/* 
 * 核心设计系统 (Design System) - Linear Inspired (Precision & Engineered)
 * 风格：精致工整、微光质感、极致细节
 * 配色：保持清爽白蓝 (Clean White & Blue)
 */
:root {
    /* 调色板 (Color Palette) */
    --color-bg-primary: #FFFFFF;    
    --color-bg-secondary: #F7F8FA;  /* 更冷淡的灰白，接近 Linear 的背景质感 */
    --color-bg-tertiary: #F2F3F5;   /* 用于 hover 或深层背景 */
    
    --color-text-primary: #1A1D21;  /* 更深的灰黑，提升对比度 */
    --color-text-secondary: #5E6473;/* 偏冷的次要文字色 */
    --color-text-tertiary: #8A91A0; /* 辅助文字 */
    
    /* 品牌色保持不变，但增加衍生色用于交互 */
    --color-accent: #0056D2;        
    --color-accent-hover: #0046AB;
    --color-accent-subtle: rgba(0, 86, 210, 0.06); /* 极淡的品牌色背景 */
    --color-accent-light: #F0F7FF; /* 恢复浅蓝背景色，用于 Auth 等页面 */
    --color-accent-border: rgba(0, 86, 210, 0.2);  /* 品牌色边框 */

    --color-white: #FFFFFF;
    --color-footer-bg: #141517;     /* 近似黑色的深灰 */
    --color-footer-text: #9CA3AF;
    
    --color-border: rgba(0, 0, 0, 0.06);     /* 极细微的边框 */
    --color-border-hover: rgba(0, 0, 0, 0.12);
    
    /* 间距与尺寸 (Spacing & Sizing) */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 32px;
    --spacing-xl: 64px;
    --container-width: 1200px;
    
    --radius-sm: 6px;
    --radius-md: 8px;   /* 标准圆角 */
    --radius-lg: 12px;  /* 卡片圆角 */
    --radius-full: 999px;
    
    /* 阴影与特效 (Shadows & Effects) - Linear 风格核心 */
    --transition-fast: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: all 0.3s cubic-bezier(0.25, 0.1, 0.25, 1.0);
    
    /* 漫射阴影，非硬阴影 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.04), 0 1px 3px rgba(0,0,0,0.02);
    --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.06), 0 4px 12px rgba(0,0,0,0.03);
    
    /* 卡片阴影：强调悬浮感 */
    --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.03), 0 0 0 1px rgba(0,0,0,0.04); 
    --shadow-card-hover: 0 12px 40px rgba(0, 0, 0, 0.08), 0 0 0 1px rgba(0,0,0,0.06);
    
    --backdrop-blur: blur(16px);
}

/* 基础重置 */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

ul {
    list-style: none;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition-fast);
}

/* 基础排版 (Typography) - 精致化 */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', Roboto, sans-serif;
    background-color: var(--color-bg-primary); 
    color: var(--color-text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    letter-spacing: -0.01em; /* 稍微紧凑的字间距 */
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    letter-spacing: -0.02em; /* 标题更紧凑 */
    font-weight: 600;
}

/* 顶部通知栏 - 更纤细 */
.notification-bar {
    background-color: var(--color-accent);
    color: #FFFFFF;
    font-size: 0.85rem;
    position: relative;
    z-index: 1001;
}

.notification-content {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 8px 0;
}

.notification-link {
    color: #FFFFFF;
    text-decoration: none;
    margin-left: 10px;
    font-weight: 500;
    border-bottom: 1px solid rgba(255,255,255,0.4);
    transition: var(--transition-fast);
}

.notification-link:hover {
    border-bottom-color: #FFFFFF;
}

.notification-close {
    background: none;
    border: none;
    color: #FFFFFF;
    cursor: pointer;
    position: absolute;
    right: 20px;
    padding: 4px;
    display: flex;
    align-items: center;
    opacity: 0.8;
}

.notification-close:hover {
    opacity: 1;
}

/* 按钮 (Buttons) - 物理按键感 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0 1.25rem;
    height: 36px; /* 稍微压扁，更精致 */
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-fast);
    border: 1px solid transparent;
    user-select: none;
}

.btn-primary {
    background-color: var(--color-accent);
    color: #FFFFFF;
    /* 内阴影增加质感 */
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.1), 0 1px 2px rgba(0,0,0,0.1); 
}

