/*
  Design tokens shared by the website, the charts and the 3D viewer (static/viewer/index.html).
  Colours, type, spacing, radius and shadow are defined here only.

  Typeface (DLR corporate design: Frutiger or Arial).
  Arial is installed on Windows, macOS and iOS; Arimo / Liberation Sans are metric-compatible
  substitutes on Linux and Android. To switch to Frutiger (step by step: docs/fonts.md), add the licensed DLR web fonts
  (static/fonts/*.woff2) and un-comment the @font-face rules below – "Frutiger DLR" is then
  used everywhere, Arial stays the fallback.

  @font-face { font-family: "Frutiger DLR"; src: url("../fonts/frutiger-regular.woff2") format("woff2"); font-weight: 400; font-display: swap; }
  @font-face { font-family: "Frutiger DLR"; src: url("../fonts/frutiger-bold.woff2") format("woff2"); font-weight: 700; font-display: swap; }

  --data-1..3: chart categories (OEM / fuel / payload; payload-range uses 1 and 2).
  Validated as a set for colour-vision deficiencies (all pairs) and >= 3:1 contrast on white.
*/
:root {
  /* type */
  --font-sans: "Frutiger DLR", Arial, "Helvetica Neue", Helvetica, Arimo, "Liberation Sans", sans-serif;
  --fs-small: 13px;            /* captions, footer, notes */
  --fs-ui: 14px;               /* tables, navigation, controls */
  --fs-body: 16px;             /* running text */
  --fs-h3: 18px;               /* subsections, card titles */
  --fs-h2: 24px;               /* sections */
  --fs-h1: 40px;               /* page title */
  --fs-hero: clamp(36px, 6vw, 56px);
  --lh-body: 1.6;
  --lh-tight: 1.25;
  --measure: none;             /* longest line of running text (none = full container width, e.g. 70ch to limit) */

  /* spacing scale */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;

  --radius: 2px;               /* the only corner radius (circles stay circles) */
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.05), 0 4px 14px rgba(0, 0, 0, 0.07);   /* the only shadow: cards, menus */

  /* colour */
  --brand: #00668D;            /* DLR blue: links, buttons, active states, page header */
  --brand-dark: #003D52;       /* hover, headings on light panels */

  --data-1: #00668D;           /* blue */
  --data-2: #C47A2E;           /* copper */
  --data-3: #2A9D8F;           /* petrol */
  --data-tint-base: #F4F6F8;   /* lighter shades of a data colour are mixed towards this */

  --ink: #2B3034;              /* all text */
  --ink-muted: #6B7075;        /* units, notes, meta */
  --line: #E3E6EA;             /* grid lines, table rules, separators */
  --line-strong: #C3C8CE;      /* axes, control borders */
  --surface: #FFFFFF;
  --surface-subtle: #F4F6F8;   /* panels, hover rows, viewer background */
  --tooltip: rgba(38, 42, 46, 0.94);
  --highlight: #D2AE3D;        /* highlight flag (e.g. MDO Benchmark) */

  --model: #7F91A2;            /* 3D aircraft surface */
  --model-highlight: #00668D;  /* hovered component */
}