:root {
    /* Color Palette - Premium Dark Mode with Neon Accents */
    --bg-color: #0b0f19;
    --text-primary: #f0f6fc;
    --text-secondary: #8b949e;
    /* 兼容工具页历史变量名，避免局部页面颜色回退 */
    --text-color: var(--text-primary);
    --text-muted: var(--text-secondary);
    --card-bg: var(--glass-bg);
    
    --primary-color: #2f81f7;
    --primary-hover: #388bfd;
    --primary-glow: rgba(47, 129, 247, 0.4);
    
    --secondary-color: #a371f7;
    --success-color: #3fb950;
    --warning-color: #d29922;
    
    /* Glassmorphism Variables */
    --glass-bg: rgba(22, 27, 34, 0.65);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #2f81f7 0%, #a371f7 100%);
    --gradient-text: linear-gradient(to right, #79c0ff, #d2a8ff);
    
    /* Fonts */
    --font-heading: 'Orbitron', sans-serif;
    --font-body: 'Roboto', sans-serif;
}

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

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

/* Background Effects */
.background-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    overflow: hidden;
}

.glow {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.5;
    animation: float 20s infinite alternate ease-in-out;
}

.glow-1 {
    top: -10%;
    left: -10%;
    width: 50vw;
    height: 50vw;
    background: radial-gradient(circle, rgba(47,129,247,0.3) 0%, rgba(11,15,25,0) 70%);
}

.glow-2 {
    bottom: -20%;
    right: -10%;
    width: 60vw;
    height: 60vw;
    background: radial-gradient(circle, rgba(163,113,247,0.25) 0%, rgba(11,15,25,0) 70%);
    animation-delay: -5s;
}

.glow-3 {
    top: 40%;
    left: 50%;
    width: 40vw;
    height: 40vw;
    background: radial-gradient(circle, rgba(63,185,80,0.15) 0%, rgba(11,15,25,0) 70%);
    animation-delay: -10s;
}

/* Typography Utilities */
.text-gradient {
    background: var(--gradient-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.mb-4 { margin-bottom: 1rem; }
.mt-4 { margin-top: 1rem; }
.mt-5 { margin-top: 2rem; }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 24px;
    border-radius: 30px;
    font-size: 15px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
}

.btn-lg {
    padding: 14px 32px;
    font-size: 16px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 4px 15px var(--primary-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(163, 113, 247, 0.5);
    filter: brightness(1.1);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(10px);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--primary-color);
}

.btn-glass {
    background: var(--glass-bg);
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(10px);
}

.btn-glass:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

/* Navigation */
.glass-nav {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(11, 15, 25, 0.7);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--glass-border);
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.brand-icon {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    object-fit: cover;
    flex: 0 0 auto;
    box-shadow: 0 0 18px rgba(47, 129, 247, 0.28);
}

.logo-text {
    font-family: var(--font-heading);
    font-size: 22px;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: 1px;
    text-transform: uppercase;
}

.nav-links a {
    color: var(--text-primary);
    text-decoration: none;
    margin: 0 16px;
    font-size: 15px;
    font-weight: 500;
    transition: color 0.3s ease;
}

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

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

/* 搜索辅助模块：面包屑、说明区和底部信任链接 */
.seo-breadcrumb {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    margin-bottom: 22px;
    color: var(--text-secondary);
    font-size: 13px;
}

.seo-breadcrumb a {
    color: var(--text-secondary);
    text-decoration: none;
}

.seo-breadcrumb a:hover {
    color: var(--primary-color);
}

.seo-breadcrumb .separator {
    color: rgba(255, 255, 255, 0.28);
}

.tool-seo-block {
    margin-top: 24px;
}

.tool-seo-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
}

.tool-seo-card {
    padding: 20px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
}

.tool-seo-card h2,
.tool-seo-card h3 {
    margin-bottom: 10px;
    color: var(--text-primary);
    font-size: 1.05rem;
}

.tool-seo-card p,
.tool-seo-card li {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.75;
}

.tool-seo-card ul {
    padding-left: 18px;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 14px;
    margin: 18px 0 8px;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
}

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

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 120px 20px 60px;
    position: relative;
}

.hero-content {
    max-width: 800px;
    z-index: 10;
}

.badge-pill {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    border-radius: 50px;
    background: rgba(47, 129, 247, 0.1);
    border: 1px solid rgba(47, 129, 247, 0.3);
    color: #79c0ff;
    font-size: 13px;
    font-weight: 500;
}

.pulse-dot {
    width: 8px;
    height: 8px;
    background-color: var(--primary-color);
    border-radius: 50%;
    box-shadow: 0 0 0 0 rgba(47, 129, 247, 0.7);
    animation: pulse 2s infinite;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: 3.5rem;
    font-weight: 900;
    line-height: 1.2;
    margin-bottom: 20px;
    letter-spacing: -1px;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.hero-stats {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 30px;
}

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

.stat-value {
    font-family: var(--font-heading);
    font-size: 2rem;
    color: var(--text-primary);
    display: inline-block;
}

.stat-suffix {
    font-size: 1.2rem;
    color: var(--primary-color);
    font-weight: bold;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: var(--glass-border);
}

/* Floating Cards in Hero */
.hero-decoration {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    pointer-events: none;
    z-index: 5;
}