.btn-primary:hover {
    background-color: var(--color-accent-hover);
    transform: translateY(-1px);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.1), 0 4px 12px rgba(0, 86, 210, 0.25);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-outline {
    background-color: transparent;
    border: 1px solid rgba(0,0,0,0.1); /* 边框更明显一点 */
    color: var(--color-text-primary);
    box-shadow: 0 1px 2px rgba(0,0,0,0.02);
}

.btn-outline:hover {
    background-color: var(--color-bg-secondary);
    border-color: rgba(0,0,0,0.15);
    color: var(--color-text-primary); /* 保持黑色，除非强调 */
}

/* 导航栏 (Navbar) - 磨砂玻璃与精细边框 */
.navbar {
    position: sticky;
    top: 0;
    width: 100%;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 5%;
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: var(--backdrop-blur);
    -webkit-backdrop-filter: var(--backdrop-blur);
    z-index: 1000;
    border-bottom: 1px solid rgba(0,0,0,0.06);
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text-primary); /* Linear 倾向于黑色 Logo */
    letter-spacing: -0.03em;
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Logo 前加个小图标模拟 */
.logo::before {
    content: '';
    display: block;
    width: 20px;
    height: 20px;
    background: var(--color-accent);
    border-radius: 4px;
}

.nav-links {
    display: flex;
    gap: 24px;
    height: 100%;
}

.nav-item {
    height: 100%;
    display: flex;
    align-items: center;
    position: relative;
}

.nav-link {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    font-weight: 500;
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
}

.nav-link:hover {
    color: var(--color-text-primary);
    background-color: rgba(0,0,0,0.04);
}

.arrow-icon {
    margin-left: 4px;
    opacity: 0.5;
    transition: transform 0.2s;
}

.nav-item:hover .arrow-icon {
    transform: rotate(180deg);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* 搜索框 - 胶囊式 (Linear Style) */
.nav-search-container {
    position: relative;
    display: flex;
    align-items: center;
}

.search-input-group {
    display: flex;
    align-items: center;
    background-color: var(--color-bg-secondary);
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    padding: 0 8px;
    height: 32px;
    width: 240px;
    transition: all 0.2s cubic-bezier(0.165, 0.84, 0.44, 1);
    box-shadow: inset 0 0 0 1px rgba(0,0,0,0.04);
}

.search-input-group:hover {
    background-color: var(--color-bg-tertiary);
    box-shadow: inset 0 0 0 1px rgba(0,0,0,0.08);
}

.search-input-group:focus-within {
    background-color: #FFFFFF;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(0, 86, 210, 0.1);
    width: 280px; /* Expand slightly on focus */
}

.search-icon {
    color: var(--color-text-secondary);
    margin-right: 8px;
    flex-shrink: 0;
}

.search-input {
    background: transparent;
    border: none;
    outline: none;
    font-size: 0.85rem;
    color: var(--color-text-primary);
    width: 100%;
    height: 100%;
}

.search-input::placeholder {
    color: var(--color-text-tertiary);
}

.search-shortcut {
    display: flex;
    gap: 2px;
    margin-left: 8px;
    opacity: 0.6;
    flex-shrink: 0;
}

.shortcut-key {
    font-size: 0.75rem;
    color: var(--color-text-secondary);
    background-color: rgba(255,255,255,0.5);
    border: 1px solid rgba(0,0,0,0.1);
    border-radius: 4px;
    padding: 0 4px;
    min-width: 18px;
    text-align: center;
    line-height: 16px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

/* Mega Menu & Dropdowns */
.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    background-color: #FFFFFF;
    border: 1px solid rgba(0,0,0,0.08);
    box-shadow: 0 12px 32px rgba(0,0,0,0.08), 0 4px 12px rgba(0,0,0,0.04);
    padding: 8px;
    border-radius: var(--radius-lg);
    opacity: 0;
    visibility: hidden;
    transition: all 0.2s cubic-bezier(0.2, 0, 0, 1);
    z-index: 1002;
    min-width: 200px;
}

.nav-item:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* Mega Menu Specifics */
.mega-menu {
    min-width: 500px;
    padding: 12px;
}

