/* ============================================================
   Portfolio Optimization Book — landing page styling
   CSS-only restyle. Targets the rmarkdown/Bootstrap-3 output of
   index.md, so it survives every re-render and needs no recompile.
   ============================================================ */

:root {
  --ink:        #232730;   /* body text            */
  --muted:      #6b7280;   /* secondary text       */
  --accent:     #1f4e79;   /* deep academic blue (headings/structure) */
  --accent-alt: #2e75b6;   /* brighter, for hover  */
  --link:       #1a6dc4;   /* links — brighter, clearly clickable     */
  --link-hover: #0d4f99;   /* link hover                              */
  --rule:       #e6e9ef;   /* hairline dividers    */
  --bg:         #ffffff;
}

/* ---- Base ------------------------------------------------- */
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               Helvetica, Arial, sans-serif;
  font-size: 16.5px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* Slightly narrower reading column than the default 940px.
   `body` prefix raises specificity to beat the later inline rule. */
body .main-container {
  max-width: 880px;
  padding-left: 22px;
  padding-right: 22px;
  padding-bottom: 64px;
}

/* ---- Page title (editorial serif) ------------------------- */
h1.title {
  font-family: Georgia, "Iowan Old Style", "Palatino Linotype", Palatino, serif;
  font-size: 40px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: #1a1d23;
  margin: 8px 0 26px;
}

/* ---- Section headings ------------------------------------- */
h2 {
  font-size: 27px;
  font-weight: 650;
  color: #1a1d23;
  margin-top: 2.1em;
  padding-bottom: 0.32em;
  border-bottom: 1px solid var(--rule);
}

h3 {
  font-size: 21px;
  font-weight: 650;
  color: var(--accent);
  margin-top: 1.7em;
  padding-left: 12px;
  border-left: 3px solid var(--accent);
}

/* ---- Links ------------------------------------------------ */
a {
  color: var(--link);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
  text-decoration-color: rgba(26, 109, 196, 0.4);   /* soft underline    */
  transition: color 0.15s ease, text-decoration-color 0.15s ease;
}
a:hover,
a:focus {
  color: var(--link-hover);
  text-decoration-color: currentColor;              /* full on hover     */
}

/* Font Awesome icons sit a touch tighter to their label */
i.fas, i.fab, i.far {
  margin-right: 2px;
}

/* ---- Book-cover header ------------------------------------ */
table.imgtable {
  margin: 0 0 8px;
  border-spacing: 0;
}
table.imgtable td {
  vertical-align: top;
  padding: 0;
}
table.imgtable td:first-child {
  padding-right: 22px;
}
table.imgtable img {
  border-radius: 6px;
  box-shadow: 0 6px 18px rgba(20, 35, 60, 0.18);
}
table.imgtable p {
  font-size: 17px;
  line-height: 1.5;
  color: var(--muted);
  margin-top: 4px;
}
table.imgtable a {
  font-weight: 600;
}

/* ---- Lists (recognition + chapters) ----------------------- */
ul {
  padding-left: 22px;
}
li {
  margin-bottom: 0.5em;
}

/* ---- Small responsive tidy -------------------------------- */
@media (max-width: 600px) {
  body .main-container { padding-left: 16px; padding-right: 16px; }
  h1.title { font-size: 32px; }
  table.imgtable td:first-child { padding-right: 14px; }
}