/* ================================================================
   8. НАВИГАЦИЯ
================================================================ */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-nav);
    padding: 1rem 0;
    transition: background var(--transition), padding var(--transition), box-shadow var(--transition);
}

.nav.scrolled::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    opacity: 0.7;
    mix-blend-mode: overlay;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='1' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23g)'/%3E%3C/svg%3E");
    background-repeat: repeat;
    background-size: 400px 400px;
}

[data-theme="dark"] .nav.scrolled::before {
    opacity: 0.2;
    mix-blend-mode: screen;
}

[data-theme="accessible"] .nav.scrolled::before {
    display: none;
}

.nav.scrolled {
    background: var(--glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 0.75rem 0;
}

.nav.menu-open {
    background: var(--bg-primary);
}

.nav__container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    position: relative;
}

.nav__logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav__logo-img {
    height: 55px;
    width: auto;
    mix-blend-mode: lighten;
}

.nav__logo-text {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
}

.nav__logo-text span {
    display: block;
    font-size: 0.7rem;
    font-weight: 500;
    color: var(--text-muted);
}

.nav:not(.scrolled) .nav__logo-text,
.nav:not(.scrolled) .nav__links a {
    color: #ffffff;
}

.nav:not(.scrolled) .nav__logo-text span {
    color: rgba(255, 255, 255, 0.7);
}

.nav__links {
    display: flex;
    gap: 2.5rem;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    white-space: nowrap;
}

.nav__links a {
    font-weight: 500;
    font-size: 0.95rem;
    position: relative;
    padding: 0.5rem 0;
    color: var(--text-primary);
}

.nav__links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-blue);
    transition: width var(--transition);
}

.nav__links a:hover::after {
    width: 100%;
}

/* Переключатель темы в навбаре прижат вправо (десктоп) */
.nav__container .theme-toggle {
    margin-left: auto;
    margin-right: 3rem;
}

.nav__burger {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 0.5rem;
    z-index: calc(var(--z-mobile-menu) + 10);
}

.nav__burger span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: transform var(--transition), opacity var(--transition);
}

.nav:not(.scrolled) .nav__burger:not(.active) span {
    background: #ffffff;
}

.nav__burger.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

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

.nav__burger.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

.nav__mobile {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    width: 100%;
    max-width: none;
    height: auto;
    max-height: 0;
    background: var(--bg-primary);
    z-index: var(--z-mobile-menu);
    padding: 0 2rem;
    margin-top: -1px;
    transition: max-height 0.35s ease, padding 0.35s ease;
    overflow: hidden;
    box-shadow: none;
}

.nav.scrolled .nav__mobile {
    background: var(--glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.nav__mobile.open {
    max-height: 80vh;
    padding: 1.5rem 2rem 2rem;
    box-shadow: var(--shadow-xl);
    overflow-y: auto;
}

.nav__mobile ul {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1.5rem;
}

.nav__mobile a {
    font-size: 1.2rem;
    font-weight: 500;
    color: var(--text-primary);
}

.nav__mobile a,
.nav__mobile li {
    color: var(--text-primary);
}

.nav__mobile .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.nav__mobile .btn--primary {
    background: var(--primary-blue);
    color: #ffffff;
    border: none;
}

.nav__mobile .btn--secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}