.mega-menu-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.mega-menu-list {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.dropdown-item {
    display: flex;
    align-items: flex-start;
    padding: 12px;
    border-radius: var(--radius-sm);
    color: var(--color-text-primary);
    text-decoration: none;
    transition: var(--transition-fast);
    gap: 12px;
}

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

.item-icon {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    background: #FFFFFF;
    border: 1px solid rgba(0,0,0,0.06);
    box-shadow: 0 1px 2px rgba(0,0,0,0.04);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-primary);
    transition: var(--transition-fast);
}

.dropdown-item:hover .item-icon {
    border-color: var(--color-accent);
    color: var(--color-accent);
    background: #FFFFFF;
    box-shadow: 0 2px 8px rgba(0, 86, 210, 0.15);
}

.item-content {
    display: flex;
    flex-direction: column;
}

.item-title {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 2px;
    color: var(--color-text-primary);
}

.item-desc {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    line-height: 1.4;
}

/* Simple Item (Icon + Text) */
.simple-item {
    align-items: center;
    padding: 10px 16px;
}

.item-icon-small {
    font-size: 1.1rem;
    margin-right: 8px;
    display: inline-block;
    width: 20px;
    text-align: center;
}

/* Hero 区域 - 网格与微光 (Grid & Glow) */
.hero {
    min-height: 80vh;
    padding: 120px 0 80px;
    background: #FFFFFF;
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 极细网格 */
.hero-bg-grid {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: 40px 40px;
    background-image: linear-gradient(to right, rgba(0,0,0,0.03) 1px, transparent 1px),
                      linear-gradient(to bottom, rgba(0,0,0,0.03) 1px, transparent 1px);
    mask-image: radial-gradient(circle at center, black 0%, transparent 70%);
    pointer-events: none;
    z-index: 0;
}

.hero-glow-effect {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 80%;
    height: 80%;
    background: radial-gradient(circle at 50% 50%, rgba(0, 86, 210, 0.08) 0%, transparent 50%);
    filter: blur(60px);
    opacity: 0.6;
    pointer-events: none;
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 900px;
    padding: 0 20px;
}

.hero-pre {
    color: var(--color-accent);
    background: rgba(0, 86, 210, 0.06);
    border: 1px solid rgba(0, 86, 210, 0.1);
    font-size: 0.8rem;
    padding: 4px 10px;
    border-radius: var(--radius-full);
    margin-bottom: 24px;
    display: inline-block;
    font-weight: 600;
    font-family: monospace;
}

.hero-title {
    font-size: 4rem;
    line-height: 1.1;
    letter-spacing: -0.03em;
    background: linear-gradient(180deg, rgba(0,0,0,0.9) 0%, rgba(0,0,0,0.7) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 24px;
    font-weight: 800;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    max-width: 640px;
    line-height: 1.6;
    margin: 0 auto 48px;
}

.cta-group {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 60px;
}

/* Hero Footer Features (Restored) */
.hero-features {
    display: flex;
    justify-content: center;
    gap: 40px;
    border-top: 1px solid rgba(0,0,0,0.06);
    padding-top: 40px;
    margin-top: 40px;
    text-align: left;
}

.hero-feature-item {
    display: flex;
    align-items: center;
    gap: 16px;
}

.feature-icon-wrapper {
    width: 44px;
    height: 44px;
    background: #FFFFFF;
    border: 1px solid rgba(0,0,0,0.08);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-accent);
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
}

.feature-text-wrapper {
    display: flex;
    flex-direction: column;
}

.feature-title {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-text-primary);
}

.feature-desc {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

/* 产品矩阵 (Product Matrix) */
.products {
    padding: var(--spacing-xl) 0;
}

.section-title {
    font-size: 2rem;
    text-align: center;
    margin-bottom: 40px;
    letter-spacing: -0.02em;
    color: var(--color-text-primary);
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

/* 卡片 (Cards) - 悬浮与边框 */
.product-card {
    background: #FFFFFF;
    border: 1px solid rgba(0,0,0,0.06);
    box-shadow: var(--shadow-sm);
    padding: 32px;
    transition: var(--transition-smooth);
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.product-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(0,0,0,0.08);
}

.product-icon {
    color: var(--color-text-primary); /* 图标改用深色，更稳重 */
    background: var(--color-bg-secondary);
    padding: 12px;
    border-radius: var(--radius-md);
    width: 56px;
    height: 56px;
    margin-bottom: 24px;
}

