/* ============================================================
   David Spatholt — Shared Stylesheet
   Polished academic/developer hybrid design.
   WCAG 2.1 AA compliant.
   ============================================================ */

/* --- Design Tokens ----------------------------------------- */
:root {
  /* Colors — deep navy academic + warm amber accent */
  --c-bg:          #f8f8f6;
  --c-bg-alt:      #efefec;
  --c-surface:     #ffffff;
  --c-border:      #dededb;
  --c-border-lt:   #ebebeb;

  --c-text:        #1c1c1a;
  --c-text-muted:  #5a5a58;
  --c-text-inv:    #ffffff;

  --c-primary:     #1a365d;   /* deep navy */
  --c-primary-lt:  #264a7a;
  --c-primary-bg:  #eef2f8;
  --c-accent:      #d97706;   /* amber-600 */
  --c-accent-lt:   #f59e0b;
  --c-accent-bg:   #fef3e7;
  --c-link:        #2563eb;   /* blue-600 */
  --c-link-vis:    #7c3aed;   /* violet-600 */

  /* Typography */
  --font-sans:  system-ui, -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  --font-serif: Georgia, "Times New Roman", serif;
  --font-mono:  "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;

  /* Layout */
  --max-w:      1140px;
  --content-w:  740px;
  --gap:        1.5rem;
  --section-v:  4rem;
}

/* --- Reset ------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
img, svg { display: block; max-width: 100%; }
ul, ol { list-style: none; }
a { color: var(--c-link); }
a:hover { text-decoration: none; }
a:focus-visible {
  outline: 2px solid var(--c-accent);
  outline-offset: 3px;
  border-radius: 2px;
}

/* --- Base -------------------------------------------------- */
body {
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -4rem;
  left: 0;
  background: var(--c-primary);
  color: var(--c-text-inv);
  padding: .5rem 1.25rem;
  text-decoration: none;
  font-weight: 600;
  border-radius: 0 0 4px 0;
  z-index: 200;
  transition: top .15s;
}
.skip-link:focus { top: 0; }

/* --- Site Header ------------------------------------------- */
.site-header {
  background: var(--c-surface);
  border-bottom: 1px solid var(--c-border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.site-header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gap);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}
.site-logo {
  font-family: var(--font-serif);
  font-size: 1.125rem;
  font-weight: normal;
  color: var(--c-primary);
  text-decoration: none;
  letter-spacing: .01em;
  white-space: nowrap;
}
.site-logo:hover { color: var(--c-accent); text-decoration: none; }
.site-logo strong { font-weight: 700; }

.site-nav ul {
  display: flex;
  gap: .25rem;
}
.site-nav a {
  display: block;
  padding: .4rem .7rem;
  font-size: .875rem;
  font-weight: 500;
  color: var(--c-text);
  text-decoration: none;
  border-radius: 4px;
  transition: background .12s, color .12s;
}
.site-nav a:hover,
.site-nav a[aria-current="page"] {
  background: var(--c-primary-bg);
  color: var(--c-primary);
}
.site-nav a[aria-current="page"] { font-weight: 600; }

/* Hamburger (mobile) */
.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--c-border);
  border-radius: 4px;
  padding: .4rem .6rem;
  cursor: pointer;
  font-size: .85rem;
  color: var(--c-text);
  font-family: var(--font-sans);
}

@media (max-width: 760px) {
  .nav-toggle { display: block; }
  .site-nav {
    display: none;
    position: absolute;
    top: 4rem;
    left: 0;
    right: 0;
    background: var(--c-surface);
    border-bottom: 1px solid var(--c-border);
    padding: .75rem var(--gap);
    box-shadow: 0 8px 24px rgba(0,0,0,.1);
  }
  .site-nav.open { display: block; }
  .site-nav ul { flex-direction: column; gap: 0; }
  .site-nav a { padding: .6rem .5rem; font-size: .95rem; }
}

