/* ===== 导航栏 ===== */
.glass-nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    border-bottom: 1px solid var(--glass-border);
}
[data-theme="dark"] .glass-nav {
    box-shadow: 0 2px 16px rgba(0,0,0,0.4);
    border-bottom: 1px solid rgba(90,138,255,0.08);
}

/* ===== 日夜选择器（胶囊） ===== */
.theme-switch {
    position: fixed; right: 12px; top: 50%; transform: translateY(-50%);
    z-index: 999;
    display: flex; flex-direction: column; align-items: center;
    gap: 4px; padding: 10px 8px;
    border-radius: 99px; border: none;
    background: linear-gradient(135deg, #0052ff22, #00a2ff22, #0052ff22, #00a2ff22);
    background-size: 300% 300%;
    animation: gradientFlow 4s ease infinite;
    box-shadow: var(--shadow);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}
[data-theme="dark"] .theme-switch {
    background: linear-gradient(135deg, #5a8aff22, #8a7aff22, #5a8aff22, #8a7aff22);
    background-size: 300% 300%;
}
.theme-switch:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-50%) scale(1.06);
}

@keyframes gradientFlow {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}
/* 每个选项可点击（语义化 button，重置浏览器默认样式） */
.theme-opt {
    display: flex; align-items: center; justify-content: center;
    width: 32px; height: 32px; border-radius: 50%;
    cursor: pointer;
    background: none; border: none; padding: 0;
    color: inherit; font: inherit;
    -webkit-appearance: none; appearance: none;
    -webkit-tap-highlight-color: transparent;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}
.theme-opt:hover { background: rgba(255,255,255,0.2); }
.theme-opt:active { transform: scale(0.9); }
.theme-opt:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }
/* 图标基础样式 */
.theme-opt svg {
    width: 20px; height: 20px; display: block;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}
/* 非活跃：统一灰色 */
.theme-opt .sun,
.theme-opt .moon {
    color: var(--text-muted);
    transform: scale(0.7); opacity: 0.35;
}
/* 活跃图标：提亮放大 */
[data-theme="dark"] .theme-opt .moon,
[data-theme="light"] .theme-opt .sun {
    transform: scale(1.5); opacity: 1;
    color: #fff;
}

/* 页面加载时禁用过渡防止闪现 */
.theme-loading * { transition: none !important; }
.nav-flex { height: 80px; display: flex; align-items: center; justify-content: space-between; }
.logo {
    display: flex; align-items: center; gap: 8px;
    font-weight: 800; font-size: 1.25rem;
    text-decoration: none; color: var(--dark);
}
.logo img { width: 32px; height: 32px; }
.logo-text-nav span { color: var(--primary); }

.desktop-nav { display: flex; align-items: center; gap: 24px; }
.desktop-nav a {
    text-decoration: none; color: var(--text-main);
    font-size: 0.9rem; font-weight: 500;
    display: inline-flex; align-items: center; gap: 6px;
    transition: var(--transition);
    position: relative;
}
.desktop-nav a:not(.nav-btn)::after {
    content: ''; position: absolute; bottom: -2px; left: 50%;
    width: 0; height: 2px;
    background: var(--primary);
    border-radius: 2px;
    transition: all 0.3s ease;
    transform: translateX(-50%);
}
.desktop-nav a:not(.nav-btn):hover::after { width: 100%; }
[data-theme="dark"] .desktop-nav a:not(.nav-btn)::after { background: #6a9aff; }
.desktop-nav a svg { width: 16px; height: 16px; }
.desktop-nav a:hover { color: var(--primary); }
.desktop-nav a:hover { color: var(--primary); transform: translateY(-1px); }
/* 鼠标移出恢复动画 */
.desktop-nav a:not(:hover) { transform: translateY(0); transition-duration: 0.5s; }

