/* Общая навигация (бургер) для подстраниц — переменные совместимы с index и внутренними страницами */
:root {
    --nav-bg-header: var(--bg-header, var(--bg-header-footer, #ffffff));
    --nav-text-title: var(--text-title, var(--text-primary, #111111));
    --nav-text-muted: var(--text-muted, #555555);
    --nav-text-light: var(--text-light, #777777);
    --nav-border-color: var(--border-color, #e8e8e8);
    --nav-border-light: var(--border-light, var(--border-color, #e5e5e5));
    --nav-shadow-header: var(--shadow-header, rgba(0, 0, 0, 0.06));
    --nav-shadow-overlay: var(--shadow-overlay, rgba(0, 0, 0, 0.3));
    --nav-overlay-blur: var(--overlay-blur, blur(4px));
}

body.dark-theme,
.dark-theme {
    --nav-bg-header: var(--bg-header, var(--bg-header-footer, #1a1a1a));
    --nav-text-title: var(--text-title, var(--text-primary, #ffffff));
    --nav-text-muted: var(--text-muted, #cccccc);
    --nav-text-light: var(--text-light, #aaaaaa);
    --nav-border-color: var(--border-color, #2d2d2d);
    --nav-border-light: var(--border-color, #2d2d2d);
    --nav-shadow-header: rgba(0, 0, 0, 0.3);
    --nav-shadow-overlay: rgba(0, 0, 0, 0.6);
}

body.nav-open {
    overflow: hidden;
    touch-action: none;
}

body.nav-open .site-header {
    z-index: 10003;
}

.site-header .header-container {
    position: relative;
}

.site-header .theme-toggle-btn {
    margin-left: auto;
    margin-right: 20px;
}

.hamburger-btn {
    width: 30px;
    height: 22px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    cursor: pointer;
    z-index: 10002;
    background: transparent;
    border: none;
    flex-shrink: 0;
    padding: 0;
    color: var(--text-title, var(--text-primary, #111111));
    transition: color 0.4s ease;
}

.hamburger-btn span {
    display: block;
    width: 100%;
    height: 3px;
    background-color: currentColor;
    transition: all 0.3s cubic-bezier(0.215, 0.610, 0.355, 1);
    transform-origin: left center;
}

.hamburger-btn.is-active span:nth-child(1) {
    transform: rotate(45deg) translateY(-2px);
    background-color: #d62828;
}

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

.hamburger-btn.is-active span:nth-child(3) {
    transform: rotate(-45deg) translateY(2px);
    background-color: #d62828;
}

.side-nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: min(420px, 100vw);
    max-width: 100%;
    height: 100vh;
    height: 100dvh;
    background: var(--nav-bg-header);
    box-shadow: -10px 0 40px var(--nav-shadow-header);
    z-index: 10001;
    padding: calc(var(--site-header-h, 75px) + 16px) 40px 40px;
    padding-bottom: max(40px, env(safe-area-inset-bottom));
    display: flex;
    flex-direction: column;
    gap: 24px;
    overflow-x: hidden;
    overflow-y: auto;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;
    transition: right 0.5s cubic-bezier(0.215, 0.610, 0.355, 1), background-color 0.4s ease;
    border-left: 1px solid var(--nav-border-color);
}

.side-nav-menu.is-open {
    right: 0;
}

.side-nav-close {
    display: none;
    position: absolute;
    top: max(12px, env(safe-area-inset-top));
    right: 16px;
    width: 40px;
    height: 40px;
    border: none;
    background: transparent;
    color: var(--nav-text-title);
    font-size: 2.1rem;
    font-weight: 300;
    line-height: 1;
    cursor: pointer;
    z-index: 2;
    align-items: center;
    justify-content: center;
    padding: 0;
    transition: color 0.2s ease;
}

.side-nav-close:hover {
    color: #d62828;
}

.side-nav-menu.is-open .side-nav-close {
    display: flex;
}

.side-nav-contacts {
    display: none;
    flex-direction: column;
    gap: 8px;
    padding-bottom: 18px;
    margin-bottom: 4px;
    border-bottom: 1px solid var(--nav-border-color);
}

.side-nav-phone,
.side-nav-email {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 0.3px;
    color: var(--nav-text-title);
}

.side-nav-phone:hover,
.side-nav-email:hover {
    color: #d62828;
}

.side-nav-email {
    font-size: 0.88rem;
    font-weight: 500;
    color: var(--nav-text-muted);
}

.side-menu-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.side-menu-link {
    font-family: var(--font-heading);
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--nav-text-title);
    letter-spacing: 0.5px;
    display: block;
}

.side-menu-link:hover {
    color: #d62828;
    padding-left: 8px;
}

.menu-submenu-trigger {
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    user-select: none;
    transition: color 0.25s ease, padding-left 0.25s ease;
}

.menu-submenu-trigger.is-active {
    color: #d62828;
    padding-left: 6px;
}

.menu-submenu-trigger::after {
    content: '➔';
    font-size: 0.8rem;
    transition: transform 0.3s;
    color: var(--nav-text-light);
    flex-shrink: 0;
    margin-left: 12px;
}

.menu-submenu-trigger.is-active::after {
    transform: rotate(90deg);
    color: #d62828;
}

.menu-submenu {
    max-height: 0;
    overflow: hidden;
    list-style: none;
    padding-left: 15px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-top: 0;
    opacity: 0;
    transform: translateY(-6px);
    transition:
        max-height 0.45s cubic-bezier(0.4, 0, 0.2, 1),
        opacity 0.32s ease,
        transform 0.38s cubic-bezier(0.4, 0, 0.2, 1),
        margin-top 0.32s ease;
}

.menu-submenu.is-visible {
    margin-top: 10px;
    opacity: 1;
    transform: translateY(0);
}