/* --- Page Hero --------------------------------------------- */
.page-hero {
  background: var(--c-primary);
  color: var(--c-text-inv);
  padding: 3.5rem var(--gap);
  text-align: center;
}
.page-hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: normal;
  line-height: 1.2;
  margin-bottom: .75rem;
}
.page-hero p {
  font-size: 1.125rem;
  opacity: .88;
  max-width: 600px;
  margin: 0 auto;
}

/* --- Wrapper / Layout -------------------------------------- */
.wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gap);
}
.wrap--content {
  max-width: var(--content-w);
}
section { padding: var(--section-v) var(--gap); }
section + section { padding-top: 0; }

.section-label {
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--c-accent);
  margin-bottom: .6rem;
}
.section-heading {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3.5vw, 2.125rem);
  font-weight: normal;
  color: var(--c-text);
  line-height: 1.25;
  margin-bottom: 1rem;
}
.section-lead {
  font-size: 1.0625rem;
  color: var(--c-text-muted);
  max-width: 620px;
  margin-bottom: 2.5rem;
}
.rule {
  width: 3rem;
  height: 3px;
  background: var(--c-accent);
  border: none;
  margin-bottom: 2rem;
}

/* --- Homepage Hero ----------------------------------------- */
.home-hero {
  background: linear-gradient(135deg, #132942 0%, #1a365d 55%, #d97706 120%);
  color: var(--c-text-inv);
  padding: 5rem var(--gap) 4.5rem;
}
.home-hero-inner {
  max-width: var(--max-w);
  margin: 0 auto;
}
.home-hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: normal;
  line-height: 1.18;
  max-width: 680px;
  margin-bottom: .75rem;
}
.home-hero .subtitle {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  opacity: .75;
  margin-bottom: .75rem;
  font-family: var(--font-sans);
}
.home-hero .tagline {
  font-size: .95rem;
  opacity: .7;
  margin-bottom: 2.25rem;
  font-family: var(--font-mono);
  max-width: 560px;
}
.btn-group { display: flex; flex-wrap: wrap; gap: .75rem; }
.btn {
  display: inline-block;
  padding: .7rem 1.4rem;
  border-radius: 4px;
  font-size: .9375rem;
  font-weight: 600;
  text-decoration: none;
  transition: background .15s, color .15s, transform .1s;
}
.btn:hover { transform: translateY(-1px); text-decoration: none; }
.btn--primary {
  background: var(--c-surface);
  color: var(--c-primary);
}
.btn--primary:hover { background: #eef2f8; }
.btn--ghost {
  background: transparent;
  color: var(--c-text-inv);
  border: 1.5px solid rgba(255,255,255,.55);
}
.btn--ghost:hover { border-color: #fff; background: rgba(255,255,255,.1); }
.btn--accent {
  background: var(--c-accent);
  color: #fff;
}
.btn--accent:hover { background: var(--c-accent-lt); }
.btn--outline {
  background: transparent;
  color: var(--c-primary);
  border: 1.5px solid var(--c-primary);
}
.btn--outline:hover { background: var(--c-primary-bg); }

/* --- Stats Bar --------------------------------------------- */
.stats-bar {
  background: var(--c-surface);
  border-bottom: 1px solid var(--c-border);
  padding: 2.5rem var(--gap);
}
.stats-grid {
  max-width: var(--max-w);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 1.5rem;
  text-align: center;
}
.stat-num {
  font-family: var(--font-serif);
  font-size: 2.25rem;
  color: var(--c-primary);
  line-height: 1;
  margin-bottom: .25rem;
}
.stat-label {
  font-size: .8125rem;
  color: var(--c-text-muted);
  text-transform: uppercase;
  letter-spacing: .05em;
}

