/* ==========================================================================
   HTAsiaLink design tokens — the ONLY file allowed to contain raw colour values.
   Every other stylesheet must reference these custom properties.
   Palette is derived from the HTAsiaLink logo:
     navy #2F3964 (wordmark) · yellow #FDCF01 · blue #1C73E3 · green #88CD28 (the three dots)
   ========================================================================== */
:root {
  /* Brand */
  --navy: #2f3964;          /* primary: bands, headings, footer          (11.1:1 on paper) */
  --navy-deep: #232b4d;     /* footer bottom bar, hover on navy          */
  --blue: #1c73e3;          /* brand accent: marks, large text on paper  (4.55:1 on paper — never for small text on tint) */
  --blue-text: #1559b3;     /* links and small accent text               (6.75:1 on paper, 6.2:1 on tint) */
  --yellow: #fdcf01;        /* decorative mark; text only on navy         (7.5:1 on navy) */
  --green: #88cd28;         /* decorative mark; text only on navy         (5.7:1 on navy) */

  /* Neutral axis, tinted toward the navy hue */
  --ink: #1a1f33;           /* body text                                 (16.3:1) */
  --ink-2: #555c74;         /* secondary text, captions                  (6.6:1) */
  --rule: #dde1ea;          /* hairlines, borders                        */
  --tint: #f4f5f8;          /* tinted paper for alternating bands        */
  --paper: #ffffff;

  /* On-navy text */
  --on-navy: #ffffff;
  --on-navy-2: #b9c6e6;     /* secondary text on navy                    (6.5:1) */

  /* Semantic (used sparingly) */
  --focus: var(--blue);
  --link: var(--blue-text);

  /* Print */
  --print-ink: #000000;
  --print-paper: #ffffff;
  --print-muted: #444444;

  /* Type */
  --font-serif: "Source Serif 4 Variable", "Source Serif 4", Georgia, "Times New Roman", "Noto Serif", "Noto Serif CJK TC", "PingFang TC", serif;
  --font-sans: "Source Sans 3 Variable", "Source Sans 3", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "Noto Sans CJK TC", "PingFang TC", "Microsoft JhengHei", sans-serif;

  /* Type scale — base 17px, ratio 1.25 (major third) */
  --text-xs: 0.8125rem;   /* 13.8px  meta, eyebrows */
  --text-sm: 0.9375rem;   /* 16px    captions, nav   */
  --text-base: 1.0625rem; /* 17px    body            */
  --text-md: 1.25rem;     /* 21px    lead, h4        */
  --text-lg: 1.5625rem;   /* 26.5px  h3              */
  --text-xl: 1.953rem;    /* 33px    h2              */
  --text-2xl: 2.441rem;   /* 41.5px  h1              */
  --text-3xl: 3.052rem;   /* 52px    display numbers */

  --leading-tight: 1.15;
  --leading-snug: 1.3;
  --leading-body: 1.6;
  --measure: 66ch;

  /* Spacing scale */
  --s-1: 0.25rem;  /* 4  */
  --s-2: 0.5rem;   /* 8  */
  --s-3: 0.75rem;  /* 12 */
  --s-4: 1rem;     /* 16 */
  --s-6: 1.5rem;   /* 24 */
  --s-8: 2rem;     /* 32 */
  --s-12: 3rem;    /* 48 */
  --s-16: 4rem;    /* 64 */
  --s-24: 6rem;    /* 96 */

  /* Layout */
  --container: 72rem;                       /* 1152px */
  --gutter: clamp(1rem, 4vw, 2.5rem);
  --radius: 2px;                            /* deliberately near-square */
  --rule-w: 1px;
  --brand-rule-h: 4px;

  /* Image treatment — applied to every photograph on the site */
  --img-filter: saturate(0.85) contrast(1.02);
  --img-ratio-portrait: 4 / 5;
  --img-ratio-landscape: 3 / 2;
}