/* ==================== HEADER ==================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background: var(--color-background);
  border-bottom: 1px solid var(--color-border);
  z-index: var(--z-fixed);
  transition: all var(--transition-normal);
  backdrop-filter: blur(10px);
  background: rgba(255, 255, 255, 0.95);
}

body.dark-theme .header {
  background: rgba(15, 23, 42, 0.95);
}

.header.scroll-header {
  box-shadow: var(--shadow-lg);
}

/* Navigation */
.nav {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-xl);
  font-weight: 700;
  font-family: var(--font-heading);
  color: var(--color-text);
  cursor: pointer;
}

.logo-img {
  width: 40px;
  height: 40px;
}

.logo-text {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav__menu {
  display: flex;
  align-items: center;
  gap: var(--spacing-2xl);
}

.nav__list {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
  list-style: none;
}

.nav__link {
  font-size: var(--font-size-base);
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  position: relative;
  transition: all var(--transition-fast);
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  transform: translateX(-50%);
  transition: width var(--transition-fast);
}

.nav__link:hover,
.nav__link.active {
  color: var(--color-primary);
}

.nav__link:hover::after,
.nav__link.active::after {
  width: 80%;
}

.nav__actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

/* Theme Toggle */
.theme-toggle {
  width: 45px;
  height: 45px;
  border: none;
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: var(--font-size-lg);
  color: var(--color-text);
  transition: all var(--transition-normal);
}

.theme-toggle:hover {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
  transform: rotate(180deg);
}

/* Cart Button */
.cart-button {
  position: relative;
  width: 45px;
  height: 45px;
  border: none;
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: var(--font-size-lg);
  color: var(--color-text);
  transition: all var(--transition-fast);
}

.cart-button:hover {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

.cart-count {
  position: absolute;
  top: -5px;
  right: -5px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: white;
  font-size: var(--font-size-xs);
  font-weight: 700;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Mobile Navigation */
.nav__toggle,
.nav__close {
  display: none;
  font-size: var(--font-size-2xl);
  color: var(--color-text);
  cursor: pointer;
}

/* ==================== RESPONSIVE ==================== */
@media screen and (max-width: 768px) {
  .nav__menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 75%;
    height: 100vh;
    background: var(--color-background);
    padding: var(--spacing-3xl) var(--spacing-xl);
    flex-direction: column;
    align-items: flex-start;
    box-shadow: var(--shadow-2xl);
    transition: right var(--transition-normal);
  }

  .nav__menu.show-menu {
    right: 0;
  }

  .nav__list {
    flex-direction: column;
    align-items: flex-start;
    width: 100%;
    gap: var(--spacing-md);
  }

  .nav__link {
    width: 100%;
    padding: var(--spacing-md);
    font-size: var(--font-size-lg);
  }

  .nav__link::after {
    display: none;
  }

  .nav__close {
    display: block;
    position: absolute;
    top: var(--spacing-xl);
    right: var(--spacing-xl);
  }

  .nav__toggle {
    display: block;
  }
}

@media screen and (max-width: 576px) {
  .nav__logo {
    font-size: var(--font-size-lg);
  }

  .logo-img {
    width: 32px;
    height: 32px;
  }

  .theme-toggle,
  .cart-button {
    width: 40px;
    height: 40px;
    font-size: var(--font-size-base);
  }
}