/* /css/header.css */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 72px;
  padding: 0 clamp(20px, 5vw, 56px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  z-index: 1000;
  background: rgba(5, 5, 8, 0.78);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.logo {
  color: #fff;
  text-decoration: none;
  font-size: clamp(14px, 2vw, 18px);
  letter-spacing: 0.12em;
  font-weight: 700;
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(18px, 3vw, 32px);
}

.nav a {
  color: #bbb;
  text-decoration: none;
  font-size: 12px;
  letter-spacing: 0.18em;
  transition: color 0.25s ease;
}

.nav a:hover {
  color: #fff;
}

.menu-button {
  display: none;
}

@media (max-width: 768px) {
  .site-header {
    height: 64px;
  }

  .menu-button {
    width: 36px;
    height: 24px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    background: none;
    border: none;
    padding: 0;
    cursor: pointer;
  }

  .menu-button span {
    display: block;
    height: 1px;
    background: #fff;
    transition: transform 0.3s ease;
  }

  .nav {
    position: fixed;
    top: 64px;
    right: 0;
    width: 100%;
    padding: 32px 24px;
    flex-direction: column;
    background: rgba(5, 5, 8, 0.96);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    opacity: 0;
    pointer-events: none;
    transform: translateY(-12px);
    transition: opacity 0.3s ease, transform 0.3s ease;
  }

  .nav.is-open {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
  }

  .nav a {
    font-size: 14px;
  }

  .menu-button.is-open span:first-child {
    transform: translateY(11px) rotate(35deg);
  }

  .menu-button.is-open span:last-child {
    transform: translateY(-12px) rotate(-35deg);
  }
}