/* ========================================
   Sora2中文指南 - 样式表
   ======================================== */

/* CSS变量 */
:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #0f172a;
    --text-color: #1e293b;
    --text-light: #64748b;
    --text-lighter: #94a3b8;
    --bg-color: #ffffff;
    --bg-light: #f8fafc;
    --bg-dark: #0f172a;
    --border-color: #e2e8f0;
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
    --gradient-hero: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #334155 100%);
    --shadow-sm: 0 1px 2px 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);
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --transition: all 0.3s ease;
}

/* 基础重置 */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

ul {
    list-style: none;
}

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

/* 容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ========================================
   导航栏
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid transparent;
    transition: var(--transition);
}

.header.scrolled {
    background: rgba(255, 255, 255, 0.98);
    border-bottom-color: var(--border-color);
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--secondary-color);
}

.logo-img {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    object-fit: cover;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-menu a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-light);
    position: relative;
}

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

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: var(--transition);
}

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

.nav-btn {
    padding: 10px 20px;
    background: var(--gradient-primary);
    color: #fff;
    font-weight: 500;
    font-size: 0.9rem;
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.nav-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--text-color);
    transition: var(--transition);
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ========================================
   Hero区域
   ======================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-hero);
    padding: 120px 24px 80px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 30%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(168, 85, 247, 0.15) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero-tag {
    display: inline-block;
    padding: 8px 16px;
    background: rgba(99, 102, 241, 0.2);
    color: var(--primary-light);
    font-size: 0.85rem;
    font-weight: 500;
    border-radius: 100px;
    margin-bottom: 24px;
    border: 1px solid rgba(99, 102, 241, 0.3);
}

.hero h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    color: #fff;
    line-height: 1.2;
    margin-bottom: 24px;
    letter-spacing: -0.02em;
}

.hero-desc {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.8);
    max-width: 700px;
    margin: 0 auto 40px;
    line-height: 1.8;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 48px;
    margin-bottom: 48px;
    flex-wrap: wrap;
}

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

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.6);
}

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

/* 按钮 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: var(--transition);
    cursor: pointer;
}

.btn-primary {
    background: var(--gradient-primary);
    color: #fff;
    border: none;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 24px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
}

/* ========================================
   通用区块样式
   ======================================== */
.section {
    padding: 100px 0;
}

.section-tag {
    display: inline-block;
    padding: 6px 14px;
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color);
    font-size: 0.85rem;
    font-weight: 600;
    border-radius: 100px;
    margin-bottom: 16px;
}

.section h2 {
    font-size: clamp(2rem, 4vw, 2.75rem);
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.section-intro {
    font-size: 1.1rem;
    color: var(--text-light);
    max-width: 700px;
    margin: 0 auto 56px;
}

.container {
    text-align: center;
}

/* ========================================
   关于Sora2
   ======================================== */
.about-section {
    background: var(--bg-light);
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    text-align: left;
}

.about-card {
    background: #fff;
    padding: 40px 32px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.about-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.about-card h3 {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 12px;
}

.about-card p {
    font-size: 0.95rem;
    color: var(--text-light);
    line-height: 1.8;
}

/* ========================================
   核心功能
   ======================================== */
.features-section {
    background: #fff;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
    text-align: left;
}

.feature-card {
    background: var(--bg-light);
    padding: 40px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.feature-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-lg);
}

.feature-number {
    position: absolute;
    top: 24px;
    right: 24px;
    font-size: 3rem;
    font-weight: 700;
    color: rgba(99, 102, 241, 0.1);
}

.feature-card h3 {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.feature-card h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 16px;
}

.feature-card p {
    font-size: 0.95rem;
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 20px;
}

.feature-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.feature-list li {
    font-size: 0.9rem;
    color: var(--text-color);
    padding-left: 24px;
    position: relative;
}

.feature-list li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 600;
}

/* ========================================
   Sora2能力
   ======================================== */
.capabilities-section {
    background: var(--bg-dark);
    color: #fff;
}

.capabilities-section h2 {
    color: #fff;
}

.capabilities-section .section-intro {
    color: rgba(255, 255, 255, 0.7);
}

.capabilities-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    text-align: left;
}

