/* ===================================
   HEADER & NAVIGATION STYLES
   =================================== */

.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height-mobile);
    background: transparent;
    backdrop-filter: blur(0px);
    /* Transition start */
    -webkit-backdrop-filter: blur(0px);
    border-bottom: 1px solid transparent;
    z-index: var(--z-fixed);
    transition: background-color 0.18s linear,
        border-color 0.18s linear,
        box-shadow 0.18s linear,
        backdrop-filter 0.18s linear,
        -webkit-backdrop-filter 0.18s linear;
}

@media (min-width: 768px) {
    .header {
        height: var(--header-height);
    }
}

.header.scrolled {
    background-color: rgba(var(--bg-elevated-rgb), 0.82);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(var(--accent-rgb), 0.1);
    box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.15);
}

[data-theme="dark"] .header.scrolled {
    background-color: rgba(0, 0, 0, 0.75);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

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

.nav-logo {
    font-family: var(--font-display);
    font-size: var(--text-2xl);
    font-weight: var(--font-black);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: transform var(--transition-base) var(--ease-out);
    display: flex;
    align-items: center;
    height: 40px;
}

.nav-logo-img {
    height: 100%;
    width: auto;
    max-width: 60px;
}

/* Show default logo (pink) by default */
.nav-logo-default {
    display: block;
}

.nav-logo-blue {
    display: none;
}

/* Show blue logo when in secret blue theme */
.theme-secret-blue .nav-logo-default {
    display: none;
}

.theme-secret-blue .nav-logo-blue {
    display: block;
}

.nav-logo svg {
    display: none;
    /* Hide any remaining SVG logos */
}


.nav-logo:hover {
    transform: scale(1.05);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.nav-list {
    display: flex;
    align-items: center;
    gap: var(--space-8);
    list-style: none;
}

.nav-link {
    position: relative;
    font-size: var(--text-base);
    font-weight: var(--font-medium);
    color: var(--text-secondary);
    padding: var(--space-2) 0;
    transition: color var(--transition-base) var(--ease-out);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: width var(--transition-base) var(--ease-out);
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent-color);
}

.nav-link.active::after {
    width: 100%;
}

.nav-link:hover::after {
    width: 100%;
}

/* Theme Toggle */
.theme-toggle {
    position: relative;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border-radius: 50%;
    cursor: pointer;
    transition: all var(--transition-base) var(--ease-out);
}

.theme-toggle:hover {
    background: var(--accent-color);
    color: var(--text-inverse);
    transform: rotate(180deg);
}

.theme-icon {
    position: absolute;
    transition: all var(--transition-base) var(--ease-out);
}

.sun-icon {
    opacity: 1;
    transform: rotate(0deg) scale(1);
}

.moon-icon {
    opacity: 0;
    transform: rotate(180deg) scale(0);
}

[data-theme="dark"] .sun-icon {
    opacity: 0;
    transform: rotate(-180deg) scale(0);
}

[data-theme="dark"] .moon-icon {
    opacity: 1;
    transform: rotate(0deg) scale(1);
}

/* Language Toggle */
.lang-toggle-wrapper {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-left: 12px;
}

.lang-toggle {
    background: none;
    border: none;
    font-family: var(--font-body);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
    opacity: 0.5;
    cursor: pointer;
    padding: 2px;
    transition: opacity 0.2s ease;
}

.lang-toggle:hover {
    opacity: 0.8;
}

.lang-toggle.active {
    opacity: 1;
    font-weight: 700;
    color: var(--accent-color);
}

.lang-separator {
    color: var(--text-primary);
    opacity: 0.3;
}

/* Mobile Menu Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 6px;
    width: 44px;
    height: 44px;
    background: transparent;
    cursor: pointer;
}

.nav-toggle-line {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: all var(--transition-base) var(--ease-out);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(2) {
    opacity: 0;
    transform: translateX(-20px);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

@media (max-width: 767px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: var(--header-height-mobile);
        left: 0;
        width: 100%;
        height: calc(100vh - var(--header-height-mobile));
        background: var(--bg-primary);
        backdrop-filter: blur(10px);
        -webkit-backdrop-filter: blur(10px);
        /* Mobile menu needs a solid base for readability */
        flex-direction: column;
        justify-content: flex-start;
        padding: var(--space-8);
        gap: var(--space-6);
        transform: translateX(-100%);
        transition: transform var(--transition-base) var(--ease-out);
    }

    .nav-menu.active {
        transform: translateX(0);
    }

    .nav-list {
        flex-direction: column;
        width: 100%;
        gap: var(--space-4);
    }

    .nav-link {
        display: block;
        width: 100%;
        padding: var(--space-4);
        font-size: var(--text-lg);
        text-align: center;
        background: var(--bg-secondary);
        border-radius: var(--radius-base);
    }
}