width: 100%; }
ul, ol { list-style: none; }
button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}
button:focus-visible {
  outline: 2px solid var(--copilot-purple);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* =============================================================================
   3. ACCESSIBILITY
   ============================================================================= */
.skip-link {
  position: absolute;
  top: -100px;
  left: var(--space-4);
  padding: var(--space-2) var(--space-4);
  background: var(--copilot-purple);
  color: #fff;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  z-index: var(--z-top);
  transition: top var(--transition-fast);
}
.skip-link:focus { top: var(--space-4); }

.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;
}

/* =============================================================================
   4. LAYOUT UTILITIES
   ============================================================================= */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-6);
}
.container-narrow {
  max-width: var(--container-narrow);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

section {
  padding-block: var(--space-20);
}
section:first-of-type { padding-top: 0; }

.section-label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--copilot-purple-light);
  padding: var(--space-1) var(--space-3);
  background: rgba(137, 87, 229, 0.12);
  border: 1px solid rgba(137, 87, 229, 0.25);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-4);
}

.section-heading {
  font-size: clamp(var(--text-3xl), 5vw, var(--text-5xl));
  font-weight: var(--weight-extrabold);
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: var(--space-4);
}

.section-subheading {
  font-size: clamp(var(--text-base), 2vw, var(--text-xl));
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  max-width: 640px;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-12);
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* =============================================================================
   5. NAVIGATION
   ============================================================================= */
#navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-nav);
  height: var(--nav-height);
  background: rgba(13, 17, 23, 0.85);
  border-bottom: 1px solid transparent;
  backdrop-filter: blur(12px) saturate(180%);
  -webkit-backdrop-filter: blur(12px) saturate(180%);
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal);
}
[data-theme="light"] #navbar {
  background: rgba(255, 255, 255, 0.92);
}
#navbar.scrolled {
  border-bottom-color: var(--border-default);
  box-shadow: var(--shadow-sm);
}

#main-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-6);
  gap: var(--space-6);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  flex-shrink: 0;
}
.nav-logo:hover { text-decoration: none; }

.nav-logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--copilot-purple), var(--github-blue));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

.nav-logo-img {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  object-fit: contain;
  flex-shrink: 0;
}

.nav-logo-text {
  display: flex;
  flex-direction: column;
}
.nav-logo-primary {
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
  line-height: 1.2;
}
.nav-logo-secondary {
  font-size: var(--text-xs);
  color: var(--copilot-purple-light);
  font-weight: var(--weight-medium);
  line-height: 1.2;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  flex: 1;
  justify-content: center;
}

.nav-link {
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), background-color var(--transition-fast);
  white-space: nowrap;
}
.nav-link:hover, .nav-link.active {
  color: var(--text-primary);
  background: var(--bg-muted);
  text-decoration: none;
}
.nav-link.active { color: var(--copilot-purple-light); }

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

.btn-theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: transparent;
  border: 1px solid var(--border-default);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  transition: all var(--transition-fast);
}
.btn-theme-toggle:hover {
  background: var(--bg-muted);
  color: var(--text-primary);
  border-color: var(--border-muted);
}

/* Mobile menu button */
.nav-mobile-toggle {
  display: none;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: transparent;
  border: 1px solid var(--border-default);
  color: var(--text-secondary);
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
  padding: 9px;
  transition: all var(--transition-fast);
}
.nav-mobile-toggle span {
  width: 100%;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
  display: block;
}
.nav-mobile-toggle:hover { background: var(--bg-muted); color: var(--text-primary); }
.nav-mobile-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-mobile-toggle.open span:nth-child(2) { opacity: 0; }
.nav-mobile-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile nav overlay */
.nav-mobile-overlay {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-canvas);
  z-index: var(--z-nav);
  padding: var(--space-4);
  overflow-y: auto;
}
.nav-mobile-overlay.open { display: flex; flex-direction: column; gap: var(--space-2); }
.nav-mobile-link {
  display: block;
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-base);
  font-weight: var(--weight-medium);
  color: var(--text-primary);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  text-decoration: none;
  transition: all var(--transition-fast);
}
.nav-mobile-link:hover {
  background: var(--bg-muted);
  border-color: var(--border-default);
  text-decoration: none;
}

/* =============================================================================
   6. BUTTONS
   ============================================================================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 9px var(--space-4);
  font-family: inherit;
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  line-height: 1.25;
  white-space: nowrap;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-fast);
  user-select: none;
  -webkit-user-select: none;
}
.btn:focus-visible {
  outline: 2px solid var(--copilot-purple);
  outline-offset: 2px;
}

.btn-primary {
  background: var(--copilot-purple);
  color: #ffffff;
  border-color: rgba(255,255,255,0.1);
  box-shadow: var(--inset-shadow), 0 2px 8px rgba(137, 87, 229, 0.3);
}
.btn-primary:hover {
  background: var(--copilot-purple-light);
  text-decoration: none;
  color: #ffffff;
  box-shadow: var(--inset-shadow), 0 4px 16px rgba(137, 87, 229, 0.4);
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--bg-muted);
  color: var(--text-primary);
  border-color: var(--border-default);
}
.btn-secondary:hover {
  background: var(--bg-overlay);
  color: var(--text-primary);
  text-decoration: none;
  border-color: var(--border-muted);
}

