/* 幡动，风动，心动 - Zen Subtle Animation */
@keyframes heart-stir {
    0%, 100% {
        background: rgba(250, 250, 250, 0.948);
    }
    50% {
        background: rgba(250, 250, 250, 0.952);
    }
}

/* Navigation Bar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(250, 250, 250, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-divider);
    z-index: 1000;
    transition: all 0.3s ease;
    /* Initial state for animation */
    opacity: 0;
    transform: translateY(-10px);
}

/* Enable subtle animation on desktop only - 心动 */
@media (min-width: 769px) and (prefers-reduced-motion: no-preference) {
    .navbar {
        animation: heart-stir 75s ease-in-out infinite;
    }
}

.navbar.fade-in {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94), transform 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-logo {
    font-size: var(--font-size-xl);
    font-weight: 300;
    color: var(--color-text);
    text-decoration: none;
    letter-spacing: 2px;
    transition: color 0.2s ease;
}

.nav-logo:hover {
    color: var(--color-text-light);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
    align-items: center;
    margin: 0;
    padding: 0;
}

.nav-item {
    margin: 0;
}

.nav-link {
    color: var(--color-text);
    text-decoration: none;
    font-size: var(--font-size-base);
    font-weight: 300;
    letter-spacing: 0.5px;
    transition: color 0.2s ease;
    position: relative;
    padding: var(--spacing-xs) 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--color-text);
    transition: width 0.3s ease;
}

.nav-link:hover {
    color: var(--color-text);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-link.active {
    color: var(--color-text);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    gap: 4px;
}

.nav-toggle span {
    width: 24px;
    height: 1px;
    background: var(--color-text);
    transition: all 0.3s ease;
}

/* Language Switcher Wrapper */
.lang-switcher-wrapper {
    position: relative;
    margin-left: var(--spacing-md);
}

/* Language Switcher in Navbar */
.navbar .lang-switcher {
    background: transparent;
    border: 1px solid var(--color-text-lighter);
    border-radius: 2px;
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-base);
    color: var(--color-text);
    cursor: pointer;
    transition: all 0.2s ease;
    font-weight: 300;
    letter-spacing: 0.5px;
    min-width: 60px;
    text-align: center;
}

.navbar .lang-switcher:hover {
    border-color: var(--color-text);
    background: var(--color-white);
}

.lang-switcher:hover {
    border-color: var(--color-text);
    background: var(--color-white);
}

/* Language Dropdown Menu */
.lang-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    background: var(--color-white);
    border: 1px solid var(--color-divider);
    border-radius: 4px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    min-width: 120px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.2s ease;
    z-index: 1001;
    /* 防止在移动端造成布局问题 */
    max-width: 90vw;
    /* 确保不会超出屏幕 */
    left: auto;
    /* 确保隐藏时完全不可见且不影响布局 */
    pointer-events: none;
    display: none;
}

.lang-dropdown.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
    display: block;
}

.lang-option {
    display: block;
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: transparent;
    border: none;
    text-align: left;
    font-size: var(--font-size-base);
    color: var(--color-text);
    cursor: pointer;
    transition: background 0.2s ease;
    font-weight: 300;
    letter-spacing: 0.5px;
}

.lang-option:hover {
    background: var(--color-bg);
}

.lang-option.active {
    background: var(--color-bg);
    font-weight: 500;
    color: var(--color-primary);
}

.lang-option:first-child {
    border-radius: 4px 4px 0 0;
}

.lang-option:last-child {
    border-radius: 0 0 4px 4px;
}

/* Mobile-first Navigation */
.nav-container {
    height: 60px;
    padding: 0 var(--spacing-sm);
}

.nav-logo {
    font-size: var(--font-size-lg);
}

.nav-menu {
    position: fixed;
    left: -100%;
    top: 60px;
    flex-direction: column;
    background: rgba(250, 250, 250, 0.98);
    backdrop-filter: blur(10px);
    width: 100%;
    text-align: center;
    transition: left 0.3s ease;
    border-bottom: 1px solid var(--color-divider);
    padding: var(--spacing-md) 0;
    gap: 0;
    z-index: 999;
}

.nav-menu.active {
    left: 0;
}

.nav-item {
    width: 100%;
    padding: var(--spacing-sm) 0;
}

.nav-link {
    display: block;
    padding: var(--spacing-sm);
    min-height: 44px; /* Touch target size */
    display: flex;
    align-items: center;
    justify-content: center;
}

.nav-toggle {
    display: flex;
    min-width: 44px; /* Touch target size */
    min-height: 44px;
}

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

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

.lang-switcher-wrapper {
    margin-left: var(--spacing-sm);
}

.navbar .lang-switcher {
    padding: 6px 12px;
    font-size: 0.875rem;
    min-width: 44px; /* Touch target size */
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Desktop Navigation */
@media (min-width: 769px) {
    .nav-container {
        height: 70px;
        padding: 0 var(--spacing-md);
    }

    .nav-logo {
        font-size: var(--font-size-xl);
    }

    .nav-menu {
        position: static;
        flex-direction: row;
        background: transparent;
        backdrop-filter: none;
        width: auto;
        text-align: left;
        border-bottom: none;
        padding: 0;
        gap: var(--spacing-lg);
    }

    .nav-item {
        width: auto;
        padding: 0;
    }

    .nav-link {
        display: inline-block;
        padding: var(--spacing-xs) 0;
        min-height: auto;
        display: inline-block;
    }

    .nav-toggle {
        display: none;
    }

    .lang-switcher-wrapper {
        margin-left: var(--spacing-md);
    }
    
    .navbar .lang-switcher {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: var(--font-size-base);
        min-width: 60px;
        min-height: auto;
    }
}