/* 当前页导航高亮：药丸高亮，日夜模式自适应 */
.desktop-nav a.active {
    color: var(--primary);
    background: var(--primary-light);
    border: 1px solid rgba(0, 82, 255, 0.16);
    padding: 7px 15px;
    border-radius: var(--radius-full);
    font-weight: 600;
}
[data-theme="dark"] .desktop-nav a.active {
    background: rgba(90, 138, 255, 0.14);
    border-color: rgba(90, 138, 255, 0.35);
}
.desktop-nav a.active::after { display: none; }

.nav-btn {
    background: var(--primary); color: white !important;
    padding: 10px 24px; border-radius: var(--radius-full);
    font-weight: 600; font-size: 0.9rem;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transition: var(--transition);
}
.nav-btn:hover { background: var(--primary-deep); transform: translateY(-2px); box-shadow: 0 8px 20px rgba(0,82,255,0.2) !important; color: white !important; }

/* 汉堡按钮 */
.menu-toggle { display: none; background: none; border: none; cursor: pointer; padding: 10px; }
.hamburger span {
    display: block; width: 22px; height: 1.5px;
    background: var(--dark); margin: 6px 0;
    transition: var(--transition);
}
.hamburger.active span:nth-child(1) { transform: translateY(4px) rotate(45deg); }
.hamburger.active span:nth-child(2) { transform: translateY(-4px) rotate(-45deg); }

/* 移动端弹窗 */
.mobile-popup {
    display: none;
    position: absolute; top: 85px; left: 20px; right: 20px;
    background: var(--card-bg); border-radius: 20px; padding: 20px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.12);
    border: 1px solid rgba(0,0,0,0.05); z-index: 1500;
    opacity: 0; transform: translateY(-10px) scale(0.98);
    pointer-events: none; transition: all 0.4s cubic-bezier(0.16,1,0.3,1);
}
.mobile-popup.open { display: block; opacity: 1; transform: translateY(0) scale(1); pointer-events: auto; }
.popup-content { display: flex; flex-direction: column; gap: 8px; }
.popup-item {
    display: flex; align-items: center; gap: 12px;
    padding: 14px; text-decoration: none; color: var(--text-main);
    font-weight: 600; font-size: 1rem; border-radius: 12px;
    transition: background 0.2s;
}
.popup-item:active { background: var(--bg-gray); }
.popup-item.active { color: var(--primary); background: var(--primary-light); }
.popup-item svg { width: 20px; height: 20px; flex-shrink: 0; color: var(--primary); }
.popup-divider { height: 1px; background: var(--border); margin: 10px 0; }
.popup-cta {
    display: block; background: var(--primary); color: white !important;
    text-align: center; padding: 16px; border-radius: 50px;
    font-weight: 700; text-decoration: none;
}
.overlay {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(255,255,255,0.4); backdrop-filter: blur(4px);
    z-index: 400;
}

/* ===== 导航响应式（所有页面通用，适配手机/平板/电脑） ===== */
@media (max-width: 1024px) {
    .desktop-nav { display: none; }
    .menu-toggle { display: block; }
    .mobile-popup { display: block; }
}
@media (max-width: 768px) {
    .nav-flex { height: 70px; }
    .nav-btn { padding: 8px 16px; font-size: 0.85rem; }
    /* 浮动主题切换：小屏收窄，避免遮挡正文卡片 */
    .theme-switch { right: 6px; padding: 7px 5px; gap: 2px; }
    .theme-opt { width: 26px; height: 26px; }
    .theme-opt svg { width: 16px; height: 16px; }
    [data-theme="dark"] .theme-opt .moon,
    [data-theme="light"] .theme-opt .sun { transform: scale(1.25); }
}
@media (max-width: 560px) {
    /* 手机端把主题切换固定到右下角，横向排列，彻底避让内容 */
    .theme-switch {
        right: 10px;
        top: auto;
        bottom: 16px;
        transform: none;
        flex-direction: row;
        padding: 5px 7px;
        background: var(--card-bg);
        border: 1px solid var(--border);
        animation: none;
    }
    .theme-switch:hover { transform: none; }
    .theme-opt .sun, .theme-opt .moon { color: var(--text-muted); }
    [data-theme="dark"] .theme-opt .moon,
    [data-theme="light"] .theme-opt .sun { color: var(--primary); }
}