/* assets/css/common.css */
:root {
    /* 主背景浅色 (原深色) */
    --bg-dark: #FFFFFF;
    --bg-darker: #F8F9FA;
    --bg-card: #FFFFFF;
    --bg-card-hover: #F1F3F5;
    
    /* 主色调：绿蓝渐变 (科技感) */
    --primary-color: #0088CC; /* 使用偏科技感的深蓝色作为按钮边框/高亮文字的主色 */
    --primary-gradient: linear-gradient(135deg, #8BBA19 0%, #0088CC 100%);
    --primary-gradient-hover: linear-gradient(135deg, #9CCD2A 0%, #0099E6 100%);
    
    /* 辅助色 */
    --accent-blue: #0088CC;
    --accent-cyan: #00B4D8;
    
    /* 文本颜色 */
    --text-main: #1A1D24;
    --text-regular: #4A505C;
    --text-muted: #8A92A3;
    
    /* 边框与效果 */
    --border-light: rgba(0, 0, 0, 0.08);
    --border-lighter: rgba(0, 0, 0, 0.04);
    --radius-sm: 0;
    --radius-md: 0;
    --radius-lg: 0;
    --radius-xl: 0;
    
    /* 间距 */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 32px;
    --spacing-lg: 64px;
    --spacing-xl: 120px;
    
    /* 布局 */
    --container-width: 1200px;
    --header-height: 80px;
    
    /* 动画 */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-regular);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--text-main);
    font-weight: 600;
    line-height: 1.2;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
    width: 100%;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-light);
    z-index: 100;
    transition: background var(--transition-normal);
}

.header.scrolled {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}

.header .container {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: nowrap;
    gap: 12px;
    min-width: 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}

.logo-img {
    height: 40px;
    width: auto;
    border-radius: 50%;
}

.logo-text {
    display: flex;
    flex-direction: column;
    min-width: 175px; /* Prevent layout shift during typing animation */
}

.logo-main {
    font-size: 24px;
    font-weight: 700;
    letter-spacing: 1px;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.logo-sub {
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* 文本输入光标动画 */
.typing-cursor {
    display: inline-block;
    font-weight: 300;
    animation: typing-blink 1s step-end infinite;
    -webkit-text-fill-color: var(--primary-color);
    color: var(--primary-color);
}

@keyframes typing-blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
}

.nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm); /* 减小间距以适应内容 */
    flex-wrap: nowrap;
    flex: 1 1 auto;
    justify-content: flex-end;
    min-width: 0;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 4px; /* 减小链接间距 */
    position: relative;
    flex-wrap: nowrap; /* 防止换行 */
    flex: 0 0 auto;
    /* 避免 Flex 子项被压窄后 Edge/中文逐字竖排 */
    min-width: max-content;
}

.nav-links > a,
.nav-links > .nav-dropdown {
    flex-shrink: 0;
}

.nav-links > a, .nav-dropdown-toggle {
    position: relative;
    color: var(--text-regular);
    font-size: 15px;
    font-weight: 500;
    padding: 8px 12px; /* 默认稍微减小左右内边距，从16px降到12px */
    border-radius: 0;
    transition: all var(--transition-fast);
    z-index: 2;
    border: 1px solid transparent;
    white-space: nowrap; /* 关键修改：防止文字换行 */
    word-break: keep-all;
}

/* 导航滑动背景 */
.nav-slider {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    background: transparent;
    border: 1px solid var(--primary-color);
    border-radius: 0;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1;
    pointer-events: none;
    opacity: 0;
}

/* 主导航悬停效果 */
.nav-links > a:hover, .nav-dropdown-toggle:hover {
    color: var(--primary-color);
}

/* 确保悬停时文字层级在滑动框之上 */
.nav-links > a, .nav-dropdown-toggle {
    z-index: 2;
    position: relative;
}

/* 主导航选中(高亮)效果 */
.nav-links > a.active, .nav-dropdown-toggle.active {
    color: var(--text-main);
    font-weight: 500;
    background: transparent;
    transition: color 0.3s ease;
}

