:root {
    --web-app-banner-height: 32px;
    --mobile-nav-width: 280px;
    --nav-padding-y: 14px;
    --nav-row-height: calc(var(--nav-padding-y) * 2 + 16px);
    --nav-bar-height: var(--nav-row-height);
    --section-gap: 24px;
    --tap-min: 44px;
}

/* --- WEB APP BANNER --- */
.web-app-banner {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 2600;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: var(--web-app-banner-height);
    padding: 0 16px;
    background: var(--accent);
    color: #fff;
    text-decoration: none;
    text-align: center;
    transition: background-color 0.2s ease, color 0.2s ease;
}

.web-app-banner:hover {
    background: var(--accent-hover);
    color: #fff;
}

.web-app-banner__title {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 13px;
    letter-spacing: 0.02em;
    line-height: 1;
    white-space: nowrap;
}

/* --- NAVIGATION --- */
nav {
    left: 0;
    right: 0;
    background-color: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: var(--nav-padding-y) 0;
    position: fixed;
    top: var(--web-app-banner-height);
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 28px;
    box-sizing: border-box;
    padding-right: 56px;
    border-bottom: 1px solid var(--nav-border);
}

nav .desktop-link {
    color: var(--nav-fg);
    text-decoration: none;
    margin: 0;
    font-family: var(--font-sans);
    font-size: 14px;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    min-height: var(--tap-min);
    white-space: nowrap;
    transition: color 0.15s ease;
}

nav a.desktop-link:hover {
    color: var(--accent);
}

nav a.desktop-link.active {
    color: var(--accent);
    font-weight: 700;
}

/* --- MOBILE MENU --- */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
    z-index: 2800;
    min-width: var(--tap-min);
    min-height: var(--tap-min);
}

.mobile-menu-icon {
    display: block;
    width: 22px;
    height: 2px;
    background-color: var(--nav-fg);
    margin: 5px 0;
    transition: 0.35s;
}

.mobile-nav-overlay {
    height: 100%;
    width: 0;
    position: fixed;
    z-index: 2700;
    top: 0;
    left: 0;
    background-color: var(--overlay-bg);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-right: 1px solid var(--nav-border);
    overflow-x: hidden;
    transition: 0.35s ease-out;
    padding-top: calc(var(--nav-row-height) + var(--web-app-banner-height) + 16px);
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    box-shadow: 4px 0 24px rgba(15, 28, 36, 0.12);
}

.mobile-nav-overlay a {
    padding: 16px 16px 16px 28px;
    text-decoration: none;
    font-family: var(--font-sans);
    font-size: 18px;
    font-weight: 500;
    color: var(--fg);
    display: block;
    width: 100%;
    border-bottom: 1px solid var(--border-subtle);
    box-sizing: border-box;
    min-height: var(--tap-min);
}

.mobile-nav-overlay a:hover {
    color: var(--accent);
}

.mobile-nav-overlay a.active {
    color: var(--accent);
    font-weight: 700;
}

.change .bar1 {
    transform: translate(0, 7px) rotate(-45deg);
}

.change .bar2 {
    opacity: 0;
}

.change .bar3 {
    transform: translate(0, -7px) rotate(45deg);
}

body.menu-open .content,
body.menu-open footer {
    opacity: 0.35;
    pointer-events: none;
}

@media (min-width: 769px) {
    nav {
        padding-left: 24px;
        padding-right: 56px;
    }

    .mobile-menu-btn {
        display: none;
    }
}

@media (max-width: 768px) {
    :root {
        --web-app-banner-height: 30px;
    }

    .web-app-banner__title {
        font-size: 12px;
    }

    nav {
        height: var(--nav-row-height);
        padding: 0 48px 0 20px;
        justify-content: flex-start;
        align-items: center;
    }

    nav .desktop-link {
        display: none;
    }

    .mobile-menu-btn {
        display: block;
        position: fixed;
        left: 12px;
        top: calc(var(--web-app-banner-height) + var(--nav-row-height) / 2);
        transform: translateY(-50%);
        z-index: 2800;
    }
}

/* Language switcher */
nav .lang-switcher-slot {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 2600;
    display: flex;
    align-items: center;
}

.lang-switcher {
    position: relative;
}

.lang-switcher__trigger,
.lang-switcher__option {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin: 0;
    padding: 4px;
    min-width: var(--tap-min);
    min-height: var(--tap-min);
    border: 1px solid transparent;
    border-radius: 6px;
    background: transparent;
    color: inherit;
    cursor: pointer;
    line-height: 0;
}

.lang-switcher__trigger {
    border-color: var(--nav-border);
}

.lang-switcher__trigger:hover,
.lang-switcher.is-open .lang-switcher__trigger {
    border-color: var(--accent);
}

.lang-switcher__menu {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    z-index: 3100;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    min-width: 48px;
    padding: 8px 6px;
    border: 1px solid var(--nav-border);
    border-radius: 10px;
    background: var(--surface);
    box-shadow: 0 8px 24px rgba(15, 28, 36, 0.12);
}

.lang-switcher__menu[hidden] {
    display: none;
}

.lang-switcher__option.active {
    border-color: var(--accent);
}

.lang-switcher__option.is-unavailable {
    opacity: 0.4;
    cursor: default;
    position: relative;
}

.lang-switcher__option.is-unavailable:hover {
    opacity: 0.55;
}

.lang-switcher__option.is-unavailable::after {
    content: attr(data-tooltip);
    position: absolute;
    top: 50%;
    right: calc(100% + 8px);
    z-index: 3200;
    width: max-content;
    max-width: min(280px, 70vw);
    padding: 8px 10px;
    border: 1px solid var(--nav-border);
    border-radius: 8px;
    background: var(--surface);
    box-shadow: 0 4px 12px rgba(15, 28, 36, 0.14);
    color: var(--fg);
    font-family: var(--font-sans);
    font-size: 12px;
    font-weight: 400;
    line-height: 1.35;
    text-align: center;
    white-space: normal;
    opacity: 0;
    pointer-events: none;
    transform: translateY(-50%) translateX(4px);
    transition: opacity 0.15s, transform 0.15s;
}

.lang-switcher__option.is-unavailable:hover::after,
.lang-switcher__option.is-unavailable.is-tooltip-visible::after {
    opacity: 1;
    transform: translateY(-50%) translateX(0);
}

.lang-flag {
    display: block;
    width: 20px;
    height: 13px;
    border-radius: 2px;
    overflow: hidden;
    box-shadow: 0 0 0 1px rgba(15, 28, 36, 0.08);
}

.lang-flag--ch {
    width: 13px;
    height: 13px;
}

.lang-flag svg {
    display: block;
    width: 100%;
    height: 100%;
}

.lang-flag--en {
    position: relative;
}

.lang-flag__half {
    position: absolute;
    top: 0;
    width: 50%;
    height: 100%;
    overflow: hidden;
}

.lang-flag__half--us {
    left: 0;
}

.lang-flag__half--gb {
    right: 0;
}

.lang-flag__half svg {
    width: 200%;
    height: 100%;
    max-width: none;
}

.lang-flag__half--gb svg {
    margin-left: -100%;
}