/* --- Card Grid --------------------------------------------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}
.card {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: 6px;
  padding: 1.75rem;
  transition: box-shadow .2s, border-color .15s, transform .15s;
}
.card:hover {
  box-shadow: 0 6px 20px rgba(0,0,0,.07);
  border-color: #c0c0bb;
  transform: translateY(-2px);
}
.card-date {
  display: block;
  font-size: .75rem;
  color: var(--c-text-muted);
  margin-bottom: .5rem;
  font-family: var(--font-mono);
}
.card-tag {
  display: inline-block;
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  padding: .2rem .6rem;
  border-radius: 20px;
  margin-bottom: 1rem;
}
.tag--navy  { background: var(--c-primary-bg); color: var(--c-primary); }
.tag--teal  { background: #eef6f4; color: #1a6b5e; }
.tag--amber { background: var(--c-accent-bg); color: var(--c-accent); }
.tag--gray  { background: var(--c-bg-alt); color: var(--c-text-muted); }
.card h3 {
  font-family: var(--font-serif);
  font-size: 1.125rem;
  font-weight: normal;
  margin-bottom: .6rem;
  line-height: 1.35;
}
.card h3 a { color: inherit; text-decoration: none; }
.card h3 a:hover { color: var(--c-link); }
.card p { font-size: .9375rem; color: var(--c-text-muted); }
.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem;
  margin-top: .85rem;
}
.tag {
  display: inline-block;
  font-size: .7rem;
  font-weight: 600;
  letter-spacing: .05em;
  padding: .15rem .55rem;
  border-radius: 20px;
}
.card a.read-more {
  display: inline-block;
  margin-top: .75rem;
  font-size: .875rem;
  font-weight: 600;
}

/* --- Project Entry (experience/research listing style) ----- */
.project-entry {
  border-left: 3px solid var(--c-accent);
  padding: 1.5rem 1.75rem;
  background: var(--c-surface);
  border-radius: 0 6px 6px 0;
  margin-bottom: 1.5rem;
  transition: box-shadow .15s;
}
.project-entry:hover {
  box-shadow: 0 2px 12px rgba(0,0,0,.06);
}
.project-entry + .project-entry { margin-top: 0; }
.project-entry h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-bottom: .35rem;
}
.project-entry h3 a { color: var(--c-text); text-decoration: none; }
.project-entry h3 a:hover { color: var(--c-link); }
.project-entry .meta {
  font-size: .85rem;
  color: var(--c-text-muted);
  margin-bottom: .5rem;
  font-family: var(--font-mono);
}
.project-entry p { font-size: .9375rem; color: var(--c-text-muted); }
.project-entry ul { font-size: .9375rem; }

/* --- Section: alternating bg ------------------------------ */
.bg-alt  { background: var(--c-bg-alt); }
.bg-navy {
  background: linear-gradient(135deg, #132942 0%, #1a365d 100%);
  color: var(--c-text-inv);
}
.bg-navy .section-heading,
.bg-navy p { color: var(--c-text-inv); }
.bg-navy .section-label { color: #fbbf24; }
.bg-navy .rule { background: #fbbf24; }

/* --- Publications Table ------------------------------------ */
.pub-table { width: 100%; border-collapse: collapse; font-size: .9rem; }
.pub-table th {
  text-align: left;
  padding: .6rem .75rem;
  background: var(--c-bg-alt);
  font-size: .75rem;
  text-transform: uppercase;
  letter-spacing: .07em;
  font-weight: 600;
  color: var(--c-text-muted);
  border-bottom: 2px solid var(--c-border);
}
.pub-table td {
  padding: .85rem .75rem;
  border-bottom: 1px solid var(--c-border-lt);
  vertical-align: top;
}
.pub-table tr:last-child td { border-bottom: none; }
.pub-table tr:hover td { background: var(--c-primary-bg); }
.pub-first-author { font-weight: 600; color: var(--c-primary); }
.pub-journal { font-style: italic; }

/* --- Grants Table ------------------------------------------ */
.grants-table { width: 100%; border-collapse: collapse; font-size: .875rem; overflow-x: auto; display: block; }
.grants-table th {
  text-align: left;
  padding: .5rem .75rem;
  background: var(--c-primary);
  color: #fff;
  font-size: .75rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  white-space: nowrap;
}
.grants-table td {
  padding: .75rem .75rem;
  border-bottom: 1px solid var(--c-border-lt);
  vertical-align: top;
}
.grants-table tr:nth-child(even) td { background: var(--c-bg-alt); }

