/* ============================================================
   Evolution of Cooperation — Shared Design System
   shared.css
   ============================================================ */

/* ── Google Fonts ─────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&family=Source+Serif+4:ital,opsz,wght@0,8..60,400;0,8..60,600;1,8..60,400&display=swap');

/* ── CSS Custom Properties (Design Tokens) ────────────────── */
:root {
  --color-primary:     #1a5276;
  --color-accent:      #d4a017;
  --color-coop:        #1a56a0;
  --color-defect:      #c0392b;
  --color-bg:          #fafaf8;
  --color-surface:     #f0ede6;
  --color-text:        #1c1c1c;
  --color-text-muted:  #555550;
  --color-border:      #d0ccc4;
  --color-nav-bg:      #1a3a4a;
  --color-nav-text:    #eef2f5;

  --text-xs:   0.75rem;
  --text-sm:   0.875rem;
  --text-base: 1rem;
  --text-lg:   1.125rem;
  --text-xl:   1.375rem;
  --text-2xl:  1.75rem;
  --text-3xl:  2.25rem;

  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-12: 3rem;
  --space-16: 4rem;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.12);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: 'Source Serif 4', Georgia, 'Times New Roman', serif;
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* ── Accessibility ────────────────────────────────────────── */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-accent);
  color: #000;
  padding: var(--space-2) var(--space-4);
  z-index: 9999;
  font-family: 'Inter', sans-serif;
  font-weight: 600;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: top 0.2s;
}

.skip-link:focus {
  top: 0;
}

:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* ── Typography ───────────────────────────────────────────── */
h1, h2, h3, h4, h5, h6 {
  font-family: 'Inter', system-ui, sans-serif;
  font-weight: 700;
  line-height: 1.25;
  color: var(--color-primary);
}

p {
  margin-bottom: var(--space-4);
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
}

a:hover {
  color: var(--color-accent);
}

strong, b {
  font-weight: 600;
}

tt, code, kbd {
  font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  font-size: var(--text-sm);
  background: var(--color-surface);
  padding: 0.1em 0.3em;
  border-radius: var(--radius-sm);
}

ul, ol {
  padding-left: var(--space-6);
  margin-bottom: var(--space-4);
}

li {
  margin-bottom: var(--space-1);
}

dl dd {
  margin-left: var(--space-6);
  margin-bottom: var(--space-3);
}

blockquote {
  border-left: 4px solid var(--color-accent);
  padding-left: var(--space-4);
  margin-left: 0;
  color: var(--color-text-muted);
  font-style: italic;
}

/* ── Sticky Site Navigation ───────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--color-nav-bg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-6);
  box-shadow: var(--shadow-md);
  flex-wrap: wrap;
  gap: var(--space-2);
}

.site-nav__logo {
  font-family: 'Inter', sans-serif;
  font-weight: 700;
  font-size: var(--text-base);
  color: var(--color-nav-text) !important;
  text-decoration: none;
  letter-spacing: 0.01em;
  flex-shrink: 0;
}

.site-nav__logo:hover {
  color: var(--color-accent) !important;
}

.site-nav__links {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-1);
}

.site-nav__links a {
  font-family: 'Inter', sans-serif;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-nav-text);
  text-decoration: none;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
  transition: background 0.15s, color 0.15s;
  white-space: nowrap;
}

.site-nav__links a:hover {
  background: rgba(255,255,255,0.15);
  color: var(--color-accent);
}

.site-nav__links a.active {
  background: var(--color-accent);
  color: #1a1a1a;
}

/* ── Page Layout ──────────────────────────────────────────── */
.page-container {
  max-width: 860px;
  margin: 0 auto;
  padding: var(--space-8) var(--space-6);
}

/* ── Page Header (replaces GIF title images) ──────────────── */
.page-header {
  margin-bottom: var(--space-8);
  padding-bottom: var(--space-6);
  border-bottom: 3px solid var(--color-border);
}

.page-header__title {
  font-size: var(--text-3xl);
  color: var(--color-primary);
  margin-bottom: var(--space-2);
  font-weight: 700;
}

.page-header__subtitle {
  font-size: var(--text-xl);
  color: var(--color-accent);
  font-weight: 600;
}

/* ── Hub Navigation (replaces GIF button tables) ──────────── */
.hub-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  justify-content: center;
  padding: var(--space-6) 0;
  margin-top: var(--space-8);
  border-top: 2px solid var(--color-border);
}

.hub-nav__btn {
  display: inline-block;
  font-family: 'Inter', sans-serif;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-primary) !important;
  text-decoration: none !important;
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  transition: all 0.15s;
  white-space: nowrap;
}

.hub-nav__btn:hover {
  background: var(--color-primary);
  color: #fff !important;
  border-color: var(--color-primary);
}

.hub-nav__btn.active {
  background: var(--color-primary);
  color: #fff !important;
  border-color: var(--color-primary);
}

/* Model links (suggest/interpret pages) */
.model-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  justify-content: center;
  margin: var(--space-6) 0;
}

