/* ==========================================================================
   ABC TREK IN NEPAL (abctrekinnepal.com)
   CORE DESIGN SYSTEM & VISUAL TOKENS
   Version: 1.0.0
   ========================================================================== */

/* @import Google Fonts: Playfair Display (Cinematic Editorial) & Plus Jakarta Sans (Modern UI) */
@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,500;0,600;0,700;0,800;1,400;1,600&family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500&display=swap');

/* --- 1. DESIGN TOKENS & CSS CUSTOM PROPERTIES --- */
:root {
  /* Core Brand Colors */
  --color-bg: #FFFFFF;
  --color-brand-dark: #0F2D5C;
  --color-brand-dark-deep: #081B3A;
  --color-brand-dark-surface: #143870;
  --color-brand-dark-tint: #EEF4FA;
  
  /* Primary Action / Kinetic Accent */
  --color-accent: #F97316;
  --color-accent-hover: #EA580C;
  --color-accent-active: #C2410C;
  --color-accent-subtle: #FFF7ED;
  --color-accent-border: #FDBA74;

  /* Editorial Neutrals & Slate Hierarchy */
  --color-surface-pure: #FFFFFF;
  --color-surface-subtle: #F8FAFC;
  --color-surface-muted: #F1F5F9;
  --color-surface-card: #FFFFFF;
  
  --color-border-subtle: #E2E8F0;
  --color-border-medium: #CBD5E1;
  --color-border-dark: #0F2D5C;

  /* Typography Colors */
  --color-text-headline: #0F2D5C;
  --color-text-body: #1E293B;
  --color-text-muted: #475569;
  --color-text-light: #64748B;
  --color-text-inverse: #FFFFFF;
  --color-text-inverse-muted: #CBD5E1;

  /* Semantic Feedback & Trail Data */
  --color-success: #059669;
  --color-success-bg: #ECFDF5;
  --color-success-border: #A7F3D0;

  --color-warning: #D97706;
  --color-warning-bg: #FFFBEB;
  --color-warning-border: #FDE68A;

  --color-danger: #DC2626;
  --color-danger-bg: #FEF2F2;
  --color-danger-border: #FECACA;

  --color-altitude-low: #059669;
  --color-altitude-mid: #0284C7;
  --color-altitude-high: #D97706;
  --color-altitude-extreme: #DC2626;

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

  /* Type Scale & Hierarchy */
  --text-display-xl: 3.75rem;   /* 60px */
  --text-display-lg: 3.00rem;   /* 48px */
  --text-display-md: 2.25rem;   /* 36px */
  --text-h1: 2.25rem;           /* 36px */
  --text-h2: 1.875rem;          /* 30px */
  --text-h3: 1.50rem;           /* 24px */
  --text-h4: 1.25rem;           /* 20px */
  --text-h5: 1.125rem;          /* 18px */
  --text-body-lg: 1.125rem;     /* 18px */
  --text-body: 1.00rem;         /* 16px */
  --text-body-sm: 0.875rem;     /* 14px */
  --text-caption: 0.75rem;      /* 12px */
  --text-telemetry: 0.8125rem;   /* 13px */

  /* Line Heights */
  --lh-tight: 1.15;
  --lh-heading: 1.25;
  --lh-normal: 1.6;
  --lh-relaxed: 1.75;

  /* Letter Spacing */
  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0em;
  --letter-spacing-wide: 0.05em;
  --letter-spacing-eyebrow: 0.12em;

  /* Spacing Scale (8pt Grid) */
  --space-2: 0.125rem;  /* 2px */
  --space-4: 0.25rem;   /* 4px */
  --space-8: 0.5rem;    /* 8px */
  --space-12: 0.75rem;  /* 12px */
  --space-16: 1rem;     /* 16px */
  --space-20: 1.25rem;  /* 20px */
  --space-24: 1.5rem;   /* 24px */
  --space-32: 2rem;     /* 32px */
  --space-40: 2.5rem;   /* 40px */
  --space-48: 3rem;     /* 48px */
  --space-64: 4rem;     /* 64px */
  --space-80: 5rem;     /* 80px */
  --space-96: 6rem;     /* 96px */
  --space-128: 8rem;    /* 128px */

  /* Container Widths */
  --container-max: 1320px;
  --container-reading: 780px;
  --container-narrow: 980px;