.btn-outline {
  background: transparent;
  color: var(--copilot-purple-light);
  border-color: var(--copilot-purple);
}
.btn-outline:hover {
  background: rgba(137, 87, 229, 0.1);
  color: var(--copilot-purple-light);
  text-decoration: none;
}

.btn-share {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 0.55rem 1rem;
  font-size: 0.85rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-default);
  font-weight: 500;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, border-color 0.15s, transform 0.1s;
}
.btn-share:hover {
  transform: translateY(-1px);
  text-decoration: none;
}
.btn-share-linkedin {
  background: #0a66c2;
  color: #ffffff;
  border-color: #0a66c2;
}
.btn-share-linkedin:hover {
  background: #004182;
  border-color: #004182;
  color: #ffffff;
}
.btn-share-x {
  background: #000000;
  color: #ffffff;
  border-color: #333333;
}
.btn-share-x:hover {
  background: #1a1a1a;
  border-color: #555555;
  color: #ffffff;
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border-color: transparent;
}
.btn-ghost:hover {
  background: var(--bg-muted);
  color: var(--text-primary);
  text-decoration: none;
}

.btn-lg {
  padding: 12px var(--space-6);
  font-size: var(--text-base);
  gap: var(--space-3);
}
.btn-sm {
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
}

/* =============================================================================
   7. HERO SECTION
   ============================================================================= */
#hero {
  position: relative;
  min-height: 100svh;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--nav-height);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(ellipse 100% 60% at 50% 0%, rgba(137, 87, 229, 0.25) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 70%, rgba(88, 166, 255, 0.12) 0%, transparent 50%),
    radial-gradient(ellipse 40% 30% at 20% 80%, rgba(63, 185, 80, 0.08) 0%, transparent 40%);
}
[data-theme="light"] .hero-bg {
  background:
    radial-gradient(ellipse 100% 60% at 50% 0%, rgba(137, 87, 229, 0.12) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 70%, rgba(88, 166, 255, 0.08) 0%, transparent 50%);
}

/* Geometric grid overlay */
.hero-grid {
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image:
    linear-gradient(var(--border-subtle) 1px, transparent 1px),
    linear-gradient(90deg, var(--border-subtle) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 80% at 50% 0%, black 0%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 80% 80% at 50% 0%, black 0%, transparent 70%);
}

.hero-content {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-6);
  padding-block: var(--space-20);
  text-align: center;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--copilot-purple-light);
  padding: var(--space-2) var(--space-4);
  background: rgba(137, 87, 229, 0.1);
  border: 1px solid rgba(137, 87, 229, 0.3);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-6);
  animation: fadeInDown 0.6s ease both;
}
.hero-eyebrow .hero-dot {
  width: 6px; height: 6px;
  background: var(--github-green);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--github-green);
  animation: pulse 2s ease infinite;
}

.hero-title {
  font-size: clamp(var(--text-4xl), 7vw, 5.5rem);
  font-weight: var(--weight-extrabold);
  letter-spacing: -0.03em;
  line-height: 1.05;
  color: var(--text-primary);
  margin-bottom: var(--space-6);
  animation: fadeInUp 0.6s ease 0.1s both;
}

.hero-title .highlight {
  background: linear-gradient(135deg, var(--copilot-purple-light) 0%, var(--github-blue) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-description {
  font-size: clamp(var(--text-lg), 2.5vw, var(--text-xl));
  color: var(--text-secondary);
  max-width: 680px;
  margin-inline: auto;
  margin-bottom: var(--space-8);
  line-height: var(--leading-relaxed);
  animation: fadeInUp 0.6s ease 0.2s both;
}

.hero-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--space-4) var(--space-6);
  margin-bottom: var(--space-8);
  animation: fadeInUp 0.6s ease 0.25s both;
}
.hero-meta-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
}
.hero-meta-item svg, .hero-meta-item .icon { color: var(--copilot-purple-light); flex-shrink: 0; }

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-bottom: var(--space-12);
  animation: fadeInUp 0.6s ease 0.3s both;
}

/* Hero stats bar */
.hero-stats {
  display: flex;
  align-items: stretch;
  justify-content: center;
  flex-wrap: wrap;
  gap: 1px;
  background: var(--border-default);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  overflow: hidden;
  max-width: 700px;
  margin-inline: auto;
  animation: fadeInUp 0.6s ease 0.4s both;
}
.hero-stat {
  flex: 1;
  min-width: 120px;
  padding: var(--space-4) var(--space-6);
  background: var(--bg-overlay);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
}
.hero-stat-value {
  font-size: var(--text-2xl);
  font-weight: var(--weight-extrabold);
  color: var(--text-primary);
  line-height: 1;
}
.hero-stat-label {
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  font-weight: var(--weight-medium);
  white-space: nowrap;
}

/* Countdown */
.countdown-container {
  margin-top: var(--space-8);
  text-align: center;
  animation: fadeInUp 0.6s ease 0.5s both;
}
.countdown-title {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-tertiary);
  margin-bottom: var(--space-3);
  font-weight: var(--weight-semibold);
}
.countdown {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
}
.countdown-unit {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
}
.countdown-number {
  font-size: var(--text-3xl);
  font-weight: var(--weight-extrabold);
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
  min-width: 2.5ch;
  text-align: center;
  line-height: 1;
  padding: var(--space-3) var(--space-4);
  background: var(--bg-overlay);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
}
.countdown-label {
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  font-weight: var(--weight-medium);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.countdown-separator {
  font-size: var(--text-3xl);
  font-weight: var(--weight-bold);
  color: var(--text-tertiary);
  margin-bottom: var(--space-4);
}

