/* ───────────────────────────────────────────────────────────
   Gustavo Düring — research group
   Shared stylesheet
   ─────────────────────────────────────────────────────────── */

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

:root {
  --bg:        #fafaf8;
  --surface:   #ffffff;
  --border:    #e4e4df;
  --border-2:  #d0d0c8;
  --text:      #1a1a18;
  --muted:     #6b6b66;
  --muted-2:   #9a9a92;
  --accent:    #2a4a7f;
  --accent-lt: #eef2f9;
  --font-serif: 'Georgia', 'Times New Roman', serif;
  --font-mono:  'Courier New', 'Courier', monospace;
  --max-w:     760px;
  --gap:       2.5rem;
}

html { font-size: 17px; scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-serif);
  line-height: 1.7;
  padding: 0 1.25rem;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 0.5px;
}
a:hover { text-decoration: none; }

::selection { background: var(--accent-lt); color: var(--accent); }

/* ── Layout ───────────────────────────────────────────── */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
}

/* ── Nav ──────────────────────────────────────────────── */
nav {
  position: sticky;
  top: 0;
  background: rgba(250, 250, 248, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}

nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 0;
  gap: 1rem;
}

nav .brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-size: 0.9rem;
  color: var(--text);
  letter-spacing: 0.01em;
  text-decoration: none;
}
nav .brand:hover { color: var(--accent); }

nav .brand-mark {
  width: 22px;
  height: 22px;
  display: inline-block;
  flex-shrink: 0;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 1.6rem;
}

nav ul a {
  font-size: 0.85rem;
  color: var(--muted);
  text-decoration: none;
  letter-spacing: 0.04em;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: color 120ms, border-color 120ms;
}
nav ul a:hover { color: var(--text); }
nav ul a.active {
  color: var(--text);
  border-bottom-color: var(--accent);
}

/* ── Sections / headings ──────────────────────────────── */
section {
  padding: var(--gap) 0;
  border-bottom: 1px solid var(--border);
}

h1 {
  font-size: 2.1rem;
  font-weight: normal;
  letter-spacing: -0.01em;
  line-height: 1.2;
  margin-bottom: 0.35rem;
  text-wrap: balance;
}

h2 {
  font-size: 0.72rem;
  font-weight: normal;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 1.5rem;
}

h3 {
  font-size: 0.68rem;
  font-weight: normal;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted-2);
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.4rem;
  margin-bottom: 1.25rem;
}

.title-line {
  font-size: 0.92rem;
  color: var(--muted);
  margin-bottom: 1.2rem;
  font-style: italic;
}

.page-header {
  padding: calc(var(--gap) * 1.5) 0 var(--gap);
  border-bottom: 1px solid var(--border);
}

.page-header h1 { font-size: 1.6rem; }

.page-subtitle {
  font-size: 0.875rem;
  color: var(--muted);
}

/* ── Footer ───────────────────────────────────────────── */
footer {
  padding: 2.25rem 0;
  font-size: 0.78rem;
  color: var(--muted);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* ── Utility ──────────────────────────────────────────── */
.mono { font-family: var(--font-mono); }

.button {
  font-size: 0.83rem;
  font-family: var(--font-mono);
  color: var(--accent);
  text-decoration: none;
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 0.35rem 0.75rem;
  display: inline-block;
  transition: background 120ms, border-color 120ms;
}
.button:hover { background: var(--accent-lt); border-color: var(--accent); }

/* ── Responsive ───────────────────────────────────────── */
@media (max-width: 560px) {
  h1 { font-size: 1.6rem; }
  nav ul { gap: 1rem; }
  nav .brand span { display: none; }
}