:root {
    --color-primary: #333333;
    --color-primary-hover: #1a1a1a;
    --color-primary-light: #666666;
    --color-success: #333333;
    --color-success-hover: #1a1a1a;
    --color-danger: #333333;
    --color-danger-hover: #1a1a1a;
    --color-warning: #333333;
    --color-warning-hover: #1a1a1a;
    --color-info: #333333;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-tertiary: #f0f0f0;
    --bg-hover: #e5e5e5;
    
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --text-tertiary: #999999;
    --text-disabled: #cccccc;
    
    --border-color: #e0e0e0;
    --border-color-hover: #d0d0d0;
    --border-color-focus: #333333;
    
    --sidebar-width: 240px;
    --header-height: 60px;
    --tabbar-height: 60px;
    
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 10px;
    --radius-xl: 12px;
    --radius-2xl: 16px;
    --radius-full: 9999px;
    
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-2xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    
    --transition-fast: 0.15s ease;
    --transition-base: 0.2s ease;
    --transition-slow: 0.3s ease;
    
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    max-width: 100%;
}

html {
    overflow-x: hidden;
    height: auto;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-secondary);
    min-height: 100vh;
    color: var(--text-primary);
    overflow-x: hidden;
    overflow-y: scroll;
    transition: background var(--transition-slow), color var(--transition-slow);
}

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

html.dark-mode, body.dark-mode {
    background: #1a1a1a;
    color: #e5e5e5;
}

a {
    color: inherit;
    text-decoration: none;
}

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

.header {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: var(--z-fixed);
    transition: background var(--transition-slow), border-color var(--transition-slow);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-height);
    gap: 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--color-primary);
    text-decoration: none;
}

.site-logo-img {
    height: 40px;
    max-width: 150px;
    object-fit: contain;
}

.site-logo-icon {
    font-size: 24px;
    color: var(--color-primary);
}

.site-name {
    font-weight: 700;
    color: var(--text-primary);
}

.search-box {
    flex: 1;
    max-width: 400px;
    position: relative;
}

.search-input {
    width: 100%;
    padding: 9px 14px;
    padding-right: 40px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 14px;
    transition: all var(--transition-base);
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.search-input:focus {
    outline: none;
    border-color: var(--color-primary);
    background: var(--bg-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.search-btn {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-tertiary);
    cursor: pointer;
    font-size: 15px;
    padding: 4px;
    border-radius: var(--radius-sm);
    transition: all var(--transition-base);
}

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

.nav-menu {
    display: flex;
    gap: 24px;
    list-style: none;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    padding: 8px 12px;
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.nav-link:hover {
    color: var(--color-primary);
    background: var(--bg-hover);
}

.nav-link.active {
    color: var(--color-primary);
    background: rgba(59, 130, 246, 0.1);
}

.nav-actions {
    display: flex;
    gap: 12px;
    align-items: center;
}

.btn {
    padding: 7px 16px;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all var(--transition-base);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

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

.btn-primary:hover {
    background: var(--color-primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

.btn-lg {
    padding: 10px 24px;
    font-size: 15px;
}

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

.btn-white:hover {
    background: #f9fafb;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-outline-white {
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: #fff;
}

.btn-outline-white:hover {
    border-color: #fff;
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-1px);
}



.hero {
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(135deg, #f5f5f5 0%, #e0e0e0 100%);
}

.hero .container {
    display: flex;
    align-items: center;
    gap: 40px;
}

.hero-content {
    flex: 1;
    max-width: 500px;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.hero-subtitle {
    display: block;
    font-size: 20px;
    font-weight: 500;
    color: var(--color-primary);
    margin-top: var(--spacing-sm);
}

.hero-description {
    font-size: 18px;
    line-height: 1.6;
    margin-bottom: var(--spacing-xl);
    color: var(--text-secondary);
}

.hero-actions {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.hero-visual {
    flex: 1;
    max-width: 600px;
}

.hero-image {
    width: 100%;
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-2xl);
    border: 1px solid var(--border-color);
}

