.site-theme-toggle {
    flex-shrink: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: auto;
    height: auto;
    padding: 0;
    border: none;
    border-radius: 0;
    background: transparent;
    color: var(--mb-text-secondary);
    cursor: pointer;
    box-shadow: none;
    transform: none;
    transition: color var(--mb-transition-fast);
    will-change: auto;
}

.site-theme-toggle:hover,
.site-theme-toggle:active {
    transform: none;
    box-shadow: none;
}

.site-theme-toggle:hover {
    color: var(--mb-primary-soft);
}

.site-theme-toggle:focus-visible {
    outline: none;
}

.site-theme-toggle:focus-visible .site-theme-toggle__track {
    box-shadow: 0 0 0 3px var(--mb-focus-ring-strong);
}

.site-theme-toggle__track {
    --mb-toggle-w: 56px;
    --mb-toggle-h: 30px;
    --mb-toggle-pad: 4px;
    --mb-toggle-thumb: calc(var(--mb-toggle-h) - var(--mb-toggle-pad) * 2);
    display: block;
    width: var(--mb-toggle-w);
    height: var(--mb-toggle-h);
    border-radius: var(--mb-radius-pill);
    background: var(--mb-bg-subtle);
    border: 1px solid var(--mb-border-strong);
    position: relative;
}

.site-theme-toggle[aria-pressed="true"] .site-theme-toggle__track {
    background: rgba(115, 81, 218, 0.28);
    border-color: var(--mb-primary-soft);
}

.site-theme-toggle__thumb {
    position: absolute;
    top: var(--mb-toggle-pad);
    left: var(--mb-toggle-pad);
    width: var(--mb-toggle-thumb);
    height: var(--mb-toggle-thumb);
    border-radius: 50%;
    background: var(--mb-surface);
    border: 1px solid var(--mb-border);
    box-shadow: var(--mb-shadow);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 360ms cubic-bezier(0.4, 0, 0.2, 1);
}

.site-theme-toggle[aria-pressed="true"] .site-theme-toggle__thumb {
    transform: translateX(calc(var(--mb-toggle-w) - var(--mb-toggle-thumb) - var(--mb-toggle-pad) * 2));
}

.site-theme-toggle__icon {
    position: absolute;
    width: 13px;
    height: 13px;
    transition:
        opacity 360ms cubic-bezier(0.4, 0, 0.2, 1),
        transform 360ms cubic-bezier(0.4, 0, 0.2, 1);
}

.site-theme-toggle__icon--sun {
    opacity: 1;
    transform: rotate(0deg) scale(1);
    color: #f59e0b;
}

.site-theme-toggle__icon--moon {
    opacity: 0;
    transform: rotate(-24deg) scale(0.72);
    color: var(--mb-primary-soft);
}

.site-theme-toggle[aria-pressed="true"] .site-theme-toggle__icon--sun {
    opacity: 0;
    transform: rotate(24deg) scale(0.72);
}

.site-theme-toggle[aria-pressed="true"] .site-theme-toggle__icon--moon {
    opacity: 1;
    transform: rotate(0deg) scale(1);
}

.login-theme-toggle-wrap {
    position: fixed;
    top: max(12px, env(safe-area-inset-top, 0px));
    right: max(12px, env(safe-area-inset-right, 0px));
    z-index: 20;
}

/* View Transitions API — circle reveal из кнопки */
::view-transition-old(root),
::view-transition-new(root) {
    animation-duration: 720ms;
    animation-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
}

::view-transition-old(root) {
    z-index: 1;
    animation: none;
}

::view-transition-new(root) {
    z-index: 2;
    animation-name: mb-theme-circle-reveal;
    clip-path: circle(var(--mb-theme-reveal-r, 0px) at var(--mb-theme-reveal-x, 50vw) var(--mb-theme-reveal-y, 50vh));
}

@keyframes mb-theme-circle-reveal {
    from {
        clip-path: circle(var(--mb-theme-reveal-r, 0px) at var(--mb-theme-reveal-x, 50vw) var(--mb-theme-reveal-y, 50vh));
    }
    to {
        clip-path: circle(150vmax at var(--mb-theme-reveal-x, 50vw) var(--mb-theme-reveal-y, 50vh));
    }
}

/* Overlay fallback (браузеры без View Transitions) */
.mb-theme-reveal-overlay {
    position: fixed;
    inset: 0;
    z-index: 99999;
    pointer-events: none;
    overflow: hidden;
}

.mb-theme-reveal-circle {
    position: absolute;
    border-radius: 50%;
    transform: scale(0);
    transition: transform 720ms cubic-bezier(0.4, 0, 0.2, 1);
    will-change: transform;
}

.mb-theme-reveal-circle.is-expanding {
    transform: scale(1);
}

@media (max-width: 900px) {
    .site-topbar__right .site-theme-toggle__track,
    .login-theme-toggle-wrap .site-theme-toggle__track {
        --mb-toggle-w: 50px;
        --mb-toggle-h: 28px;
        --mb-toggle-pad: 3px;
    }

    .site-topbar__right .site-theme-toggle__icon,
    .login-theme-toggle-wrap .site-theme-toggle__icon {
        width: 12px;
        height: 12px;
    }
}

@media (prefers-reduced-motion: reduce) {
    .site-theme-toggle__thumb,
    .site-theme-toggle__icon {
        transition: none;
    }

    ::view-transition-old(root),
    ::view-transition-new(root) {
        animation: none !important;
    }

    .mb-theme-reveal-overlay {
        display: none !important;
    }
}