/* ==========================================
   YCCGAME - SEO Optimized Stylesheet
   ========================================== */

/* CSS Variables */
:root {
    --primary-color: #2563eb;
    --secondary-color: #7c3aed;
    --accent-color: #f59e0b;
    --success-color: #10b981;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-white: #ffffff;
    --bg-light: #f9fafb;
    --bg-dark: #111827;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --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);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --border-radius: 12px;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', '微软雅黑', sans-serif;
    line-height: 1.7;
    color: var(--text-dark);
    background-color: var(--bg-white);
    overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 2rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
    color: var(--text-light);
}

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

a:hover {
    color: var(--secondary-color);
}

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

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

/* Header & Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
    background: rgba(255, 255, 255, 0.98);
}

.navbar {
    padding: 1rem 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo h1 {
    font-size: 2rem;
    color: var(--primary-color);
    margin: 0;
}

.logo h1 span {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.tagline {
    font-size: 0.75rem;
    color: var(--text-light);
    margin-top: -0.5rem;
    font-weight: 400;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    color: var(--text-dark);
    font-weight: 500;
    position: relative;
    padding: 0.5rem 0;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transition: var(--transition);
}

.nav-menu a:hover::after {
    width: 100%;
}

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

.mobile-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: var(--transition);
}

/* Hero Section */
.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;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    opacity: 0.1;
    z-index: -1;
}

.hero-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 25% 25%, rgba(37, 99, 235, 0.2) 0%, transparent 50%),
        radial-gradient(circle at 75% 75%, rgba(124, 58, 237, 0.2) 0%, transparent 50%);
    animation: pulse 10s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 1; }
}

.hero-content {
    text-align: center;
    max-width: 900px;
    padding: 2rem;
}

.hero-title {
    font-size: 4rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 1s ease-out;
}

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

.hero-subtitle {
    font-size: 1.75rem;
    color: var(--text-dark);
    margin-bottom: 1.5rem;
    animation: fadeInUp 1s ease-out 0.2s backwards;
}

.keyword-highlight {
    color: var(--primary-color);
    font-weight: 700;
    position: relative;
}

.keyword-highlight::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    opacity: 0.3;
}

.hero-description {
    font-size: 1.25rem;
    margin-bottom: 2.5rem;
    color: var(--text-light);
    animation: fadeInUp 1s ease-out 0.4s backwards;
}

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 3rem;
    animation: fadeInUp 1s ease-out 0.6s backwards;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    box-shadow: var(--shadow-lg);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-xl);
}

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

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

/* Keywords Section */
.keywords-section {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 1s ease-out 0.8s backwards;
}

.keyword-tag {
    padding: 0.75rem 1.5rem;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.1), rgba(124, 58, 237, 0.1));
    border: 2px solid var(--primary-color);
    border-radius: 50px;
    font-weight: 600;
    color: var(--primary-color);
    transition: var(--transition);
}

.keyword-tag:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    transform: translateY(-3px);
}

/* Section Styles */
section {
    padding: 6rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    position: relative;
    display: inline-block;
    margin-bottom: 1.5rem;
}

.section-header h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
}

.section-subtitle {
    font-size: 1.25rem;
    color: var(--text-light);
}

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

/* About Section */
.about-section {
    background: var(--bg-light);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

.about-text h3 {
    color: var(--text-dark);
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.about-text h3:first-child {
    margin-top: 0;
}

.about-text p {
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.feature-list {
    list-style: none;
    padding: 0;
}

.feature-list li {
    padding: 0.75rem 0;
    color: var(--text-dark);
    font-weight: 500;
    display: flex;
    align-items: center;
}

.about-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.stat-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: var(--transition);
}

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

.stat-number {
    font-size: 3rem;
    font-weight: 900;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-light);
    font-weight: 500;
}

/* Games Section */
.games-section {
    background: white;
}

.games-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.game-card {
    background: var(--bg-light);
    padding: 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 2px solid transparent;
}

