/* Variables */
:root {
  /* Colors */
  --color-background: #0d1b2a; /* midnight navy */
  --color-text: #f5e6ca; /* parchment beige */
  --color-primary: #ff6b35; /* ember orange */
  --color-primary-dark: #cc552b; /* darker ember orange */
  --color-primary-light: #ff8b5c; /* lighter ember orange */
  --color-success: #4caf50;
  --color-warning: #ff9800;
  --color-danger: #f44336;
  --color-gray-100: #f8f9fa;
  --color-gray-200: #e9ecef;
  --color-gray-300: #dee2e6;
  --color-gray-400: #ced4da;
  --color-gray-500: #adb5bd;
  --color-gray-600: #6c757d;
  --color-gray-700: #495057;
  --color-gray-800: #343a40;
  --color-gray-900: #212529;

  /* Typography */
  --font-family-base: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  --font-family-heading: 'Georgia', 'Times New Roman', 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-loose: 1.75;

  /* Spacing scale in rem, base 16px */
  --spacing-0: 0;
  --spacing-1: 0.25rem;  /* 4px */
  --spacing-2: 0.5rem;   /* 8px */
  --spacing-3: 0.75rem;  /* 12px */
  --spacing-4: 1rem;     /* 16px */
  --spacing-6: 1.5rem;   /* 24px */
  --spacing-8: 2rem;     /* 32px */
  --spacing-12: 3rem;    /* 48px */
  --spacing-16: 4rem;    /* 64px */
  --spacing-24: 6rem;    /* 96px */

  /* Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.5);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.2);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);

  /* Transitions */
  --transition-fast: 150ms;
  --transition-normal: 300ms;
  --transition-slow: 500ms;
}

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

html {
  scroll-behavior: smooth;
}

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

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

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

@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-family-heading);
  font-weight: 700;
  line-height: var(--line-height-tight);
  margin-bottom: var(--spacing-4);
  color: var(--color-text);
}

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); }

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

a:hover {
  text-decoration: underline;
}

p {
  margin-bottom: var(--spacing-4);
}

/* Utilities */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-4);
}

main.container {
  margin-top: var(--spacing-8);
  margin-bottom: var(--spacing-8);
}

.flex {
  display: flex;
}

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

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

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

.grid {
  display: grid;
}

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

.gap-1 { gap: var(--spacing-1); }
.gap-2 { gap: var(--spacing-2); }
.gap-4 { gap: var(--spacing-4); }
.gap-8 { gap: var(--spacing-8); }

.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;
}

/* Components */
.btn {
  display: inline-block;
  padding: var(--spacing-2) var(--spacing-4);
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  font-weight: 600;
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-primary);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--transition-normal) ease;
}

.btn:hover,
.btn:focus {
  background-color: var(--color-primary-dark);
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

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

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

.input {
  width: 100%;
  padding: var(--spacing-2) var(--spacing-4);
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  color: var(--color-text);
  background-color: var(--color-gray-800);
  border: 1px solid var(--color-gray-700);
  border-radius: var(--radius-sm);
  transition: border-color var(--transition-normal) ease;
}

.input:focus {
  border-color: var(--color-primary);
  outline: none;
}

.card {
  background-color: var(--color-gray-900);
  border-radius: var(--radius-md);
  padding: var(--spacing-6);
  box-shadow: var(--shadow-md);
  transition: box-shadow var(--transition-normal) ease;
}

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