/* ==========================================================================
   YOUSFUL STUDIO — CORE DESIGN SYSTEM & TOKENS
   Inspired by Reference: Deep Charcoal, Floating Glass Islands, Editorial Typography
   ========================================================================== */

:root {
  /* Color Palette */
  --bg-base: #090a0f;
  --bg-surface: #11131a;
  --bg-surface-elevated: #161922;
  --bg-surface-hover: #1c202c;
  --bg-glass: rgba(18, 20, 28, 0.65);
  --bg-glass-elevated: rgba(24, 27, 38, 0.85);

  /* Pill Navigation Capsule */
  --nav-capsule-bg: rgba(22, 24, 31, 0.75);
  --nav-capsule-border: rgba(255, 255, 255, 0.08);

  /* Borders & Dividers */
  --border-subtle: rgba(255, 255, 255, 0.07);
  --border-medium: rgba(255, 255, 255, 0.12);
  --border-highlight: rgba(255, 255, 255, 0.24);

  /* Typography Colors */
  --text-primary: #ffffff;
  --text-secondary: #9aa1b2;
  --text-muted: #656c7d;
  --text-dim: #454b59;

  /* Card Accent Gradients & Colors (Matching Reference Deck) */
  --deck-cyan: #06b6d4;
  --deck-cyan-rgb: 6, 182, 212;
  --deck-cyan-bg: linear-gradient(145deg, #0e879b 0%, #0369a1 100%);
  
  --deck-coral: #ff5e62;
  --deck-coral-rgb: 255, 94, 98;
  --deck-coral-bg: linear-gradient(145deg, #ff6b6b 0%, #d83a56 100%);

  --deck-purple: #7952f5;
  --deck-purple-rgb: 121, 82, 245;
  --deck-purple-bg: linear-gradient(145deg, #6366f1 0%, #4338ca 100%);

  --deck-lime: #10b981;
  --deck-lime-rgb: 16, 185, 129;
  --deck-lime-bg: linear-gradient(145deg, #22c55e 0%, #15803d 100%);

  --deck-blue: #3b82f6;
  --deck-blue-rgb: 59, 130, 246;
  --deck-blue-bg: linear-gradient(145deg, #2563eb 0%, #1d4ed8 100%);

  /* Global Studio Accents */
  --accent-emerald: #00f5a0;
  --accent-emerald-rgb: 0, 245, 160;
  --accent-cyan: #00d4ff;
  --accent-cyan-rgb: 0, 212, 255;
  --accent-violet: #a855f7;
  --accent-violet-rgb: 168, 85, 247;
  --accent-coral: #ff6b6b;
  --accent-coral-rgb: 255, 107, 107;
  --accent-gold: #fbbf24;

  /* App Theme Variables (Default to Studio Accent) */
  --app-accent: var(--deck-cyan);
  --app-accent-rgb: var(--deck-cyan-rgb);
  --app-glow: rgba(var(--app-accent-rgb), 0.15);

  /* Typography Families */
  --font-display: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-body: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-serif-italic: 'Instrument Serif', 'Playfair Display', Georgia, serif;
  --font-mono: 'Space Mono', monospace;

  /* Spacing Scale */
  --container-max: 1240px;
  --container-narrow: 860px;
  --header-height: 84px;

  /* Radii */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-2xl: 36px;
  --radius-pill: 9999px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-bounce: cubic-bezier(0.34, 1.56, 0.64, 1);
  --transition-fast: 0.18s var(--ease-out);
  --transition-smooth: 0.28s var(--ease-out);
  --transition-slow: 0.5s var(--ease-out);
  --transition-deck: 0.4s cubic-bezier(0.2, 0.8, 0.2, 1);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  color-scheme: dark;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-base);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

/* Starry Atmosphere & Soft Ambient Radial Illumination */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    radial-gradient(1px 1px at 20px 30px, rgba(255, 255, 255, 0.25), transparent),
    radial-gradient(1.5px 1.5px at 140px 180px, rgba(255, 255, 255, 0.3), transparent),
    radial-gradient(1px 1px at 280px 80px, rgba(255, 255, 255, 0.2), transparent),
    radial-gradient(1.5px 1.5px at 420px 240px, rgba(255, 255, 255, 0.35), transparent),
    radial-gradient(1px 1px at 580px 120px, rgba(255, 255, 255, 0.2), transparent),
    radial-gradient(1.5px 1.5px at 740px 310px, rgba(255, 255, 255, 0.3), transparent),
    radial-gradient(1px 1px at 890px 160px, rgba(255, 255, 255, 0.25), transparent),
    radial-gradient(1.5px 1.5px at 1050px 280px, rgba(255, 255, 255, 0.3), transparent),
    radial-gradient(1px 1px at 1200px 90px, rgba(255, 255, 255, 0.2), transparent),
    radial-gradient(1.5px 1.5px at 1350px 220px, rgba(255, 255, 255, 0.35), transparent);
  background-repeat: repeat;
  background-size: 1400px 500px;
  pointer-events: none;
  z-index: 0;
  opacity: 0.6;
}

/* Subtle glowing aura */
body::after {
  content: '';
  position: fixed;
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
  width: 1200px;
  height: 600px;
  background: radial-gradient(50% 50% at 50% 20%, rgba(6, 182, 212, 0.08) 0%, rgba(121, 82, 245, 0.04) 50%, transparent 100%);
  pointer-events: none;
  z-index: 0;
}

/* Typography Hierarchy */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.15;
  color: var(--text-primary);
  letter-spacing: -0.025em;
}

/* Editorial Serif Italic Accent Class */
.serif-italic, .font-italic {
  font-family: var(--font-serif-italic);
  font-style: italic;
  font-weight: 400;
  letter-spacing: -0.01em;
}

p {
  color: var(--text-secondary);
  font-size: 1rem;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

img, svg, video {
  max-width: 100%;
  display: block;
}

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

/* Container & Layout */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.container-narrow {
  width: 100%;
  max-width: var(--container-narrow);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.section {
  padding-top: 6rem;
  padding-bottom: 6rem;
  position: relative;
  z-index: 1;
}

@media (max-width: 768px) {
  .section {
    padding-top: 4rem;
    padding-bottom: 4rem;
  }
}

/* Section Header */
.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 3.5rem;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 700;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-medium);
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.section-tag.accent {
  background: rgba(var(--app-accent-rgb), 0.08);
  border-color: rgba(var(--app-accent-rgb), 0.25);
  color: var(--app-accent);
}

.section-title {
  font-size: clamp(2rem, 4vw, 3.25rem);
  margin-bottom: 1rem;
  letter-spacing: -0.025em;
}

.section-desc {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Subtle Gradient Text Highlight */
.gradient-text {
  background: linear-gradient(135deg, #ffffff 30%, var(--text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.accent-text {
  background: linear-gradient(135deg, #ffffff 0%, var(--app-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}