/**
 * BKISC Design Tokens
 *
 * Single source of truth for all visual design values.
 * No hardcoded colors, spacing, or font sizes anywhere else.
 *
 * Accent: BKISC Blue #4A9EFF
 * Dark-first: dark mode is default via data-theme + prefers-color-scheme.
 */

:root {
  /* ── Font Families ── */
  --bk-font-sans: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --bk-font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  --bk-font-family: var(--bk-font-sans);

  /* ── Type Scale ── */
  --bk-font-size-xs:   0.75rem;   /* 12px */
  --bk-font-size-sm:   0.875rem;  /* 14px */
  --bk-font-size-base: 1rem;      /* 16px */
  --bk-font-size-md:   1.125rem;  /* 18px */
  --bk-font-size-lg:   1.25rem;   /* 20px */
  --bk-font-size-xl:   1.5rem;    /* 24px */
  --bk-font-size-2xl:  1.875rem;  /* 30px */
  --bk-font-size-3xl:  2.25rem;   /* 36px */
  --bk-font-size-4xl:  3rem;      /* 48px */
  --bk-font-size-5xl:  3.75rem;   /* 60px */

  /* ── Line Heights ── */
  --bk-leading-tight: 1.15;
  --bk-leading-snug:  1.35;
  --bk-leading-body:  1.65;

  /* ── Spacing Scale (4px base) ── */
  --bk-space-1:  0.25rem;  /* 4px */
  --bk-space-2:  0.5rem;   /* 8px */
  --bk-space-3:  0.75rem;  /* 12px */
  --bk-space-4:  1rem;     /* 16px */
  --bk-space-5:  1.25rem;  /* 20px */
  --bk-space-6:  1.5rem;   /* 24px */
  --bk-space-8:  2rem;     /* 32px */
  --bk-space-10: 2.5rem;   /* 40px */
  --bk-space-12: 3rem;     /* 48px */
  --bk-space-16: 4rem;     /* 64px */
  --bk-space-24: 6rem;     /* 96px */
  --bk-space-32: 8rem;     /* 128px */

  /* ── Border Radii ── */
  --bk-radius-none: 0;
  --bk-radius-xs:   2px;
  --bk-radius-sm:   4px;
  --bk-radius-md:   8px;
  --bk-radius-lg:   12px;
  --bk-radius-xl:   16px;
  --bk-radius-full: 9999px;

  /* ── Borders ── */
  --bk-border-hairline: 1px;
  --bk-border-default:  1px;
  --bk-border-strong:   2px;

  /* ── Shadows ── */
  --bk-shadow-sm:    0 1px 2px rgba(0, 0, 0, 0.2);
  --bk-shadow-md:    0 4px 8px rgba(0, 0, 0, 0.15);
  --bk-shadow-lg:    0 8px 24px rgba(0, 0, 0, 0.2);
  --bk-shadow-focus: 0 0 0 3px rgba(74, 158, 255, 0.4);
  --bk-shadow-glow:  0 0 20px rgba(74, 158, 255, 0.15);

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

  /* ── Layout ── */
  --bk-navbar-height:  64px;
  --bk-content-max:    720px;
  --bk-container-max:  1280px;
}

/* ══════════════════════════════════════════
   DARK THEME (DEFAULT)
   ══════════════════════════════════════════ */
:root,
[data-theme="dark"] {
  --bk-color-bg-base:     #0c0d10;
  --bk-color-bg-elevated: #151619;
  --bk-color-bg-sunken:   #08090b;
  --bk-color-bg-overlay:  rgba(12, 13, 16, 0.85);

  --bk-color-fg-primary:   #e4e4e7;
  --bk-color-fg-secondary: #a1a1aa;
  --bk-color-fg-muted:     #71717a;
  --bk-color-fg-on-accent: #ffffff;

  --bk-color-border:        #27272a;
  --bk-color-border-strong: #3f3f46;
  --bk-color-border-accent: rgba(74, 158, 255, 0.3);

  --bk-color-accent:       #4A9EFF;
  --bk-color-accent-hover: #6DB3FF;
  --bk-color-accent-muted: rgba(74, 158, 255, 0.15);
  --bk-color-accent-rgb:   74, 158, 255;

  /* Override Bootstrap body variables for dark mode */
  --bs-body-bg: #0c0d10;
  --bs-body-color: #e4e4e7;
  --bs-body-bg-rgb: 12, 13, 16;

  --bk-color-success: #22c55e;
  --bk-color-warning: #eab308;
  --bk-color-danger:  #ef4444;
  --bk-color-info:    #3b82f6;

  /* Backward compatibility bridge */
  --bk-bg-primary:    var(--bk-color-bg-base);
  --bk-bg-secondary:  var(--bk-color-bg-elevated);
  --bk-bg-tertiary:   var(--bk-color-bg-sunken);
  --bk-text-primary:  var(--bk-color-fg-primary);
  --bk-text-muted:    var(--bk-color-fg-muted);
  --bk-text-lead:     var(--bk-color-fg-secondary);
  --bk-border-color:  var(--bk-color-border);