/* =============================================================================
   8. ABOUT / HIGHLIGHTS
   ============================================================================= */
#about { background: var(--bg-canvas); }

.highlights-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-8);
}

.highlight-card {
  padding: var(--space-6);
  background: var(--bg-overlay);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}
.highlight-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(137, 87, 229, 0.05) 0%, transparent 60%);
  opacity: 0;
  transition: opacity var(--transition-normal);
}
.highlight-card:hover {
  border-color: var(--copilot-purple);
  box-shadow: 0 0 0 1px var(--copilot-purple), var(--shadow-glow);
  transform: translateY(-2px);
}
.highlight-card:hover::before { opacity: 1; }

.highlight-icon {
  font-size: 2rem;
  margin-bottom: var(--space-4);
  display: inline-block;
  filter: drop-shadow(0 0 8px rgba(137, 87, 229, 0.4));
}
.highlight-title {
  font-size: var(--text-lg);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}
.highlight-desc {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
}

/* =============================================================================
   9. PREREQUISITES
   ============================================================================= */
#prerequisites {
  background: var(--bg-subtle);
}
[data-theme="light"] #prerequisites { background: var(--bg-overlay); }

.prerequisites-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-8);
}

.prereq-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--space-5);
  background: var(--bg-canvas);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  transition: border-color var(--transition-fast);
}
.prereq-card:hover { border-color: var(--copilot-purple); }

.prereq-check {
  width: 28px; height: 28px;
  border-radius: 50%;
  background: rgba(63, 185, 80, 0.15);
  border: 1px solid rgba(63, 185, 80, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--github-green);
  font-weight: var(--weight-bold);
  font-size: var(--text-sm);
  flex-shrink: 0;
}
.prereq-title {
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
}
.prereq-desc {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  flex: 1;
}
.prereq-link {
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--copilot-purple-light);
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
}
.prereq-link:hover { text-decoration: underline; }

/* =============================================================================
   10. AGENDA
   ============================================================================= */
#agenda { background: var(--bg-canvas); }

/* Coming-soon banner (agenda & any section) */
.coming-soon-banner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-16) var(--space-8);
  border: 1px dashed var(--border-default);
  border-radius: var(--radius-xl);
  max-width: 600px;
  margin-inline: auto;
  text-align: center;
}
.coming-soon-icon { font-size: 3rem; line-height: 1; }
.coming-soon-title {
  font-size: var(--text-2xl);
  font-weight: var(--weight-bold);
  color: var(--text-primary);
  margin: 0;
}
.coming-soon-msg {
  font-size: var(--text-base);
  color: var(--text-secondary);
  margin: 0;
  max-width: 440px;
}
.coming-soon-subheading {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  color: var(--text-secondary);
}

/* Variante inline: banner horizontal encima de la tabla */
.coming-soon-banner--inline {
  flex-direction: row;
  justify-content: flex-start;
  text-align: left;
  padding: var(--space-4) var(--space-6);
  max-width: 900px;
  margin-bottom: var(--space-4);
  background: rgba(137, 87, 229, 0.07);
  border-color: rgba(137, 87, 229, 0.35);
  border-style: solid;
}
.coming-soon-banner--inline .coming-soon-icon { font-size: 1.5rem; }
.coming-soon-banner--inline .coming-soon-title { font-size: var(--text-base); margin-bottom: 2px; }
.coming-soon-banner--inline .coming-soon-msg { font-size: var(--text-sm); }

/* =============================================================================
   AGENDA — tabla multi-track
   ============================================================================= */
.agenda-table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-default);
  max-width: 900px;
  margin-inline: auto;
}
.agenda-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}
.agenda-table thead tr {
  background: var(--github-green);
}
.agenda-table thead th {
  padding: var(--space-3) var(--space-5);
  font-weight: var(--weight-bold);
  color: #fff;
  text-align: left;
  white-space: nowrap;
  border-right: 1px solid rgba(255, 255, 255, 0.15);
}
.agenda-table thead th:last-child { border-right: none; }
.agenda-table tbody tr {
  border-bottom: 1px solid var(--border-default);
  transition: background var(--transition-fast);
}
.agenda-table tbody tr:last-child { border-bottom: none; }
.agenda-table tbody tr:hover { background: var(--bg-muted); }
.agenda-table tbody td {
  padding: var(--space-3) var(--space-5);
  color: var(--text-primary);
  vertical-align: middle;
  border-right: 1px solid var(--border-default);
}
.agenda-table tbody td:last-child { border-right: none; }

.agenda-row-time {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-secondary);
  white-space: nowrap;
}
.agenda-row-span td:first-child {
  text-align: center;
  color: var(--text-secondary);
}
.agenda-row-span[data-type="keynote"] td {
  color: var(--copilot-purple-light);
  font-weight: var(--weight-semibold);
}
.agenda-row-span[data-type="break"] td {
  color: var(--text-tertiary);
  background: var(--bg-muted);
}
.agenda-row-span[data-type="closing"] td { color: var(--text-secondary); }
.agenda-row-span[data-type="logistics"] td { color: var(--text-tertiary); }
.agenda-cell-empty { background: rgba(0, 0, 0, 0.18); }
[data-theme="light"] .agenda-cell-empty { background: rgba(0, 0, 0, 0.05); }

