/* ==========================================================================
   Ramtin Tech Zone — Design Tokens
   The single source of truth for the site's visual language.
   Every color, size, space, and radius in style.css must reference a token
   from this file. Never hardcode a visual value in a component.

   Breakpoints are documented in DESIGN_SYSTEM.md, not defined here:
   CSS custom properties cannot be used in media query conditions.
   ========================================================================== */

:root {
  /* ---- Color: surfaces ------------------------------------------------ */
  --color-bg: #0b0f17;              /* page background */
  --color-bg-deep: #080d15;         /* footer, darkest surface */
  --color-surface: #111827;         /* cards, inputs, nav hover */
  --color-surface-2: #151f30;       /* inline code, subtle raised surface */
  --color-surface-3: #1a2438;       /* hover state on surfaces */
  --color-code-bg: #0d1526;         /* code blocks */
  --color-border: #1f2937;          /* default border */
  --color-border-strong: #374151;   /* hover / emphasis border */

  /* ---- Color: text ---------------------------------------------------- */
  --color-text: #e5e7eb;            /* primary text */
  --color-text-muted: #9ca3af;      /* secondary text, meta, placeholders */
  --color-text-on-accent: #ffffff;  /* text on accent backgrounds */

  /* ---- Color: accent -------------------------------------------------- */
  --color-accent: #3b82f6;          /* primary actions, links */
  --color-accent-strong: #2563eb;   /* logo gradient start, pressed state */
  --color-accent-hover: #60a5fa;    /* link hover, logo gradient end */
  --color-accent-soft: rgba(59, 130, 246, 0.15); /* tag / highlight fill */

  /* ---- Color: semantic ------------------------------------------------ */
  --color-success: #22c55e;
  --color-success-soft: rgba(34, 197, 94, 0.12);
  --color-warning: #f59e0b;
  --color-warning-soft: rgba(245, 158, 11, 0.12);
  --color-error: #ef4444;
  --color-error-soft: rgba(239, 68, 68, 0.12);
  --color-info: #3b82f6;
  --color-info-soft: rgba(59, 130, 246, 0.12);

  /* ---- Color: overlays ------------------------------------------------ */
  --color-black: #000000;               /* media areas (thumbs, video) */
  --color-header-bg: rgba(11, 15, 23, 0.85); /* sticky header, blurred */
  --color-overlay: rgba(0, 0, 0, 0.8);       /* duration badge, scrims */

  /* ---- Typography: families ------------------------------------------- */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", Consolas, monospace;

  /* ---- Typography: sizes ---------------------------------------------- */
  --font-size-xs: 12px;
  --font-size-sm: 13px;
  --font-size-md: 14px;
  --font-size-base: 15px;
  --font-size-lg: 17px;   /* body text */
  --font-size-xl: 18px;
  --font-size-2xl: 19px;
  --font-size-3xl: 21px;
  --font-size-4xl: 26px;
  --font-size-h1: clamp(28px, 4vw, 42px);
  --font-size-hero: clamp(34px, 5vw, 54px);

  /* ---- Typography: line height & tracking ------------------------------ */
  --line-height-tight: 1.25;
  --line-height-snug: 1.35;
  --line-height-body: 1.65;
  --line-height-code: 1.6;
  --letter-spacing-tight: -0.02em;
  --letter-spacing-wide: 0.08em;
  --letter-spacing-wider: 0.06em;

  /* ---- Typography: weights --------------------------------------------- */
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;

  /* ---- Spacing (4px base, Tailwind-style scale) ------------------------ */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-18: 72px;

  /* ---- Radius ---------------------------------------------------------- */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 10px;
  --radius-xl: 14px;
  --radius-full: 999px;

  /* ---- Shadows (use sparingly — the theme is flat by design) ----------- */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.35);

  /* ---- Layout ---------------------------------------------------------- */
  --max-width: 1120px;
  --max-width-narrow: 780px;
  --header-height: 64px;

  /* ---- Motion ---------------------------------------------------------- */
  --duration-fast: 0.15s;
  --duration-base: 0.25s;
  --ease-default: ease;

  /* ---- Focus (accessibility — every interactive element shows it) ----- */
  --focus-ring: 0 0 0 3px rgba(59, 130, 246, 0.45);

  /* ---- Z-index --------------------------------------------------------- */
  --z-header: 50;
}