/* ==========================================================================
   PLU v3.0 - DESIGN TOKENS
   Zentrale Variablen für Farben, Typografie, Spacing, Animationen
   ITCSS Layer 1: Settings
   
   Dokumentation für Studenten:
   - Alle Werte zentral definiert für Konsistenz
   - CSS Custom Properties (Variablen) ermöglichen Theming
   - Keine hartkodierten Werte in Komponenten!
   ========================================================================== */

:root {
  /* ========================================================================
     01. COLOR SYSTEM - Core Palette
     ======================================================================== */
  
  /* Background Colors */
  --bg-primary: #0a0c10;
  --bg-primary-rgb: 10, 12, 16;
  --bg-secondary: #11131a;
  --bg-secondary-rgb: 17, 19, 26;
  --bg-tertiary: #1a1d27;
  --bg-tertiary-rgb: 26, 29, 39;
  --bg-elevated: #222635;
  --bg-card: #161922;
  
  /* Text Colors */
  --text-primary: #f0f2f5;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  --text-inverse: #111827;
  
  /* Border & Divider */
  --border-primary: rgba(255, 255, 255, 0.08);
  --border-secondary: rgba(255, 255, 255, 0.05);
  --border-focus: rgba(88, 166, 255, 0.5);
  
  /* Glassmorphism */
  --glass-bg: rgba(17, 19, 26, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-backdrop: blur(20px);
  
  /* ========================================================================
     02. ACCENT COLORS - Brand & Academy System
     ======================================================================== */
  
  /* Core Brand */
  --accent-primary: #58a6ff;
  --accent-primary-rgb: 88, 166, 255;
  --accent-primary-glow: rgba(88, 166, 255, 0.4);
  
  --accent-cyan: #39d0d8;
  --accent-cyan-rgb: 57, 208, 216;
  --accent-cyan-glow: rgba(57, 208, 216, 0.4);
  
  --accent-violet: #8b5cf6;
  --accent-violet-rgb: 139, 92, 246;
  --accent-violet-glow: rgba(139, 92, 246, 0.4);
  
  --accent-pink: #ec4899;
  --accent-pink-rgb: 236, 72, 153;
  --accent-pink-glow: rgba(236, 72, 153, 0.4);
  
  /* Semantic Colors */
  --accent-orange: #f59e0b;
  --accent-orange-rgb: 245, 158, 11;
  --accent-orange-glow: rgba(245, 158, 11, 0.4);
  
  --accent-green: #3fb950;
  --accent-green-rgb: 63, 185, 80;
  --accent-green-glow: rgba(63, 185, 80, 0.4);
  
  --accent-red: #ef4444;
  --accent-red-rgb: 239, 68, 68;
  --accent-red-glow: rgba(239, 68, 68, 0.4);
  
  /* ========================================================================
     03. ACADEMY THEME COLORS
     Altersadaptive Farbschemata
     ======================================================================== */
  
  /* Default / Premium (Erwachsene) */
  --academy-primary: var(--accent-primary);
  --academy-secondary: var(--accent-cyan);
  --academy-accent: var(--accent-violet);
  --animation-level: moderate;
  --font-size-scale: 1;
  
  /* ========================================================================
     04. GRADIENTS
     ======================================================================== */
  
  --gradient-primary: linear-gradient(135deg, #58a6ff 0%, #39d0d8 100%);
  --gradient-violet: linear-gradient(135deg, #8b5cf6 0%, #ec4899 100%);
  --gradient-orange: linear-gradient(135deg, #f59e0b 0%, #ef4444 100%);
  --gradient-green: linear-gradient(135deg, #3fb950 0%, #39d0d8 100%);
  --gradient-hero: linear-gradient(180deg, #0a0c10 0%, #11131a 50%, #0a0c10 100%);
  --gradient-glow: radial-gradient(ellipse at center, rgba(88, 166, 255, 0.15) 0%, transparent 70%);
  
  /* Category Gradients */
  --gradient-web: linear-gradient(135deg, #58a6ff 0%, #39d0d8 100%);
  --gradient-ai: linear-gradient(135deg, #8b5cf6 0%, #ec4899 100%);
  --gradient-design: linear-gradient(135deg, #ec4899 0%, #f59e0b 100%);
  --gradient-audio: linear-gradient(135deg, #f59e0b 0%, #ef4444 100%);
  
  /* Parallax Overlay Gradient */
  --gradient-parallax: linear-gradient(
    180deg,
    rgba(10, 12, 16, 0.7) 0%,
    rgba(10, 12, 16, 0.4) 50%,
    rgba(10, 12, 16, 0.7) 100%
  );
}

