/* ===================================
   多娜多娜一起干坏事吧 - 主样式表
   符合2025年SEO和性能优化标准
   =================================== */

/* CSS变量定义 - 漫画多彩色主题 */
:root {
    --primary-color: #FF6B9D;
    --secondary-color: #C06C84;
    --accent-color: #F67280;
    --bg-color: #FFF5F7;
    --text-color: #2C3E50;
    --heading-color: #1A1A2E;
    --card-bg: #FFFFFF;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 8px 15px rgba(0, 0, 0, 0.2);
    --gradient-1: linear-gradient(135deg, #FF6B9D 0%, #F67280 100%);
    --gradient-2: linear-gradient(135deg, #C06C84 0%, #6C5B7B 100%);
    --transition: all 0.3s ease;
}

/* 重置和基础样式 */
* {
    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: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    overflow-x: hidden;
}

/* 性能优化 - 减少重绘 */
img, picture {
    display: block;
    max-width: 100%;
    height: auto;
}

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

ul {
    list-style: none;
}

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

/* ===================================
   Header 导航栏
   =================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.logo img {
    width: 50px;
    height: 50px;
    object-fit: contain;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: bold;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    gap: 30px;
    align-items: center;
}

.nav-link {
    font-weight: 500;
    position: relative;
    padding: 5px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-1);
    transition: width 0.3s ease;
}

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

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    border-radius: 3px;
    transition: var(--transition);
}

/* ===================================
   Hero Section
   =================================== */
.hero-section {
    margin-top: 80px;
    position: relative;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-content {
    position: relative;
    width: 100%;
    height: 100%;
}

.hero-image {
    width: 100%;
    height: 100%;
    min-height: 600px;
    object-fit: cover;
    object-position: center;
}

.hero-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: white;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.7);
    width: 90%;
    max-width: 800px;
    background: rgba(0, 0, 0, 0.4);
    padding: 40px 30px;
    border-radius: 20px;
    backdrop-filter: blur(8px);
}

.hero-title {
    font-size: 3rem;
    font-weight: bold;
    margin-bottom: 20px;
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 30px;
    animation: fadeInUp 1.2s ease;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    animation: fadeInUp 1.4s ease;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 30px;
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

.btn-primary {
    background: var(--gradient-1);
    color: white;
}

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

.btn-secondary {
    background: white;
    color: #000000;
    border: 2px solid var(--primary-color);
    text-shadow: none;
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    text-shadow: none;
}

/* ===================================
   Main Content Sections
   =================================== */
.main-content {
    padding-top: 40px;
}

.section {
    padding: 60px 0;
}

.section-title {
    font-size: 2.5rem;
    color: var(--heading-color);
    text-align: center;
    margin-bottom: 40px;
    position: relative;
    padding-bottom: 15px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--gradient-1);
    border-radius: 2px;
}

/* ===================================
   Game Introduction Section
   =================================== */
.game-intro {
    background: white;
}

.content-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}

.content-text p {
    margin-bottom: 20px;
    line-height: 1.8;
    font-size: 1.1rem;
}

.intro-text {
    font-size: 1.2rem;
}

.content-image img {
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.content-image img:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-hover);
}

/* ===================================
   Game Features Section
   =================================== */
.game-features {
    background: linear-gradient(135deg, #FFF5F7 0%, #FFE5EC 100%);
}

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

.feature-card {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-align: center;
}

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

.feature-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.feature-title {
    font-size: 1.5rem;
    color: var(--heading-color);
    margin-bottom: 15px;
}

.feature-desc {
    line-height: 1.8;
    margin-bottom: 20px;
}

.feature-image {
    border-radius: 10px;
    margin-top: 20px;
}

/* ===================================
   Gameplay Systems Section
   =================================== */
.gameplay-systems {
    background: white;
}

.subsection-title {
    font-size: 1.8rem;
    color: var(--heading-color);
    margin-bottom: 30px;
    text-align: center;
}

.gameplay-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
}

.gameplay-item {
    background: linear-gradient(135deg, #FFE5EC 0%, #FFF5F7 100%);
    padding: 25px;
    border-radius: 12px;
    border-left: 4px solid var(--primary-color);
    transition: var(--transition);
}