.nav-links > a.active.hide-underline, .nav-dropdown-toggle.active.hide-underline {
    color: var(--text-main);
}

.nav-links > a.active::before, .nav-dropdown-toggle.active::before {
    content: '';
    position: absolute;
    bottom: -2px; /* 稍微往下移一点，避免贴着文字 */
    left: 50%;
    transform: translateX(-50%);
    width: 24px;
    height: 3px;
    background: var(--primary-gradient);
    border-radius: 0;
    z-index: 3;
    transition: opacity 0.3s ease;
}

.nav-links > a.active.hide-underline::before, .nav-dropdown-toggle.active.hide-underline::before {
    opacity: 0;
}

.nav-dropdown {
    position: relative;
    display: inline-block;
}

.nav-dropdown-toggle {
    display: flex !important;
    align-items: center;
    gap: 4px;
}

.nav-dropdown-toggle::after {
    content: '▾';
    font-size: 12px;
    margin-left: 2px;
    transition: transform var(--transition-fast);
}

.nav-dropdown:hover .nav-dropdown-toggle::after {
    transform: rotate(180deg);
}

.nav-dropdown-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    background: var(--bg-darker);
    border: 1px solid var(--border-light);
    border-radius: 0;
    padding: var(--spacing-xs) 0;
    min-width: 160px;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-fast);
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    z-index: 200;
}

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

.nav-dropdown-menu a {
    display: block;
    padding: 10px 20px !important;
    white-space: nowrap;
    border-radius: 0 !important;
    font-size: 14px;
    font-weight: 400;
    color: var(--text-regular);
    transition: all var(--transition-fast);
}

.nav-dropdown-menu a:hover, .nav-dropdown-menu a.active {
    background: rgba(0, 136, 204, 0.05) !important;
    color: var(--primary-color) !important;
}

.nav-actions {
    display: flex;
    gap: var(--spacing-xs);
    white-space: nowrap; /* 关键修改：防止按钮换行 */
    flex-shrink: 0; /* 防止被挤压 */
    flex: 0 0 auto;
}

.header .nav-actions .btn {
    white-space: nowrap;
    flex-shrink: 0;
}

.mobile-menu-btn {
    display: none;
    font-size: 24px;
    color: var(--text-main);
}

/* Footer */
.footer {
    background-color: var(--bg-darker);
    padding: var(--spacing-lg) 0 var(--spacing-md);
    border-top: 1px solid var(--border-light);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.footer-brand h3 {
    font-size: 20px;
    margin-bottom: var(--spacing-sm);
}

.footer-brand p {
    color: var(--text-muted);
    font-size: 14px;
    max-width: 300px;
}

.footer-links h4 {
    font-size: 16px;
    margin-bottom: var(--spacing-sm);
    color: var(--text-main);
}

.footer-links ul li {
    margin-bottom: var(--spacing-xs);
}

.footer-links ul li a {
    color: var(--text-muted);
    font-size: 14px;
    transition: color var(--transition-fast);
}

.footer-links ul li a:hover {
    color: var(--primary-color);
}

.footer-contact h4 {
    font-size: 16px;
    margin-bottom: var(--spacing-sm);
    color: var(--text-main);
}

.footer-contact ul li {
    margin-bottom: var(--spacing-xs);
}
.footer-contact li {
    color: var(--text-muted);
    font-size: 14px;
    margin-bottom: var(--spacing-xs);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-light);
    color: var(--text-muted);
    font-size: 12px;
}

/* Back to Top Button */
.back-to-top-wrapper {
    display: flex;
    justify-content: center;
    margin-bottom: var(--spacing-lg);
    margin-top: -16px;
}

.back-to-top {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    color: var(--text-regular);
    transition: all var(--transition-normal);
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.back-to-top:hover {
    background: var(--primary-gradient);
    color: #fff;
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 136, 204, 0.2);
    border-color: transparent;
}