/* ==================== 全局样式 ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* 颜色变量 */
    --primary-color: #3498db;
    --secondary-color: #2ecc71;
    --text-color: #2c3e50;
    --bg-color: #f5f7fa;
    --accent-color: #e74c3c;
    --white: #ffffff;
    --gray-light: #ecf0f1;
    --gray-dark: #7f8c8d;
    --shadow: rgba(0, 0, 0, 0.1);
    --shadow-hover: rgba(0, 0, 0, 0.2);
    
    /* 渐变色 */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-blue: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --gradient-green: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
    
    /* 字体 */
    --font-primary: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
    --font-heading: "PingFang SC", "Microsoft YaHei", sans-serif;
    
    /* 间距 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 4rem;
    
    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 50%;
    
    /* 过渡 */
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.6;
    overflow-x: hidden;
}

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

/* ==================== 导航栏 ==================== */
.navbar {
    background: var(--white);
    box-shadow: 0 2px 20px var(--shadow);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: var(--transition);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem var(--spacing-md);
}

.logo h1 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu ul {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--primary-color);
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 80%;
}

.menu-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-color);
}

/* ==================== 主横幅 ==================== */
.hero {
    background: var(--gradient-primary);
    color: var(--white);
    padding: 120px 0 80px;
    text-align: center;
    position: relative;
    overflow: hidden;
    margin-top: 70px;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.btn {
    padding: 0.875rem 2rem;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    display: inline-block;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: transparent;
    color: var(--white);
    border-color: var(--white);
}

.btn-secondary:hover {
    background: var(--white);
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* 浮动图标装饰 */
.hero-decoration {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    pointer-events: none;
}

.floating-icon {
    position: absolute;
    font-size: 3rem;
    opacity: 0.1;
    animation: float 6s ease-in-out infinite;
}

.floating-icon.icon-1 {
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.floating-icon.icon-2 {
    top: 60%;
    right: 15%;
    animation-delay: 2s;
}

.floating-icon.icon-3 {
    bottom: 20%;
    left: 20%;
    animation-delay: 4s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) rotate(0deg);
    }
    50% {
        transform: translateY(-20px) rotate(10deg);
    }
}

/* ==================== 主要内容区 ==================== */
.main-content {
    padding: var(--spacing-xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--gray-dark);
}

/* ==================== 个人卡片 ==================== */
.cards-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.profile-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: 0 10px 40px var(--shadow);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.profile-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--gradient-primary);
}

.profile-card:nth-child(2)::before {
    background: var(--gradient-secondary);
}

.profile-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 60px var(--shadow-hover);
}

/* 卡片头部 */
.card-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.avatar-wrapper {
    position: relative;
    display: inline-block;
    margin-bottom: var(--spacing-md);
}

.avatar-placeholder {
    width: 150px;
    height: 150px;
    border-radius: var(--radius-full);
    overflow: hidden;
    border: 4px solid var(--primary-color);
    box-shadow: 0 8px 24px var(--shadow);
    position: relative;
}

.profile-card:nth-child(2) .avatar-placeholder {
    border-color: var(--secondary-color);
}

.avatar-placeholder img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.avatar-default {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-blue);
    font-size: 4rem;
    color: var(--white);
}

.profile-card:nth-child(2) .avatar-default {
    background: var(--gradient-green);
}

.avatar-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
    border-radius: var(--radius-full);
    color: var(--white);
    font-size: 2rem;
}

.avatar-wrapper:hover .avatar-overlay {
    opacity: 1;
}

.profile-name {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    color: var(--text-color);
}

.profile-bio {
    color: var(--gray-dark);
    font-size: 1rem;
}

/* 卡片内容 */
.card-content {
    margin-bottom: var(--spacing-lg);
}

.content-section {
    background: var(--bg-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    transition: var(--transition);
}

.content-section:hover {
    background: var(--gray-light);
    transform: translateX(5px);
}

.content-section:last-child {
    margin-bottom: 0;
}

.section-icon {
    width: 50px;
    height: 50px;
    border-radius: var(--radius-md);
    background: var(--gradient-blue);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.profile-card:nth-child(2) .content-section:nth-child(2) .section-icon {
    background: var(--gradient-green);
}

.content-section h4 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-color);
}

.content-section p {
    color: var(--gray-dark);
    margin-bottom: var(--spacing-sm);
    font-size: 0.95rem;
}

.card-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.card-link:hover {
    gap: 0.75rem;
    color: var(--accent-color);
}

/* 卡片统计 */
.card-stats {
    display: flex;
    justify-content: space-around;
    padding-top: var(--spacing-md);
    border-top: 2px solid var(--gray-light);
}

.stat-item {
    text-align: center;
}

.stat-item i {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
}

.profile-card:nth-child(2) .stat-item i {
    color: var(--secondary-color);
}

.stat-number {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-color);
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    color: var(--gray-dark);
}

/* ==================== 关于部分 ==================== */
.about-section {
    background: var(--white);
    padding: var(--spacing-xl) 0;
}

.about-content {
    max-width: 800px;
    margin: var(--spacing-lg) auto 0;
    text-align: center;
}

.about-content p {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
    color: var(--text-color);
}

/* ==================== 页脚 ==================== */
.footer {
    background: var(--text-color);
    color: var(--white);
    padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-section h4 {
    margin-bottom: var(--spacing-sm);
    font-size: 1.25rem;
}

.footer-section p {
    opacity: 0.8;
    line-height: 1.6;
}

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

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

.footer-section a {
    color: var(--white);
    text-decoration: none;
    opacity: 0.8;
    transition: var(--transition);
}

.footer-section a:hover {
    opacity: 1;
    color: var(--primary-color);
}

.social-links {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-sm);
}

.social-links a {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0.8;
}

.footer-bottom a {
    color: var(--primary-color);
}

/* ==================== 返回顶部按钮 ==================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    color: var(--white);
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    box-shadow: 0 5px 20px var(--shadow);
    transition: var(--transition);
    z-index: 999;
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px var(--shadow-hover);
}

.back-to-top.show {
    display: flex;
}

/* ==================== 动画 ==================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* 滚动动画 */
[data-aos] {
    opacity: 0;
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-aos].aos-animate {
    opacity: 1;
}

[data-aos="fade-right"] {
    transform: translateX(-50px);
}

[data-aos="fade-right"].aos-animate {
    transform: translateX(0);
}

[data-aos="fade-left"] {
    transform: translateX(50px);
}

[data-aos="fade-left"].aos-animate {
    transform: translateX(0);
}