/* 重置和基础样式 */
:root {
    /* 浅色主题变量 */
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border-color: #e2e8f0;
    --card-bg: #ffffff;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-cn: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    --transition: all 0.3s ease;
}

/* 深色主题变量 */
.dark-mode {
    --primary-color: #3b82f6;
    --primary-dark: #2563eb;
    --primary-light: #60a5fa;
    --secondary-color: #a78bfa;
    --accent-color: #22d3ee;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --border-color: #475569;
    --card-bg: #1e293b;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.3);
}

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

html {
    scroll-behavior: smooth;
}

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

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

p {
    margin-bottom: 1rem;
}

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

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

ul, ol {
    list-style-position: inside;
    margin-bottom: 1rem;
}

img {
    max-width: 100%;
    height: auto;
}

.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* 按钮样式 */
.btn-primary, .btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    gap: 0.5rem;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

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

.btn-login {
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    font-weight: 500;
    transition: var(--transition);
}

.btn-login:hover {
    background-color: var(--bg-tertiary);
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(var(--bg-primary-rgb), 0.9);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.5rem;
    max-width: 1280px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--text-primary);
}

.logo-icon {
    width: 2.5rem;
    height: 2.5rem;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.25rem;
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.logo-main {
    font-weight: 800;
    font-size: 1.25rem;
    letter-spacing: -0.025em;
}

.logo-sub {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 500;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
    transition: var(--transition);
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
    border-radius: 1px;
}

.nav-dropdown {
    position: relative;
}

.dropdown-content {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 12rem;
    background-color: var(--card-bg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: 0.5rem 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: var(--transition);
    z-index: 100;
}

.nav-dropdown:hover .dropdown-content {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-content a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    color: var(--text-secondary);
    transition: var(--transition);
}

.dropdown-content a:hover {
    background-color: var(--bg-secondary);
    color: var(--primary-color);
    padding-left: 1.25rem;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-toggle {
    width: 2.5rem;
    height: 2.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

.theme-toggle:hover {
    background-color: var(--bg-tertiary);
    transform: rotate(15deg);
}

.search-container {
    display: flex;
    align-items: center;
    background-color: var(--bg-secondary);
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.search-input {
    padding: 0.5rem 1rem;
    background: transparent;
    border: none;
    color: var(--text-primary);
    width: 12rem;
    outline: none;
}

.search-btn {
    padding: 0.5rem 1rem;
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition);
}

.search-btn:hover {
    color: var(--primary-color);
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
}

/* 移动端菜单 */
.mobile-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 320px;
    height: 100vh;
    background-color: var(--bg-primary);
    z-index: 1100;
    box-shadow: var(--shadow-xl);
    transition: right 0.3s ease;
    display: flex;
    flex-direction: column;
}

.mobile-menu.active {
    right: 0;
}

.mobile-menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    font-weight: 600;
    font-size: 1.25rem;
}

.mobile-close {
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.25rem;
}

.mobile-menu-links {
    display: flex;
    flex-direction: column;
    padding: 1rem 0;
}

.mobile-link {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.5rem;
    color: var(--text-primary);
    font-weight: 500;
    transition: var(--transition);
}

.mobile-link:hover, .mobile-link.active {
    background-color: var(--bg-secondary);
    color: var(--primary-color);
    padding-left: 2rem;
}

/* 英雄区域 */
.hero {
    padding: 8rem 1.5rem 5rem;
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    overflow: hidden;
}

.hero-bg-shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(40px);
    opacity: 0.1;
}

.shape-1 {
    width: 300px;
    height: 300px;
    background-color: var(--primary-color);
    top: -100px;
    right: -100px;
}

.shape-2 {
    width: 400px;
    height: 400px;
    background-color: var(--secondary-color);
    bottom: -200px;
    left: -100px;
}

.shape-3 {
    width: 200px;
    height: 200px;
    background-color: var(--accent-color);
    top: 50%;
    right: 20%;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 1280px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 3rem;
    flex-wrap: wrap;
}

.hero-text {
    flex: 1;
    min-width: 300px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.hero-image {
    flex: 1;
    min-width: 300px;
}

