#header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    z-index: var(--z-dropdown);
    background: rgba(0, 0, 0, 0.8);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s ease, transform 0.3s ease, background 0.3s ease;
}

body.light-mode #header {
    background: rgba(255, 255, 255, 0.8);
}

#header.scrolled {
    border-bottom-color: var(--store-hairline-soft);
}

#header.hidden {
    transform: translateY(-100%);
}

.header-container {
    width: min(1024px, calc(100% - 44px));
    margin: 0 auto;
    height: 100%;
    display: flex;
    align-items: center;
    gap: 32px;
}

.header-logo {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.header-logo img {
    height: 24px;
    width: auto;
    border-radius: 6px;
    display: block;
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 28px;
    flex: 1;
    justify-content: center;
}

.header-nav__link {
    background: none;
    border: none;
    color: var(--store-text-secondary);
    font-family: var(--font-body);
    font-size: 12px;
    letter-spacing: -0.01em;
    padding: 6px 0;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.header-nav__link:hover,
.header-nav__link.is-active {
    color: var(--store-text);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 14px;
    flex-shrink: 0;
}

.header-icon-btn {
    background: none;
    border: none;
    color: var(--store-text-secondary);
    width: 32px;
    height: 32px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    cursor: pointer;
    transition: color var(--transition-fast), background var(--transition-fast);
}

.header-icon-btn:hover {
    color: var(--store-text);
    background: rgba(255, 255, 255, 0.08);
}

body.light-mode .header-icon-btn:hover {
    background: rgba(0, 0, 0, 0.06);
}

.cart-count {
    position: absolute;
    top: -1px;
    right: -3px;
    min-width: 15px;
    height: 15px;
    padding: 0 4px;
    border-radius: 8px;
    background: var(--store-primary);
    color: #fff;
    font-size: 10px;
    font-weight: var(--font-weight-semibold);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.cart-count.empty {
    opacity: 0;
    transform: scale(0.5);
}

.cart-count.has-items {
    opacity: 1;
    transform: scale(1);
}

.user-profile { display: flex; align-items: center; }

.login-button,
.user-profile button {
    background: none;
    border: 1px solid var(--store-hairline);
    color: var(--store-text);
    font-family: var(--font-body);
    font-size: 12px;
    padding: 5px 14px;
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: background var(--transition-fast), border-color var(--transition-fast);
}

.login-button:hover,
.user-profile button:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--store-border);
}

body.light-mode .login-button:hover,
body.light-mode .user-profile button:hover {
    background: rgba(0, 0, 0, 0.05);
}

.user-profile img,
.user-profile .user-avatar {
    width: 26px;
    height: 26px;
    border-radius: 50%;
    object-fit: cover;
}

.mega-menu-overlay {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    z-index: calc(var(--z-dropdown) - 1);
    background: rgba(0, 0, 0, 0.88);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--store-hairline-soft);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s ease;
}

body.light-mode .mega-menu-overlay {
    background: rgba(255, 255, 255, 0.92);
}

.mega-menu-overlay.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.mega-menu__inner {
    width: min(1024px, calc(100% - 44px));
    margin: 0 auto;
    padding: 36px 0 44px;
}

.mega-menu__title {
    font-size: 12px;
    color: var(--store-text-muted);
    margin-bottom: 14px;
}

.mega-menu__list {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
}

.mega-menu__item {
    font-size: 22px;
    font-weight: var(--font-weight-semibold);
    letter-spacing: -0.02em;
    color: var(--store-text);
    transition: color var(--transition-fast);
}

.mega-menu__item:hover {
    color: var(--store-primary-light);
}

.mega-menu__view-all {
    display: inline-block;
    margin-top: 18px;
    font-size: 13px;
    color: var(--store-primary-light);
}

.mega-menu__view-all:hover { text-decoration: underline; }

.mega-menu__empty {
    color: var(--store-text-muted);
    font-size: 14px;
}

.mega-menu__loading {
    display: flex;
    gap: 6px;
    padding: 8px 0;
}

.mega-menu__loading span {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--store-text-muted);
    animation: megaPulse 1.2s ease-in-out infinite;
}

.mega-menu__loading span:nth-child(2) { animation-delay: 0.15s; }
.mega-menu__loading span:nth-child(3) { animation-delay: 0.3s; }

@keyframes megaPulse {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 1; }
}

.search-flyout-overlay {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    z-index: calc(var(--z-dropdown) - 1);
    background: rgba(0, 0, 0, 0.88);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--store-hairline-soft);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s ease;
}

body.light-mode .search-flyout-overlay {
    background: rgba(255, 255, 255, 0.92);
}

.search-flyout-overlay.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.search-flyout-inner {
    width: min(680px, calc(100% - 44px));
    margin: 0 auto;
    padding: 32px 0 40px;
}

.search-input-wrapper {
    display: flex;
    align-items: center;
    gap: 12px;
    border-bottom: 1px solid var(--store-hairline);
    padding-bottom: 10px;
}

.search-input {
    flex: 1;
    background: none;
    border: none;
    color: var(--store-text);
    font-family: var(--font-body);
    font-size: 24px;
    font-weight: var(--font-weight-semibold);
    letter-spacing: -0.02em;
}

.search-input::placeholder {
    color: var(--store-text-muted);
}

.search-button {
    background: none;
    border: none;
    color: var(--store-text-muted);
    font-size: 18px;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.search-button:hover { color: var(--store-text); }

.search-results {
    margin-top: 18px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.search-results a,
.search-result-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 12px;
    border-radius: var(--radius-md);
    color: var(--store-text-secondary);
    font-size: 15px;
    transition: background var(--transition-fast), color var(--transition-fast);
}

.search-results a:hover,
.search-result-item:hover {
    background: rgba(255, 255, 255, 0.06);
    color: var(--store-text);
}

body.light-mode .search-results a:hover,
body.light-mode .search-result-item:hover {
    background: rgba(0, 0, 0, 0.05);
}

@media (max-width: 860px) {
    .header-nav { display: none; }
    .header-container { justify-content: space-between; }
}

@media (max-width: 576px) {
    .header-container { width: calc(100% - 32px); gap: 16px; }
    .login-button { font-size: 11px; padding: 4px 11px; }
}