.float-card {
    position: absolute;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 20px;
    border-radius: 16px;
    font-weight: 500;
    font-size: 14px;
    animation: float 6s infinite ease-in-out;
}

.card-1 {
    top: 25%;
    left: 10%;
    animation-delay: 0s;
}

.card-2 {
    bottom: 25%;
    right: 15%;
    animation-delay: -2s;
}

.card-3 {
    top: 60%;
    left: 15%;
    animation-delay: -4s;
}

.text-success { color: var(--success-color); }
.text-warning { color: var(--warning-color); }
.text-primary { color: var(--primary-color); }

/* Common Section Styles */
section {
    max-width: 1200px;
    margin: 0 auto;
    padding: 80px 20px;
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-title {
    font-family: var(--font-heading);
    font-size: 2.2rem;
    margin-bottom: 10px;
}

.title-underline {
    width: 60px;
    height: 4px;
    background: var(--gradient-primary);
    margin: 0 auto;
    border-radius: 2px;
}

/* Glass Panels */
.glass-panel {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    box-shadow: var(--glass-shadow);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
}

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

.feature-card {
    padding: 40px 30px;
    text-align: center;
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
}

.feature-icon {
    width: 70px;
    height: 70px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
    font-size: 32px;
    color: white;
}

.bg-gradient-blue { background: linear-gradient(135deg, #0052d4, #4364f7, #6fb1fc); }
.bg-gradient-purple { background: linear-gradient(135deg, #8E2DE2, #4A00E0); }
.bg-gradient-green { background: linear-gradient(135deg, #11998e, #38ef7d); }

.feature-card h3 {
    margin-bottom: 16px;
    font-size: 1.3rem;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

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

.category-card {
    display: flex;
    align-items: center;
    padding: 24px;
    text-decoration: none;
    color: var(--text-primary);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.hover-glow:hover {
    border-color: var(--primary-color);
    box-shadow: 0 0 20px rgba(47, 129, 247, 0.2);
    transform: translateY(-5px);
}

.cat-icon {
    font-size: 36px;
    margin-right: 20px;
    flex-shrink: 0;
}

.text-tg { color: #0088cc; }
.text-twitter { color: #1DA1F2; }
.text-apple { color: #f0f6fc; }
.text-gpt { color: #10a37f; }

.cat-content h3 {
    font-size: 1.1rem;
    margin-bottom: 4px;
}

.cat-content p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.cat-arrow {
    position: absolute;
    right: 20px;
    font-size: 24px;
    color: var(--text-secondary);
    transition: transform 0.3s ease;
}

.category-card:hover .cat-arrow {
    transform: translateX(5px);
    color: var(--primary-color);
}

/* Help Section */
.notice-box {
    padding: 40px;
    position: relative;
    overflow: hidden;
}

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

.notice-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
    font-size: 1.5rem;
    color: var(--primary-color);
}

.help-links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 16px;
}

.help-link {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.95rem;
    transition: background 0.3s ease;
}

.help-link:hover {
    background: rgba(47, 129, 247, 0.15);
}

/* Footer */
.footer {
    border-top: 1px solid var(--glass-border);
    background: rgba(11, 15, 25, 0.9);
    padding: 60px 20px 20px;
    text-align: center;
}

.footer-content {
    max-width: 600px;
    margin: 0 auto 40px;
}

.footer-logo {
    font-family: var(--font-heading);
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 16px;
}

.footer-desc {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.footer-social {
    display: flex;
    justify-content: center;
    gap: 16px;
}

.social-link {
    width: 42px;
    height: 42px;
    border-radius: 10px;
    background: transparent;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 20px;
    transition: all 0.3s ease;
}

.footer-social-icon {
    width: 36px;
    height: 36px;
    border-radius: 9px;
    object-fit: cover;
    display: block;
    box-shadow: 0 0 18px rgba(47, 129, 247, 0.24);
}

.social-link:hover {
    transform: translateY(-3px);
    filter: brightness(1.08);
}

.footer-bottom {
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* Animations */
@keyframes pulse {
    0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(47, 129, 247, 0.7); }
    70% { transform: scale(1); box-shadow: 0 0 0 10px rgba(47, 129, 247, 0); }
    100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(47, 129, 247, 0); }
}

@keyframes float {
    0% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(2deg); }
    100% { transform: translateY(0px) rotate(0deg); }
}

.fade-in {
    opacity: 0;
    transition: opacity 0.8s ease-out;
}

.fade-in.visible {
    opacity: 1;
}

.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

.shine-effect {
    position: relative;
    overflow: hidden;
}

.shine-effect::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -60%;
    width: 20%;
    height: 200%;
    background: rgba(255, 255, 255, 0.2);
    transform: rotate(30deg);
    animation: shine 4s infinite linear;
}

@keyframes shine {
    0% { left: -60%; }
    20% { left: 150%; }
    100% { left: 150%; }
}

/* Responsive */
@media (max-width: 768px) {
    .d-none-mobile {
        display: none;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-stats {
        gap: 15px;
    }
    
    .float-card {
        display: none;
    }
    
    .nav-container {
        padding: 12px 16px;
    }
    
    section {
        padding: 60px 16px;
    }

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

    .seo-breadcrumb {
        font-size: 12px;
    }
}