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

.section-title {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.section-description {
    font-size: 16px;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.features {
    padding: var(--spacing-2xl) 0;
    background: var(--bg-primary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.feature-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: 32px 24px;
    text-align: center;
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--color-primary);
}

.feature-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 24px;
    color: var(--color-primary);
}

.feature-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.feature-description {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-secondary);
}

.tools {
    padding: var(--spacing-2xl) 0;
    background: var(--bg-secondary);
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.tool-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 24px;
    text-align: center;
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
}

.tool-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

.tool-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
    font-size: 20px;
    color: var(--color-primary);
}

.tool-title {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.tool-description {
    font-size: 14px;
    line-height: 1.5;
    color: var(--text-secondary);
}

.cta {
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-hover) 100%);
    color: #fff;
    text-align: center;
}

.cta-content {
    max-width: 600px;
    margin: 0 auto;
}

.cta-title {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: #fff;
}

.cta-description {
    font-size: 16px;
    line-height: 1.6;
    margin-bottom: var(--spacing-xl);
    color: rgba(255, 255, 255, 0.9);
}

.cta-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.contact {
    padding: var(--spacing-2xl) 0;
    background: var(--bg-primary);
}

.contact-content {
    max-width: 800px;
    margin: 0 auto;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 24px;
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.contact-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

.contact-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 20px;
    color: var(--color-primary);
}

.contact-text h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--text-primary);
}

.contact-text p {
    font-size: 14px;
    color: var(--text-secondary);
}

.footer {
    background: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-xl) 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 32px;
    margin-bottom: var(--spacing-xl);
}

.footer-brand {
    max-width: 300px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--color-primary);
    text-decoration: none;
    margin-bottom: 16px;
}

.footer-description {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.footer-links h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--text-primary);
}

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

.footer-links li {
    margin-bottom: 8px;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    transition: all var(--transition-base);
    display: inline-block;
    padding: 4px 0;
}

.footer-links a:hover {
    color: var(--color-primary);
    transform: translateX(4px);
}

.friend-links {
    margin-bottom: var(--spacing-xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--border-color);
}

.friend-links h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.friend-links-list {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    list-style: none;
}

.friend-links-list li {
    margin-bottom: 0;
}

.friend-links-list a {
    padding: 6px 16px;
    background: var(--bg-secondary);
    border-radius: var(--radius-full);
    font-size: 13px;
    color: var(--text-secondary);
    transition: all var(--transition-base);
}

.friend-links-list a:hover {
    background: var(--color-primary);
    color: #fff;
    transform: none;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--border-color);
}

.footer-bottom p {
    font-size: 14px;
    color: var(--text-tertiary);
    margin-bottom: 8px;
}

.current-year {
    font-weight: 500;
}

@media (max-width: 1024px) {
    .hero {
        padding: var(--spacing-xl) 0;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
    
    .hero-description {
        font-size: 16px;
    }
    
    .hero-visual {
        max-width: 450px;
    }
}

@media (max-width: 768px) {
    .nav {
        gap: 12px;
        flex-wrap: wrap;
        align-items: center;
    }
    
    .search-box {
        display: none;
    }
    
    .nav-menu {
        display: none;
    }
    
    .hero .container {
        flex-direction: column;
        text-align: center;
        gap: 30px;
    }
    
    .hero-content {
        max-width: 100%;
        order: 2;
    }
    
    .hero-visual {
        max-width: 100%;
        order: 1;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .hero-description {
        font-size: 14px;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .section-description {
        font-size: 14px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .tools-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }
    
    .contact-info {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
    
    .friend-links-list {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .nav-actions {
        gap: 8px;
    }
    
    .btn {
        padding: 6px 12px;
        font-size: 13px;
    }
    
    .btn-lg {
        padding: 8px 20px;
        font-size: 14px;
    }
    
    .hero-title {
        font-size: 24px;
    }
    
    .hero-subtitle {
        font-size: 14px;
    }
    
    .hero-description {
        font-size: 13px;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-brand {
        max-width: 100%;
    }
}