/* ========================================================================
   ACADEMY THEME OVERRIDES
   ======================================================================== */

/* Junior Academy (Jugendliche 14-20) */
[data-academy="junior"] {
  --academy-primary: #58a6ff;
  --academy-secondary: #39d0d8;
  --academy-accent: #8b5cf6;
  --animation-level: playful;
  --font-size-scale: 1;
  
  /* Playful Gradients */
  --gradient-academy: linear-gradient(135deg, #58a6ff 0%, #8b5cf6 100%);
}

/* Premium Academy (Erwachsene 25-50) */
[data-academy="premium"] {
  --academy-primary: #f59e0b;
  --academy-secondary: #ec4899;
  --academy-accent: #8b5cf6;
  --animation-level: moderate;
  --font-size-scale: 1;
  
  --gradient-academy: linear-gradient(135deg, #f59e0b 0%, #ec4899 100%);
}

/* Senior Academy (50+) */
[data-academy="senior"] {
  --academy-primary: #3fb950;
  --academy-secondary: #27ae60;
  --academy-accent: #39d0d8;
  --animation-level: calm;
  --font-size-scale: 1.125; /* 18px Base */
  
  --gradient-academy: linear-gradient(135deg, #3fb950 0%, #39d0d8 100%);
}

/* ========================================================================
   LIGHT THEME
   ======================================================================== */

html.light-theme {
  /* Background - Neutral warm for adults/seniors */
  --bg-primary: #f8fafc;        /* slate-50 - Hero section */
  --bg-primary-rgb: 248, 250, 252;
  --bg-secondary: #ffffff;       /* Clean white - KI Charter */
  --bg-secondary-rgb: 255, 255, 255;
  --bg-tertiary: #f1f5f9;        /* slate-100 - About KI */
  --bg-tertiary-rgb: 241, 245, 249;
  --bg-elevated: #f5f3ff;        /* violet-50 - softer than violet-100 */
  --bg-card: #ffffff;
  
  /* Text */
  --text-primary: #111827;
  --text-secondary: #374151;
  --text-muted: #6b7280;
  --text-inverse: #f0f2f5;
  
  /* Border */
  --border-primary: rgba(0, 0, 0, 0.08);
  --border-secondary: rgba(0, 0, 0, 0.05);
  --border-focus: rgba(37, 99, 235, 0.5);
  
  /* Glass */
  --glass-bg: rgba(255, 255, 255, 0.8);
  --glass-border: rgba(0, 0, 0, 0.08);
  
  /* Accents - Desaturated for adult/senior-friendly light mode */
  --accent-primary: #4a90e2;
  --accent-primary-rgb: 74, 144, 226;
  --accent-primary-glow: rgba(74, 144, 226, 0.2);

  --accent-cyan: #0e7490;
  --accent-cyan-rgb: 14, 116, 144;
  --accent-cyan-glow: rgba(14, 116, 144, 0.2);

  --accent-violet: #6d28d9;
  --accent-violet-rgb: 109, 40, 217;
  --accent-violet-glow: rgba(109, 40, 217, 0.2);

  --accent-pink: #c2185b;
  --accent-pink-rgb: 194, 24, 91;
  --accent-pink-glow: rgba(194, 24, 91, 0.2);

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #4a90e2 0%, #7c3aed 100%);
  --gradient-violet: linear-gradient(135deg, #6d28d9 0%, #c2185b 100%);
  --gradient-hero: linear-gradient(180deg, #fafafa 0%, #ffffff 50%, #fafafa 100%);
  
  /* Parallax Overlay - Darker for light theme */
  --gradient-parallax: linear-gradient(
    180deg,
    rgba(0, 0, 0, 0.6) 0%,
    rgba(0, 0, 0, 0.3) 50%,
    rgba(0, 0, 0, 0.6) 100%
  );
}

/* Academy Themes in Light Mode */
html.light-theme[data-academy="junior"] {
  --academy-primary: #2563eb;
  --gradient-academy: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
}

html.light-theme[data-academy="premium"] {
  --academy-primary: #b45309;
  --gradient-academy: linear-gradient(135deg, #b45309 0%, #be185d 100%);
}

html.light-theme[data-academy="senior"] {
  --academy-primary: #059669;
  --gradient-academy: linear-gradient(135deg, #059669 0%, #0891b2 100%);
}

/* ========================================================================
   05. TYPOGRAPHY SCALE
   Fluid Typography mit clamp() für responsiven Text
   ======================================================================== */

:root {
  /* Font Families */
  --font-display: 'Inter', 'SF Pro Display', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
  
