/* ==========================================================================
   Game Algorithms Showcase — Shared Design System
   Matches the editorial black + gold portfolio at rachitagrawal146.github.io
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Custom properties
   -------------------------------------------------------------------------- */
:root {
  /* Colors — Background */
  --color-bg:             #0c0c0b;
  --color-bg-card:        #141413;
  --color-bg-card-hover:  #1c1c1a;
  --color-surface:        #141413;
  --color-surface-2:      #1c1c1a;
  --color-border:         rgba(255, 255, 255, 0.07);
  --color-border-hover:   rgba(255, 255, 255, 0.12);

  /* Colors — Text */
  --color-text:           #e8e6df;
  --color-text-muted:     #8a887f;
  --color-text-dim:       #4a4844;
  --color-text-heading:   #e8e6df;

  /* Colors — Accents (gold is primary; others used sparingly for algorithm domains) */
  --color-gold:           #c9a96e;
  --color-gold-bright:    #e8d5b0;
  --color-gold-dim:       rgba(201, 169, 110, 0.5);
  --color-blue:           #7ab0a8;
  --color-green:          #8fb28a;
  --color-amber:          #c9a96e;
  --color-red:            #c97b6e;
  --color-purple:         #a896c8;

  /* Typography */
  --font-display:         'Cormorant Garamond', Georgia, serif;
  --font-heading:         'Cormorant Garamond', Georgia, serif;
  --font-body:            'Inter', system-ui, sans-serif;
  --font-mono:            'DM Mono', ui-monospace, 'Cascadia Code', monospace;

  /* Spacing scale (4px base) */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Radii (minimal — editorial style) */
  --radius-sm:  2px;
  --radius-md:  3px;
  --radius-lg:  4px;
  --radius-full: 9999px;

  /* Shadows (subtle) */
  --shadow-sm:  0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-md:  0 4px 16px rgba(0, 0, 0, 0.25);
  --shadow-glow: 0 0 40px rgba(201, 169, 110, 0.08);

  /* Transitions */
  --duration-fast:   150ms;
  --duration-normal: 300ms;
  --duration-slow:   600ms;
  --ease-out:        cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out:     cubic-bezier(0.645, 0.045, 0.355, 1);
}

/* --------------------------------------------------------------------------
   2. Reset + base
   -------------------------------------------------------------------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
html {
  scroll-behavior: smooth;
}
body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-weight: 300;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
}

/* Noise texture overlay — fixed, non-interactive */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 256px 256px;
}

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }

::selection {
  background: rgba(201, 169, 110, 0.3);
  color: var(--color-text);
}

/* Scrollbar — thin, dark */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--color-bg); }
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.08);
  border-radius: 5px;
}
::-webkit-scrollbar-thumb:hover { background: rgba(255, 255, 255, 0.15); }
* { scrollbar-width: thin; scrollbar-color: rgba(255,255,255,0.08) var(--color-bg); }

/* --------------------------------------------------------------------------
   3. Typography
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 300;
  color: var(--color-text-heading);
  letter-spacing: -0.01em;
  line-height: 1.15;
}

h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); font-style: italic; }
h2 { font-size: clamp(1.8rem, 3.5vw, 2.6rem); font-style: italic; }
h3 { font-size: clamp(1.3rem, 2.5vw, 1.8rem); }
h4 { font-size: 1.2rem; }

p { font-weight: 300; color: var(--color-text-muted); }

em, i { font-style: italic; }

code, pre {
  font-family: var(--font-mono);
  font-weight: 400;
  font-size: 0.85em;
}

/* --------------------------------------------------------------------------
   4. Layout — container
   -------------------------------------------------------------------------- */
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}
.container-wide { max-width: 1100px; margin: 0 auto; padding: 0 var(--space-6); }
.container-narrow { max-width: 720px; margin: 0 auto; padding: 0 var(--space-6); }

/* --------------------------------------------------------------------------
   5. Site navigation
   -------------------------------------------------------------------------- */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(12, 12, 11, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 0.5px solid var(--color-border);
  transition: transform 0.4s var(--ease-out);
  height: 70px;
}
.site-nav.nav-hidden { transform: translateY(-100%); }
.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 var(--space-6);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 400;
  font-size: 1.15rem;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  transition: color var(--duration-normal) var(--ease-out);
}
.nav-logo:hover { color: var(--color-gold); }
.nav-logo-icon { color: var(--color-gold); font-size: 0.7em; }
.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}
.nav-links a {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--color-text-muted);
  transition: color var(--duration-normal) var(--ease-out);
  position: relative;
  padding: 4px 0;
}
.nav-links a:hover,
.nav-links a.active { color: var(--color-gold); }
.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 0.5px;
  background: var(--color-gold);
}
.nav-mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-text);
  cursor: pointer;
  font-size: 1.4rem;
  padding: 4px 8px;
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: rgba(12, 12, 11, 0.95);
    backdrop-filter: blur(20px);
    padding: var(--space-6);
    gap: var(--space-4);
    border-bottom: 0.5px solid var(--color-border);
  }
  .site-nav.nav-open .nav-links { display: flex; }
  .nav-mobile-toggle { display: block; }
}

