/**
 * Syllabix - Core Stylesheet & Design Tokens
 * Responsive, accessible (WCAG AA/AAA), modern design system
 * Designed for GDC RIT Dubai × +TWE DesignAthon 2026
 * Created by Yassin Ragab · Freshman, Computer Engineering @ University of Sharjah (UoS)
 */

@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
  /* Color Palette - Light Mode */
  --bg-base: #F8FAFC;
  --bg-surface: #FFFFFF;
  --bg-surface-raised: #F1F5F9;
  --bg-surface-subtle: #F8FAFC;
  --bg-input: #FFFFFF;
  --border-subtle: #E2E8F0;
  --border-strong: #CBD5E1;
  --border-focus: #6366F1;
  
  --text-main: #0F172A;
  --text-body: #334155;
  --text-muted: #64748B;
  --text-subtle: #94A3B8;

  /* Brand Accents */
  --primary: #4F46E5;
  --primary-hover: #4338CA;
  --primary-light: #EEF2FF;
  --primary-glow: rgba(79, 70, 229, 0.15);

  --accent-emerald: #10B981;
  --accent-emerald-bg: #ECFDF5;
  --accent-emerald-border: #A7F3D0;

  --accent-amber: #F59E0B;
  --accent-amber-bg: #FFFBEB;
  --accent-amber-border: #FDE68A;

  --accent-rose: #EF4444;
  --accent-rose-bg: #FEF2F2;
  --accent-rose-border: #FECACA;

  --accent-purple: #8B5CF6;
  --accent-cyan: #06B6D4;
  --accent-pink: #EC4899;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.08), 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.08), 0 2px 4px -2px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, 0.08), 0 4px 6px -4px rgba(15, 23, 42, 0.03);
  --shadow-xl: 0 20px 25px -5px rgba(15, 23, 42, 0.1), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
  --shadow-glow: 0 0 25px rgba(79, 70, 229, 0.25);

  /* Typography */
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 350ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Radii */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  /* Neo-Swiss Precision Tokens - Light */
  --card-hairline: 1px solid var(--border-subtle);
  --card-inner-highlight: inset 0 1px 0 0 rgba(255, 255, 255, 0.85);
  --card-shadow: 0 1px 3px rgba(15, 23, 42, 0.05), 0 10px 25px -5px rgba(15, 23, 42, 0.04);
}

[data-theme="dark"] {
  --bg-base: #0B0F19;
  --bg-surface: #111827;
  --bg-surface-raised: #1E293B;
  --bg-surface-subtle: #161F30;
  --bg-input: #1E293B;
  --border-subtle: #243048;
  --border-strong: #334155;
  --border-focus: #818CF8;

  --text-main: #F8FAFC;
  --text-body: #CBD5E1;
  --text-muted: #94A3B8;
  --text-subtle: #64748B;

  --primary: #6366F1;
  --primary-hover: #4F46E5;
  --primary-light: rgba(99, 102, 241, 0.15);
  --primary-glow: rgba(99, 102, 241, 0.3);

  --accent-emerald: #34D399;
  --accent-emerald-bg: rgba(52, 211, 153, 0.12);
  --accent-emerald-border: rgba(52, 211, 153, 0.25);

  --accent-amber: #FBBF24;
  --accent-amber-bg: rgba(251, 191, 36, 0.12);
  --accent-amber-border: rgba(251, 191, 36, 0.25);

  --accent-rose: #F87171;
  --accent-rose-bg: rgba(248, 113, 113, 0.12);
  --accent-rose-border: rgba(248, 113, 113, 0.25);

  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 12px 20px rgba(0, 0, 0, 0.6);
  --shadow-xl: 0 20px 30px rgba(0, 0, 0, 0.7);
  --shadow-glow: 0 0 35px rgba(99, 102, 241, 0.35);

  /* Neo-Swiss Precision Tokens - Dark */
  --card-hairline: 1px solid rgba(255, 255, 255, 0.08);
  --card-inner-highlight: inset 0 1px 0 0 rgba(255, 255, 255, 0.06);
  --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.4), 0 12px 30px -4px rgba(0, 0, 0, 0.5);
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-base);
  color: var(--text-main);
  line-height: 1.6;
  scroll-behavior: smooth;
  scroll-padding-top: 5.5rem;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: 'cv02', 'cv03', 'cv04', 'cv11';
  font-variant-numeric: tabular-nums lining-nums;
}

body {
  min-height: 100vh;
  width: 100%;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
  background-color: var(--bg-base);
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Accessibility Focus States */
:focus-visible {
  outline: 2px solid var(--border-focus);
  outline-offset: 3px;
}

a {
  color: inherit;
  text-decoration: none;
}

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
}

/* ==========================================================================
   Neo-Swiss Utility Primitives
   ========================================================================== */
.tabular-nums {
  font-variant-numeric: tabular-nums lining-nums;
  font-feature-settings: "tnum" 1;
}