  /* Fluid Font Sizes */
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.9rem + 0.5vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.65vw, 1.25rem);
  --text-xl: clamp(1.25rem, 1.1rem + 0.75vw, 1.5rem);
  --text-2xl: clamp(1.5rem, 1.2rem + 1.5vw, 2rem);
  --text-3xl: clamp(1.875rem, 1.4rem + 2.4vw, 3rem);
  --text-4xl: clamp(2.25rem, 1.5rem + 3.75vw, 4rem);
  --text-5xl: clamp(3rem, 2rem + 5vw, 5rem);
  
  /* Line Heights */
  --leading-none: 1;
  --leading-tight: 1.25;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;
  --leading-loose: 2;
  
  /* Font Weights */
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  --font-extrabold: 800;
  
  /* Letter Spacing */
  --tracking-tight: -0.02em;
  --tracking-normal: 0;
  --tracking-wide: 0.05em;
  --tracking-wider: 0.1em;
}

/* ========================================================================
   06. SPACING SYSTEM (8-Point Grid)
   ======================================================================== */

:root {
  --space-0: 0;
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.25rem;   /* 20px */
  --space-6: 1.5rem;    /* 24px */
  --space-8: 2rem;      /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */
  --space-16: 4rem;     /* 64px */
  --space-20: 5rem;     /* 80px */
  --space-24: 6rem;     /* 96px */
  --space-32: 8rem;     /* 128px */
  
  /* Section Spacing */
  --section-padding-y: clamp(3rem, 5vw, 7.5rem);
  --section-padding-x: clamp(1rem, 3vw, 2rem);
  
  /* Container */
  --container-max: 1280px;
  --container-padding: var(--space-4);
  
  /* Header */
  --header-height: 80px;
}

/* ========================================================================
   07. BORDER RADIUS
   ======================================================================== */

:root {
  --radius-none: 0;
  --radius-sm: 0.5rem;    /* 8px */
  --radius-md: 0.75rem;   /* 12px */
  --radius-lg: 1.25rem;   /* 20px */
  --radius-xl: 1.75rem;   /* 28px */
  --radius-2xl: 2rem;     /* 32px */
  --radius-full: 9999px;
}

/* ========================================================================
   08. SHADOWS
   ======================================================================== */

:root {
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  
  /* Glow Shadows */
  --shadow-glow-primary: 0 0 20px var(--accent-primary-glow);
  --shadow-glow-violet: 0 0 20px var(--accent-violet-glow);
  --shadow-glow-cyan: 0 0 20px var(--accent-cyan-glow);
}

/* ========================================================================
   09. TRANSITIONS & ANIMATION
   ======================================================================== */

:root {
  /* Durations */
  --duration-fast: 150ms;
  --duration-normal: 300ms;
  --duration-slow: 500ms;
  --duration-slower: 700ms;
  
  /* Easing Functions */
  --ease-linear: linear;
  --ease-in: cubic-bezier(0.4, 0, 1, 1);
  --ease-out: cubic-bezier(0, 0, 0.2, 1);
  --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  
  /* Transition Presets */
  --transition-colors: color var(--duration-fast) var(--ease-out), background-color var(--duration-fast) var(--ease-out), border-color var(--duration-fast) var(--ease-out);
  --transition-transform: transform var(--duration-normal) var(--ease-spring);
  --transition-opacity: opacity var(--duration-fast) var(--ease-out);
  --transition-shadow: box-shadow var(--duration-fast) var(--ease-out);
  --transition-all: all var(--duration-normal) var(--ease-out);
}

/* ========================================================================
   10. Z-INDEX SCALE
   ======================================================================== */

:root {
  --z-behind: -1;
  --z-base: 0;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal-backdrop: 400;
  --z-modal: 500;
  --z-popover: 600;
  --z-tooltip: 700;
  --z-toast: 800;
  --z-preloader: 900;
}

/* ========================================================================
   11. BREAKPOINTS (Reference for JS)
   ======================================================================== */

:root {
  --breakpoint-sm: 640px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 1024px;
  --breakpoint-xl: 1280px;
  --breakpoint-2xl: 1536px;
}

/* ========================================================================
   12. PARALLAX VARIABLES
   ======================================================================== */

:root {
  /* Parallax Section Heights */
  --parallax-sm: 40vh;
  --parallax-md: 60vh;
  --parallax-lg: 80vh;
  
  /* Overlay Opacity */
  --parallax-overlay-opacity: 0.7;
}

/* ========================================================================
   13. KI ACCENT - Academic Consistency
   ======================================================================== */

/* KI in "KI Grundlagen" - White in Dark Mode */
.ki-accent {
  color: #ffffff;
}

/* Light Mode: Black */
html.light-theme .ki-accent {
  color: #000000;
}