/* --------------------------------------------------------------------------
   6. Hero
   -------------------------------------------------------------------------- */
.hero {
  padding: var(--space-24) 0 var(--space-16);
  text-align: center;
}
.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.3em;
  color: var(--color-gold);
  margin-bottom: var(--space-8);
  display: inline-block;
}
.hero-title {
  font-family: var(--font-display);
  font-style: italic;
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  line-height: 1.05;
  letter-spacing: -0.015em;
  margin-bottom: var(--space-6);
  color: var(--color-text-heading);
  font-weight: 300;
}
.hero-subtitle {
  font-family: var(--font-display);
  font-style: italic;
  font-size: clamp(1.2rem, 2vw, 1.5rem);
  color: var(--color-gold);
  margin-bottom: var(--space-8);
  font-weight: 300;
}
.hero-description {
  font-size: 1rem;
  color: var(--color-text-muted);
  max-width: 640px;
  margin: 0 auto var(--space-10);
  line-height: 1.75;
}

/* --------------------------------------------------------------------------
   7. Section labels (gold with extending line)
   -------------------------------------------------------------------------- */
.section-label {
  font-family: var(--font-mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.25em;
  color: var(--color-gold);
  display: flex;
  align-items: center;
  gap: var(--space-6);
  margin-bottom: var(--space-12);
}
.section-label::after {
  content: '';
  flex: 1;
  height: 0.5px;
  background: var(--color-border);
}

/* --------------------------------------------------------------------------
   8. Shiny text (gradient sweep animation)
   -------------------------------------------------------------------------- */
.shiny-text {
  background: linear-gradient(
    110deg,
    rgba(201, 169, 110, 0.5) 0%,
    rgba(201, 169, 110, 0.5) 35%,
    rgba(255, 240, 200, 1) 50%,
    rgba(201, 169, 110, 0.5) 65%,
    rgba(201, 169, 110, 0.5) 100%
  );
  background-size: 200% auto;
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  animation: shinySweep 4s linear infinite;
}
@keyframes shinySweep {
  0%   { background-position: 200% center; }
  100% { background-position: -200% center; }
}

/* --------------------------------------------------------------------------
   9. Cards
   -------------------------------------------------------------------------- */
.card {
  background: var(--color-surface);
  border: 0.5px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-8);
  transition: border-color var(--duration-normal) var(--ease-out),
              transform var(--duration-normal) var(--ease-out),
              background var(--duration-normal) var(--ease-out);
}
.card:hover {
  border-color: var(--color-border-hover);
  background: var(--color-bg-card-hover);
  transform: translateY(-2px);
}
.card h3 {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 400;
  margin-bottom: var(--space-3);
}
.card p {
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--color-text-muted);
}
.card-accent {
  height: 2px;
  width: 40px;
  background: var(--color-gold);
  margin-bottom: var(--space-5);
}
.card-link {
  display: inline-block;
  margin-top: var(--space-5);
  font-family: var(--font-mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--color-gold);
  position: relative;
  padding-bottom: 2px;
  transition: color var(--duration-normal) var(--ease-out);
}
.card-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 0.5px;
  background: var(--color-gold);
  transition: width var(--duration-normal) var(--ease-out);
}
.card-link:hover::after { width: 100%; }
.card-link:hover { color: var(--color-gold-bright); }

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}
@media (max-width: 1024px) {
  .card-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .card-grid { grid-template-columns: 1fr; }
}

/* --------------------------------------------------------------------------
   10. Buttons
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  background: transparent;
  border: 0.5px solid var(--color-border);
  color: var(--color-text);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--duration-normal) var(--ease-out);
  text-decoration: none;
}
.btn:hover {
  border-color: var(--color-gold);
  color: var(--color-gold);
  transform: translateY(-1px);
}
.btn:active { transform: translateY(0); }
.btn-primary {
  background: var(--color-gold);
  border-color: var(--color-gold);
  color: var(--color-bg);
}
.btn-primary:hover {
  background: var(--color-gold-bright);
  border-color: var(--color-gold-bright);
  color: var(--color-bg);
}
.btn-ghost {
  background: transparent;
  border-color: var(--color-border);
  color: var(--color-text-muted);
}
.btn-ghost:hover {
  border-color: var(--color-gold);
  color: var(--color-gold);
}
.btn-small {
  padding: var(--space-2) var(--space-4);
  font-size: 9px;
}

