/* ============================================================
   CAMPUSLINK — Design System
   Premium dark-mode-first tokens, typography, glassmorphism,
   gradients, micro-animations, and utility classes.
   ============================================================ */

/* ---------- Google Font ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800;900&display=swap');

/* ---------- Color Tokens ---------- */
:root {
  /* Core palette — dark mode first */
  --bg-primary:    hsl(228, 18%, 8%);
  --bg-secondary:  hsl(228, 16%, 11%);
  --bg-elevated:   hsl(228, 14%, 14%);
  --bg-surface:    hsl(228, 12%, 17%);
  --bg-hover:      hsl(228, 12%, 20%);

  /* Glass */
  --glass-bg:      hsla(228, 16%, 14%, 0.65);
  --glass-border:  hsla(0, 0%, 100%, 0.08);
  --glass-shadow:  0 8px 32px hsla(0, 0%, 0%, 0.35);
  --glass-blur:    16px;

  /* Text */
  --text-primary:   hsl(210, 20%, 96%);
  --text-secondary: hsl(218, 12%, 65%);
  --text-muted:     hsl(218, 10%, 45%);
  --text-inverse:   hsl(228, 18%, 8%);

  /* Borders & Lines */
  --border-subtle:  hsla(0, 0%, 100%, 0.06);
  --border-default: hsla(0, 0%, 100%, 0.10);
  --border-strong:  hsla(0, 0%, 100%, 0.16);

  /* Accent — Electric Blue */
  --accent-hue: 217;
  --accent:        hsl(var(--accent-hue), 91%, 60%);
  --accent-hover:  hsl(var(--accent-hue), 91%, 55%);
  --accent-soft:   hsla(var(--accent-hue), 91%, 60%, 0.12);
  --accent-glow:   0 0 20px hsla(var(--accent-hue), 91%, 60%, 0.25);

  /* Semantic colors */
  --success:       hsl(152, 60%, 48%);
  --success-soft:  hsla(152, 60%, 48%, 0.12);
  --warning:       hsl(38, 92%, 58%);
  --warning-soft:  hsla(38, 92%, 58%, 0.12);
  --danger:        hsl(0, 72%, 60%);
  --danger-soft:   hsla(0, 72%, 60%, 0.12);
  --info:          hsl(199, 89%, 55%);
  --info-soft:     hsla(199, 89%, 55%, 0.12);

  /* Gradients */
  --gradient-accent:  linear-gradient(135deg, hsl(217, 91%, 60%), hsl(270, 80%, 65%));
  --gradient-warm:    linear-gradient(135deg, hsl(38, 92%, 58%), hsl(10, 90%, 60%));
  --gradient-success: linear-gradient(135deg, hsl(152, 60%, 48%), hsl(180, 65%, 50%));
  --gradient-glow:    linear-gradient(135deg, hsla(217, 91%, 60%, 0.15), hsla(270, 80%, 65%, 0.08));
  --gradient-mesh:    radial-gradient(ellipse at 20% 50%, hsla(217, 91%, 60%, 0.08) 0%, transparent 50%),
                      radial-gradient(ellipse at 80% 20%, hsla(270, 80%, 65%, 0.06) 0%, transparent 50%),
                      radial-gradient(ellipse at 50% 100%, hsla(152, 60%, 48%, 0.04) 0%, transparent 50%);

  /* Spacing scale (4px base) */
  --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;

  /* Radius */
  --radius-sm:  6px;
  --radius-md:  10px;
  --radius-lg:  14px;
  --radius-xl:  20px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm:  0 1px 2px hsla(0,0%,0%,0.2);
  --shadow-md:  0 4px 12px hsla(0,0%,0%,0.25);
  --shadow-lg:  0 8px 28px hsla(0,0%,0%,0.35);
  --shadow-xl:  0 20px 60px hsla(0,0%,0%,0.45);

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

  /* Z-index layers */
  --z-base:     1;
  --z-dropdown: 100;
  --z-sticky:   200;
  --z-modal:    500;
  --z-toast:    700;
  --z-tooltip:  900;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --duration-fast: 150ms;
  --duration-normal: 250ms;
  --duration-slow: 400ms;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-primary);
  overflow-x: hidden;
}

/* ---------- Typography ---------- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

h1 { font-size: 32px; font-weight: 800; }
h2 { font-size: 22px; }
h3 { font-size: 17px; }
h4 { font-size: 15px; font-weight: 600; }

p {
  color: var(--text-secondary);
  line-height: 1.65;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--duration-fast) var(--ease-out);
}

a:hover {
  color: var(--accent-hover);
}

/* ---------- Accessibility ---------- */
.skip-link {
  position: fixed;
  top: -100px;
  left: var(--space-4);
  background: var(--accent);
  color: #fff;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  z-index: var(--z-tooltip);
  font-weight: 600;
  transition: top var(--duration-fast) var(--ease-out);
}

