/* ===== Header ===== */
.header {
    /* فیکس بالای صفحه */
    position: fixed;
    inset: 0 0 auto 0;
    z-index: 1000;
    height: var(--header-height);
    /* پیش‌فرض شفاف و بدون سنگینی روی پس‌زمینه روشن */
    background: transparent;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    border-bottom: 1px solid transparent;
    /* انیمیشن‌ها فقط با transform تا ری‌فلوی کمتر */
    will-change: transform, backdrop-filter;
    transform: translateY(0);
    transition: transform var(--t-normal) var(--ease), box-shadow var(--t-normal), background-color var(--t-normal);
}

/* حالت کوچک‌شده هنگام اسکرول (compact) */
.header.scrolled {
    height: var(--header-height);
    transform: translateY(0) scaleY(0.985);
    background-color: rgba(255,253,248,0.82);
    backdrop-filter: blur(10px) saturate(1.05);
    -webkit-backdrop-filter: blur(10px) saturate(1.05);
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 10px 30px rgba(31,27,23,0.06);
}

/* وقتی باید هدر مخفی شود (اسکرول به پایین) */
.header.hidden {
    transform: translateY(-110%);
}

.header-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    max-width: 1240px;
    margin: 0 auto;
    padding: 0 20px;
}

/* --- Logo --- */
.logo-link {
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.logo-img {
    height: 76px; /* افزایش سایز لوگو در حالت عادی */
    width: auto;
    transform-origin: left center;
    will-change: transform;
    transition: transform var(--t-normal), height var(--t-normal);
}

/* کوچک‌تر شدن نرم لوگو در حالت compact */
.header.scrolled .logo-img {
    transform: scale(0.78);
}

.logo-link:hover .logo-img {
    transform: scale(1.02);
}

.logo-text {
    font-size: var(--fs-lg);
    font-weight: 700;
    color: var(--color-text);
}

/* --- Nav Desktop --- */
.nav-list {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1.1rem;
    border-radius: var(--radius-full);
    font-size: var(--fs-sm);
    font-weight: 600;
    color: var(--color-text-muted);
    transition: transform var(--t-fast), background-color var(--t-fast), color var(--t-fast);
    position: relative;
    will-change: transform, background-color;
}

.nav-link i {
    font-size: 1.05rem;
    color: var(--color-accent-dark);
}

.nav-link svg.nav-icon {
    color: var(--color-accent-dark);
    flex-shrink: 0;
}

/* حالت hover ظریف و شیک */
.nav-link:hover {
    color: var(--color-text);
    background-color: var(--color-secondary);
    transform: translateY(-2px);
}

.nav-link.active {
    background: var(--gradient-accent);
    color: #3d342b;
    box-shadow: var(--shadow-sm);
}

.nav-link.active i {
    color: var(--color-text);
}

/* --- Mobile Menu Button --- */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 46px;
    height: 46px;
    z-index: 1001;
}

.menu-line {
    width: 100%;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: transform var(--t-normal), opacity var(--t-normal), background-color var(--t-normal);
}

.nav-icon {
    width: 20px;
    height: 20px;
    vertical-align: middle;
}

.mobile-menu-btn.active .menu-line:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
    background: var(--color-accent-dark);
}
.mobile-menu-btn.active .menu-line:nth-child(2) {
    opacity: 0;
}
.mobile-menu-btn.active .menu-line:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
    background: var(--color-accent-dark);
}

/* --- Overlay --- */
.nav-overlay {
    position: fixed;
    inset: 0;
    background: rgba(30,27,24,0.06);
    backdrop-filter: blur(4px);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--t-normal), visibility var(--t-normal);
    z-index: 999;
}

.nav-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* ===== Mobile ===== */
@media (max-width: 1024px) {
    .mobile-menu-btn {
        display: flex;
    }

    .main-nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 82%;
        max-width: 360px;
        height: 100vh;
        background: rgba(255,253,248,0.96);
        border-left: 1px solid var(--color-border);
        padding: calc(var(--header-height) + 1rem) 1.5rem 2rem;
        transition: right var(--t-normal);
        z-index: 1000;
        overflow-y: auto;
        box-shadow: var(--shadow-md);
    }

    .main-nav.active {
        right: 0;
    }

    .nav-list {
        flex-direction: column;
        align-items: stretch;
        gap: 0.8rem;
    }

    .nav-link {
        width: 100%;
        padding: 1rem 1.3rem;
        background: var(--color-surface-2);
        border: 1px solid var(--color-border);
    }

    .logo-img {
        height: 54px;
    }
}

.header::after {
    content: "";
    position: absolute;
    bottom: 0;
    right: 0;
    left: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-border) 20%, var(--color-border) 80%, transparent);
}