.hero-visual {
    position: relative;
    height: 300px;
}

.hero-visual-main {
    width: 100%;
    height: 100%;
    border-radius: var(--radius-2xl);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    background-color: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.floating-icon {
    position: absolute;
    width: 60px;
    height: 60px;
    border-radius: var(--radius-lg);
    background-color: var(--card-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-color);
    box-shadow: var(--shadow-lg);
    animation: float 6s ease-in-out infinite;
}

.floating-icon:nth-child(1) {
    top: -20px;
    left: 10%;
    background-color: var(--primary-color);
    color: white;
    animation-delay: 0s;
}

.floating-icon:nth-child(2) {
    top: 30%;
    right: 10%;
    background-color: var(--secondary-color);
    color: white;
    animation-delay: 2s;
}

.floating-icon:nth-child(3) {
    bottom: 20%;
    left: 5%;
    background-color: var(--accent-color);
    color: white;
    animation-delay: 4s;
}

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

.stats-container {
    position: relative;
    z-index: 1;
    max-width: 1280px;
    margin: 3rem auto 0;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.stat-card {
    background-color: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--text-secondary);
    font-weight: 500;
}

/* 区域通用样式 */
section {
    padding: 5rem 1.5rem;
}

.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 3rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 服务/资源区域 */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    max-width: 1280px;
    margin: 0 auto;
}

.service-card {
    background-color: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.service-icon {
    width: 4rem;
    height: 4rem;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    color: white;
    font-size: 1.5rem;
}

.service-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.service-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.service-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-top: auto;
}

.service-link:hover {
    gap: 1rem;
}

/* 用户角色区 */
.roles-tabs {
    max-width: 1280px;
    margin: 0 auto;
    background-color: var(--card-bg);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
}

.tabs-header {
    display: flex;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    overflow-x: auto;
}

.tab-btn {
    padding: 1.25rem 2rem;
    background: none;
    border: none;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
    border-bottom: 3px solid transparent;
    font-size: 1rem;
}

.tab-btn:hover {
    color: var(--primary-color);
    background-color: var(--bg-tertiary);
}

.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
    background-color: var(--bg-primary);
}

.tabs-content {
    padding: 2rem;
}

.tab-pane {
    display: none;
}

.tab-pane.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.tab-content {
    display: flex;
    align-items: center;
    gap: 3rem;
    flex-wrap: wrap;
}

.tab-image {
    flex: 1;
    min-width: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 8rem;
    color: var(--primary-color);
    opacity: 0.7;
}

.tab-text {
    flex: 2;
    min-width: 300px;
}

.tab-text h3 {
    font-size: 1.75rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.tab-text ul {
    list-style: none;
    margin-top: 1rem;
}

.tab-text li {
    margin-bottom: 0.75rem;
    padding-left: 1.5rem;
    position: relative;
    color: var(--text-secondary);
}

.tab-text li:before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* 公益支持区域 */
.contribute-content {
    max-width: 1280px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 4rem;
    flex-wrap: wrap;
}

.contribute-text {
    flex: 1;
    min-width: 300px;
}

.contribute-text h3 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.contribute-text p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-size: 1.125rem;
    line-height: 1.7;
}

.mission-items {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.mission-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.mission-item i {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-top: 0.25rem;
    flex-shrink: 0;
}

.mission-item h4 {
    font-size: 1.25rem;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.mission-item p {
    font-size: 1rem;
    margin-bottom: 0;
    color: var(--text-secondary);
}

.contribute-image {
    flex: 1;
    min-width: 300px;
}

.quote-card {
    background-color: var(--card-bg);
    border-radius: var(--radius-xl);
    padding: 2.5rem;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

.quote-card:before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 6px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary-color), var(--secondary-color));
}

.quote-icon {
    font-size: 2rem;
    color: var(--primary-color);
    opacity: 0.3;
    margin-bottom: 1rem;
}

.quote-text {
    font-size: 1.25rem;
    font-style: italic;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.quote-author {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.author-avatar {
    width: 3.5rem;
    height: 3.5rem;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 1.25rem;
}

.author-name {
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.author-title {
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* 工具展示区 */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    max-width: 1280px;
    margin: 0 auto;
}

.tool-card {
    background-color: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.tool-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.tool-icon {
    width: 3rem;
    height: 3rem;
    border-radius: var(--radius-md);
    background-color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.25rem;
}

.tool-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.tool-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.tool-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-top: auto;
}

