/* OnePageKit v1 - Design Tokens & Utilities */

/* ===== DESIGN TOKENS ===== */
:root {
  /* Colors */
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #6b7280;
  --brand: #3b82f6;
  --accent: #10b981;
  --border: #e5e7eb;
  --bg-elev: #f9fafb;
  
  /* Spacing Scale */
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.5rem;    /* 24px */
  --space-6: 2rem;      /* 32px */
  --space-7: 3rem;      /* 48px */
  
  /* Border Radius */
  --radius-1: 0.125rem; /* 2px */
  --radius-2: 0.25rem;  /* 4px */
  --radius-3: 0.375rem; /* 6px */
  --radius-4: 0.5rem;   /* 8px */
  --radius-5: 0.75rem;  /* 12px */
  
  /* Shadows */
  --shadow-1: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-2: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-3: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Consolas, "Liberation Mono", Menlo, monospace;
  --size-sm: 0.875rem;   /* 14px */
  --size-md: 1rem;       /* 16px */
  --size-lg: 1.125rem;   /* 18px */
  --size-xl: 1.25rem;    /* 20px */
  --size-2xl: 1.5rem;    /* 24px */
  --size-3xl: 1.875rem;  /* 30px */
  --size-4xl: 2.25rem;   /* 36px */
  --line-md: 1.5;
  --line-tight: 1.25;
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a;
    --fg: #f1f5f9;
    --muted: #94a3b8;
    --border: #334155;
    --bg-elev: #1e293b;
  }
}

.theme-dark {
  --bg: #0f172a;
  --fg: #f1f5f9;
  --muted: #94a3b8;
  --border: #334155;
  --bg-elev: #1e293b;
}

.theme-light {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #6b7280;
  --border: #e5e7eb;
  --bg-elev: #f9fafb;
}

/* ===== BASE STYLES ===== */
* {
  box-sizing: border-box;
}

html {
  font-family: var(--font-sans);
  font-size: var(--size-md);
  line-height: var(--line-md);
  color: var(--fg);
  background-color: var(--bg);
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
}

/* Skip link for accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: 6px;
  background: var(--brand);
  color: white;
  padding: 8px;
  text-decoration: none;
  border-radius: var(--radius-2);
  z-index: 1000;
}

.skip-link:focus {
  top: 6px;
}

/* Focus styles */
:focus {
  outline: 2px solid var(--brand);
  outline-offset: 2px;
}

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

/* ===== UTILITY CLASSES ===== */

/* Spacing */
.m-1 { margin: var(--space-1); }
.m-2 { margin: var(--space-2); }
.m-3 { margin: var(--space-3); }
.m-4 { margin: var(--space-4); }
.m-5 { margin: var(--space-5); }

.p-1 { padding: var(--space-1); }
.p-2 { padding: var(--space-2); }
.p-3 { padding: var(--space-3); }
.p-4 { padding: var(--space-4); }
.p-5 { padding: var(--space-5); }

.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-5 { gap: var(--space-5); }

/* Layout */
.flex { display: flex; }
.grid { display: grid; }
.center { justify-content: center; align-items: center; }
.wrap { flex-wrap: wrap; }

/* Sizing */
.w-full { width: 100%; }
.w-half { width: 50%; }
.maxw-prose { max-width: 65ch; }
.maxw-wide { max-width: 80ch; }

/* Typography */
.text-sm { font-size: var(--size-sm); }
.text-md { font-size: var(--size-md); }
.text-lg { font-size: var(--size-lg); }
.text-xl { font-size: var(--size-xl); }
.text-2xl { font-size: var(--size-2xl); }
.text-3xl { font-size: var(--size-3xl); }
.text-4xl { font-size: var(--size-4xl); }

.fw-bold { font-weight: 700; }
.fw-normal { font-weight: 400; }

/* Colors */
.bg-base { background-color: var(--bg); }
.bg-elev { background-color: var(--bg-elev); }
.fg-muted { color: var(--muted); }
.border { border: 1px solid var(--border); }

/* ===== LAYOUT PRIMITIVES ===== */

/* Stack - vertical spacing */
.stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.stack > * + * {
  margin-top: 0;
}

/* Cluster - horizontal grouping with wrapping */
.cluster {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: center;
  justify-content: center;
}

/* Switcher - responsive layout switch */
.switcher {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.switcher > * {
  flex-grow: 1;
  flex-basis: calc((30rem - 100%) * 999);
}

/* Cover - centered content with optional header/footer */
.cover {
  display: flex;
  flex-direction: column;
  width: 100%;
  max-width: 100%;
}

.cover > * {
  margin-top: auto;
  margin-bottom: auto;
}

.cover > :first-child:not(.cover__centered) {
  margin-top: 0;
}

.cover > :last-child:not(.cover__centered) {
  margin-bottom: 0;
}

.cover__centered {
  margin-top: auto;
  margin-bottom: auto;
  width: 100%;
  max-width: 65ch;
  margin-left: auto;
  margin-right: auto;
}

/* Grid auto - auto-fit grid */
.grid-auto {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-4);
  justify-items: center;
}

/* ===== BLOCK STYLES ===== */

/* Hero Block */
.block-hero {
  padding: var(--space-7) var(--space-4);
  text-align: center;
  background: linear-gradient(135deg, var(--bg) 0%, var(--bg-elev) 100%);
  min-height: 60vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.block-hero h1 {
  font-size: var(--size-4xl);
  font-weight: 700;
  line-height: var(--line-tight);
  margin: 0 0 var(--space-4) 0;
}

.block-hero p {
  font-size: var(--size-lg);
  color: var(--muted);
  margin: 0 0 var(--space-5) 0;
  max-width: 60ch;
  margin-left: auto;
  margin-right: auto;
}

/* Generic Section Block */
.block-section {
  padding: var(--space-6) var(--space-4);
  display: flex;
  justify-content: center;
}

.block-section > div {
  width: 100%;
  max-width: 65ch;
  text-align: center;
}

.block-section h2 {
  font-size: var(--size-3xl);
  font-weight: 600;
  margin: 0 0 var(--space-4) 0;
}

.block-section p {
  margin: 0 0 var(--space-4) 0;
  max-width: 65ch;
  margin-left: auto;
  margin-right: auto;
}

/* Footer Block */
.block-footer {
  padding: var(--space-5) var(--space-4);
  background-color: var(--bg-elev);
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--muted);
}

.block-footer p {
  margin: 0;
  font-size: var(--size-sm);
}


/* ===== COMPONENTS ===== */

/* Button */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-3) var(--space-5);
  background-color: var(--brand);
  color: white;
  text-decoration: none;
  border-radius: var(--radius-3);
  font-weight: 500;
  border: none;
  cursor: pointer;
  transition: background-color 0.2s ease;
}

.btn:hover {
  background-color: var(--brand);
  opacity: 0.9;
}

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

.btn--secondary {
  background-color: transparent;
  color: var(--brand);
  border: 1px solid var(--brand);
}

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


/* Card component */
.card {
  border-radius: var(--radius-4);
  width: 100%;
  max-width: 300px;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .block-hero {
    padding: var(--space-5) var(--space-3);
  }
  
  .block-hero h1 {
    font-size: var(--size-3xl);
  }
  
  .block-section {
    padding: var(--space-5) var(--space-3);
  }
  
  .switcher > * {
    flex-basis: 100%;
  }
}