/* ═══════════════════════════════════════════════════════════════
   Design Tokens — Ved Gupta design system (Geist, monochrome neutrals)
   ═══════════════════════════════════════════════════════════════ */

/* Self-hosted variable fonts (latin subset); other scripts fall back to the system stack. */
@font-face {
  font-family: "Geist"; font-style: normal; font-weight: 100 900; font-display: swap;
  src: url("../fonts/geist-latin.woff2") format("woff2");
}
@font-face {
  font-family: "Geist Mono"; font-style: normal; font-weight: 100 900; font-display: swap;
  src: url("../fonts/geist-mono-latin.woff2") format("woff2");
}

:root {
  /* ── Typography ──────────────────────────────────────────── */
  --font-sans: "Geist", "Geist Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "Geist Mono", ui-monospace, SFMono-Regular, "Roboto Mono", Menlo, Monaco, monospace;
  --font-heading: var(--font-sans);

  /* Font weights */
  --weight-normal: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 600; /* design system tops out at semibold */

  /* Font sizes */
  --text-xs: 0.75rem;    /* 12px */
  --text-sm: 0.8125rem;  /* 13px */
  --text-base: 0.875rem; /* 14px */
  --text-md: 0.9375rem;  /* 15px */
  --text-lg: 1.125rem;   /* 18px */
  --text-xl: 1.25rem;    /* 20px */
  --text-2xl: 1.5rem;    /* 24px */
  --text-3xl: 1.875rem;  /* 30px */
  --text-4xl: 2.25rem;   /* 36px */

  /* Line heights */
  --leading-tight: 1.2;
  --leading-snug: 1.35;
  --leading-normal: 1.5;
  --leading-relaxed: 1.65;

  /* Letter spacing */
  --tracking-tighter: -0.05em; /* headings: matches vedgupta.in (-1.2px @ 24px) */
  --tracking-tight: -0.025em;
  --tracking-normal: 0;
  --tracking-wide: 0.025em;
  --tracking-wider: 0.05em;

  /* ── Spacing ─────────────────────────────────────────────── */
  --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 */

  /* ── Border Radius ───────────────────────────────────────── */
  --r-sm: 4px;
  --r-md: 6px;
  --r-lg: 8px;
  --r-xl: 12px;
  --r-2xl: 16px;
  --r-full: 999px;

  /* ── Layout ──────────────────────────────────────────────── */
  --topbar-h: 52px;
  --sidebar-w: 280px;
  --content-max: 760px;
  --reading-max: 680px;

  /* ── Transitions ─────────────────────────────────────────── */
  --dur-fast: 120ms;
  --dur-normal: 200ms;
  --dur-slow: 350ms;
  --ease-out: cubic-bezier(0, 0, 0.2, 1);
  --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);

  /* ── Shadows ─────────────────────────────────────────────── */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.16);

  /* ── Z-Index Scale ───────────────────────────────────────── */
  --z-sidebar: 20;
  --z-topbar: 30;
  --z-dropdown: 40;
  --z-modal: 50;
  --z-toast: 60;
}

/* ── Dark Theme (Default) ──────────────────────────────────── */
/* Ved Gupta design system (vedgupta.in · sso.vedgupta.in · resume.vedgupta.in):
   monochrome neutral palette, pure-black canvas, white primary. */
[data-theme="dark"], :root {
  --bg: #000000;
  --bg-alt: #0a0a0a;
  --surface: #0a0a0a;
  --surface-hover: #171717;
  --surface-active: #262626;
  --sidebar-bg: #0a0a0a;
  --topbar-bg: rgba(0, 0, 0, 0.88);
  --topbar-glass: rgba(0, 0, 0, 0.8);
  --panel-glass: rgba(10, 10, 10, 0.96);

  /* Borders & Dividers */
  --border: #262626;
  --border-strong: #404040;
  --border-focus: #525252;
  --divider: #171717;

  /* Typography Palette */
  --fg: #ffffff;
  --fg-prose: #e5e5e5;
  --fg-muted: #a1a1a1;
  --fg-faint: #8f8f8f; /* 5.5:1 on #171717 */
  --fg-inv: #000000;

  /* Primary (monochrome: white on black) */
  --accent: #ffffff;
  --accent-hover: #e5e5e5;
  --accent-muted: rgba(255, 255, 255, 0.08);
  --accent-border: rgba(255, 255, 255, 0.22);
  --accent-fg: #000000;
  --link: #54a2ff;
  --selection: #47a3f3;

  /* Status Colors (design-system chart palette) */
  --success: #05df72;
  --success-muted: rgba(5, 223, 114, 0.12);
  --warning: #ffd236;
  --warning-muted: rgba(255, 210, 54, 0.12);
  --error: #fb2c36;
  --error-muted: rgba(251, 44, 54, 0.12);
  --info: #54a2ff;
  --info-muted: rgba(84, 162, 255, 0.12);