/* --- Team / Person Card ------------------------------------ */
.person-card {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: 6px;
  padding: 1.5rem;
}
.person-card .name {
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: .15rem;
  color: var(--c-primary);
}
.person-card .role {
  font-size: .85rem;
  color: var(--c-accent);
  font-weight: 600;
  margin-bottom: .6rem;
}
.person-card .detail {
  font-size: .8125rem;
  color: var(--c-text-muted);
  margin-bottom: .4rem;
}

/* --- Footer ------------------------------------------------ */
.site-footer {
  background: var(--c-surface);
  border-top: 1px solid var(--c-border);
  margin-top: 3rem;
}
.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 3rem var(--gap) 2rem;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 2rem;
}
.footer-brand .site-logo { font-size: 1.0625rem; }
.footer-brand p {
  font-size: .875rem;
  color: var(--c-text-muted);
  margin-top: .5rem;
  max-width: 320px;
}
.footer-col h4 {
  font-size: .75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--c-text-muted);
  margin-bottom: .75rem;
}
.footer-col li { margin-bottom: .4rem; }
.footer-col a {
  font-size: .875rem;
  text-decoration: none;
}
.footer-col a:hover { text-decoration: underline; }
.footer-bottom {
  text-align: center;
  padding: 1.25rem var(--gap);
  border-top: 1px solid var(--c-border);
  font-size: .8125rem;
  color: var(--c-text-muted);
}

@media (max-width: 700px) {
  .footer-inner { grid-template-columns: 1fr; }
}

/* --- Utils ------------------------------------------------- */
.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mb-1 { margin-bottom: 1rem; }
.text-center { text-align: center; }

/* --- Blog Card List ---------------------------------------- */
.blog-list {
  max-width: var(--content-w);
  margin: 0 auto;
}
.blog-card {
  border-left: 3px solid var(--c-accent);
  padding: 1.5rem 1.75rem;
  background: var(--c-surface);
  border-radius: 0 6px 6px 0;
  margin-bottom: 1.25rem;
  transition: box-shadow .15s, transform .15s;
}
.blog-card:hover {
  box-shadow: 0 4px 16px rgba(0,0,0,.06);
  transform: translateX(3px);
}
.blog-card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  align-items: center;
  margin-bottom: .5rem;
  font-size: .8125rem;
  color: var(--c-text-muted);
  font-family: var(--font-mono);
}
.blog-card-author {
  font-family: var(--font-sans);
  font-weight: 500;
}
.blog-card h2 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: .5rem;
  line-height: 1.35;
}
.blog-card h2 a {
  color: var(--c-text);
  text-decoration: none;
}
.blog-card h2 a:hover {
  color: var(--c-link);
}
.blog-card p {
  font-size: .9375rem;
  color: var(--c-text-muted);
}
.blog-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem;
  margin-top: .75rem;
}

/* --- Content Prose (blog posts, about page) ---------------- */
.prose {
  max-width: var(--content-w);
  margin: 0 auto;
  font-size: 1.0625rem;
  line-height: 1.75;
}
.prose h2 {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  margin: 2.5rem 0 .75rem;
}
.prose h3 {
  font-weight: 600;
  font-size: 1.125rem;
  margin: 2rem 0 .5rem;
}
.prose p { margin-bottom: 1.25rem; }
.prose ul, .prose ol {
  margin: 0 0 1.25rem 1.5rem;
  list-style: disc;
}
.prose ol { list-style: decimal; }
.prose li { margin-bottom: .35rem; }
.prose code {
  font-family: var(--font-mono);
  font-size: .875rem;
  background: var(--c-bg-alt);
  padding: .1rem .35rem;
  border-radius: 3px;
}
.prose a { font-weight: 500; }
pre {
  background: var(--c-bg-alt);
  border: 1px solid var(--c-border);
  border-radius: 4px;
  padding: .75rem 1rem;
  overflow-x: auto;
  margin-bottom: 1.25rem;
  font-size: .85rem;
  line-height: 1.5;
}
pre code {
  background: none;
  padding: 0;
  font-size: .8125rem;
}