.gameplay-item:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow);
}

.gameplay-item h4 {
    font-size: 1.3rem;
    color: var(--heading-color);
    margin-bottom: 10px;
}

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

/* ===================================
   Game Guide Section
   =================================== */
.game-guide {
    background: linear-gradient(135deg, #FFE5EC 0%, #FFF5F7 100%);
}

.guide-content {
    max-width: 900px;
    margin: 0 auto;
}

.guide-section {
    background: white;
    padding: 30px;
    border-radius: 15px;
    margin-bottom: 30px;
    box-shadow: var(--shadow);
}

.guide-section h3 {
    font-size: 1.8rem;
    color: var(--heading-color);
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--primary-color);
}

.guide-list {
    list-style: none;
}

.guide-list li {
    padding: 15px 0;
    border-bottom: 1px solid #f0f0f0;
    line-height: 1.8;
}

.guide-list li:last-child {
    border-bottom: none;
}

/* ===================================
   FAQ Section
   =================================== */
.faq-section {
    background: white;
}

.faq-content {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    background: var(--card-bg);
    margin-bottom: 15px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.faq-question {
    padding: 20px;
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--heading-color);
    cursor: pointer;
    list-style: none;
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--bg-color);
    color: var(--primary-color);
}

.faq-answer {
    padding: 0 20px 20px;
    line-height: 1.8;
}

/* ===================================
   Download Section
   =================================== */
.download-section {
    background: var(--gradient-1);
    color: white;
    text-align: center;
}

.download-section .section-title {
    color: white;
}

.download-section .section-title::after {
    background: white;
}

.download-desc {
    font-size: 1.2rem;
    margin-bottom: 30px;
}

.download-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-bottom: 40px;
}

.btn-download {
    padding: 15px 40px;
    font-size: 1.1rem;
}

.system-requirements {
    background: rgba(255, 255, 255, 0.1);
    padding: 30px;
    border-radius: 15px;
    backdrop-filter: blur(10px);
}

.system-requirements h3 {
    font-size: 1.5rem;
    margin-bottom: 20px;
}

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    text-align: left;
}

.requirement-item {
    padding: 10px;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--gradient-2);
    color: white;
    padding: 40px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 30px;
}

.footer-section h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
}

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

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

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

.footer-keywords {
    line-height: 1.8;
    opacity: 0.9;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
}

/* ===================================
   Back to Top Button
   =================================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-1);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow);
    z-index: 999;
}

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

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

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

/* ===================================
   Lazy Loading Images
   =================================== */
.lazy-image {
    opacity: 0;
    transition: opacity 0.5s ease;
}

.lazy-image.loaded {
    opacity: 1;
}

/* ===================================
   Responsive Design - Mobile First
   =================================== */

/* Tablet */
@media (max-width: 768px) {
    html {
        font-size: 14px;
    }

    .nav-menu {
        position: fixed;
        top: 80px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 80px);
        background: white;
        flex-direction: column;
        padding: 30px;
        transition: left 0.3s ease;
        box-shadow: var(--shadow);
    }

    .nav-menu.active {
        left: 0;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .hero-section {
        min-height: 500px;
    }

    .hero-image {
        min-height: 500px;
        object-fit: cover;
    }

    .hero-text {
        width: 95%;
        padding: 30px 20px;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .hero-buttons {
        flex-direction: column;
        gap: 15px;
    }

    .content-grid {
        grid-template-columns: 1fr;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .gameplay-grid {
        grid-template-columns: 1fr;
    }

    .download-buttons {
        flex-direction: column;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }
}

/* Mobile */
@media (max-width: 480px) {
    html {
        font-size: 13px;
    }

    .hero-section {
        min-height: 400px;
    }

    .hero-image {
        min-height: 400px;
        object-fit: cover;
    }

    .hero-text {
        width: 95%;
        padding: 25px 15px;
    }

    .hero-title {
        font-size: 1.5rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .btn {
        padding: 10px 20px;
    }

    .back-to-top {
        width: 40px;
        height: 40px;
        bottom: 20px;
        right: 20px;
    }
}

/* Performance Optimizations */
@media (prefers-reduced-motion: reduce) {
    * {
        animation: none !important;
        transition: none !important;
    }
}