.mono-tag {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.swiss-kicker {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.swiss-divider {
  height: 1px;
  background: var(--border-subtle);
  margin: 1.5rem 0;
  width: 100%;
}

.swiss-panel {
  background-color: var(--bg-surface);
  border: var(--card-hairline);
  box-shadow: var(--card-shadow), var(--card-inner-highlight);
  border-radius: var(--radius-md);
}

/* Container */
.container {
  width: 100%;
  max-width: 1280px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
  box-sizing: border-box;
}

/* Navigation Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-subtle);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

[data-theme="dark"] .site-header {
  background-color: rgba(17, 24, 39, 0.85);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.5rem;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 800;
  font-size: 1.35rem;
  letter-spacing: -0.03em;
  color: var(--text-main);
}

.logo-symbol {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--primary) 0%, #8B5CF6 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #FFFFFF;
  box-shadow: 0 4px 10px var(--primary-glow);
}

.brand-badge {
  font-size: 0.6875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-full);
  background-color: var(--primary-light);
  color: var(--primary);
  border: 1px solid rgba(99, 102, 241, 0.2);
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-link {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-body);
  padding: 0.5rem 0.875rem;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-link:hover {
  color: var(--primary);
  background-color: var(--bg-surface-raised);
}

.nav-link.active {
  color: var(--primary);
  background-color: var(--primary-light);
}




.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.theme-toggle-btn {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-body);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  background-color: var(--bg-surface-raised);
  color: var(--text-main);
  border-color: var(--border-strong);
}

.hamburger-btn {
  display: none;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-sm);
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--text-main);
  cursor: pointer;
  align-items: center;
  justify-content: center;
}

/* Page Layout */
main {
  flex: 1;
}

.page-hero {
  padding: 4.5rem 0 3rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-pill-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  background-color: var(--primary-light);
  border: 1px solid rgba(99, 102, 241, 0.25);
  border-radius: var(--radius-full);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 1.5rem;
}

.hero-pill-badge a {
  text-decoration: underline;
  font-weight: 700;
}

.page-title {
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.035em;
  color: var(--text-main);
  margin-bottom: 1.25rem;
}

.page-subtitle {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  font-weight: 400;
  color: var(--text-body);
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.65;
  margin-bottom: 2rem;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.9375rem;
  padding: 0.75rem 1.35rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-normal);
  border: 1px solid transparent;
  text-decoration: none;
}

.btn-primary {
  background-color: var(--primary);
  color: #FFFFFF;
  box-shadow: 0 4px 14px var(--primary-glow);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px var(--primary-glow);
}

.btn-secondary {
  background-color: var(--bg-surface);
  color: var(--text-main);
  border-color: var(--border-strong);
}

.btn-secondary:hover {
  background-color: var(--bg-surface-raised);
  transform: translateY(-1px);
}

.btn-sm {
  padding: 0.45rem 0.85rem;
  font-size: 0.8125rem;
}

/* Footer & Creator Attribution */
.site-footer {
  margin-top: 5rem;
  background-color: var(--bg-surface);
  border-top: 1px solid var(--border-subtle);
  padding: 4rem 0 2.5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand h3 {
  font-size: 1.25rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
  color: var(--text-main);
}

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.9375rem;
  line-height: 1.6;
  max-width: 380px;
}

.footer-col h4 {
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links a {
  color: var(--text-body);
  font-size: 0.9375rem;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--primary);
}

/* Creator Profile Card in Footer */
.creator-card {
  background: var(--bg-surface-raised);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.creator-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.creator-avatar {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent-cyan) 100%);
  color: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1rem;
}

.creator-info h5 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
}

.creator-info p {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.creator-portfolio-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--primary);
  margin-top: 0.25rem;
}

.creator-portfolio-link:hover {
  text-decoration: underline;
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.footer-credits-tag {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.partner-logo-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  background-color: var(--bg-surface-raised);
  border: 1px solid var(--border-subtle);
  font-size: 0.75rem;
  font-weight: 600;
}

/* ==========================================================================
   Apple-Inspired Fluid Micro-Interactions & Scroll Animations
   ========================================================================== */

/* Apple-style interactive link hover effect */
.desktop-nav .nav-link {
  position: relative;
  transition: color 0.3s cubic-bezier(0.16, 1, 0.3, 1), background-color 0.3s cubic-bezier(0.16, 1, 0.3, 1), transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.desktop-nav .nav-link::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  width: 0%;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), #8B5CF6);
  border-radius: 2px;
  transform: translateX(-50%);
  transition: width 0.35s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.35s ease;
  opacity: 0;
}