@media (max-width: 480px) {
  .agenda-table thead th,
  .agenda-table tbody td { padding: var(--space-2) var(--space-3); }
}
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-8);
  justify-content: center;
}
.agenda-filter-btn {
  padding: var(--space-1) var(--space-4);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
  background: var(--bg-muted);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
}
.agenda-filter-btn:hover {
  color: var(--text-primary);
  border-color: var(--copilot-purple);
}
.agenda-filter-btn.active {
  color: #fff;
  background: var(--copilot-purple);
  border-color: var(--copilot-purple);
}

.agenda-timeline {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  max-width: 900px;
  margin-inline: auto;
}

.agenda-item {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: var(--space-4);
  align-items: start;
  padding: var(--space-4) var(--space-5);
  background: var(--bg-overlay);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  border-left-width: 3px;
  transition: all var(--transition-fast);
  text-align: left;
}
.agenda-item:hover {
  background: var(--bg-muted);
  border-color: var(--border-muted);
  transform: translateX(2px);
}
.agenda-item[data-type="keynote"]  { border-left-color: var(--agenda-keynote); }
.agenda-item[data-type="session"]  { border-left-color: var(--agenda-session); }
.agenda-item[data-type="workshop"] { border-left-color: var(--agenda-workshop); }
.agenda-item[data-type="break"]    { border-left-color: var(--agenda-break); opacity: 0.75; }
.agenda-item[data-type="panel"]    { border-left-color: var(--agenda-panel); }
.agenda-item[data-type="closing"]  { border-left-color: var(--agenda-closing); }
.agenda-item[data-type="logistics"]{ border-left-color: var(--agenda-logistics); opacity: 0.75; }
.agenda-item.hidden                { display: none; }

.agenda-time {
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  font-weight: var(--weight-medium);
  color: var(--text-tertiary);
  padding-top: 2px;
  white-space: nowrap;
}

.agenda-body { min-width: 0; }

.agenda-badges {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-2);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  font-size: 11px;
  font-weight: var(--weight-semibold);
  letter-spacing: 0.03em;
  border-radius: var(--radius-full);
  white-space: nowrap;
}
.badge-keynote  { background: rgba(137, 87, 229, 0.15); color: var(--copilot-purple-light); border: 1px solid rgba(137, 87, 229, 0.3); }
.badge-session  { background: rgba(88, 166, 255, 0.15);  color: #79c0ff; border: 1px solid rgba(88, 166, 255, 0.3); }
.badge-workshop { background: rgba(63, 185, 80, 0.15);   color: #56d364; border: 1px solid rgba(63, 185, 80, 0.3); }
.badge-panel    { background: rgba(227, 179, 65, 0.15);  color: #e3b341; border: 1px solid rgba(227, 179, 65, 0.3); }
.badge-closing  { background: rgba(210, 153, 34, 0.15);  color: #d29922; border: 1px solid rgba(210, 153, 34, 0.3); }
.badge-break    { background: var(--bg-muted); color: var(--text-tertiary); border: 1px solid var(--border-muted); }
.badge-logistics{ background: var(--bg-muted); color: var(--text-tertiary); border: 1px solid var(--border-muted); }
.badge-level    { background: rgba(88, 166, 255, 0.12); color: #79c0ff; border: 1px solid rgba(88, 166, 255, 0.25); }
.badge-lang     { background: var(--bg-muted); color: var(--text-secondary); border: 1px solid var(--border-default); font-family: var(--font-mono); font-size: 10px; }
.badge-track    { background: rgba(137, 87, 229, 0.1); color: var(--copilot-purple-light); border: 1px solid rgba(137, 87, 229, 0.2); }
.badge-green    { background: rgba(63, 185, 80, 0.15); color: #56d364; border: 1px solid rgba(63, 185, 80, 0.3); }

.agenda-title {
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-1);
  line-height: var(--leading-snug);
}
.agenda-desc {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-2);
}
.agenda-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  font-size: var(--text-xs);
  color: var(--text-tertiary);
}
.agenda-meta-item {
  display: flex;
  align-items: center;
  gap: 4px;
}
.agenda-speakers {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-2);
}
.agenda-speaker-chip {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 3px 8px 3px 4px;
  background: var(--bg-muted);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}
.agenda-speaker-chip:hover {
  border-color: var(--copilot-purple);
  color: var(--copilot-purple-light);
  background: rgba(137, 87, 229, 0.08);
}
.speaker-chip-avatar {
  width: 20px; height: 20px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 9px;
  font-weight: var(--weight-bold);
  color: #fff;
  flex-shrink: 0;
  overflow: hidden;
}
.speaker-chip-avatar img { width: 100%; height: 100%; object-fit: cover; }

/* =============================================================================
   11. SPEAKERS
   ============================================================================= */
#speakers { background: var(--bg-subtle); }
[data-theme="light"] #speakers { background: var(--bg-overlay); }

