.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: rgba(10, 10, 10, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: var(--z-navbar);
    transition: transform var(--transition-base);
}

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

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

/* ---- Logo ---- */

.header-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex-shrink: 0;
}

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

.header-logo span {
    font-family: var(--font-heading);
    font-size: var(--font-size-xl);
    color: var(--color-text-primary);
    letter-spacing: var(--letter-spacing-wider);
}

/* ---- Search (expandable) ---- */

.header-search-wrap {
    display: none;
    flex: 1;
    max-width: 360px;
    margin: 0 var(--spacing-lg);
}

.header-search-wrap.active {
    display: block;
}

.header-search {
    position: relative;
    display: flex;
    align-items: center;
}

.header-search .search-icon {
    position: absolute;
    left: 12px;
    color: var(--color-text-muted);
    font-size: 0.85rem;
    pointer-events: none;
    z-index: 1;
}

.header-search .search-input {
    width: 100%;
    height: 38px;
    padding: 0 40px 0 36px;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-family: var(--font-body);
    font-size: var(--font-size-sm);
    outline: none;
    transition: all var(--transition-fast);
}

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

.header-search .search-input:focus {
    border-color: var(--color-primary);
    background: var(--color-bg-card);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.search-close {
    position: absolute;
    right: 4px;
    width: 30px;
    height: 30px;
    display: none;
    align-items: center;
    justify-content: center;
    background: none;
    border: none;
    color: var(--color-text-muted);
    cursor: pointer;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    transition: color var(--transition-fast);
}

.search-close:hover {
    color: var(--color-text-primary);
}

.search-input:not(:placeholder-shown) ~ .search-close {
    display: flex;
}

.search-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    right: 0;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    display: none;
    z-index: var(--z-dropdown);
    max-height: 360px;
    overflow-y: auto;
}

.search-dropdown.active {
    display: block;
}

.search-dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 10px 12px;
    cursor: pointer;
    transition: background var(--transition-fast);
    text-decoration: none;
}

.search-dropdown-item:hover {
    background: var(--color-bg-secondary);
}

.search-dropdown-item img {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    object-fit: cover;
    flex-shrink: 0;
}

.search-dropdown-item .item-info {
    flex: 1;
    min-width: 0;
}

.search-dropdown-item .item-name {
    font-family: var(--font-heading);
    font-size: var(--font-size-sm);
    color: var(--color-text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.search-dropdown-item .item-category {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
}

.search-dropdown-empty {
    padding: 16px;
    text-align: center;
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
}

.search-dropdown::-webkit-scrollbar {
    width: 6px;
}

.search-dropdown::-webkit-scrollbar-track {
    background: transparent;
}

.search-dropdown::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: var(--radius-full);
}

/* ---- Nav ---- */

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

.header-nav a {
    font-family: var(--font-body);
    font-weight: var(--font-weight-semibold);
    font-size: var(--font-size-md);
    color: var(--color-text-secondary);
    transition: color var(--transition-fast);
    position: relative;
    text-transform: uppercase;
    letter-spacing: var(--letter-spacing-wide);
}

.header-nav a:hover,
.header-nav a.active {
    color: var(--color-text-primary);
}

.header-nav a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-primary);
    transition: width var(--transition-base);
}

.header-nav a:hover::after,
.header-nav a.active::after {
    width: 100%;
}

/* ---- Action buttons ---- */

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.header-icon-btn {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    cursor: pointer;
    font-size: 1rem;
    transition: all var(--transition-fast);
    flex-shrink: 0;
    position: relative;
}

.header-icon-btn:hover {
    border-color: var(--color-primary);
    color: var(--color-text-primary);
    background: rgba(37, 99, 235, 0.08);
}

/* ---- Account dropdown ---- */

.header-account-wrap {
    position: relative;
}

.account-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    min-width: 160px;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    display: none;
    z-index: var(--z-dropdown);
    overflow: hidden;
}

.account-dropdown.active {
    display: block;
}

.account-info {
    padding: 12px 16px;
    font-size: var(--font-size-sm);
    color: var(--color-text-primary);
    border-bottom: 1px solid var(--color-border);
}

.account-link {
    display: block;
    padding: 10px 16px;
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: all var(--transition-fast);
    text-transform: uppercase;
    letter-spacing: var(--letter-spacing-wide);
    font-family: var(--font-body);
    font-weight: var(--font-weight-semibold);
}

.account-link:hover {
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
}

.account-link:not(:last-child) {
    border-bottom: 1px solid var(--color-border);
}

/* ---- Hamburger ---- */

.hamburger {
    flex-direction: column;
    gap: 5px;
    padding: 0;
    background: none;
    border: none;
    width: 40px;
    height: 40px;
}

.hamburger span {
    display: block;
    width: 18px;
    height: 2px;
    background: var(--color-text-primary);
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ---- Responsive ---- */

@media (max-width: 900px) {
    .header-search-wrap {
        max-width: 280px;
    }
}

@media (max-width: 768px) {
    .header-inner {
        padding: 0 var(--spacing-sm);
        gap: var(--spacing-sm);
    }
    .header-logo img {
        height: 32px;
    }
    .header-nav {
        display: none;
    }
    .header-search-wrap {
        position: absolute;
        top: var(--header-height);
        left: 0;
        right: 0;
        max-width: none;
        margin: 0;
        padding: var(--spacing-sm);
        background: var(--color-bg-primary);
        border-bottom: 1px solid var(--color-border);
    }
    .header-search-wrap.active {
        display: block;
    }
    .header-search .search-input {
        height: 42px;
        font-size: var(--font-size-base);
    }
    .search-dropdown {
        position: fixed;
        top: calc(var(--header-height) + 58px);
        left: 0;
        right: 0;
        border-radius: 0;
        border-left: none;
        border-right: none;
        max-height: 60vh;
    }
    .search-close {
        display: flex;
    }
}

@media (max-width: 480px) {
    .header-icon-btn {
        width: 36px;
        height: 36px;
        font-size: 0.9rem;
    }
    .hamburger {
        width: 36px;
        height: 36px;
    }
}