/* ==========================================================================
   bISCuits Research Group — Main Stylesheet
   Design tokens from Stitch "Crumb & Cipher" design system
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. CSS Custom Properties (Design Tokens)
   -------------------------------------------------------------------------- */
:root {
  /* Colors — Light Mode */
  --color-bg:               #F8FAFC;
  --color-surface:          rgba(255, 255, 255, 0.85);
  --color-border:           #E2E8F0;
  --color-text:             #1E293B;
  --color-text-variant:     #475569;
  --color-footer-bg:        #ffffff;

  /* Colors — Brand */
  --color-primary:          #f59e0b;
  --color-primary-dim:      #d97706;
  --color-on-primary:       #1a0a00;

  /* Spacing */
  --margin-desktop:         64px;
  --margin-mobile:          16px;
  --gutter:                 24px;
  --max-width:              1280px;

  /* Typography */
  --font-display:           'Geist', sans-serif;
  --font-body:              'Inter', sans-serif;
  --font-mono:              'JetBrains Mono', monospace;

  /* Transitions */
  --transition-base:        150ms ease;
  --transition-colors:      300ms ease;
}

.dark {
  /* Colors — Dark Mode */
  --color-bg:               #051424;
  --color-surface:          rgba(18, 33, 49, 0.85);
  --color-border:           #1c2b3c;
  --color-text:             #d4e4fa;
  --color-text-variant:     #94a3b8;
  --color-footer-bg:        #0d1c2d;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background-color: var(--color-bg);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  transition: background-color var(--transition-colors), color var(--transition-colors);
}

/* --------------------------------------------------------------------------
   3. Typography
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-text);
}

h1 { font-size: clamp(2rem, 5vw, 3rem); }
h2 { font-size: clamp(1.5rem, 3vw, 1.75rem); }
h3 { font-size: 1.25rem; }

p {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text-variant);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: opacity var(--transition-base);
}

a:hover {
  opacity: 0.8;
}

code, pre, .mono {
  font-family: var(--font-mono);
}

/* --------------------------------------------------------------------------
   4. Layout Utilities
   -------------------------------------------------------------------------- */
.container {
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

@media (min-width: 768px) {
  .container {
    padding-inline: var(--margin-desktop);
  }
}

.section {
  padding-block: 5rem;
}

.section--sm {
  padding-block: 3rem;
}

/* --------------------------------------------------------------------------
   5. Buttons
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  border-radius: 0.25rem;
  cursor: pointer;
  transition: all 200ms ease;
  text-decoration: none;
  border: none;
}

.btn:active { transform: scale(0.97); }

.btn--primary {
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  box-shadow: 0 0 20px rgba(245, 158, 11, 0.25);
}

.btn--primary:hover {
  background-color: var(--color-primary-dim);
  opacity: 1;
}

.btn--outline {
  background-color: transparent;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
}

.btn--outline:hover {
  background-color: rgba(245, 158, 11, 0.1);
  opacity: 1;
}

/* --------------------------------------------------------------------------
   6. Cards
   -------------------------------------------------------------------------- */
.card {
  background: var(--color-surface);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
  padding: 1.5rem;
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.card:hover {
  border-color: var(--color-primary);
  box-shadow: 0 0 20px rgba(245, 158, 11, 0.1);
}

/* --------------------------------------------------------------------------
   7. Section Headers
   -------------------------------------------------------------------------- */
.section-header {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--color-border);
  transition: color var(--transition-colors), border-color var(--transition-colors);
}

.section-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 0.75rem;
  display: block;
}

/* --------------------------------------------------------------------------
   8. Page Hero (reusable for inner pages)
   -------------------------------------------------------------------------- */
.page-hero {
  background: linear-gradient(135deg, var(--color-surface), transparent);
  border-bottom: 1px solid var(--color-border);
  padding-block: 4rem 3rem;
}

.page-hero__label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 1rem;
}

.page-hero__title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 6vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
  color: var(--color-text);
  margin-bottom: 1.5rem;
}

.page-hero__description {
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--color-text-variant);
  max-width: 48rem;
}

/* --------------------------------------------------------------------------
   9. Tags / Chips
   -------------------------------------------------------------------------- */
.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0.25rem 0.625rem;
  border-radius: 0.25rem;
  border: 1px solid currentColor;
  opacity: 0.9;
}

.tag--primary {
  color: var(--color-primary);
  background-color: rgba(245, 158, 11, 0.1);
}

.tag--secondary {
  color: #6366f1;
  background-color: rgba(99, 102, 241, 0.1);
}

.tag--tertiary {
  color: #10b981;
  background-color: rgba(16, 185, 129, 0.1);
}

/* --------------------------------------------------------------------------
   10. Prose (markdown content)
   -------------------------------------------------------------------------- */
.prose h2 {
  margin-top: 2.5rem;
  margin-bottom: 1rem;
}

.prose h3 {
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

.prose p {
  margin-bottom: 1.25rem;
}

.prose ul, .prose ol {
  padding-left: 1.5rem;
  margin-bottom: 1.25rem;
}

.prose li {
  margin-bottom: 0.5rem;
  color: var(--color-text-variant);
  line-height: 1.7;
}

.prose a {
  color: var(--color-primary);
  border-bottom: 1px solid rgba(245, 158, 11, 0.4);
  transition: border-color var(--transition-base);
}

.prose a:hover {
  border-bottom-color: var(--color-primary);
  opacity: 1;
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-surface);
  padding: 0.15em 0.4em;
  border-radius: 0.2rem;
  border: 1px solid var(--color-border);
}

.prose pre {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
  padding: 1.25rem;
  overflow-x: auto;
  margin-bottom: 1.5rem;
}

.prose blockquote {
  border-left: 3px solid var(--color-primary);
  padding-left: 1.25rem;
  margin-block: 1.5rem;
  font-style: italic;
  color: var(--color-text-variant);
}

/* --------------------------------------------------------------------------
   11. Animations & Micro-interactions
   -------------------------------------------------------------------------- */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes glowPulse {
  0%, 100% { box-shadow: 0 0 20px rgba(245,158,11,0.2); }
  50%       { box-shadow: 0 0 35px rgba(245,158,11,0.4); }
}

.animate-fade-in {
  animation: fadeInUp 0.6s ease forwards;
}

.animate-glow {
  animation: glowPulse 3s ease-in-out infinite;
}

/* Stagger delays for grid children */
.stagger > *:nth-child(1) { animation-delay: 0ms; }
.stagger > *:nth-child(2) { animation-delay: 100ms; }
.stagger > *:nth-child(3) { animation-delay: 200ms; }
.stagger > *:nth-child(4) { animation-delay: 300ms; }

/* --------------------------------------------------------------------------
   12. Scrollbar (webkit)
   -------------------------------------------------------------------------- */
::-webkit-scrollbar {
  width: 6px;
}
::-webkit-scrollbar-track {
  background: var(--color-bg);
}
::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--color-primary);
}

/* --------------------------------------------------------------------------
   13. Selection
   -------------------------------------------------------------------------- */
::selection {
  background-color: rgba(245, 158, 11, 0.25);
  color: var(--color-text);
}