.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background-color: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.header__inner {
  max-width: var(--container-width);
  margin-inline: auto;
  padding: 0 var(--spacing-md);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header__logo {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--color-primary);
}

.header__nav {
  display: block;
}

.header__list {
  display: flex;
  gap: var(--spacing-md);
}

.header__item a {
  font-weight: 500;
  position: relative;
}

.header__item a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-accent);
  transition: width 0.3s ease;
}

.header__item a:hover::after {
  width: 100%;
}

/* Hamburger Button */
.header__hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 30px;
  height: 20px;
  position: relative;
  z-index: 1001;
}

.header__hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-primary);
  position: absolute;
  left: 0;
  transition: all 0.3s ease;
}

.header__hamburger span:nth-child(1) {
  top: 0;
}
.header__hamburger span:nth-child(2) {
  top: 50%;
  transform: translateY(-50%);
}
.header__hamburger span:nth-child(3) {
  bottom: 0;
}

/* Hamburger Active State */
.header.is-active .header__hamburger span:nth-child(1) {
  top: 50%;
  transform: translateY(-50%) rotate(45deg);
}

.header.is-active .header__hamburger span:nth-child(2) {
  opacity: 0;
}

.header.is-active .header__hamburger span:nth-child(3) {
  bottom: 50%;
  transform: translateY(50%) rotate(-45deg);
}

@media (width < 768px) {
  .header__hamburger {
    display: block;
  }

  .header__nav {
    display: block;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background-color: var(--color-white);
    padding-top: var(--header-height);
    transform: translateX(100%);
    transition: transform 0.3s ease;
    z-index: 1000;
    overflow-y: auto;
  }

  .header.is-active .header__nav {
    transform: translateX(0);
  }

  .header__list {
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    gap: var(--spacing-sm);
  }

  .header__item a {
    font-size: 1.5rem;
  }
}