.skip-link:focus {
  top: var(--space-4);
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: hsla(0, 0%, 100%, 0.1);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: hsla(0, 0%, 100%, 0.18);
}

/* ---------- Selection ---------- */
::selection {
  background: hsla(var(--accent-hue), 91%, 60%, 0.3);
  color: var(--text-primary);
}

/* ---------- Keyframe Animations ---------- */
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-12px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes slideInLeft {
  from { opacity: 0; transform: translateX(-20px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes slideInRight {
  from { opacity: 0; transform: translateX(20px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.95); }
  to   { opacity: 1; transform: scale(1); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0.5; }
}

@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

@keyframes glow {
  0%, 100% { box-shadow: 0 0 8px hsla(var(--accent-hue), 91%, 60%, 0.3); }
  50%      { box-shadow: 0 0 20px hsla(var(--accent-hue), 91%, 60%, 0.5); }
}

@keyframes gradientShift {
  0%   { background-position: 0% 50%; }
  50%  { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-6px); }
}

@keyframes ringProgress {
  from { stroke-dashoffset: var(--ring-circumference); }
  to   { stroke-dashoffset: var(--ring-offset); }
}

@keyframes countUp {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes barGrow {
  from { width: 0; }
}

@keyframes dotPulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50%      { transform: scale(1.5); opacity: 0.5; }
}

@keyframes toastIn {
  from { opacity: 0; transform: translateX(100%) scale(0.9); }
  to   { opacity: 1; transform: translateX(0) scale(1); }
}

@keyframes toastOut {
  from { opacity: 1; transform: translateX(0) scale(1); }
  to   { opacity: 0; transform: translateX(100%) scale(0.9); }
}

/* ---------- Animation Utility Classes ---------- */
.animate-fade-in     { animation: fadeIn var(--duration-normal) var(--ease-out) both; }
.animate-fade-in-up  { animation: fadeInUp var(--duration-slow) var(--ease-out) both; }
.animate-fade-in-down{ animation: fadeInDown var(--duration-normal) var(--ease-out) both; }
.animate-slide-left  { animation: slideInLeft var(--duration-slow) var(--ease-out) both; }
.animate-slide-right { animation: slideInRight var(--duration-slow) var(--ease-out) both; }
.animate-scale-in    { animation: scaleIn var(--duration-normal) var(--ease-spring) both; }
.animate-pulse       { animation: pulse 2s ease-in-out infinite; }
.animate-float       { animation: float 3s ease-in-out infinite; }

/* Stagger children animations */
.stagger-children > *:nth-child(1)  { animation-delay: 0ms; }
.stagger-children > *:nth-child(2)  { animation-delay: 60ms; }
.stagger-children > *:nth-child(3)  { animation-delay: 120ms; }
.stagger-children > *:nth-child(4)  { animation-delay: 180ms; }
.stagger-children > *:nth-child(5)  { animation-delay: 240ms; }
.stagger-children > *:nth-child(6)  { animation-delay: 300ms; }
.stagger-children > *:nth-child(7)  { animation-delay: 360ms; }
.stagger-children > *:nth-child(8)  { animation-delay: 420ms; }
.stagger-children > *:nth-child(9)  { animation-delay: 480ms; }
.stagger-children > *:nth-child(10) { animation-delay: 540ms; }

/* ---------- Glassmorphism Utilities ---------- */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
}

.glass-light {
  background: hsla(228, 16%, 18%, 0.45);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid hsla(0, 0%, 100%, 0.06);
}

.glass-accent {
  background: hsla(var(--accent-hue), 50%, 20%, 0.35);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid hsla(var(--accent-hue), 91%, 60%, 0.15);
}

/* ---------- Gradient Text ---------- */
.gradient-text {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gradient-text-warm {
  background: var(--gradient-warm);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ---------- Skeleton Loading ---------- */
.skeleton {
  background: linear-gradient(
    90deg,
    hsla(0, 0%, 100%, 0.04) 25%,
    hsla(0, 0%, 100%, 0.08) 50%,
    hsla(0, 0%, 100%, 0.04) 75%
  );
  background-size: 400% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-sm);
}

.skeleton-text {
  height: 14px;
  width: 80%;
  margin-bottom: var(--space-2);
}

.skeleton-title {
  height: 22px;
  width: 60%;
  margin-bottom: var(--space-3);
}

.skeleton-circle {
  border-radius: 50%;
}

/* ---------- Reduced Motion ---------- */
@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;
  }
}