.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: rgba(245, 245, 245, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid #000000;
  z-index: 1000;
  transition: background-color var(--transition-normal);
}
.site-header__container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}
.site-header__brand {
  font-family: var(--font-serif);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 1px;
}
.site-header__brand:hover {
  color: var(--color-primary-hover);
}
.site-header__nav {
  display: flex;
}
.site-header__menu {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  list-style: none;
}
.site-header__link {
  font-size: var(--text-sm);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text);
  position: relative;
}
.site-header__link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background-color: var(--color-primary);
  transition: width var(--transition-normal);
}
.site-header__link:hover {
  color: var(--color-primary);
}
.site-header__link:hover::after {
  width: 100%;
}
.site-header__toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 30px;
  height: 20px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: 1001;
}
.site-header__toggle-line {
  width: 100%;
  height: 2px;
  background-color: var(--color-primary);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}
@media (max-width: 991px) {
  .site-header__toggle {
    display: flex;
  }
  .site-header__nav {
    position: fixed;
    top: 0;
    right: -100%;
    width: 100%;
    max-width: 400px;
    height: 100vh;
    background-color: var(--color-bg);
    border-left: 1px solid var(--color-gray-800);
    padding: 100px var(--space-8) var(--space-8);
    transition: right var(--transition-normal);
    overflow-y: auto;
  }
  .site-header__nav.is-open {
    right: 0;
    box-shadow: var(--shadow-lg);
  }
  .site-header__menu {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-6);
  }
  .site-header__toggle[aria-expanded="true"] .site-header__toggle-line:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
  }
  .site-header__toggle[aria-expanded="true"] .site-header__toggle-line:nth-child(2) {
    opacity: 0;
  }
  .site-header__toggle[aria-expanded="true"] .site-header__toggle-line:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
  }
}