/* =====================================================
   IEEE COMPUTER SOCIETY UNAP — DESIGN SYSTEM
   ===================================================== */
/* Fuentes cargadas via <link> en HTML para mejor rendimiento */

:root {
  /* Surfaces */
  --surface:                  #0b1326;
  --surface-dim:              #0b1326;
  --surface-bright:           #31394d;
  --surface-container-lowest: #060e20;
  --surface-container-low:    #131b2e;
  --surface-container:        #171f33;
  --surface-container-high:   #222a3d;
  --surface-container-highest:#2d3449;
  --on-surface:         #dae2fd;
  --on-surface-variant: #bdc8d1;
  --outline:         #87929a;
  --outline-variant: #3e484f;
  /* Primary Tech Blue */
  --primary:              #8ed5ff;
  --on-primary:           #00354a;
  --primary-container:    #38bdf8;
  --on-primary-container: #004965;
  /* Secondary Cyan */
  --secondary:              #44e2cd;
  --on-secondary:           #003731;
  --secondary-container:    #03c6b2;
  --on-secondary-container: #004d44;
  /* Tertiary Indigo */
  --tertiary:           #c5c9ff;
  --tertiary-container: #a3abff;
  /* Error */
  --error:           #ffb4ab;
  --error-container: #93000a;
  /* Background */
  --background:    #0b1326;
  --on-background: #dae2fd;
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #38bdf8 0%, #44e2cd 100%);
  --gradient-hero:    linear-gradient(135deg, #060e20 0%, #0b1326 60%, #131b2e 100%);
  /* Glows */
  --glow-primary:   0 0 24px rgba(56,189,248,0.35);
  --glow-secondary: 0 0 24px rgba(68,226,205,0.3);
  /* Glassmorphism */
  --glass-bg:           rgba(23,31,51,0.7);
  --glass-border:       rgba(255,255,255,0.06);
  --glass-border-hover: rgba(56,189,248,0.3);
  /* Shadows */
  --shadow-light:  0 1px 3px rgba(0,0,0,0.4);
  --shadow-medium: 0 4px 16px rgba(0,0,0,0.5);
  --shadow-large:  0 8px 32px rgba(0,0,0,0.6);
  /* Border radius */
  --border-radius:       8px;
  --border-radius-large: 12px;
  --border-radius-small: 4px;
  --border-radius-full:  9999px;
  /* Transitions */
  --transition-fast: all 0.15s ease;
  --transition:      all 0.25s ease;
  --transition-slow: all 0.4s ease;
  /* Fonts */
  --font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono:   "Space Grotesk", "SFMono-Regular", Consolas, monospace;
  /* Font sizes */
  --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:  1.875rem;
  --text-4xl:  2.25rem;
  /* Spacing 4px base */
  --spacing-xs:  0.25rem;
  --spacing-sm:  0.5rem;
  --spacing-md:  1rem;
  --spacing-lg:  1.5rem;
  --spacing-xl:  2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  /* Layout */
  --container-max-width: 1280px;
  --container-padding:   24px;
  /* Aliases backward compat */
  --white:             #dae2fd;
  --text-primary:      #dae2fd;
  --text-secondary:    #bdc8d1;
  --text-muted:        #87929a;
  --accent-blue:       #38bdf8;
  --accent-cyan:       #44e2cd;
  --github-dark:       #060e20;
  --github-border:     #3e484f;
  --github-light-gray: #171f33;
  --github-bg:         #0b1326;
  --github-red:        #38bdf8;
}

/* RESET */
*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-family);
  line-height: 1.6;
  color: var(--on-surface);
  background: var(--background);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}
main { flex:1; }

