/* ── NAV ── */
nav {
  border-bottom: 1.5px solid var(--border2);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: background 0.25s, border-color 0.25s;
}

.nav-inner {
  width: 100%;
  max-width: 1600px;
  margin: 0 auto;
  padding: 0 48px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
}
.nav-logo:hover { opacity: 0.8; }

.logo-slash { color: #4040cc; font-weight: 400; }
[data-theme="dark"] .logo-slash { color: #8888ff; }

.nav-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links { display: flex; }

.nav-link {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink);
  padding: 6px 16px;
  cursor: pointer;
  border: none;
  background: transparent;
  letter-spacing: 0.04em;
  font-weight: 500;
  border-bottom: 2px solid transparent;
  transition: border-color 0.1s;
  text-decoration: none;
  display: inline-block;
}
.nav-link:hover  { border-bottom: 2px solid var(--ink); }
.nav-link.active { border-bottom: 2px solid var(--ink); }

.theme-btn {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink3);
  border: 1px solid var(--border);
  background: transparent;
  padding: 4px 10px;
  cursor: pointer;
  letter-spacing: 0.06em;
  transition: border-color 0.1s, color 0.1s;
  display: flex;
  align-items: center;
  gap: 5px;
}
.theme-btn:hover { border-color: var(--ink); color: var(--ink); }