/* Shared top navigation (Home, Wall, Profile, Login/Logout) */
.site-header {
  padding: 6px 20px;
  border-bottom: 1px solid #e5e7eb;
  background: #fff;
  position: sticky;
  top: 0;
  z-index: 200;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
  flex-shrink: 0;
}

body.dark .site-header {
  border-bottom-color: #444;
  background: #252525;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: #1976d2;
  text-decoration: none;
  letter-spacing: -0.02em;
}

.logo:hover {
  color: #1565c0;
}

body.dark .logo {
  color: #42a5f5;
}

body.dark .logo:hover {
  color: #64b5f6;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn-login,
.btn-home,
.btn-wall,
.btn-profile {
  display: inline-block;
  padding: 10px 20px;
  background: #1976d2;
  color: #fff;
  border: none;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s, transform 0.2s;
  box-shadow: 0 2px 6px rgba(25, 118, 210, 0.35);
}

.btn-login:hover,
.btn-home:hover,
.btn-wall:hover,
.btn-profile:hover {
  background: #1565c0;
  transform: translateY(-1px);
}

body.dark .btn-login,
body.dark .btn-home,
body.dark .btn-wall,
body.dark .btn-profile {
  background: #1e88e5;
  box-shadow: 0 2px 6px rgba(30, 136, 229, 0.4);
}

body.dark .btn-login:hover,
body.dark .btn-home:hover,
body.dark .btn-wall:hover,
body.dark .btn-profile:hover {
  background: #1976d2;
}

.btn-logout {
  display: inline-block;
  padding: 10px 20px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s, transform 0.2s;
  background: #c62828;
  color: #fff;
  box-shadow: 0 2px 6px rgba(198, 40, 40, 0.35);
}

.btn-logout:hover {
  background: #b71c1c;
  transform: translateY(-1px);
}

body.dark .btn-logout {
  background: #e53935;
}

body.dark .btn-logout:hover {
  background: #c62828;
}

.theme-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
}

.theme-toggle {
  width: 44px;
  height: 44px;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  font-size: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #1976d2;
  color: #fff;
  box-shadow: 0 2px 8px rgba(25, 118, 210, 0.4);
  transition: transform 0.2s, box-shadow 0.2s;
}

body.dark .theme-toggle {
  background: #f57c00;
  box-shadow: 0 2px 8px rgba(245, 124, 0, 0.4);
}

.theme-toggle:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(25, 118, 210, 0.45);
}

body.dark .theme-toggle:hover {
  box-shadow: 0 4px 12px rgba(245, 124, 0, 0.5);
}

@media (max-width: 600px) {
  .site-header {
    padding: 4px 12px;
  }

  .header-nav {
    gap: 8px;
    flex-wrap: wrap;
    justify-content: flex-end;
  }

  .logo {
    font-size: 1.25rem;
  }

  .btn-login,
  .btn-home,
  .btn-wall,
  .btn-profile,
  .btn-logout {
    padding: 8px 12px;
    font-size: 0.85rem;
  }

  .theme-toggle {
    width: 40px;
    height: 40px;
    font-size: 18px;
  }
}