/* 全局样式 */
:root {
    --primary-color: #A6192E;  /* 上海传统红 */
    --primary-light: #D42A42;  /* 亮红色 */
    --primary-dark: #7A1222;   /* 暗红色 */
    --secondary-color: #CDAF71; /* 古典金 */
    --secondary-light: #E5D0A3; /* 亮金色 */
    --secondary-dark: #A38A4D;  /* 暗金色 */
    --accent-color: #F5F1E3;   /* 柔和米白 */
    --text-color: #333;
    --text-light: #666;
    --text-dark: #111;
    --light-bg: #F5F1E3;
    --dark-bg: #2C2C2C;
    --spacing: 20px;
    --border-radius: 10px;
    --box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    --transition-fast: 0.3s ease;
    --transition-medium: 0.5s ease;
    --transition-slow: 0.8s ease;
    --gradient-primary: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    --gradient-secondary: linear-gradient(135deg, var(--secondary-color), var(--secondary-dark));
    --gradient-accent: linear-gradient(135deg, var(--accent-color), #FFFFFF);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Microsoft YaHei', '微软雅黑', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--accent-color);
    background-image: 
        radial-gradient(circle at 10% 20%, rgba(205, 175, 113, 0.05) 0%, transparent 20%),
        radial-gradient(circle at 90% 80%, rgba(166, 25, 46, 0.05) 0%, transparent 20%);
    background-attachment: fixed;
    overflow-x: hidden;
}

/* Typography enhancements */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 1rem;
    position: relative;
}

h1 {
    font-size: 2.8rem;
    letter-spacing: -0.5px;
}

h2 {
    font-size: 2.2rem;
    letter-spacing: -0.3px;
}

h3 {
    font-size: 1.8rem;
}

p {
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

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

a:hover {
    color: var(--primary-light);
}

/* 头部样式 */
header {
    background: white;
    padding: var(--spacing);
    box-shadow: 0 2px 15px rgba(166, 25, 46, 0.15);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: transform var(--transition-medium), box-shadow var(--transition-medium);
}

header.scrolled {
    box-shadow: 0 5px 20px rgba(166, 25, 46, 0.2);
    padding: 10px var(--spacing);
}

.logo {
    float: left;
    transition: transform var(--transition-fast);
}

.logo:hover {
    transform: scale(1.05);
}

.logo-img {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.logo-img:hover {
    box-shadow: 0 5px 15px rgba(166, 25, 46, 0.2);
    transform: rotate(5deg);
}

/* 主要内容区域 */
main {
    margin-top: 180px;
    padding: var(--spacing);
    min-height: calc(100vh - 280px);
}

/* 页脚样式 */
footer {
    text-align: center;
    padding: 40px 20px;
    background: var(--gradient-secondary);
    color: white;
    margin-top: 80px;
    position: relative;
    overflow: hidden;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: var(--gradient-primary);
}

footer p {
    position: relative;
    z-index: 1;
    margin-bottom: 0;
    font-weight: 500;
}

/* 语言切换相关样式 */
.en {
    display: none;
}

body.english .en {
    display: block;
}

body.english .zh {
    display: none;
}

/* 对于内联元素（如span）的特殊处理 */
span.en {
    display: none;
}

body.english span.en {
    display: inline;
}

body.english span.zh {
    display: none;
}

span.zh {
    display: inline;
}

/* 导航标签的双语显示 */
nav ul li a span.zh,
nav ul li a span.en {
    display: inline;
}

body.english nav ul li a span.zh,
body.english nav ul li a span.en {
    display: inline;
}

/* 导航标签中的分隔符 */
nav ul li a span.zh::after {
    content: " | ";
    color: var(--text-color);
}

/* 标题中的语言切换 */
h1 span, h2 span, h3 span {
    display: none;
}

body.english h1 span.en,
body.english h2 span.en,
body.english h3 span.en {
    display: inline;
}

.zh h1 span.zh,
.zh h2 span.zh,
.zh h3 span.zh {
    display: inline;
}

/* Utility classes */
.text-center {
    text-align: center;
}

.text-right {
    text-align: right;
}

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

.text-secondary {
    color: var(--secondary-color);
}

.bg-primary {
    background-color: var(--primary-color);
    color: white;
}

.bg-secondary {
    background-color: var(--secondary-color);
    color: white;
}

.bg-accent {
    background-color: var(--accent-color);
}

.bg-gradient-primary {
    background: var(--gradient-primary);
    color: white;
}

.bg-gradient-secondary {
    background: var(--gradient-secondary);
    color: white;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing);
}

.section-padding {
    padding: 80px 0;
}

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.mb-5 { margin-bottom: 3rem; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mt-5 { margin-top: 3rem; }

/* 响应式设计基础 */
@media (max-width: 768px) {
    main {
        margin-top: 300px;
    }
    
    h1 {
        font-size: 2.2rem;
    }
    
    h2 {
        font-size: 1.8rem;
    }
    
    h3 {
        font-size: 1.5rem;
    }
}