.tool-link:hover {
    gap: 1rem;
}

/* 最新内容区域 */
.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1280px;
    margin: 0 auto 3rem;
}

.content-card {
    background-color: var(--card-bg);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    height: 100%;
}

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

.content-badge {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background-color: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    z-index: 1;
}

.content-date {
    padding: 1.5rem 1.5rem 0.5rem;
    color: var(--text-muted);
    font-size: 0.875rem;
}

.content-title {
    padding: 0 1.5rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.content-excerpt {
    padding: 0 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.content-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    background-color: var(--bg-secondary);
    color: var(--primary-color);
    font-weight: 600;
    transition: var(--transition);
    margin-top: auto;
}

.content-link:hover {
    background-color: var(--bg-tertiary);
    gap: 1rem;
}

.section-footer {
    text-align: center;
    margin-top: 2rem;
}

/* 关于我们区域 */
.about-container {
    max-width: 1280px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 4rem;
    flex-wrap: wrap;
}

.about-content {
    flex: 1;
    min-width: 300px;
}

.about-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.about-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.about-features {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2rem;
}

.about-feature {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.about-feature i {
    color: var(--primary-color);
    font-size: 1.25rem;
}

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

.about-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.about-image {
    flex: 1;
    min-width: 300px;
    position: relative;
    height: 400px;
}

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

.main-image {
    width: 100%;
    height: 100%;
    border-radius: var(--radius-2xl);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2rem;
    font-weight: 700;
    box-shadow: var(--shadow-xl);
}

.main-image span:first-child {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
}

.main-image span:last-child {
    font-size: 1.25rem;
    opacity: 0.9;
}

.floating-element {
    position: absolute;
    width: 60px;
    height: 60px;
    border-radius: var(--radius-lg);
    background-color: var(--card-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-color);
    box-shadow: var(--shadow-lg);
    animation: float 6s ease-in-out infinite;
}

.el1 {
    top: -20px;
    left: -20px;
    animation-delay: 0s;
}

.el2 {
    top: 50%;
    right: -20px;
    animation-delay: 2s;
}

.el3 {
    bottom: -20px;
    left: 20%;
    animation-delay: 4s;
}

/* 页脚 */
.footer {
    background-color: var(--bg-secondary);
    padding: 4rem 1.5rem 2rem;
    border-top: 1px solid var(--border-color);
}

.footer-container {
    max-width: 1280px;
    margin: 0 auto;
}

.footer-main {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-col {
    display: flex;
    flex-direction: column;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.footer-logo .logo-icon {
    width: 2.5rem;
    height: 2.5rem;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.25rem;
}

.footer-logo .logo-text {
    display: flex;
    flex-direction: column;
}

.footer-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.footer-social {
    display: flex;
    gap: 1rem;
}

.social-link {
    width: 2.5rem;
    height: 2.5rem;
    border-radius: 50%;
    background-color: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    transition: var(--transition);
}

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

.footer-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.footer-links a {
    color: var(--text-secondary);
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-color);
    padding-left: 0.5rem;
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.5rem;
}

.footer-copyright p {
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
}

.footer-legal {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.footer-legal a {
    color: var(--text-muted);
    font-size: 0.875rem;
    transition: var(--transition);
}

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

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 3rem;
    height: 3rem;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: var(--primary-dark);
    transform: translateY(-5px);
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 2.75rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .tab-content {
        flex-direction: column;
        text-align: center;
    }
    
    .tab-image {
        font-size: 6rem;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .mobile-toggle {
        display: block;
    }
    
    .search-container {
        display: none;
    }
    
    .hero {
        padding: 6rem 1rem 3rem;
    }
    
    .hero-title {
        font-size: 2.25rem;
    }
    
    .hero-content {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    section {
        padding: 3rem 1rem;
    }
    
    .tabs-header {
        flex-wrap: wrap;
    }
    
    .tab-btn {
        flex: 1;
        min-width: 120px;
        padding: 1rem;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-legal {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.875rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .hero-actions {
        flex-direction: column;
        width: 100%;
    }
    
    .btn-primary, .btn-secondary {
        width: 100%;
    }
    
    .stats-container {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .services-grid, .tools-grid, .content-grid {
        grid-template-columns: 1fr;
    }
}