.menu-submenu > li {
    opacity: 0;
    transform: translateX(-10px);
    transition:
        opacity 0.28s ease,
        transform 0.32s cubic-bezier(0.4, 0, 0.2, 1);
}

.menu-submenu.is-visible > li {
    opacity: 1;
    transform: translateX(0);
}

.menu-submenu.is-visible > li:nth-child(1) { transition-delay: 0.06s; }
.menu-submenu.is-visible > li:nth-child(2) { transition-delay: 0.1s; }
.menu-submenu.is-visible > li:nth-child(3) { transition-delay: 0.14s; }
.menu-submenu.is-visible > li:nth-child(4) { transition-delay: 0.18s; }
.menu-submenu.is-visible > li:nth-child(5) { transition-delay: 0.22s; }
.menu-submenu.is-visible > li:nth-child(6) { transition-delay: 0.26s; }

.menu-submenu:not(.is-visible) > li {
    transition-delay: 0s;
}

.menu-sub-submenu {
    max-height: 0;
    overflow: hidden;
    list-style: none;
    padding-left: 15px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: 0;
    opacity: 0;
    transform: translateY(-4px);
    transition:
        max-height 0.38s cubic-bezier(0.4, 0, 0.2, 1),
        opacity 0.28s ease,
        transform 0.32s cubic-bezier(0.4, 0, 0.2, 1),
        margin-top 0.28s ease;
}

.menu-sub-submenu.is-visible {
    margin-top: 8px;
    margin-bottom: 5px;
    opacity: 1;
    transform: translateY(0);
}

.menu-sub-submenu > li {
    opacity: 0;
    transform: translateX(-8px);
    transition:
        opacity 0.24s ease,
        transform 0.28s cubic-bezier(0.4, 0, 0.2, 1);
}

.menu-sub-submenu.is-visible > li {
    opacity: 1;
    transform: translateX(0);
}

.menu-sub-submenu.is-visible > li:nth-child(1) { transition-delay: 0.05s; }
.menu-sub-submenu.is-visible > li:nth-child(2) { transition-delay: 0.08s; }
.menu-sub-submenu.is-visible > li:nth-child(3) { transition-delay: 0.11s; }
.menu-sub-submenu.is-visible > li:nth-child(4) { transition-delay: 0.14s; }
.menu-sub-submenu.is-visible > li:nth-child(5) { transition-delay: 0.17s; }
.menu-sub-submenu.is-visible > li:nth-child(6) { transition-delay: 0.2s; }
.menu-sub-submenu.is-visible > li:nth-child(7) { transition-delay: 0.23s; }
.menu-sub-submenu.is-visible > li:nth-child(8) { transition-delay: 0.26s; }

.menu-sub-submenu:not(.is-visible) > li {
    transition-delay: 0s;
}

.menu-sub-submenu li a {
    font-size: 0.85rem !important;
    color: var(--nav-text-light);
    line-height: 1.45;
    padding: 2px 0;
    transition: color 0.2s ease, padding-left 0.2s ease;
}

.menu-sub-submenu li a:hover {
    color: var(--nav-text-title);
    padding-left: 6px;
}

.submenu-subtrigger {
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.95rem;
    color: var(--nav-text-muted);
    padding: 6px 0;
    font-weight: 500;
    user-select: none;
    transition: color 0.25s ease, padding-left 0.25s ease;
}

.submenu-subtrigger::after {
    content: '➔';
    font-size: 0.7rem;
    transition: transform 0.3s;
    color: var(--nav-text-light);
    flex-shrink: 0;
    margin-left: 10px;
}

.submenu-subtrigger.is-active {
    color: #d62828;
    padding-left: 6px;
}

.submenu-subtrigger.is-active::after {
    transform: rotate(90deg);
    color: #d62828;
}

.menu-submenu li a {
    font-size: 0.9rem;
    color: var(--nav-text-light);
    line-height: 1.45;
    display: block;
    padding: 2px 0;
    transition: color 0.2s ease, padding-left 0.2s ease;
}

.menu-submenu li a:hover {
    color: var(--nav-text-title);
    padding-left: 6px;
}

.nav-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    height: 100dvh;
    background: var(--nav-shadow-overlay);
    backdrop-filter: var(--nav-overlay-blur);
    z-index: 9998;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.4s ease, visibility 0.4s;
}

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

@media (prefers-reduced-motion: reduce) {
    .menu-submenu,
    .menu-sub-submenu,
    .menu-submenu > li,
    .menu-sub-submenu > li,
    .menu-submenu-trigger,
    .submenu-subtrigger,
    .menu-submenu li a,
    .menu-sub-submenu li a {
        transition: none !important;
        transform: none !important;
        opacity: 1 !important;
    }
}

@media (max-width: 950px) {
    .site-header .theme-toggle-btn {
        margin-right: 0;
        padding: 4px 10px;
        font-size: 0.72rem;
        white-space: nowrap;
    }

    .side-nav-contacts {
        display: flex;
    }

    .side-nav-menu {
        width: min(360px, 100vw);
        padding: calc(var(--site-header-h, 60px) + 12px) 24px 32px;
        padding-bottom: max(32px, env(safe-area-inset-bottom));
        gap: 18px;
    }

    .side-nav-menu.is-open {
        padding-right: 52px;
    }

    .side-menu-link {
        font-size: 1.12rem;
    }

    .menu-submenu li a,
    .menu-sub-submenu li a {
        font-size: 0.88rem !important;
    }
}

@media (max-width: 600px) {
    .side-nav-menu {
        width: 100%;
        border-left: none;
        box-shadow: none;
    }

    .side-menu-link {
        font-size: 1.05rem;
    }
}