/* ==========================================================================
   Design System: Energy Services Corporate Platform
   Style: Corporate, Technical, Sustainable, Sophisticated
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Variables
   -------------------------------------------------------------------------- */
:root {
  /* Colors - Energy & Sustainability Palette */
  --color-background: #ffffff;
  --color-surface: #f8fafc;
  --color-text: #0f172a;
  --color-text-secondary: #64748b;
  --color-primary: #0033a0;        /* Deep Electric Blue */
  --color-primary-light: #0052cc;
  --color-secondary: #00a651;      /* Vibrant Green */
  --color-secondary-light: #00c853;
  --color-accent: #ff9f00;         /* Warm Amber */
  --color-accent-light: #ffb84d;
  --color-neutral-50: #f8fafc;
  --color-neutral-100: #f1f5f9;
  --color-neutral-200: #e2e8f0;
  --color-neutral-300: #cbd5e1;
  --color-neutral-400: #94a3b8;
  --color-neutral-500: #64748b;
  --color-neutral-600: #475569;
  --color-neutral-700: #334155;
  --color-neutral-800: #1e293b;
  --color-neutral-900: #0f172a;
  --color-success: #00a651;
  --color-warning: #ff9f00;
  --color-danger: #dc2626;
  --color-info: #0066ff;

  /* Typography */
  --font-family-base: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-family-heading: 'Inter', system-ui, -apple-system, sans-serif;
  --font-size-xs: 0.75rem;      /* 12px */
  --font-size-sm: 0.875rem;     /* 14px */
  --font-size-base: 1rem;       /* 16px */
  --font-size-lg: 1.125rem;     /* 18px */
  --font-size-xl: 1.25rem;      /* 20px */
  --font-size-2xl: 1.5rem;      /* 24px */
  --font-size-3xl: 1.875rem;    /* 30px */
  --font-size-4xl: 2.25rem;     /* 36px */
  --font-size-5xl: 3rem;        /* 48px */
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  /* Spacing Scale (0-96px) */
  --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 */

  /* Border Radius */
  --radius-sm: 0.25rem;   /* 4px */
  --radius-md: 0.5rem;    /* 8px */
  --radius-lg: 0.75rem;   /* 12px */
  --radius-xl: 1rem;      /* 16px */
  --radius-full: 9999px;

  /* Shadows - Sophisticated Depth */
  --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-primary: 0 4px 14px 0 rgba(0, 51, 160, 0.25);

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Layout */
  --container-max-width: 1280px;
  --container-padding: var(--space-4);
}

/* --------------------------------------------------------------------------
   2. Reset & Normalize
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100vh;
  text-rendering: optimizeSpeed;
  line-height: var(--line-height-normal);
}

img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
  height: auto;
}

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

ul[role='list'],
ol[role='list'] {
  list-style: none;
}

/* --------------------------------------------------------------------------
   3. Base Styles
   -------------------------------------------------------------------------- */
body {
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  color: var(--color-text);
  background-color: var(--color-background);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-family-heading);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

h1 { font-size: var(--font-size-5xl); }
h2 { font-size: var(--font-size-4xl); }
h3 { font-size: var(--font-size-3xl); }
h4 { font-size: var(--font-size-2xl); }
h5 { font-size: var(--font-size-xl); }
h6 { font-size: var(--font-size-lg); }

p {
  margin-bottom: var(--space-4);
  color: var(--color-text-secondary);
  max-width: 65ch;
}

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

a:hover {
  color: var(--color-primary-light);
  text-decoration: underline;
}

/* --------------------------------------------------------------------------
   4. Utilities
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--container-padding);
  padding-right: var(--container-padding);
}

/* Layout Utilities */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

.grid {
  display: grid;
}

.gap-4 {
  gap: var(--space-4);
}

.gap-6 {
  gap: var(--space-6);
}

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

/* --------------------------------------------------------------------------
   5. Components
   -------------------------------------------------------------------------- */

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-3) var(--space-6);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  line-height: var(--line-height-tight);
  border-radius: var(--radius-md);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  gap: var(--space-2);
}

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.btn--primary {
  background-color: var(--color-primary);
  color: white;
  box-shadow: var(--shadow-primary);
}

.btn--primary:hover {
  background-color: var(--color-primary-light);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(0, 51, 160, 0.3);
  text-decoration: none;
  color: white;
}

.btn--secondary {
  background-color: var(--color-secondary);
  color: white;
}

.btn--secondary:hover {
  background-color: var(--color-secondary-light);
  transform: translateY(-1px);
  text-decoration: none;
  color: white;
}

.btn--outline {
  background-color: transparent;
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn--outline:hover {
  background-color: var(--color-primary);
  color: white;
  text-decoration: none;
}

/* Form Inputs */
.input {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-background);
  border: 1px solid var(--color-neutral-300);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.input:hover {
  border-color: var(--color-neutral-400);
}

.input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 51, 160, 0.1);
}

.input:disabled {
  background-color: var(--color-neutral-100);
  cursor: not-allowed;
}

.input::placeholder {
  color: var(--color-neutral-400);
}

/* Cards */
.card {
  background-color: var(--color-background);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-neutral-200);
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.card:hover {
  box-shadow: var(--shadow-lg);
}

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

/* --------------------------------------------------------------------------
   6. Accessibility & 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;
  }
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
  :root {
    --color-primary: #0000ee;
    --color-text: #000000;
  }
  
  .card {
    border: 2px solid currentColor;
  }
  
  .btn {
    border: 2px solid currentColor;
  }
}

/* Print Styles */
@media print {
  .no-print {
    display: none !important;
  }
  
  body {
    font-size: 12pt;
    line-height: 1.5;
  }
  
  a {
    text-decoration: underline;
  }
  
  .card {
    box-shadow: none;
    border: 1px solid #000;
  }
}