/* TYPOGRAPHY */
h1,h2,h3,h4,h5,h6 { font-weight:600; line-height:1.3; margin-bottom:var(--spacing-md); color:var(--on-surface); }
h1 { font-size:var(--text-4xl); }
h2 { font-size:var(--text-3xl); }
h3 { font-size:var(--text-2xl); }
h4 { font-size:var(--text-xl); }
h5 { font-size:var(--text-lg); }
h6 { font-size:var(--text-base); }
p  { margin-bottom:var(--spacing-md); color:var(--on-surface-variant); }
a  { color:var(--primary); text-decoration:none; transition:var(--transition); }
a:hover { color:var(--secondary); text-decoration:none; }

/* CONTAINERS */
.container { max-width:var(--container-max-width); margin:0 auto; padding:0 var(--container-padding); }

/* BUTTONS */
.btn {
  display:inline-flex; align-items:center; gap:var(--spacing-sm);
  padding:12px 24px; border:none; border-radius:var(--border-radius);
  font-weight:600; font-size:var(--text-sm); text-decoration:none;
  cursor:pointer; transition:var(--transition); font-family:inherit; letter-spacing:0.02em;
}
.btn-primary {
  background:var(--gradient-primary); color:var(--on-primary); border:none; box-shadow:var(--glow-primary);
}
.btn-primary:hover {
  color:var(--on-primary); text-decoration:none; transform:translateY(-2px);
  box-shadow:0 0 32px rgba(56,189,248,0.5); filter:brightness(1.08);
}
.btn-secondary {
  background:transparent; color:var(--primary); border:1px solid var(--primary);
}
.btn-secondary:hover {
  background:rgba(56,189,248,0.1); border-color:var(--secondary);
  color:var(--secondary); text-decoration:none; transform:translateY(-2px); box-shadow:var(--glow-secondary);
}

/* CODE */
code {
  background:var(--surface-container); padding:2px 6px; border-radius:var(--border-radius-small);
  font-family:var(--font-mono); font-size:var(--text-sm); color:var(--secondary); border:1px solid var(--outline-variant);
}
.code-example {
  background:var(--surface-container-lowest); border:1px solid var(--outline-variant);
  border-radius:var(--border-radius); padding:var(--spacing-lg); margin:var(--spacing-md) 0;
  overflow-x:auto; position:relative;
}
.code-example::before {
  content:''; position:absolute; top:0; left:0; right:0; height:2px;
  background:var(--gradient-primary); border-radius:var(--border-radius) var(--border-radius) 0 0;
}
.code-example pre { margin:0; color:var(--on-surface); font-family:var(--font-mono); font-size:var(--text-sm); line-height:1.6; }
.code-example code { background:transparent; border:none; padding:0; color:var(--on-surface); }

/* HEADER */
.header {
  background:rgba(11,19,38,0.88); backdrop-filter:blur(20px); -webkit-backdrop-filter:blur(20px);
  border-bottom:1px solid var(--outline-variant); position:sticky; top:0; z-index:1000;
}
.header-container {
  max-width:var(--container-max-width); margin:0 auto; padding:0 var(--container-padding);
  display:flex; align-items:center; justify-content:space-between; height:72px;
}
.header-title { display:flex; align-items:center; }
.header-title h1 {
  font-size:1.3rem; font-weight:700;
  background:var(--gradient-primary); -webkit-background-clip:text; -webkit-text-fill-color:transparent; background-clip:text;
  margin:0; letter-spacing:-0.01em; font-family:var(--font-mono);
}
.header-nav { display:flex; align-items:center; gap:4px; }
.nav-link {
  color:var(--on-surface-variant); font-weight:500; font-size:var(--text-sm);
  padding:8px 14px; border-radius:var(--border-radius-small); transition:var(--transition);
  position:relative; display:inline-block; letter-spacing:0.01em;
}
.nav-link:hover { color:var(--primary); background:rgba(56,189,248,0.08); text-decoration:none; }
.nav-link:focus { outline:2px solid var(--primary); outline-offset:2px; }
.nav-link.active { color:var(--primary); background:rgba(56,189,248,0.1); }
.nav-link.active::after {
  content:""; position:absolute; bottom:0; left:14px; right:14px;
  height:2px; background:var(--gradient-primary); border-radius:2px;
}