.game-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.game-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    display: inline-block;
}

.game-card h3 {
    color: var(--text-dark);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.game-card p {
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.game-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.tag {
    padding: 0.5rem 1rem;
    background: white;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--primary-color);
    border: 1px solid var(--border-color);
}

/* Features Section */
.features-section {
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.05), rgba(124, 58, 237, 0.05));
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2.5rem;
}

.feature-item {
    background: white;
    padding: 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    text-align: center;
}

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

.feature-icon {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    display: inline-block;
}

.feature-item h3 {
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.feature-item p {
    line-height: 1.7;
}

/* News Section */
.news-section {
    background: white;
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2.5rem;
}

.news-card {
    background: var(--bg-light);
    padding: 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border-left: 4px solid var(--primary-color);
}

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

.news-date {
    font-size: 0.9rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1rem;
}

.news-card h3 {
    color: var(--text-dark);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.news-card p {
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.news-tags {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.news-tags span {
    padding: 0.5rem 1rem;
    background: white;
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--secondary-color);
    font-weight: 500;
}

/* SEO Content Section */
.seo-content-section {
    background: var(--bg-light);
    padding: 6rem 0;
}

.seo-content {
    max-width: 900px;
    margin: 0 auto;
    background: white;
    padding: 4rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
}

.seo-content h2 {
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-dark);
}

.seo-text h3 {
    color: var(--text-dark);
    margin-top: 2.5rem;
    margin-bottom: 1.5rem;
    font-size: 1.75rem;
}

.seo-text p {
    line-height: 1.9;
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
}

.highlight-keyword {
    color: var(--primary-color);
    font-weight: 700;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.1), rgba(124, 58, 237, 0.1));
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
}

.seo-list {
    padding-left: 2rem;
    margin: 2rem 0;
}

.seo-list li {
    margin-bottom: 1rem;
    line-height: 1.8;
    color: var(--text-dark);
}

.seo-list li strong {
    color: var(--primary-color);
}

/* Contact Section */
.contact-section {
    background: white;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
}

.contact-item {
    background: var(--bg-light);
    padding: 2.5rem 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: var(--transition);
}

.contact-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.contact-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.contact-item h3 {
    color: var(--text-dark);
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.contact-item p {
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.contact-item a {
    color: var(--primary-color);
    text-decoration: underline;
}

/* Footer */
.footer {
    background: var(--bg-dark);
    color: white;
    padding: 4rem 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-brand h3 {
    font-size: 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
}

.footer-brand p {
    color: #9ca3af;
    margin-bottom: 0.5rem;
}

.footer-links h4 {
    color: white;
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

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

.footer-links li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    color: #9ca3af;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
}

.keywords-footer {
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.keywords-footer a {
    color: var(--primary-color);
    margin: 0 0.5rem;
    font-weight: 500;
}

.footer-bottom p {
    color: #6b7280;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.seo-footer-text {
    font-size: 0.85rem !important;
    margin-top: 1rem;
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
}

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

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

/* Responsive Design */
@media (max-width: 1024px) {
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .contact-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    h3 { font-size: 1.5rem; }
    
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 2rem;
        box-shadow: var(--shadow-lg);
        gap: 1rem;
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .mobile-toggle {
        display: flex;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.25rem;
    }
    
    .games-grid,
    .features-grid,
    .news-grid,
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
    
    .seo-content {
        padding: 2rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    section {
        padding: 4rem 0;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        text-align: center;
    }
    
    .keywords-section {
        flex-direction: column;
    }
    
    .keyword-tag {
        width: 100%;
        text-align: center;
    }
}

/* Animation Classes */
.fade-in {
    animation: fadeIn 1s ease-out;
}

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

.slide-in-left {
    animation: slideInLeft 1s ease-out;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.slide-in-right {
    animation: slideInRight 1s ease-out;
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Print Styles */
@media print {
    .header,
    .hero-buttons,
    .back-to-top,
    .footer {
        display: none;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.5;
    }
}