  /* Radius (Restrained & Architectural - NO excessive pills/bubbly curves) */
  --radius-xs: 2px;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;
  --radius-full: 9999px; /* Reserved exclusively for small status dots and telemetry badges */

  /* Shadows (Subtle, Atmospheric, Non-Muddy) */
  --shadow-subtle: 0 1px 3px rgba(15, 45, 92, 0.05);
  --shadow-card: 0 4px 16px -2px rgba(15, 45, 92, 0.06), 0 2px 6px -1px rgba(15, 45, 92, 0.03);
  --shadow-elevated: 0 12px 32px -4px rgba(15, 45, 92, 0.10), 0 4px 12px -2px rgba(15, 45, 92, 0.05);
  --shadow-modal: 0 24px 60px -8px rgba(15, 45, 92, 0.22);
  --shadow-glow-orange: 0 4px 18px rgba(249, 115, 22, 0.28);

  /* Transitions & Micro-Interactions */
  --transition-fast: 150ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 250ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 400ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Z-Index Hierarchy */
  --z-base: 1;
  --z-sticky: 100;
  --z-header: 500;
  --z-mobile-drawer: 600;
  --z-modal-backdrop: 900;
  --z-modal: 1000;
}

/* --- 2. CSS RESET & EDITORIAL BASE DEFAULTS --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-body);
  line-height: var(--lh-normal);
  color: var(--color-text-body);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* Typography Defaults */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-text-headline);
  font-weight: 700;
  line-height: var(--lh-heading);
  letter-spacing: var(--letter-spacing-tight);
}

h1, .font-display-xl {
  font-family: var(--font-serif);
  font-size: var(--text-display-lg);
  font-weight: 700;
}

h2, .font-display-md {
  font-family: var(--font-serif);
  font-size: var(--text-h2);
  font-weight: 700;
}

h3 {
  font-family: var(--font-sans);
  font-size: var(--text-h3);
  font-weight: 700;
}

h4 {
  font-family: var(--font-sans);
  font-size: var(--text-h4);
  font-weight: 600;
}

p {
  margin-bottom: var(--space-16);
  color: var(--color-text-body);
}

p.lead {
  font-size: var(--text-body-lg);
  line-height: var(--lh-relaxed);
  color: var(--color-text-muted);
}

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

a:hover {
  color: var(--color-accent);
}

/* Accessible Focus States (Never remove focus rings without replacing) */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

/* Images & Media */
img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
  height: auto;
}

/* Base Layout Containers */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-24);
  padding-right: var(--space-24);
}

.container-narrow {
  width: 100%;
  max-width: var(--container-narrow);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-24);
  padding-right: var(--space-24);
}

.container-reading {
  width: 100%;
  max-width: var(--container-reading);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-24);
  padding-right: var(--space-24);
}

/* Section Spacing System */
.section {
  padding-top: var(--space-80);
  padding-bottom: var(--space-80);
  position: relative;
}

.section-sm {
  padding-top: var(--space-48);
  padding-bottom: var(--space-48);
}

.section-dark {
  background-color: var(--color-brand-dark);
  color: var(--color-text-inverse);
}

.section-dark h1,
.section-dark h2,
.section-dark h3,
.section-dark h4 {
  color: var(--color-text-inverse);
}

.section-dark p {
  color: var(--color-text-inverse-muted);
}

.section-tint {
  background-color: var(--color-brand-dark-tint);
}

.section-subtle {
  background-color: var(--color-surface-subtle);
}

/* Section Header Editorial Pattern */
.section-header {
  margin-bottom: var(--space-48);
}

.section-header.text-center {
  text-align: center;
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: var(--text-caption);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: var(--letter-spacing-eyebrow);
  color: var(--color-accent);
  margin-bottom: var(--space-8);
}

.section-title {
  margin-bottom: var(--space-16);
}

.section-subtitle {
  font-size: var(--text-body-lg);
  color: var(--color-text-muted);
  line-height: var(--lh-relaxed);
  max-width: 680px;
}

.section-dark .section-subtitle {
  color: var(--color-text-inverse-muted);
}

/* Utility Helpers */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.font-mono { font-family: var(--font-mono); }
.font-serif { font-family: var(--font-serif); }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Responsive Fluid Typography */
@media (min-width: 1024px) {
  :root {
    --text-display-xl: 4.25rem;
    --text-display-lg: 3.50rem;
    --text-h1: 2.75rem;
    --text-h2: 2.25rem;
  }
}