.speakers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-4);
}

/* Veiled state: cards show structure but content is blurred/invisible */
.speakers-grid--veiled { pointer-events: none; user-select: none; }
.speaker-card--veiled {
  cursor: default;
  filter: blur(6px);
  opacity: 0.45;
  transform: none !important;
  pointer-events: none;
}
.speaker-card--veiled:hover {
  border-color: var(--border-default);
  box-shadow: none;
  transform: none;
}
.speaker-card--veiled::after { display: none; }

.speaker-card {
  background: var(--bg-canvas);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  cursor: pointer;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  position: relative;
  overflow: hidden;
}
.speaker-card::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--copilot-purple), var(--github-blue));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-normal);
}
.speaker-card:hover {
  border-color: var(--copilot-purple);
  box-shadow: 0 8px 32px rgba(137, 87, 229, 0.15);
  transform: translateY(-4px);
  text-decoration: none;
}
.speaker-card:hover::after { transform: scaleX(1); }

.speaker-avatar {
  width: 72px; height: 72px;
  border-radius: 50%;
  border: 3px solid var(--border-default);
  overflow: hidden;
  flex-shrink: 0;
  transition: border-color var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xl);
  font-weight: var(--weight-bold);
  color: #fff;
}
.speaker-card:hover .speaker-avatar { border-color: var(--copilot-purple); }
.speaker-avatar img { width: 100%; height: 100%; object-fit: cover; }

.speaker-name {
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
  line-height: var(--leading-tight);
}
.speaker-role {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-snug);
}
.speaker-company {
  font-size: var(--text-sm);
  color: var(--copilot-purple-light);
  font-weight: var(--weight-medium);
}
.speaker-bio-preview {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.speaker-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  margin-top: auto;
}
.speaker-tag {
  padding: 2px 8px;
  font-size: 11px;
  font-weight: var(--weight-medium);
  color: var(--text-tertiary);
  background: var(--bg-muted);
  border: 1px solid var(--border-muted);
  border-radius: var(--radius-full);
}
.speaker-social {
  display: flex;
  gap: var(--space-2);
  margin-top: var(--space-1);
}
.speaker-social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px; height: 28px;
  border-radius: var(--radius-sm);
  background: var(--bg-muted);
  color: var(--text-tertiary);
  font-size: 14px;
  transition: all var(--transition-fast);
  text-decoration: none;
}
.speaker-social-link:hover {
  background: rgba(137, 87, 229, 0.15);
  color: var(--copilot-purple-light);
  text-decoration: none;
  transform: translateY(-1px);
}
.featured-badge {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  padding: 2px 8px;
  font-size: 10px;
  font-weight: var(--weight-bold);
  color: var(--github-yellow);
  background: rgba(210, 153, 34, 0.15);
  border: 1px solid rgba(210, 153, 34, 0.3);
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* =============================================================================
   12. VENUE
   ============================================================================= */
#venue { background: var(--bg-canvas); }

.venue-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
  align-items: start;
}

.venue-card {
  background: var(--bg-overlay);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
}
.venue-name {
  font-size: var(--text-2xl);
  font-weight: var(--weight-bold);
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}
.venue-address {
  font-size: var(--text-base);
  color: var(--text-secondary);
  margin-bottom: var(--space-6);
  line-height: var(--leading-relaxed);
}
.venue-description {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-6);
}
.venue-map-wrapper {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-default);
  margin-bottom: var(--space-2);
}
.venue-map-iframe {
  display: block;
  width: 100%;
  height: 280px;
  border: 0;
  border-radius: var(--radius-lg);
  filter: grayscale(0.2) contrast(0.95);
}
[data-theme="dark"] .venue-map-iframe {
  filter: invert(0.9) hue-rotate(180deg) grayscale(0.1) contrast(0.9);
}
.venue-map-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  text-decoration: none;
  padding: var(--space-1) var(--space-2);
  transition: color var(--transition-fast);
}
.venue-map-link:hover { color: var(--copilot-purple-light); }
.venue-map-icon { font-size: 2.5rem; }

.transport-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
  margin-top: var(--space-4);
}
@media (max-width: 900px) {
  .transport-list { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) {
  .transport-list { grid-template-columns: 1fr; }
}
.transport-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--bg-canvas);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
}
.transport-icon {
  font-size: 1.25rem;
  flex-shrink: 0;
  width: 32px;
  text-align: center;
}
.transport-label {
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
  display: block;
  margin-bottom: 2px;
}
.transport-info {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}
.venue-amenities {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-6);
}
.venue-amenity {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: rgba(63, 185, 80, 0.08);
  border: 1px solid rgba(63, 185, 80, 0.2);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  color: #56d364;
}

/* =============================================================================
   13. REGISTRATION
   ============================================================================= */
#registration { background: var(--bg-subtle); }
[data-theme="light"] #registration { background: var(--bg-overlay); }

