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

:root {
  --bg:      #D7D1CF;
  --black:   #111111;
  --blue:    #1565C0;
  --red:     #FF0000;
  --muted:   #5a5350;
  --border:  rgba(0,0,0,0.12);
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--black);
  font-family: 'Source Sans 3', 'Source Sans Pro', sans-serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 32px;
}

/* ── NAV ── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1.5px solid var(--black);
  padding: 14px 0;
}
nav .inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
nav .logo {
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--black);
  text-decoration: none;
}
nav .logo span { color: var(--blue); }
nav ul {
  list-style: none;
  display: flex;
  gap: 28px;
}
nav ul a {
  text-decoration: none;
  color: var(--muted);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  transition: color 0.2s;
}
nav ul a:hover { color: var(--black); }

/* ── SECTION COMMON ── */
section { padding: 64px 0; border-bottom: 1.5px solid var(--black); }
section:last-of-type { border-bottom: none; }
.section-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--red);
  margin-bottom: 10px;
}
.section-title {
  font-size: clamp(26px, 3.5vw, 36px);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 36px;
}

/* ── BACK LINK ── */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  text-decoration: none;
  margin-bottom: 40px;
  transition: color 0.2s;
}
.back-link:hover { color: var(--black); }

/* ── PAGE HERO ── */
.page-hero {
  padding: 64px 0 56px;
  border-bottom: 1.5px solid var(--black);
  opacity: 0;
  animation: fadeUp 0.6s ease forwards;
}
.page-hero .eyebrow {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 16px;
}
.page-hero h1 {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}
.page-hero .lead {
  max-width: 580px;
  font-size: 18px;
  color: var(--muted);
  line-height: 1.7;
}

/* ── NOTEBOOK FILE LIST ── */
.file-list {
  display: flex;
  flex-direction: column;
  border: 1.5px solid var(--black);
}
.file-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  border-bottom: 1.5px solid var(--black);
  text-decoration: none;
  color: inherit;
  transition: background 0.18s;
  gap: 16px;
}
.file-item:last-child { border-bottom: none; }
.file-item:hover { background: rgba(21,101,192,0.06); }
.file-item:hover .file-arrow { transform: translate(3px,-3px); }
.file-info { flex: 1; }
.file-name {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 4px;
}
.file-desc {
  font-size: 13px;
  color: var(--muted);
}
.file-arrow {
  font-size: 16px;
  color: var(--blue);
  flex-shrink: 0;
  transition: transform 0.2s;
}

/* ── GALLERY GRID ── */
.gallery-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  border: 1.5px solid var(--black);
}
.gallery-item {
  padding: 22px 24px;
  border-right: 1.5px solid var(--black);
  border-bottom: 1.5px solid var(--black);
  text-decoration: none;
  color: inherit;
  transition: background 0.18s;
}
.gallery-item:nth-child(2n) { border-right: none; }
.gallery-item:nth-last-child(-n+2) { border-bottom: none; }
.gallery-item:hover { background: rgba(21,101,192,0.06); }
.gallery-icon { font-size: 22px; margin-bottom: 10px; }
.gallery-title { font-size: 15px; font-weight: 700; margin-bottom: 6px; }
.gallery-desc { font-size: 13px; color: var(--muted); line-height: 1.5; }

/* ── FOOTER ── */
.site-footer {
  padding: 36px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}
.site-footer .copy { font-size: 13px; color: var(--muted); }
.site-footer .copy strong { color: var(--black); }
.site-footer .footer-links { display: flex; gap: 20px; }
.site-footer .footer-links a {
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
  text-decoration: none;
  letter-spacing: 0.04em;
}
.site-footer .footer-links a:hover { color: var(--black); }

/* ── ANIMATION ── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}
section {
  opacity: 0;
  animation: fadeUp 0.6s ease forwards;
}
section:nth-of-type(1) { animation-delay: 0.1s; }
section:nth-of-type(2) { animation-delay: 0.2s; }
section:nth-of-type(3) { animation-delay: 0.3s; }

/* ── RESPONSIVE ── */
@media (max-width: 640px) {
  .gallery-grid { grid-template-columns: 1fr; }
  .gallery-item { border-right: none !important; }
  nav ul { display: none; }
}