.capability-item {
    background: rgba(255, 255, 255, 0.05);
    padding: 32px;
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: var(--transition);
}

.capability-item:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(99, 102, 241, 0.5);
    transform: translateY(-4px);
}

.capability-item h3 {
    font-size: 1.15rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: #fff;
}

.capability-item p {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.7;
}

/* ========================================
   使用指南
   ======================================== */
.guide-section {
    background: var(--bg-light);
}

.guide-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    text-align: left;
}

.step-card {
    background: #fff;
    padding: 32px 28px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    position: relative;
    transition: var(--transition);
}

.step-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-xl);
}

.step-number {
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    color: #fff;
    font-size: 1.25rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    margin-bottom: 20px;
}

.step-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 8px;
}

.step-card h4 {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--primary-color);
    margin-bottom: 12px;
}

.step-card p {
    font-size: 0.9rem;
    color: var(--text-light);
    line-height: 1.7;
}

/* ========================================
   适用人群
   ======================================== */
.audience-section {
    background: #fff;
}

.audience-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    text-align: center;
}

.audience-card {
    padding: 40px 24px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.audience-card:hover {
    border-color: var(--primary-light);
    background: var(--bg-light);
}

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

.audience-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 12px;
}

.audience-card p {
    font-size: 0.9rem;
    color: var(--text-light);
    line-height: 1.7;
}

/* ========================================
   CTA区域
   ======================================== */
.cta-section {
    background: var(--gradient-hero);
    text-align: center;
    padding: 80px 24px;
}

.cta-section h2 {
    color: #fff;
    margin-bottom: 16px;
}

.cta-section p {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.8);
    max-width: 700px;
    margin: 0 auto 40px;
    line-height: 1.8;
}

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

/* ========================================
   页脚
   ======================================== */
.footer {
    background: var(--bg-dark);
    color: rgba(255, 255, 255, 0.8);
    padding: 80px 0 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: 64px;
    text-align: left;
    padding-bottom: 48px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.25rem;
    color: #fff;
    margin-bottom: 16px;
}

.footer-brand p {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.6);
    line-height: 1.8;
    max-width: 320px;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.footer-col h4 {
    font-size: 1rem;
    font-weight: 600;
    color: #fff;
    margin-bottom: 20px;
}

.footer-col ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-col a {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.6);
    transition: var(--transition);
}

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

.footer-bottom {
    padding: 24px 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.5);
}

/* ========================================
   响应式设计
   ======================================== */
@media (max-width: 1024px) {
    .about-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .capabilities-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .guide-steps {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .audience-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 48px;
    }
    
    .footer-links {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        border-bottom: 1px solid var(--border-color);
        transform: translateY(-150%);
        opacity: 0;
        transition: var(--transition);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
    }
    
    .nav-btn {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .hero {
        padding: 100px 20px 60px;
        min-height: auto;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero-desc {
        font-size: 1rem;
    }
    
    .hero-stats {
        gap: 24px;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
    
    .section {
        padding: 60px 0;
    }
    
    .section h2 {
        font-size: 1.75rem;
    }
    
    .capabilities-grid {
        grid-template-columns: 1fr;
    }
    
    .guide-steps {
        grid-template-columns: 1fr;
    }
    
    .audience-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-brand {
        text-align: center;
    }
    
    .footer-brand p {
        max-width: 100%;
    }
    
    .footer-logo {
        justify-content: center;
    }
    
    .btn {
        padding: 12px 24px;
        font-size: 0.95rem;
    }
    
    .hero-btns {
        flex-direction: column;
        align-items: center;
    }
    
    .cta-btns {
        flex-direction: column;
        align-items: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .nav-container {
        padding: 0 16px;
    }
    
    .about-card,
    .feature-card,
    .step-card,
    .capability-item,
    .audience-card {
        padding: 28px 20px;
    }
    
    .feature-number {
        font-size: 2rem;
    }
    
    .hero h1 {
        font-size: 1.75rem;
    }
    
    .section-intro {
        font-size: 1rem;
    }
}

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

.hero-content {
    animation: fadeInUp 0.8s ease-out;
}