.registration-tier {
  max-width: 600px;
  margin-inline: auto;
  background: var(--bg-canvas);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.registration-tier::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--copilot-purple), var(--github-blue), var(--github-green));
}
.tier-badge {
  display: inline-block;
  padding: var(--space-1) var(--space-4);
  font-size: var(--text-xs);
  font-weight: var(--weight-bold);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-4);
}
.tier-badge-green {
  background: rgba(63, 185, 80, 0.15);
  color: #56d364;
  border: 1px solid rgba(63, 185, 80, 0.3);
}
.tier-name {
  font-size: var(--text-2xl);
  font-weight: var(--weight-bold);
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}
.tier-price {
  font-size: var(--text-5xl);
  font-weight: var(--weight-extrabold);
  color: var(--github-green);
  line-height: 1;
  margin-bottom: var(--space-4);
}
.tier-desc {
  font-size: var(--text-base);
  color: var(--text-secondary);
  margin-bottom: var(--space-6);
}
.tier-includes {
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-bottom: var(--space-8);
}
.tier-include-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  font-size: var(--text-sm);
  color: var(--text-secondary);
}
.tier-include-item::before {
  content: '✓';
  color: var(--github-green);
  font-weight: var(--weight-bold);
  flex-shrink: 0;
  margin-top: 1px;
}
.spots-indicator {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-top: var(--space-4);
  padding: var(--space-3) var(--space-4);
  background: var(--bg-muted);
  border-radius: var(--radius-lg);
}
.spots-bar {
  flex: 1;
  height: 6px;
  background: var(--bg-overlay);
  border-radius: var(--radius-full);
  overflow: hidden;
}
.spots-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--github-green), var(--copilot-purple));
  border-radius: var(--radius-full);
  transition: width 1s ease;
}
.spots-text {
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  white-space: nowrap;
}

/* =============================================================================
   14. SPONSORS
   ============================================================================= */
#sponsors { background: var(--bg-canvas); }

.sponsor-level {
  margin-bottom: var(--space-12);
}
.sponsor-level-title {
  text-align: center;
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin-bottom: var(--space-6);
  display: flex;
  align-items: center;
  gap: var(--space-4);
}
.sponsor-level-title::before, .sponsor-level-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border-default);
}

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

.sponsor-card {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4) var(--space-8);
  background: var(--bg-overlay);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  min-height: 80px;
  min-width: 160px;
  transition: all var(--transition-normal);
  text-decoration: none;
}
.sponsor-card:hover {
  border-color: var(--copilot-purple);
  box-shadow: var(--shadow-glow);
  transform: scale(1.03);
  text-decoration: none;
}
.sponsor-card img {
  max-height: 40px;
  max-width: 160px;
  object-fit: contain;
  filter: grayscale(60%) opacity(0.8);
  transition: filter var(--transition-normal);
}
.sponsor-card:hover img {
  filter: grayscale(0%) opacity(1);
}
.sponsor-name-text {
  font-size: var(--text-lg);
  font-weight: var(--weight-bold);
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}
.sponsor-card:hover .sponsor-name-text { color: var(--text-primary); }

/* Veiled sponsors */
.sponsors-veiled { pointer-events: none; user-select: none; }
.sponsor-card--veiled {
  filter: blur(5px);
  opacity: 0.4;
  cursor: default;
  pointer-events: none;
}
.sponsor-card--veiled:hover {
  border-color: var(--border-default);
  box-shadow: none;
  transform: none;
}

/* Become a sponsor CTA */
.sponsor-cta {
  text-align: center;
  margin-top: var(--space-12);
  padding: var(--space-8);
  background: var(--bg-overlay);
  border: 1px dashed var(--border-default);
  border-radius: var(--radius-xl);
}
.sponsor-cta p {
  font-size: var(--text-base);
  color: var(--text-secondary);
  margin-bottom: var(--space-4);
}

/* =============================================================================
   15. ORGANIZACIÓN
   ============================================================================= */
#organizers { background: var(--bg-canvas); }

.organizers-grid {
  display: grid;
  gap: var(--space-8);
  max-width: 720px;
  margin: 0 auto;
}

.organizer-card {
  display: flex;
  align-items: flex-start;
  gap: var(--space-6);
  background: var(--bg-overlay);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.organizer-card:hover {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 1px var(--accent-primary), var(--shadow-md);
}

.organizer-logo {
  flex-shrink: 0;
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-subtle);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-default);
  overflow: hidden;
}

.organizer-logo-img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: var(--space-2);
}

.organizer-logo-text {
  font-weight: 700;
  font-size: var(--text-sm);
  color: var(--accent-primary);
  text-align: center;
  line-height: 1.2;
  padding: var(--space-2);
}

.organizer-info {
  flex: 1;
  min-width: 0;
}

.organizer-name {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--text-primary);
  margin: 0 0 var(--space-2);
}

.organizer-description {
  font-size: var(--text-base);
  color: var(--text-secondary);
  line-height: 1.6;
  margin: 0 0 var(--space-4);
}

.organizer-links {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.organizer-socials {
  display: flex;
  gap: var(--space-3);
}

.organizer-social {
  color: var(--text-secondary);
  transition: color 0.2s;
  display: flex;
  align-items: center;
}

.organizer-social:hover { color: var(--accent-primary); }

@media (max-width: 600px) {
  .organizer-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .organizer-links {
    justify-content: center;
  }
}

/* =============================================================================
   16. RESOURCES
   ============================================================================= */
#resources { background: var(--bg-subtle); }
[data-theme="light"] #resources { background: var(--bg-overlay); }

.resources-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-4);
}
.resource-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--space-5);
  background: var(--bg-canvas);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  transition: all var(--transition-fast);
  text-decoration: none;
}
.resource-card:hover {
  border-color: var(--copilot-purple);
  transform: translateY(-2px);
  text-decoration: none;
}
.resource-icon { font-size: 1.75rem; }
.resource-title {
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
}
.resource-desc {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  flex: 1;
  line-height: var(--leading-relaxed);
}
.resource-link-text {
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  color: var(--copilot-purple-light);
}