  /* Interactive Elements */
  --chip-bg: #171717;
  --chip-border: #262626;
  --chip-fg: #a1a1a1;
  --hover-bg: #171717;
  --active-bg: #262626;
  --selected-bg: rgba(255, 255, 255, 0.06);
  --bg-card: #0a0a0a;
  --bg-hover: #171717;
  --border-subtle: #171717;

  /* Code & Syntax */
  --code-bg: #0a0a0a;
  --code-border: #262626;
  --code-fg: #f5f5f5;
  --code-inline-bg: rgba(110, 118, 129, 0.4);
  --code-inline-fg: #f47067;

  /* Callouts */
  --callout-bg: #0a0a0a;
  --callout-border: #262626;
  --callout-note: #54a2ff;
  --callout-tip: #05df72;
  --callout-warn: #ffd236;
  --callout-danger: #fb2c36;

  /* Progress */
  --progress-track: #262626;
  --progress-fill: #ffffff;

  /* Flat, hairline elevation */
  --shadow-sm: 0 0 0 1px rgba(255, 255, 255, 0.04);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.05);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.7), 0 0 0 1px rgba(255, 255, 255, 0.06);
  --shadow-card: none;
  --shadow-card-hover: 0 0 0 1px rgba(255, 255, 255, 0.08);

  color-scheme: dark;
}

/* ── Light Theme ───────────────────────────────────────────── */
[data-theme="light"] {
  --bg: #ffffff;
  --bg-alt: #fafafa;
  --surface: #ffffff;
  --surface-hover: #f5f5f5;
  --surface-active: #e5e5e5;
  --sidebar-bg: #fafafa;
  --topbar-bg: rgba(255, 255, 255, 0.9);
  --topbar-glass: rgba(255, 255, 255, 0.85);
  --panel-glass: rgba(255, 255, 255, 0.97);

  --border: #e5e5e5;
  --border-strong: #d4d4d4;
  --border-focus: #a1a1a1;
  --border-subtle: #f5f5f5;
  --divider: #f5f5f5;

  --fg: #0a0a0a;
  --fg-prose: #262626;
  --fg-muted: #525252;
  --fg-faint: #666666; /* 5.4:1 on #f5f5f5 */
  --fg-inv: #ffffff;

  --accent: #000000;
  --accent-hover: #262626;
  --accent-muted: rgba(0, 0, 0, 0.05);
  --accent-border: rgba(0, 0, 0, 0.2);
  --accent-fg: #ffffff;
  --link: #1447e6;
  --selection: #47a3f3;

  --success: #008138;
  --success-muted: rgba(0, 129, 56, 0.1);
  --warning: #b75000;
  --warning-muted: rgba(183, 80, 0, 0.1);
  --error: #e40014;
  --error-muted: rgba(228, 0, 20, 0.08);
  --info: #1447e6;
  --info-muted: rgba(20, 71, 230, 0.08);

  --chip-bg: #f5f5f5;
  --chip-border: #e5e5e5;
  --chip-fg: #404040;
  --hover-bg: #f5f5f5;
  --active-bg: #e5e5e5;
  --selected-bg: rgba(0, 0, 0, 0.04);
  --bg-card: #ffffff;
  --bg-hover: #f5f5f5;

  --code-bg: #fafafa;
  --code-border: #e5e5e5;
  --code-fg: #0a0a0a;
  --code-inline-bg: rgba(175, 184, 193, 0.2);
  --code-inline-fg: #c9463d;

  --callout-bg: #fafafa;
  --callout-border: #e5e5e5;
  --callout-note: #1447e6;
  --callout-tip: #008138;
  --callout-warn: #b75000;
  --callout-danger: #e40014;

  --progress-track: #e5e5e5;
  --progress-fill: #000000;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.08);
  --shadow-card: none;
  --shadow-card-hover: 0 0 0 1px rgba(0, 0, 0, 0.06);

  color-scheme: light;
}

::selection {
  background-color: var(--selection);
  color: #fefefe;
}

/* ── Legacy aliases ───────────────────────────────────────────
   Simulators and exercises were written against an older token set
   (css/style.css, which index.html does not load). Map those names onto
   the current tokens so they pick up borders, colours and both themes. */
:root, [data-theme="dark"], [data-theme="light"] {
  --border-color: var(--border);
  --text: var(--fg);
  --text-color: var(--fg);
  --text-muted: var(--fg-muted);
  --bg-body: var(--bg);
  --bg-surface: var(--surface);
  --bg-card-alt: var(--surface-hover);
  --bg-input: var(--bg-alt);
  --danger: var(--error);
  /* data-viz highlight: the design system's chart blue, so white labels stay readable */
  --accent-color: var(--info);
}