  /* Existing theme compat */
  --custom-bg-1: var(--bk-color-bg-base);
  --custom-bg-2: var(--bk-color-bg-elevated);
  --custom-bg-3: var(--bk-color-bg-sunken);
  --custom-text: var(--bk-color-fg-primary);
  --custom-lead-color: var(--bk-color-fg-secondary);
  --custom-partner-color: var(--bk-color-bg-sunken);
  --custom-hover-color: var(--bk-color-accent);
  --custom-text-info-color: var(--bk-color-accent);
  --custom-pagination-color: var(--bk-color-fg-primary);
  --custom-pagination-bg: var(--bk-color-bg-base);
  --custom-pagination-hover-bg: var(--bk-color-bg-elevated);

  color-scheme: dark;
}

/* ══════════════════════════════════════════
   LIGHT THEME
   ══════════════════════════════════════════ */
[data-theme="light"] {
  --bk-color-bg-base:     #ffffff;
  --bk-color-bg-elevated: #f4f4f5;
  --bk-color-bg-sunken:   #e4e4e7;
  --bk-color-bg-overlay:  rgba(255, 255, 255, 0.85);

  --bk-color-fg-primary:   #18181b;
  --bk-color-fg-secondary: #52525b;
  --bk-color-fg-muted:     #a1a1aa;
  --bk-color-fg-on-accent: #ffffff;

  --bk-color-border:        #e4e4e7;
  --bk-color-border-strong: #d4d4d8;
  --bk-color-border-accent: rgba(37, 99, 235, 0.3);

  --bk-color-accent:       #2563EB;
  --bk-color-accent-hover: #1D4ED8;
  --bk-color-accent-muted: rgba(37, 99, 235, 0.1);
  --bk-color-accent-rgb:   37, 99, 235;

  /* Override Bootstrap body variables for light mode */
  --bs-body-bg: #ffffff;
  --bs-body-color: #18181b;
  --bs-body-bg-rgb: 255, 255, 255;

  --bk-color-success: #16a34a;
  --bk-color-warning: #ca8a04;
  --bk-color-danger:  #dc2626;
  --bk-color-info:    #2563eb;

  /* Backward compatibility bridge */
  --bk-bg-primary:    var(--bk-color-bg-base);
  --bk-bg-secondary:  var(--bk-color-bg-elevated);
  --bk-bg-tertiary:   var(--bk-color-bg-sunken);
  --bk-text-primary:  var(--bk-color-fg-primary);
  --bk-text-muted:    var(--bk-color-fg-muted);
  --bk-text-lead:     var(--bk-color-fg-secondary);
  --bk-border-color:  var(--bk-color-border);

  /* Existing theme compat */
  --custom-bg-1: var(--bk-color-bg-base);
  --custom-bg-2: var(--bk-color-bg-elevated);
  --custom-bg-3: var(--bk-color-bg-sunken);
  --custom-text: var(--bk-color-fg-primary);
  --custom-lead-color: var(--bk-color-fg-secondary);
  --custom-partner-color: var(--bk-color-bg-sunken);
  --custom-hover-color: var(--bk-color-accent);
  --custom-text-info-color: var(--bk-color-accent);
  --custom-pagination-color: var(--bk-color-fg-primary);
  --custom-pagination-bg: var(--bk-color-bg-base);
  --custom-pagination-hover-bg: var(--bk-color-bg-elevated);

  color-scheme: light;
}

/* ══════════════════════════════════════════
   BASE RESETS
   ══════════════════════════════════════════ */
html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scrollbar-width: none;          /* Firefox */
}

html::-webkit-scrollbar {
  display: none;                  /* Chrome, Safari, Edge */
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  font-family: var(--bk-font-sans);
  color: var(--bk-color-fg-primary);
  background-color: var(--bk-color-bg-base);
  transition: background-color var(--bk-transition-slow),
              color var(--bk-transition-slow);
}

/* ── Focus States ── */
:focus-visible {
  outline: none;
  box-shadow: var(--bk-shadow-focus);
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[tabindex]:focus-visible {
  outline: none;
  box-shadow: var(--bk-shadow-focus);
  border-radius: var(--bk-radius-xs);
}

/* ── Skip Link ── */
.skip-link:focus {
  position: fixed !important;
  top: var(--bk-space-2);
  left: var(--bk-space-2);
  z-index: 10000;
  padding: var(--bk-space-2) var(--bk-space-4);
  background: var(--bk-color-accent);
  color: var(--bk-color-fg-on-accent);
  font-family: var(--bk-font-mono);
  font-size: var(--bk-font-size-sm);
  font-weight: 600;
  border-radius: var(--bk-radius-sm);
  text-decoration: none;
  clip: auto !important;
  width: auto !important;
  height: auto !important;
}

/* ── Monospace Accent Class ── */
.mono {
  font-family: var(--bk-font-mono);
  font-size: 0.9em;
}

/* ── Selection ── */
::selection {
  background: var(--bk-color-accent-muted);
  color: var(--bk-color-fg-primary);
}

/* ── Utility ── */
.bk-accent-divider {
  height: 2px;
  width: 48px;
  background-color: var(--bk-color-accent);
  border: none;
  margin: var(--bk-space-4) auto;
}

.bk-section-padding {
  padding: var(--bk-space-16) 0;
}

.bk-card-glow {
  border: 1px solid rgba(var(--bk-color-accent-rgb), 0.3);
  box-shadow: var(--bk-shadow-glow);
  border-radius: var(--bk-radius-md);
  transition: all var(--bk-transition-base);
}

.bk-card-glow:hover {
  box-shadow: none;
  border-color: var(--bk-border-color);
  transform: translateY(4px);
}