/* --------------------------------------------------------------------------
   11. Stats bar
   -------------------------------------------------------------------------- */
.stats-bar {
  display: flex;
  gap: var(--space-12);
  flex-wrap: wrap;
  padding: var(--space-6) 0;
  border-top: 0.5px solid var(--color-border);
  border-bottom: 0.5px solid var(--color-border);
}
.stat-item {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}
.stat-value {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 400;
  font-size: 2rem;
  color: var(--color-gold);
  line-height: 1;
}
.stat-label {
  font-family: var(--font-mono);
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--color-text-muted);
}

/* --------------------------------------------------------------------------
   12. Tags & badges
   -------------------------------------------------------------------------- */
.tag {
  display: inline-block;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 9px;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  background: transparent;
  color: var(--color-text-muted);
  border: 0.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: all var(--duration-normal) var(--ease-out);
}
.tag:hover {
  border-color: var(--color-gold-dim);
  color: var(--color-gold);
}

.algo-badge {
  display: inline-block;
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  background: rgba(201, 169, 110, 0.08);
  color: var(--color-gold);
  border: 0.5px solid rgba(201, 169, 110, 0.25);
  border-radius: var(--radius-sm);
}

/* --------------------------------------------------------------------------
   13. Code blocks
   -------------------------------------------------------------------------- */
.code-block {
  background: var(--color-surface);
  border: 0.5px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-5);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-text);
  overflow-x: auto;
  line-height: 1.6;
}
.code-inline {
  font-family: var(--font-mono);
  font-size: 0.85em;
  padding: 2px 6px;
  background: var(--color-surface);
  border: 0.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-gold);
}

/* --------------------------------------------------------------------------
   14. Complexity tables
   -------------------------------------------------------------------------- */
.complexity-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: 11px;
}
.complexity-table th,
.complexity-table td {
  padding: var(--space-3) var(--space-4);
  text-align: left;
  border-bottom: 0.5px solid var(--color-border);
}
.complexity-table th {
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--color-text-muted);
  font-weight: 500;
}
.complexity-table td { color: var(--color-text); }
.complexity-good { color: var(--color-green); }
.complexity-avg  { color: var(--color-amber); }
.complexity-bad  { color: var(--color-red); }

/* --------------------------------------------------------------------------
   15. Educational panel (collapsible)
   -------------------------------------------------------------------------- */
.educational-panel {
  background: var(--color-surface);
  border: 0.5px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-top: var(--space-8);
  overflow: hidden;
  transition: border-color var(--duration-normal) var(--ease-out);
}
.educational-panel:hover { border-color: var(--color-border-hover); }
.educational-panel-header {
  padding: var(--space-5) var(--space-6);
  font-family: var(--font-mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--color-gold);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}
.educational-panel-body {
  padding: 0 var(--space-6) var(--space-6);
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--color-text-muted);
  display: none;
}
.educational-panel.is-open .educational-panel-body { display: block; }
.educational-panel-body h4 {
  font-family: var(--font-display);
  font-style: italic;
  color: var(--color-text);
  margin: var(--space-4) 0 var(--space-2);
  font-size: 1.1rem;
}
.educational-panel-body p { margin-bottom: var(--space-3); }
.educational-panel-body ul { padding-left: var(--space-5); margin: var(--space-3) 0; }
.educational-panel-body li { margin-bottom: var(--space-2); color: var(--color-text-muted); }

/* --------------------------------------------------------------------------
   16. Animation utilities
   -------------------------------------------------------------------------- */
.fade-in {
  opacity: 0;
  transition: opacity var(--duration-slow) var(--ease-out);
}
.fade-in.visible { opacity: 1; }

.slide-up {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out);
}
.slide-up.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --------------------------------------------------------------------------
   17. Section dividers
   -------------------------------------------------------------------------- */
.section-divider {
  border: none;
  border-top: 0.5px solid var(--color-border);
  margin: var(--space-16) 0;
}

/* --------------------------------------------------------------------------
   18. 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;
  }
  .shiny-text {
    animation: none;
    background: none;
    -webkit-text-fill-color: var(--color-gold);
    color: var(--color-gold);
  }
  .reveal, .fade-in, .slide-up {
    opacity: 1 !important;
    transform: none !important;
  }
}