.product-card:hover .product-icon {
    color: var(--color-accent);
    background: var(--color-accent-subtle);
}

.product-title {
    font-size: 1.25rem;
    margin-bottom: 12px;
    font-weight: 700;
}

.product-desc {
    font-size: 1rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* 应用场景 (Scenarios) */
.scenarios {
    padding: var(--spacing-xl) 0;
    background-color: var(--color-bg-secondary);
}

/* 标签页 (Tabs) - 胶囊式切换 */
.tabs-container {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.tabs-nav {
    background: #FFFFFF;
    padding: 4px;
    border-radius: var(--radius-md);
    display: inline-flex;
    border: 1px solid rgba(0,0,0,0.04);
    gap: 4px;
    margin-bottom: 40px;
    box-shadow: var(--shadow-sm);
}

.tab-btn {
    padding: 8px 24px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    font-weight: 500;
    border: none;
    background: transparent;
    cursor: pointer;
    transition: var(--transition-fast);
}

.tab-btn:hover {
    color: var(--color-text-primary);
}

.tab-btn.active {
    background: var(--color-bg-tertiary);
    color: var(--color-text-primary);
    font-weight: 600;
}

.tab-content {
    display: none;
    width: 100%;
    max-width: 1000px;
    animation: fadeIn 0.4s cubic-bezier(0.2, 0, 0, 1);
}

.tab-content.active {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.scenario-info h3 {
    font-size: 1.75rem;
    margin-bottom: 16px;
    color: var(--color-text-primary);
}

.scenario-info p {
    color: var(--color-text-secondary);
    margin-bottom: 24px;
    font-size: 1.05rem;
    line-height: 1.6;
}

.scenario-list li {
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    color: var(--color-text-primary);
}

.scenario-list li::before {
    content: '';
    width: 6px;
    height: 6px;
    background-color: var(--color-accent);
    border-radius: 50%;
    margin-right: 12px;
}

/* 场景图抽象图形 - 更加几何化 */
.scenario-image {
    background-color: #FFFFFF;
    height: 320px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid rgba(0, 0, 0, 0.05);
    box-shadow: var(--shadow-card);
}

.abstract-shape {
    width: 160px;
    height: 160px;
    border: 1px solid rgba(0,0,0,0.1);
    background: linear-gradient(135deg, #FFFFFF 0%, #F7F8FA 100%);
    box-shadow: inset 0 0 20px rgba(0,0,0,0.02);
    border-radius: 50%;
    position: relative;
}

.abstract-shape::after {
    content: '';
    position: absolute;
    top: -20px;
    left: -20px;
    right: -20px;
    bottom: -20px;
    border: 1px dashed var(--color-accent);
    border-radius: 50%;
    opacity: 0.3;
    animation: spin 20s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 通用工具类 */
.container {
    max-width: 1100px; /* 稍微收窄，增加聚焦感 */
    margin: 0 auto;
    padding: 0 24px;
}

/* Footer */
.footer {
    background-color: #FFFFFF;
    border-top: 1px solid rgba(0,0,0,0.06);
    padding-top: 80px;
    padding-bottom: 40px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 60px;
}

.footer-col h4 {
    color: var(--color-text-primary);
    font-size: 0.95rem;
    margin-bottom: 20px;
}

.footer-col a {
    display: block;
    color: var(--color-text-secondary);
    margin-bottom: 10px;
    font-size: 0.9rem;
}

.footer-col a:hover {
    color: var(--color-accent);
}

.copyright {
    border-top: 1px solid rgba(0,0,0,0.06);
    color: var(--color-text-tertiary);
    padding-top: 24px;
    font-size: 0.85rem;
    text-align: center;
}

/* 汉堡菜单 */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.hamburger span {
    width: 24px;
    height: 2px;
    background-color: var(--color-text-primary);
}

/* 响应式微调 */
@media (max-width: 768px) {
    .navbar {
        padding: 0 20px;
    }
    
    .nav-links, .nav-actions {
        display: none;
    }
    
    .hamburger {
        display: flex;
    }

    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-features {
        flex-direction: column;
        align-items: center;
        gap: 20px;
    }
    
    .tab-content.active {
        grid-template-columns: 1fr;
    }
}