/* =============================================================================
   16. FAQ ACCORDION
   ============================================================================= */
#faq { background: var(--bg-canvas); }

.faq-list {
  max-width: 760px;
  margin-inline: auto;
  display: flex;
  flex-direction: column;
}

.faq-item {
  border-bottom: 1px solid var(--border-default);
}
.faq-item:first-child { border-top: 1px solid var(--border-default); }

.faq-question {
  width: 100%;
  text-align: left;
  padding: var(--space-5) 0;
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  transition: color var(--transition-fast);
  background: transparent;
  cursor: pointer;
}
.faq-question:hover { color: var(--copilot-purple-light); }
.faq-question-icon {
  color: var(--copilot-purple);
  flex-shrink: 0;
  transition: transform var(--transition-normal);
}
.faq-item.open .faq-question-icon { transform: rotate(45deg); }

.faq-answer {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows var(--transition-normal);
}
.faq-item.open .faq-answer { grid-template-rows: 1fr; }
.faq-answer-inner {
  overflow: hidden;
  padding-bottom: 0;
  transition: padding-bottom var(--transition-normal);
}
.faq-item.open .faq-answer-inner { padding-bottom: var(--space-5); }
.faq-answer-text {
  font-size: var(--text-base);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
}

/* =============================================================================
   17. CODE OF CONDUCT
   ============================================================================= */
#code-of-conduct { background: var(--bg-subtle); }
[data-theme="light"] #code-of-conduct { background: var(--bg-overlay); }

.coc-card {
  max-width: 760px;
  margin-inline: auto;
  background: var(--bg-canvas);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
}
.coc-summary {
  font-size: var(--text-base);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-6);
  padding: var(--space-4);
  border-left: 3px solid var(--copilot-purple);
  background: rgba(137, 87, 229, 0.05);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}
.coc-principles {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
}
.coc-principle {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
}
.coc-principle-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--copilot-purple);
  flex-shrink: 0;
  margin-top: 7px;
}

/* =============================================================================
   18. COMMUNITY / CONTACT
   ============================================================================= */
#community { background: var(--bg-canvas); }

.community-card {
  max-width: 760px;
  margin-inline: auto;
  background: var(--bg-overlay);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-2xl);
  padding: var(--space-10);
  text-align: center;
}
.community-org-name {
  font-size: var(--text-2xl);
  font-weight: var(--weight-bold);
  color: var(--text-primary);
  margin-bottom: var(--space-3);
}
.community-org-desc {
  font-size: var(--text-base);
  color: var(--text-secondary);
  max-width: 540px;
  margin-inline: auto;
  margin-bottom: var(--space-8);
  line-height: var(--leading-relaxed);
}
.social-links {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--space-3);
}
.social-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
  background: var(--bg-canvas);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
  text-decoration: none;
}
.social-link:hover {
  border-color: var(--copilot-purple);
  color: var(--copilot-purple-light);
  background: rgba(137, 87, 229, 0.08);
  text-decoration: none;
  transform: translateY(-1px);
}

/* =============================================================================
   19. SPEAKER MODAL
   ============================================================================= */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--z-modal);
  background: rgba(1, 4, 9, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-6);
  backdrop-filter: blur(4px);
  animation: fadeIn 0.2s ease;
}
.modal-overlay[hidden] { display: none; }

.modal-container {
  background: var(--bg-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  max-width: 560px;
  width: 100%;
  max-height: 80vh;
  overflow-y: auto;
  position: relative;
  animation: slideUp 0.3s cubic-bezier(0.2, 0, 0, 1);
  box-shadow: var(--shadow-lg);
}
.modal-close {
  position: sticky;
  top: 0;
  float: right;
  width: 32px; height: 32px;
  border-radius: var(--radius-md);
  background: var(--bg-muted);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  flex-shrink: 0;
  margin-bottom: var(--space-2);
}
.modal-close:hover {
  background: rgba(248, 81, 73, 0.15);
  color: var(--github-red);
}

.modal-speaker-header {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
  clear: both;
}
.modal-speaker-avatar {
  width: 88px; height: 88px;
  border-radius: 50%;
  border: 3px solid var(--border-default);
  overflow: hidden;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-2xl);
  font-weight: var(--weight-bold);
  color: #fff;
}
.modal-speaker-avatar img { width: 100%; height: 100%; object-fit: cover; }
.modal-speaker-info { flex: 1; min-width: 0; }
#modal-speaker-name {
  font-size: var(--text-xl);
  font-weight: var(--weight-bold);
  color: var(--text-primary);
  margin-bottom: var(--space-1);
}
.modal-speaker-role {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-bottom: 2px;
}
.modal-speaker-company {
  font-size: var(--text-sm);
  color: var(--copilot-purple-light);
  font-weight: var(--weight-medium);
}
.modal-speaker-bio {
  font-size: var(--text-base);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-6);
}
.modal-speaker-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}
.modal-speaker-sessions {
  margin-bottom: var(--space-6);
}
.modal-sessions-title {
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-3);
}
.modal-session-item {
  padding: var(--space-3) var(--space-4);
  background: var(--bg-muted);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-bottom: var(--space-2);
  border-left: 3px solid var(--copilot-purple);
}