/* MOBILE TOGGLE */
.mobile-menu-toggle {
  display:none; flex-direction:column; justify-content:center; align-items:center;
  width:40px; height:40px; cursor:pointer; padding:8px;
  background:transparent; border:1px solid var(--outline-variant);
  z-index:1001; transition:var(--transition); border-radius:var(--border-radius-small);
}
.mobile-menu-toggle:hover { background:rgba(56,189,248,0.1); border-color:var(--primary); }
.mobile-menu-toggle:focus { outline:2px solid var(--primary); outline-offset:2px; }
.hamburger-line { display:block; width:20px; height:2px; background:var(--on-surface-variant); margin:3px 0; transition:all 0.3s ease; border-radius:2px; }
.mobile-menu-toggle.active .hamburger-line:nth-child(1) { transform:rotate(45deg) translate(5px,5px); background:var(--primary); }
.mobile-menu-toggle.active .hamburger-line:nth-child(2) { opacity:0; }
.mobile-menu-toggle.active .hamburger-line:nth-child(3) { transform:rotate(-45deg) translate(5px,-5px); background:var(--primary); }

/* MOBILE OVERLAY */
.mobile-overlay {
  position:fixed; top:0; left:0; width:100%; height:100%;
  background:rgba(6,14,32,0.8); backdrop-filter:blur(8px);
  z-index:999; opacity:0; visibility:hidden; transition:var(--transition-slow);
}
.mobile-overlay.active { opacity:1; visibility:visible; }

/* FOOTER */
.footer {
  background:var(--surface-container-lowest); border-top:1px solid var(--outline-variant);
  padding:var(--spacing-2xl) 0 var(--spacing-lg);
}
.footer-container { max-width:var(--container-max-width); margin:0 auto; padding:0 var(--container-padding); }
.footer-content { display:grid; grid-template-columns:1fr auto; gap:var(--spacing-2xl); align-items:center; }
.footer-left { display:flex; flex-direction:column; gap:var(--spacing-sm); }
.footer-description { margin:0; color:var(--on-surface-variant); font-size:var(--text-sm); line-height:1.5; }
.footer-description b { color:var(--primary); font-family:var(--font-mono); }
.footer-partners { margin-top:var(--spacing-md); }
.partner-logos { display:flex; align-items:center; gap:var(--spacing-md); flex-wrap:wrap; }
.partner-link { display:flex; align-items:center; opacity:0.75; transition:var(--transition); }
.partner-link:hover { opacity:1; transform:scale(1.05); }
.partner-logo { height:30px; width:auto; object-fit:contain; filter:brightness(0) invert(1); }
.partner-separator { color:var(--outline); font-size:1.1rem; font-weight:300; }
.footer-ieee-badge {
  display:inline-flex; align-items:center; gap:var(--spacing-sm);
  background:rgba(56,189,248,0.1); border:1px solid rgba(56,189,248,0.3);
  border-radius:var(--border-radius-full); padding:6px 14px;
  font-family:var(--font-mono); font-size:var(--text-xs); font-weight:700;
  color:var(--primary); letter-spacing:0.08em; text-transform:uppercase;
}
.footer-right { display:flex; flex-direction:column; align-items:flex-end; gap:var(--spacing-md); }
.footer-links { display:flex; flex-direction:column; gap:var(--spacing-sm); align-items:flex-end; }
.footer-links a { display:flex; align-items:center; gap:var(--spacing-xs); color:var(--on-surface-variant); text-decoration:none; font-size:var(--text-sm); transition:var(--transition); }
.footer-links a:hover { color:var(--primary); transform:translateX(-2px); }
.footer-credit { margin:0; color:var(--outline); font-size:var(--text-xs); display:flex; align-items:center; gap:var(--spacing-xs); font-family:var(--font-mono); }

