/**
 * 全站导航 — 与首页 landing 同一套 markup / 视觉
 * 配合 head.php 里 <header class="nav app-nav"> 使用
 */

header.nav.app-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 2.5rem;
    background: rgba(250, 248, 245, 0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--line);
    transition: box-shadow 0.3s var(--ease);
    font-family: var(--font-sans);
}

header.nav.app-nav.scrolled {
    box-shadow: var(--shadow);
}

body.page-agent header.nav.app-nav {
    position: relative;
    flex-shrink: 0;
    z-index: 50;
}

body.has-app-nav:not(.page-agent) {
    padding-top: 4.25rem;
}

header.nav.app-nav .nav-logo {
    display: flex;
    align-items: center;
    text-decoration: none;
}

header.nav.app-nav .logo-text {
    font-weight: 600;
    font-size: clamp(1.15rem, 2.5vw, 1.45rem);
    letter-spacing: -0.03em;
    color: var(--fg);
    transition: opacity 0.2s;
}

header.nav.app-nav .nav-logo:hover .logo-text {
    opacity: 0.75;
    text-decoration: none;
}

header.nav.app-nav .logo-dot {
    color: var(--accent);
    font-weight: 500;
}

header.nav.app-nav .nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
    flex-wrap: nowrap;
    justify-content: center;
    margin: 0;
    padding: 0;
}

header.nav.app-nav .nav-links a {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--muted);
    position: relative;
    transition: color 0.2s;
    text-decoration: none;
    white-space: nowrap;
}

header.nav.app-nav .nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent);
    transition: width 0.3s var(--ease);
}

header.nav.app-nav .nav-links a:hover,
header.nav.app-nav .nav-links a.active {
    color: var(--fg);
    text-decoration: none;
}

header.nav.app-nav .nav-links a:hover::after,
header.nav.app-nav .nav-links a.active::after {
    width: 100%;
}

header.nav.app-nav .nav-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

header.nav.app-nav .nav-lang-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.375rem 0.75rem;
    border-radius: 100px;
    border: 1px solid var(--line);
    font-size: 0.8125rem;
    font-weight: 500;
    font-family: var(--font-sans);
    color: var(--muted);
    text-decoration: none;
    transition: color 0.2s, border-color 0.2s;
}

header.nav.app-nav .nav-lang-link:hover {
    color: var(--fg);
    border-color: rgba(26, 24, 20, 0.18);
    text-decoration: none;
}

header.nav.app-nav .btn-primary,
header.nav.app-nav .btn-ghost {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 100px;
    cursor: pointer;
    transition: all 0.25s var(--ease);
    border: none;
    text-decoration: none;
    white-space: nowrap;
}

header.nav.app-nav .btn-primary {
    background: var(--fg);
    color: var(--bg);
    padding: 0.625rem 1.25rem;
}

header.nav.app-nav .btn-primary:hover {
    background: var(--accent);
    transform: translateY(-2px);
    box-shadow: 0 12px 32px rgba(196, 92, 62, 0.3);
    text-decoration: none;
}

header.nav.app-nav .btn-ghost {
    background: transparent;
    color: var(--muted);
    padding: 0.625rem 1rem;
}

header.nav.app-nav .btn-ghost:hover {
    color: var(--fg);
    text-decoration: none;
}

header.nav.app-nav .btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.8125rem;
}

header.nav.app-nav .nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

header.nav.app-nav .nav-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--fg);
    transition: transform 0.3s var(--ease), opacity 0.3s;
}

header.nav.app-nav .nav-toggle.open span:first-child {
    transform: translateY(3.5px) rotate(45deg);
}

header.nav.app-nav .nav-toggle.open span:last-child {
    transform: translateY(-3.5px) rotate(-45deg);
}

@media (max-width: 900px) {
    header.nav.app-nav .nav-links {
        gap: 1.25rem;
    }
}

@media (max-width: 768px) {
    header.nav.app-nav {
        flex-wrap: wrap;
        padding: 1rem 1.25rem;
    }

    header.nav.app-nav .nav-links,
    header.nav.app-nav .nav-actions {
        display: none;
    }

    header.nav.app-nav .nav-links.open,
    header.nav.app-nav .nav-actions.open {
        display: flex;
    }

    header.nav.app-nav .nav-toggle {
        display: flex;
    }

    header.nav.app-nav.open .nav-links {
        order: 3;
        width: 100%;
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
        padding: 1rem 0;
        border-top: 1px solid var(--line);
    }

    header.nav.app-nav.open .nav-actions {
        order: 4;
        width: 100%;
        justify-content: flex-start;
        flex-wrap: wrap;
        padding-bottom: 0.5rem;
    }
}