/* 全局变量定义 */
:root {
    --primary-color: #fe2c55;
    --secondary-color: #25f4ee;
    --text-color: #161823;
    --background-color: #ffffff;
    --light-gray: #f1f1f2;
    --dark-gray: #4f4f4f;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    --container-width: 1200px;
    --spacing-unit: 1rem;
    --border-radius: 8px;
    --transition-speed: 0.3s;
    --card-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --card-hover-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
}

/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 基础样式 */
body {
    font-family: var(--font-family);
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--background-color);
}

/* 导航栏样式 */
.main-nav {
    background-color: var(--background-color);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
    padding: 0 20px;
}

.logo a {
    color: var(--primary-color);
    font-size: 24px;
    font-weight: bold;
    text-decoration: none;
}

.nav-links {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-links li {
    margin: 0 15px;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-speed);
}

.nav-links a:hover {
    color: var(--primary-color);
}

.nav-links a.active {
    color: var(--primary-color);
}

/* 语言选择器样式 */
.language-selector {
    position: relative;
    margin-left: 20px;
}

#languageSelect {
    padding: 8px 12px;
    border: 1px solid var(--light-gray);
    border-radius: 4px;
    background-color: var(--background-color);
    font-family: var(--font-family);
    font-size: 14px;
    cursor: pointer;
    outline: none;
}

/* 页面头部样式 */
.page-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 100px 0 60px;
    text-align: center;
}

.page-header h1 {
    font-size: 48px;
    margin-bottom: 20px;
}

.page-header p {
    font-size: 20px;
    max-width: 800px;
    margin: 0 auto;
}

/* 主要内容区域样式 */
.section {
    padding: 80px 0;
}

.section:nth-child(even) {
    background-color: var(--light-gray);
}

.section h2 {
    font-size: 36px;
    margin-bottom: 30px;
    text-align: center;
}

.section-intro {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 50px;
    font-size: 18px;
    color: var(--dark-gray);
}

/* 卡片网格样式 */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.card {
    background: var(--background-color);
    border-radius: var(--border-radius);
    padding: 30px;
    box-shadow: var(--card-shadow);
    transition: transform var(--transition-speed);
    border: 1px solid rgba(0, 0, 0, 0.05);
    position: relative;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--card-hover-shadow);
}

.card h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 24px;
}

.card p {
    margin-bottom: 20px;
    color: var(--dark-gray);
}

/* Emoji 卡片特殊样式 */
.emoji-card {
    text-align: center;
}

.emoji-display {
    font-size: 48px;
    margin: 20px 0;
}

.usage h4 {
    color: var(--primary-color);
    margin: 15px 0 10px;
}

.usage ul {
    list-style: none;
    padding: 0;
}

.usage li {
    margin: 5px 0;
    color: var(--dark-gray);
}

/* 按钮样式 */
.cta-button {
    display: inline-block;
    padding: 12px 30px;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: background-color var(--transition-speed);
}

.cta-button:hover {
    background-color: #e6294f;
}

.secondary-button {
    display: inline-block;
    padding: 12px 30px;
    background-color: transparent;
    color: var(--primary-color);
    text-decoration: none;
    border: 2px solid var(--primary-color);
    border-radius: var(--border-radius);
    font-weight: 600;
    margin-left: 15px;
    transition: all var(--transition-speed);
}

.secondary-button:hover {
    background-color: var(--primary-color);
    color: white;
}

/* 内容区域通用样式 */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-unit);
}

/* 页脚样式 */
footer {
    background-color: var(--text-color);
    color: white;
    padding: 60px 0 30px;
}

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

.footer-section h3 {
    color: var(--secondary-color);
    margin-bottom: 20px;
    font-size: 18px;
}

.footer-section ul {
    list-style: none;
    padding: 0;
}

.footer-section ul li {
    margin: 10px 0;
}

.footer-section ul li a {
    color: white;
    text-decoration: none;
    transition: color var(--transition-speed);
}

.footer-section ul li a:hover {
    color: var(--secondary-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        height: auto;
        padding: 20px;
    }

    .nav-links {
        margin: 20px 0;
    }

    .language-selector {
        margin: 10px 0;
    }

    .page-header {
        padding: 80px 0 40px;
    }

    .page-header h1 {
        font-size: 36px;
    }

    .section {
        padding: 60px 0;
    }

    .grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.6s ease-out forwards;
}

/* 特殊效果 */
.emoji-card:hover .emoji-display {
    transform: scale(1.1);
    transition: transform var(--transition-speed);
}

.feature-list {
    list-style: none;
    padding: 0;
}

.feature-list li {
    margin: 10px 0;
    padding-left: 25px;
    position: relative;
}

.feature-list li::before {
    content: "✨";
    position: absolute;
    left: 0;
    color: var(--primary-color);
}