/* WELCOME MODAL */
.welcome-modal {
  position:fixed; top:0; left:0; right:0; bottom:0;
  background:rgba(6,14,32,0.85); backdrop-filter:blur(12px);
  z-index:9999; display:flex; align-items:center; justify-content:center;
  opacity:0; visibility:hidden; transition:var(--transition-slow);
}
.welcome-modal.active { opacity:1; visibility:visible; }
.welcome-modal-content {
  background:var(--surface-container); border:1px solid var(--outline-variant);
  border-radius:var(--border-radius-large); padding:var(--spacing-2xl);
  max-width:460px; width:90%; position:relative;
  transform:scale(0.85) translateY(20px); transition:transform 0.4s ease;
  box-shadow:var(--shadow-large),0 0 60px rgba(56,189,248,0.1); text-align:center;
}
.welcome-modal.active .welcome-modal-content { transform:scale(1) translateY(0); }
.welcome-close-btn {
  position:absolute; top:12px; right:12px;
  background:var(--surface-container-high); border:1px solid var(--outline-variant);
  color:var(--on-surface-variant); cursor:pointer; border-radius:var(--border-radius-full);
  transition:var(--transition); width:36px; height:36px;
  display:flex; align-items:center; justify-content:center; font-size:18px;
}
.welcome-close-btn:hover { background:var(--error-container); border-color:var(--error); color:var(--error); transform:scale(1.1); }
.welcome-header { margin-bottom:var(--spacing-lg); }
.welcome-header h2 { font-size:1.6rem; color:var(--on-surface); margin:0; font-weight:700; }
.welcome-icon {
  width:72px; height:72px; background:rgba(56,189,248,0.1);
  border:2px solid rgba(56,189,248,0.3); border-radius:var(--border-radius-full);
  display:flex; align-items:center; justify-content:center;
  margin:0 auto var(--spacing-lg); font-size:28px; color:var(--primary);
  animation:welcomePulse 2.5s infinite;
}
@keyframes welcomePulse {
  0%,100% { transform:scale(1); box-shadow:0 0 0 0 rgba(56,189,248,0.3); }
  50%      { transform:scale(1.04); box-shadow:0 0 0 12px rgba(56,189,248,0); }
}
.welcome-body { margin-bottom:var(--spacing-xl); }
.welcome-body p { font-size:var(--text-base); color:var(--on-surface-variant); margin:0; line-height:1.6; }
.welcome-footer .btn { min-width:140px; }

/* SCROLL PROGRESS */
.scroll-progress {
  position:fixed; top:0; left:0; width:0%; height:3px;
  background:var(--gradient-primary); z-index:9999; transition:width 0.15s linear;
}

/* ANIMATIONS */
.animate-in { opacity:1!important; transform:translateY(0)!important; transition:all 0.6s ease-out; }
@keyframes fadeInUp { from{opacity:0;transform:translateY(20px)} to{opacity:1;transform:translateY(0)} }
@keyframes fadeIn   { from{opacity:0} to{opacity:1} }

/* A11Y */
@media (prefers-reduced-motion:reduce) {
  *,*::before,*::after { animation-duration:0.01ms!important; animation-iteration-count:1!important; transition-duration:0.01ms!important; scroll-behavior:auto!important; }
}
:focus-visible { outline:2px solid var(--primary); outline-offset:2px; }

/* RESPONSIVE MOBILE NAV */
@media (max-width:768px) {
  .mobile-menu-toggle { display:flex; }
  .header-nav {
    position:fixed; top:72px; left:0; right:0;
    background:var(--surface-container); border-bottom:1px solid var(--outline-variant);
    flex-direction:column; padding:var(--spacing-lg); gap:4px;
    transform:translateY(-100%); opacity:0; visibility:hidden; transition:var(--transition-slow); z-index:1000;
  }
  .header-nav.active { transform:translateY(0); opacity:1; visibility:visible; }
  .nav-link { width:100%; padding:12px 16px; border-radius:var(--border-radius); }
  .nav-link.active::after { display:none; }
  .footer-content { grid-template-columns:1fr; text-align:center; }
  .footer-right { align-items:center; }
  .partner-logos { justify-content:center; }
}