/* =============================================================================
   20. FOOTER
   ============================================================================= */
#footer {
  background: var(--bg-overlay);
  border-top: 1px solid var(--border-default);
  padding: var(--space-12) 0 var(--space-8);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-8);
  margin-bottom: var(--space-10);
}

.footer-brand {}
.footer-brand-name {
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}
.footer-brand-logo {
  width: 24px; height: 24px;
  background: linear-gradient(135deg, var(--copilot-purple), var(--github-blue));
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
}
.footer-brand-logo-img {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  object-fit: contain;
  flex-shrink: 0;
}
.footer-brand-desc {
  font-size: var(--text-sm);
  color: var(--text-tertiary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-4);
}
.footer-social {
  display: flex;
  gap: var(--space-2);
}
.footer-social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px; height: 32px;
  border-radius: var(--radius-md);
  background: var(--bg-muted);
  color: var(--text-tertiary);
  font-size: 14px;
  transition: all var(--transition-fast);
  text-decoration: none;
}
.footer-social-link:hover {
  background: rgba(137, 87, 229, 0.15);
  color: var(--copilot-purple-light);
  text-decoration: none;
}

.footer-col-title {
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-tertiary);
  margin-bottom: var(--space-4);
}
.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.footer-link {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}
.footer-link:hover { color: var(--copilot-purple-light); text-decoration: none; }

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
  padding-top: var(--space-6);
  border-top: 1px solid var(--border-muted);
  font-size: var(--text-xs);
  color: var(--text-tertiary);
}
.footer-bottom-links {
  display: flex;
  gap: var(--space-4);
}
.footer-bottom-link {
  color: var(--text-tertiary);
  text-decoration: none;
  transition: color var(--transition-fast);
}
.footer-bottom-link:hover {
  color: var(--copilot-purple-light);
  text-decoration: none;
}

/* =============================================================================
   21. BACK TO TOP BUTTON
   ============================================================================= */
#back-to-top {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  z-index: var(--z-overlay);
  width: 44px; height: 44px;
  border-radius: var(--radius-full);
  background: var(--copilot-purple);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  opacity: 0;
  transform: translateY(16px);
}
#back-to-top:not([hidden]) {
  opacity: 1;
  transform: translateY(0);
}
#back-to-top[hidden] { display: flex; }
#back-to-top:hover {
  background: var(--copilot-purple-light);
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

/* =============================================================================
   22. SCROLL ANIMATIONS
   ============================================================================= */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}
.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* =============================================================================
   23. ANIMATIONS
   ============================================================================= */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-12px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes slideUp {
  from { opacity: 0; transform: translateY(32px) scale(0.98); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes pulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 6px var(--github-green); }
  50% { opacity: 0.7; box-shadow: 0 0 12px var(--github-green); }
}
@keyframes gradient-shift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* =============================================================================
   24. SECTION-SPECIFIC DIVIDERS
   ============================================================================= */
.section-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-default), transparent);
  margin-inline: auto;
  max-width: var(--container-max);
}

/* =============================================================================
   25. RESPONSIVE — TABLET (≤1024px)
   ============================================================================= */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .footer-brand {
    grid-column: 1 / -1;
  }
  .venue-grid {
    grid-template-columns: 1fr;
  }
}

/* =============================================================================
   26. RESPONSIVE — MOBILE (≤768px)
   ============================================================================= */
@media (max-width: 768px) {
  :root {
    --nav-height: 56px;
  }

  .container, .container-narrow { padding-inline: var(--space-4); }

  section { padding-block: var(--space-12); }

  /* Nav */
  .nav-links { display: none; }
  .nav-mobile-toggle { display: flex; }

  /* Hero */
  .hero-content { padding-block: var(--space-12); }
  .hero-stats { flex-direction: row; gap: 1px; }
  .hero-stat { padding: var(--space-3); min-width: 80px; }
  .hero-stat-value { font-size: var(--text-xl); }
  .countdown-number { font-size: var(--text-2xl); padding: var(--space-2) var(--space-3); }

  /* Agenda */
  .agenda-item {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }
  .agenda-time { font-size: var(--text-xs); }

  /* Speakers */
  .speakers-grid { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }

  /* Footer */
  .footer-grid { grid-template-columns: 1fr; }
  .footer-brand { grid-column: auto; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }

  /* Modal */
  .modal-container { padding: var(--space-6); }
  .modal-speaker-header { flex-direction: column; align-items: center; text-align: center; }
}

/* =============================================================================
   27. RESPONSIVE — SMALL MOBILE (≤480px)
   ============================================================================= */
@media (max-width: 480px) {
  .hero-stats { display: grid; grid-template-columns: 1fr 1fr; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; }
  .sponsors-row { gap: var(--space-3); }
  .sponsor-card { min-width: 130px; padding: var(--space-3) var(--space-4); }
}

/* =============================================================================
   28. PRINT STYLES
   ============================================================================= */
@media print {
  #navbar, #back-to-top, .modal-overlay, .btn-theme-toggle { display: none !important; }
  body { background: white; color: black; }
  .hero-bg, .hero-grid { display: none; }
  section { padding-block: 2rem; }
  a { color: black; }
  .hero-title .highlight {
    -webkit-text-fill-color: black;
    background: none;
  }
}

/* =============================================================================
   29. 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; }
  .reveal { opacity: 1; transform: none; }
}