.desktop-nav .nav-link:hover::after,
.desktop-nav .nav-link.active::after {
  width: calc(100% - 1.5rem);
  opacity: 1;
}

.desktop-nav .nav-link:active {
  transform: scale(0.96);
}

/* Apple-grade Physics Hover on Buttons */
.btn {
  position: relative;
  overflow: hidden;
  transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1), 
              box-shadow 0.35s cubic-bezier(0.16, 1, 0.3, 1), 
              background-color 0.25s ease, 
              border-color 0.25s ease;
  will-change: transform;
}

.btn:hover {
  transform: translateY(-2px) scale(1.015);
}

.btn:active {
  transform: translateY(0px) scale(0.975);
  transition-duration: 0.1s;
}

.btn-primary::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.6s cubic-bezier(0.16, 1, 0.3, 1);
  pointer-events: none;
}

.btn-primary:hover::before {
  left: 100%;
}

/* Cards & Pills Physics Hover */
.radar-main-card, 
.student-card, 
.metric-stat-card, 
.persona-card {
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), 
              box-shadow 0.4s cubic-bezier(0.16, 1, 0.3, 1),
              border-color 0.3s ease;
  will-change: transform;
}

.radar-main-card:hover, 
.student-card:hover, 
.metric-stat-card:hover, 
.persona-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 32px -8px rgba(15, 23, 42, 0.1), 0 0 0 1px rgba(79, 70, 229, 0.15);
}

[data-theme="dark"] .radar-main-card:hover,
[data-theme="dark"] .student-card:hover,
[data-theme="dark"] .metric-stat-card:hover,
[data-theme="dark"] .persona-card:hover {
  box-shadow: 0 16px 32px -8px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(99, 102, 241, 0.25);
}

/* ==========================================================================
   Lenis Smooth Scrolling Framework
   ========================================================================== */
html.lenis, html.lenis body {
  height: auto;
}

.lenis.lenis-smooth {
  scroll-behavior: auto !important;
}

.lenis.lenis-smooth [data-lenis-prevent] {
  overscroll-behavior: contain;
}

.lenis.lenis-stopped {
  overflow: hidden;
}

/* Apple-style Top Scroll Progress Indicator */
#scroll-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--primary) 0%, #8B5CF6 50%, #10B981 100%);
  z-index: 1000;
  pointer-events: none;
  transition: width 0.1s linear;
  box-shadow: 0 0 10px var(--primary-glow);
}

/* ==========================================================================
   Silky Apple-Inspired Scroll Reveal Animations
   ========================================================================== */
.scroll-reveal {
  opacity: 0;
  transform: translateY(18px) scale(0.995);
  transition: opacity 0.75s cubic-bezier(0.16, 1, 0.3, 1) var(--reveal-delay, 0ms), 
              transform 0.75s cubic-bezier(0.16, 1, 0.3, 1) var(--reveal-delay, 0ms);
  will-change: opacity, transform;
}

.scroll-reveal.revealed {
  opacity: 1;
  transform: translateY(0) scale(1);
}

/* Respect user preferences for reduced motion */
@media (prefers-reduced-motion: reduce) {
  .scroll-reveal {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
  #scroll-progress-bar {
    display: none !important;
  }
}

/* Creative Academic Radar Preloader */
#syllabix-preloader {
  position: fixed;
  inset: 0;
  z-index: 9999;
  background-color: var(--bg-base);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  transition: opacity 0.5s cubic-bezier(0.16, 1, 0.3, 1), 
              visibility 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

#syllabix-preloader.fade-out {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.preloader-radar-wrapper {
  position: relative;
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.preloader-radar-pulse {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 2px solid var(--primary);
  animation: radar-ping 1.8s cubic-bezier(0, 0, 0.2, 1) infinite;
  opacity: 0.6;
}

.preloader-radar-pulse:nth-child(2) {
  animation-delay: 0.6s;
}

.preloader-logo-badge {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--primary) 0%, #8B5CF6 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-weight: 800;
  font-size: 1.25rem;
  box-shadow: 0 4px 15px var(--primary-glow);
  z-index: 2;
  animation: preloader-bounce 1.6s ease-in-out infinite alternate;
}

.preloader-text-status {
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.preloader-text-status span {
  color: var(--primary);
}

@keyframes radar-ping {
  0% {
    transform: scale(0.6);
    opacity: 0.9;
  }
  80%, 100% {
    transform: scale(1.7);
    opacity: 0;
  }
}

@keyframes preloader-bounce {
  0% {
    transform: scale(0.95);
  }
  100% {
    transform: scale(1.05);
  }
}