/* Navigation bar styles */
.nav-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: var(--nav-bg);
    padding: 0 24px;
    height: 60px;
    box-shadow: 0 2px 8px var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-brand {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: 1px;
    cursor: pointer;
}

.nav-links {
    display: flex;
    gap: 8px;
}

.nav-link {
    color: var(--nav-text);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 8px;
    transition: background-color 0.2s, color 0.2s;
    font-weight: 500;
}

.nav-link:hover {
    background-color: var(--accent);
    color: #ffffff;
}

.nav-link.active {
    background-color: var(--accent);
    color: #ffffff;
}

/* Hamburger button - hidden on desktop */
.hamburger-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    z-index: 110;
}

.hamburger-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--nav-text);
    border-radius: 2px;
    transition: transform 0.3s, opacity 0.3s;
}

.hamburger-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

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

.hamburger-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* Floating buttons */
.floating-btn {
    position: fixed;
    bottom: 24px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 2px solid var(--border);
    background-color: var(--floating-bg);
    color: var(--floating-text);
    font-size: 1.2rem;
    font-weight: 700;
    cursor: pointer;
    box-shadow: 0 4px 12px var(--shadow);
    transition: transform 0.2s, background-color 0.2s, color 0.2s;
    z-index: 200;
    display: flex;
    align-items: center;
    justify-content: center;
}

.floating-btn:hover {
    transform: scale(1.1);
    background-color: var(--floating-hover);
    color: #ffffff;
}

.theme-btn {
    right: 24px;
}

.lang-btn {
    right: 80px;
    font-size: 0.85rem;
}

/* Dataset dropdown in nav */
.nav-dropdown-wrapper {
    position: relative;
}

.nav-dropdown-toggle {
    background: none;
    border: none;
    color: var(--nav-text);
    font-family: inherit;
    font-size: 1rem;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s, color 0.2s;
    display: flex;
    align-items: center;
    gap: 4px;
}

.nav-dropdown-toggle::after {
    content: '▼';
    font-size: 0.65rem;
    margin-left: 4px;
    transition: transform 0.2s;
}

.nav-dropdown-toggle:hover {
    background-color: var(--accent);
    color: #ffffff;
}

.nav-dropdown-toggle.active {
    background-color: var(--accent);
    color: #ffffff;
}

.nav-dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 180px;
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    box-shadow: 0 4px 16px var(--shadow);
    z-index: 200;
    padding: 4px 0;
    margin-top: 4px;
}

.nav-dropdown-menu.open {
    display: block;
}

.nav-dropdown-item {
    display: block;
    padding: 10px 16px;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: background-color 0.15s;
    white-space: nowrap;
}

.nav-dropdown-item:hover {
    background-color: var(--bg-secondary);
    color: var(--accent);
}

.nav-dropdown-item.active {
    background-color: var(--bg-secondary);
    color: var(--accent);
    font-weight: 700;
}

/* Mobile responsive */
@media (max-width: 768px) {
    .hamburger-btn {
        display: flex;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        flex-direction: column;
        background-color: var(--nav-bg);
        padding: 8px 16px;
        box-shadow: 0 4px 12px var(--shadow);
        gap: 4px;
        z-index: 100;
    }

    .nav-links.open {
        display: flex;
    }

    .nav-link {
        padding: 12px 16px;
    }

    /* Mobile: dropdown becomes inline */
    .nav-dropdown-wrapper {
        width: 100%;
    }

    .nav-dropdown-toggle {
        width: 100%;
        justify-content: space-between;
        padding: 12px 16px;
        font-size: 1rem;
    }

    .nav-dropdown-menu {
        position: static;
        box-shadow: none;
        border: none;
        border-radius: 0;
        margin-top: 0;
        padding: 0 0 0 16px;
        background-color: transparent;
        min-width: auto;
    }

    .nav-dropdown-item {
        padding: 10px 16px;
        font-size: 0.95rem;
    }
}