/* Design tokens and base rules for the whole site. Load first on every page.
   Colours, type sizes, spacing and radii are defined here and nowhere else. */

:root {
  color-scheme: light;

  /* Colour */
  --page: #ffffff;
  --surface: #f9fafb;
  --ink: #111827;
  --body: #374151;
  --muted: #6b7280;
  --rule: #9ca3af; /* decorative only: separators and icons, never text */
  --line: #e5e7eb;
  --link: #2563eb;
  --link-dark: #1d4ed8;
  --link-soft: #eff6ff;
  --on-link: #ffffff;
  --nav-bg: rgba(255, 255, 255, 0.94);
  --logo-bg: #ffffff;

  --badge-paper-bg: #dbeafe;
  --badge-paper-fg: #1e40af;
  --badge-award-bg: #fef3c7;
  --badge-award-fg: #92400e;
  --badge-review-bg: #e0f2fe;
  --badge-review-fg: #075985;
  --badge-edu-bg: #ede9fe;
  --badge-edu-fg: #5b21b6;
  --tag-warm-bg: #fff7ed;
  --tag-warm-fg: #c2410c;
  --chart-stroke: #2563eb;

  /* Type scale */
  --fs-xs: 0.8125rem;
  --fs-sm: 0.875rem;
  --fs-md: 1rem;
  --fs-lg: 1.125rem;
  --fs-xl: 1.375rem;
  --fs-2xl: 1.75rem;
  --fs-3xl: 2.25rem;
  --font: "Inter", "Helvetica Neue", Arial, system-ui, sans-serif;

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

  /* Shape */
  --r-sm: 4px;
  --r-md: 8px;
  --r-pill: 999px;
  --shadow: 0 8px 24px rgba(17, 24, 39, 0.08);

  /* Layout. Breakpoints used site-wide: 520px, 820px, 1080px. */
  --content-w: 960px;
  --wide-w: 1120px;
  --nav-h: 56px;
  --date-col: 9rem;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --page: #16181c;
  --surface: #1e2126;
  --ink: #e7e4df;
  --body: #c7cbd1;
  --muted: #a8a29b;
  --rule: #6b7280;
  --line: #333940;
  --link: #8bb1ff;
  --link-dark: #b3caff;
  --link-soft: #1c2740;
  --on-link: #16181c;
  --nav-bg: rgba(22, 24, 28, 0.94);

  --badge-paper-bg: #20314e;
  --badge-paper-fg: #b0cbff;
  --badge-award-bg: #3a2c1f;
  --badge-award-fg: #f0cd86;
  --badge-review-bg: #16333d;
  --badge-review-fg: #9acedd;
  --badge-edu-bg: #2c2443;
  --badge-edu-fg: #c7b0f0;
  --tag-warm-bg: #35251d;
  --tag-warm-fg: #f4b68b;
  --chart-stroke: #8bb1ff;
  --shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}

/* Base */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + var(--s-4));
}

body {
  background: var(--page);
  color: var(--body);
  font-family: var(--font);
  font-size: var(--fs-md);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--link);
  text-decoration: none;
  text-underline-offset: 3px;
}
a:hover {
  color: var(--link-dark);
  text-decoration: underline;
}

:focus-visible {
  outline: 2px solid var(--link);
  outline-offset: 2px;
}

strong,
b {
  color: var(--ink);
  font-weight: 600;
}

h1,
h2,
h3,
h4 {
  color: var(--ink);
  line-height: 1.2;
}

.container {
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 0 var(--s-5);
}
.container.wide {
  max-width: var(--wide-w);
}

@media (max-width: 520px) {
  .container {
    padding: 0 var(--s-4);
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}