/* ── Narrative Navigation (replaces a85.gif/DIVID055.JPG) ── */
.narrative-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 2px solid var(--color-border);
  padding-top: var(--space-6);
  margin-top: var(--space-8);
}

.narrative-nav__back,
.narrative-nav__next {
  display: inline-block;
  font-family: 'Inter', sans-serif;
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-primary) !important;
  text-decoration: none !important;
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  padding: var(--space-2) var(--space-6);
  border-radius: var(--radius-md);
  transition: all 0.15s;
}

.narrative-nav__back:hover,
.narrative-nav__next:hover {
  background: var(--color-primary);
  color: #fff !important;
  border-color: var(--color-primary);
}

/* ── Image Figures ────────────────────────────────────────── */
.img-figure {
  margin: var(--space-6) auto;
  text-align: center;
}

.img-figure img {
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.img-figure figcaption {
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  font-style: italic;
}

/* ── Hero/Feature Images ──────────────────────────────────── */
.hero-image {
  text-align: center;
  margin-bottom: var(--space-6);
}

.hero-image img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  max-width: 100%;
}

/* ── Library Index ────────────────────────────────────────── */
.library-index {
  margin: var(--space-6) 0;
}

.library-index ul {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--space-3);
}

.library-index li {
  margin: 0;
}

.library-index a {
  display: block;
  font-family: 'Inter', sans-serif;
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-primary) !important;
  text-decoration: none !important;
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  transition: all 0.15s;
}

.library-index a::before {
  content: '📁 ';
  font-style: normal;
}

.library-index a:hover {
  background: var(--color-primary);
  color: #fff !important;
  border-color: var(--color-primary);
}

/* ── Field Notes (ideas.html) ─────────────────────────────── */
.field-notes {
  background: var(--color-surface);
  border-left: 5px solid var(--color-accent);
  border-radius: var(--radius-md);
  padding: var(--space-6);
  margin: var(--space-6) 0;
  font-style: italic;
}

.field-notes p {
  margin-bottom: var(--space-3);
}

/* ── Footer ───────────────────────────────────────────────── */
.page-footer {
  margin-top: var(--space-12);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-align: center;
}

.page-footer a {
  color: var(--color-text-muted);
}

/* ── Payoff Tables (library & model sub-pages) ────────────── */
.payoff-table {
  border-collapse: collapse;
  margin: var(--space-4) auto;
  font-family: 'Inter', sans-serif;
  font-size: var(--text-sm);
}

.payoff-table th,
.payoff-table td {
  border: 2px solid var(--color-border);
  padding: var(--space-2) var(--space-4);
  text-align: center;
}

.payoff-table th {
  background: var(--color-surface);
  font-weight: 600;
  color: var(--color-primary);
}

/* ── Model Pages — Bootstrap 3 overrides ─────────────────── */

/* Keep Bootstrap form controls looking good with new fonts */
.form-control {
  font-family: 'Inter', sans-serif !important;
  font-size: var(--text-sm) !important;
}

/* Bootstrap 3 compatibility shims */
.input-md { font-size: var(--text-base) !important; }
.input-sm { font-size: var(--text-sm) !important; }

.table-condensed > thead > tr > th,
.table-condensed > tbody > tr > td {
  padding: var(--space-1) var(--space-2);
}

.form-horizontal .control-label {
  font-family: 'Inter', sans-serif;
  font-weight: 600;
}

.btn-default {
  background: #fff;
  border: 1px solid var(--color-border);
  color: var(--color-text);
  font-family: 'Inter', sans-serif;
}

.btn-primary {
  font-family: 'Inter', sans-serif !important;
  font-weight: 600 !important;
}

/* Bootstrap 3 table improvements */
.table th {
  font-family: 'Inter', sans-serif;
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-surface);
}

/* ── Model Page Responsiveness ────────────────────────────── */

canvas {
  max-width: 100%;
  display: block;
}

#pdcadom {
  overflow-x: auto;
}

/* Highcharts container */
#container {
  width: 100%;
}

/* TFT: stack strategy tables + chart below medium breakpoint */
@media (max-width: 991px) {
  .vertical-align {
    flex-direction: column;
  }
  .vertical-align > [class^="col-"],
  .vertical-align > [class*=" col-"] {
    width: 100% !important;
    float: none !important;
  }
  #container {
    height: 300px !important;
    min-height: 250px;
  }
}

/* ── Mobile Responsive ────────────────────────────────────── */
@media (max-width: 640px) {
  .page-container {
    padding: var(--space-4);
  }

  .page-header__title {
    font-size: var(--text-2xl);
  }

  .page-header__subtitle {
    font-size: var(--text-lg);
  }

  .hub-nav {
    flex-direction: column;
    align-items: stretch;
  }

  .hub-nav__btn {
    text-align: center;
  }

  .narrative-nav {
    flex-direction: column;
    gap: var(--space-3);
    align-items: stretch;
    text-align: center;
  }

  .narrative-nav__back,
  .narrative-nav__next {
    text-align: center;
  }

  .site-nav {
    padding: var(--space-3) var(--space-4);
  }

  .library-index ul {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .site-nav__links {
    width: 100%;
  }
}