/* ===== 全局样式 ===== */
:root {
    /* 颜色变量 */
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --accent-color: #f093fb;
    --text-dark: #2d3748;
    --text-light: #718096;
    --bg-light: #ffffff;
    --bg-dark: #1a202c;
    --card-bg: #ffffff;
    --border-color: #e2e8f0;
    
    /* 渐变色 */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    
    /* 阴影 */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1);
    
    /* 动画时间 */
    --transition-fast: 0.2s;
    --transition-medium: 0.3s;
    --transition-slow: 0.5s;
}

/* 深色主题 */
[data-theme="dark"] {
    --text-dark: #f7fafc;
    --text-light: #cbd5e0;
    --bg-light: #1a202c;
    --bg-dark: #0d1117;
    --card-bg: #2d3748;
    --border-color: #4a5568;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-light);
    overflow-x: hidden;
    transition: background-color var(--transition-medium), color var(--transition-medium);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===== 加载动画 ===== */
.loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-light);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10000;
    transition: opacity 0.5s, visibility 0.5s;
}

.loader.hidden {
    opacity: 0;
    visibility: hidden;
}

.loader-circle {
    width: 50px;
    height: 50px;
    border: 3px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all var(--transition-medium);
}

[data-theme="dark"] .navbar {
    background: rgba(26, 32, 44, 0.95);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.nav-logo i {
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--text-dark);
    text-decoration: none;
    font-weight: 500;
    position: relative;
    transition: color var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: width var(--transition-medium);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-dark);
    transition: all var(--transition-medium);
}

.theme-toggle {
    background: none;
    border: 2px solid var(--border-color);
    color: var(--text-dark);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    margin-left: 2rem;
}

.theme-toggle:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* ===== 主页横幅 ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    padding-top: 80px;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: -1;
}

.shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.3;
    animation: float 20s infinite ease-in-out;
}

.shape-1 {
    width: 400px;
    height: 400px;
    background: var(--gradient-primary);
    top: -100px;
    right: -100px;
}

.shape-2 {
    width: 300px;
    height: 300px;
    background: var(--gradient-secondary);
    bottom: -50px;
    left: -50px;
    animation-delay: 5s;
}

.shape-3 {
    width: 500px;
    height: 500px;
    background: var(--gradient-accent);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation-delay: 10s;
}

@keyframes float {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    33% { transform: translateY(-20px) rotate(120deg); }
    66% { transform: translateY(20px) rotate(240deg); }
}

.hero-content {
    text-align: center;
    z-index: 1;
    animation: fadeInUp 1s ease;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto 2rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-medium);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.5);
}

.btn-secondary {
    background: transparent;
    color: var(--text-dark);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--card-bg);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.scroll-indicator i {
    font-size: 2rem;
    color: var(--text-light);
}

@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(10px); }
}

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

/* ===== 服务部分 ===== */
.services {
    padding: 100px 0;
    background: var(--bg-light);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

.section-subtitle {
    color: var(--text-light);
    font-size: 1.1rem;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.service-card {
    background: var(--card-bg);
    padding: 40px 30px;
    border-radius: 20px;
    text-align: center;
    transition: all var(--transition-medium);
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform var(--transition-medium);
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.service-card:hover::before {
    transform: scaleX(1);
}

.service-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
    transition: transform var(--transition-medium);
}

.service-card:hover .service-icon {
    transform: scale(1.1) rotate(5deg);
}

.service-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.service-card p {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 20px;
}

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

.service-link:hover {
    gap: 5px;
}

/* ===== 作品展示 ===== */
.portfolio {
    padding: 100px 0;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.05) 0%, rgba(118, 75, 162, 0.05) 100%);
}

.portfolio-filters {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 50px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 10px 25px;
    background: transparent;
    border: 2px solid var(--border-color);
    border-radius: 25px;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-weight: 600;
    color: var(--text-dark);
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--gradient-primary);
    color: white;
    border-color: transparent;
}

.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.portfolio-item {
    position: relative;
    border-radius: 15px;
    overflow: hidden;
    height: 300px;
    background: var(--gradient-primary);
    cursor: pointer;
    transition: transform var(--transition-medium);
}

.portfolio-item:hover {
    transform: scale(1.03);
}

.portfolio-image {
    width: 100%;
    height: 100%;
    position: relative;
}

.portfolio-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to bottom, rgba(0,0,0,0) 0%, rgba(0,0,0,0.8) 100%);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 30px;
    opacity: 0;
    transition: opacity var(--transition-medium);
}

.portfolio-item:hover .portfolio-overlay {
    opacity: 1;
}

.portfolio-overlay h4 {
    color: white;
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.portfolio-overlay p {
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 15px;
}

.portfolio-link {
    width: 40px;
    height: 40px;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    text-decoration: none;
    transition: transform var(--transition-fast);
}

.portfolio-link:hover {
    transform: scale(1.1);
}

/* ===== 统计数据 ===== */
.stats {
    padding: 80px 0;
    background: var(--gradient-primary);
    color: white;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    text-align: center;
}

.stat-item {
    animation: fadeIn 1s ease;
}

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 10px;
}

.stat-label {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* ===== 关于部分 ===== */
.about {
    padding: 100px 0;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.about-text p {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 30px;
}

.about-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.feature {
    display: flex;
    align-items: center;
    gap: 10px;
}

.feature i {
    color: var(--primary-color);
    font-size: 1.2rem;
}

.about-image {
    position: relative;
}

.image-container {
    position: relative;
    height: 400px;
    background: var(--gradient-primary);
    border-radius: 20px;
    overflow: hidden;
}

.image-decoration {
    position: absolute;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, transparent 30%, rgba(255,255,255,0.1) 50%, transparent 70%);
    animation: shimmer 3s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* ===== 联系表单 ===== */
.contact {
    padding: 100px 0;
    background: var(--bg-light);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    margin-top: 60px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.info-item {
    display: flex;
    gap: 20px;
    align-items: flex-start;
}

.info-item i {
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-size: 1.2rem;
}

.info-item h4 {
    margin-bottom: 5px;
    color: var(--text-dark);
}

.info-item p {
    color: var(--text-light);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 15px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    background: var(--card-bg);
    color: var(--text-dark);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* ===== 页脚 ===== */
.footer {
    background: var(--bg-dark);
    color: var(--text-light);
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3,
.footer-section h4 {
    color: white;
    margin-bottom: 20px;
}

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

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

.footer-section a {
    color: var(--text-light);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.social-links {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.social-links a {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

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

.newsletter-form {
    display: flex;
    margin-top: 20px;
}

.newsletter-form input {
    flex: 1;
    padding: 12px;
    border: none;
    border-radius: 5px 0 0 5px;
    background: rgba(255, 255, 255, 0.1);
    color: white;
}

.newsletter-form button {
    padding: 12px 20px;
    background: var(--gradient-primary);
    color: white;
    border: none;
    border-radius: 0 5px 5px 0;
    cursor: pointer;
    font-weight: 600;
    transition: opacity var(--transition-fast);
}

.newsletter-form button:hover {
    opacity: 0.9;
}

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

/* ===== 返回顶部按钮 ===== */
.scroll-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-medium);
    z-index: 999;
}

.scroll-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

/* ===== 响应式设计 ===== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--bg-light);
        flex-direction: column;
        padding: 40px 20px;
        transition: left var(--transition-medium);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .section-title {
        font-size: 1.8rem;
    }
    
    .services-grid,
    .portfolio-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}