:root {
  /* Navy Mirage: immutable brand anchors and theme-dependent semantic roles. */
  --stt-brand-navy:#141e30;
  --stt-brand-steel:#35577d;
  --color-deep:#0b1420;
  --color-dark-surface:#1c2b42;
  --color-dark-raised:#243a56;
  --color-dark-text:#f4f7fa;
  --color-dark-muted:#aab8c7;
  --color-bg:#f5f7fa;
  --color-surface:#ffffff;
  --color-surface-alt:#eaf0f5;
  --color-raised:#dfe8f1;
  --color-text:var(--stt-brand-navy);
  --color-text-secondary:#536779;
  --color-border:#d6e0ea;
  --color-border-strong:#9aafc3;
  --color-brand:var(--stt-brand-steel);
  --color-primary:#3e6a98;
  /* Slightly darker than the suggested hover to keep off-white text >= 4.5:1. */
  --color-primary-hover:#426f9e;
  --color-primary-pressed:var(--stt-brand-steel);
  --color-on-primary:var(--color-dark-text);
  --color-focus:#557fa6;
  --color-focus-ring:rgba(62,106,152,.15);
  --color-selected:#d4e1ed;
  --color-selected-text:#243d58;
  --color-disabled:#61758b;
  --color-glass-nav:rgba(245,247,250,.78);
  --color-glass-menu:rgba(245,247,250,.96);
  --color-glass-modal:rgba(245,247,250,.94);
  --color-scrim:rgba(11,20,32,.28);
  --color-border-glass:rgba(53,87,125,.15);
  --color-glass-highlight:rgba(255,255,255,.55);
  --color-error:#a2394e;
  --color-error-border:rgba(162,57,78,.6);
  --color-error-ring:rgba(162,57,78,.09);
  --color-success:#197b4e;
  --color-hover-wash:rgba(53,87,125,.07);
  --color-pressed-wash:rgba(53,87,125,.12);
  --color-overlay-hero:linear-gradient(90deg,rgba(11,20,32,.72),rgba(20,30,48,.42) 52%,rgba(53,87,125,.08));
  --color-mirage-depth:linear-gradient(145deg,rgba(53,87,125,.045),transparent 68%);
  --color-modal-shadow:0 24px 72px rgba(11,20,32,.18);
  --color-control-shadow:0 4px 12px rgba(11,20,32,.12);
  --color-metal-ring:conic-gradient(from var(--stt-metal-angle),#0b1420 0deg,#7b99b8 48deg,#f4f7fa 88deg,#667c94 128deg,#35577d 176deg,#141e30 224deg,#d5e0eb 278deg,#557fa6 326deg,#0b1420 360deg);
  /* Compatibility aliases: existing components keep their contracts. */
  --stt-color-deep:var(--color-deep);
  --stt-color-navy:var(--stt-brand-navy);
  --stt-color-navy-hover:var(--color-dark-raised);
  --stt-color-blue:var(--color-brand);
  --stt-color-blue-hover:var(--color-primary);
  --stt-color-blue-soft:var(--color-surface-alt);
  --stt-color-blue-border:var(--color-border);
  --stt-color-focus:var(--color-focus);
  --stt-color-ink:var(--color-text);
  --stt-color-white:var(--color-surface);
}