/* 字体定义 */
@font-face {
    font-family: 'Noto Serif';
    src: url('assets/font/NotoSerif-Regular.ttf') format('truetype');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Noto Serif';
    src: url('assets/font/NotoSerif-Light.ttf') format('truetype');
    font-weight: 300;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Noto Serif';
    src: url('assets/font/NotoSerif-Medium.ttf') format('truetype');
    font-weight: 500;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Noto Serif';
    src: url('assets/font/NotoSerif-SemiBold.ttf') format('truetype');
    font-weight: 600;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Noto Serif';
    src: url('assets/font/NotoSerif-Bold.ttf') format('truetype');
    font-weight: 700;
    font-style: normal;
    font-display: swap;
}

/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 根变量定义 */
:root {
    --primary-black: #000000;
    --primary-white: #ffffff;
    --gray-100: #f8f9fa;
    --gray-200: #e9ecef;
    --gray-300: #dee2e6;
    --gray-400: #ced4da;
    --gray-500: #adb5bd;
    --gray-600: #6c757d;
    --gray-700: #495057;
    --gray-800: #343a40;
    --gray-900: #212529;
    --accent-gray: #f1f3f4;
    --text-primary: #000000;
    --text-secondary: #6c757d;
    --text-light: #ffffff;
    --border-color: #e9ecef;
    --shadow-light: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 4px 20px rgba(0, 0, 0, 0.15);
    --shadow-heavy: 0 8px 30px rgba(0, 0, 0, 0.2);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-family-serif: 'Noto Serif', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, serif;
}

/* 基础样式 */
html {
    scroll-behavior: smooth;
}

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

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

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(0, 0, 0, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-white);
    letter-spacing: -0.02em;
    font-family: var(--font-family-serif);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: rgba(255, 255, 255, 0.7);
    font-weight: 400;
    font-size: 0.95rem;
    transition: var(--transition);
    position: relative;
}

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

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-white);
    transition: var(--transition);
}

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

/* 主横幅区域 */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background-color: var(--primary-black);
    padding-top: 70px;
    overflow: hidden;
}

.hero-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    position: relative;
}

.hero-visual {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-content {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-slogan {
    font-size: 4rem;
    font-weight: 300;
    color: var(--primary-white);
    letter-spacing: 0.05em;
    line-height: 1.2;
    text-align: center;
    opacity: 0;
    transform: translateX(50px);
    animation: slideInSlogan 1.5s ease-out 0.8s forwards;
}

@keyframes slideInSlogan {
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* 手机模拟器 */
.phone-mockup {
    width: 400px;
    height: 800px;
    background-color: var(--primary-black);
    border-radius: 60px;
    padding: 30px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    position: relative;
    transform: translateX(0);
    animation: slideLeft 2s ease-out 0.5s forwards;
}

@keyframes slideLeft {
    to {
        transform: translateX(-100px);
    }
}

.phone-screen {
    width: 100%;
    height: 100%;
    background-color: var(--primary-white);
    border-radius: 50px;
    overflow: hidden;
    position: relative;
}

.app-screenshot {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50px;
    display: block;
}

/* 功能特色区域 */
.features {
    padding: 6rem 0;
    background-color: var(--primary-white);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4rem;
    letter-spacing: -0.02em;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.feature-card {
    background-color: var(--primary-white);
    padding: 2.5rem;
    border-radius: 20px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    box-shadow: var(--shadow-light);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
    border-color: var(--gray-300);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    display: block;
}

.feature-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 支持语言区域 */
.languages {
    padding: 6rem 0;
    background-color: var(--gray-100);
}

.languages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.language-item {
    background-color: var(--primary-white);
    padding: 1.5rem;
    border-radius: 15px;
    text-align: center;
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    transition: var(--transition);
    box-shadow: var(--shadow-light);
}

.language-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-medium);
    border-color: var(--gray-300);
}

.languages-note {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    font-style: italic;
}

/* 下载区域 */
.download {
    padding: 6rem 0;
    background: linear-gradient(135deg, var(--primary-black) 0%, var(--gray-800) 100%);
    color: var(--text-light);
}

.download-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.download-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 2rem;
    letter-spacing: -0.02em;
}

.download-description {
    font-size: 1.2rem;
    margin-bottom: 3rem;
    opacity: 0.9;
    line-height: 1.6;
}

.download-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.download-button {
    display: inline-block;
    background-color: var(--primary-white);
    color: var(--text-primary);
    padding: 1rem 2rem;
    border-radius: 15px;
    text-decoration: none;
    transition: var(--transition);
    box-shadow: var(--shadow-light);
    min-width: 200px;
}

.download-button:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-medium);
}

.button-content {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.button-icon {
    font-size: 1.5rem;
}

.button-text {
    text-align: left;
}

.button-label {
    display: block;
    font-weight: 600;
    font-size: 1rem;
    font-family: var(--font-family-serif);
}

.button-subtitle {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 0.2rem;
    font-family: var(--font-family-serif);
}

/* 页脚 */
.footer {
    background-color: var(--gray-900);
    color: var(--text-light);
    padding: 3rem 0 1rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.footer-logo h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    font-family: var(--font-family-serif);
}

.footer-logo p {
    color: var(--gray-400);
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-links a {
    color: var(--gray-400);
    text-decoration: none;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--gray-700);
    color: var(--gray-500);
    font-size: 0.9rem;
    font-family: var(--font-family-serif);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero-container {
        flex-direction: column;
        gap: 3rem;
        text-align: center;
    }
    
    .hero-slogan {
        font-size: 2.5rem;
        order: 2;
    }
    
    .hero-visual {
        order: 1;
    }
    
    .phone-mockup {
        width: 350px;
        height: 700px;
        animation: slideUp 2s ease-out 0.5s forwards;
    }
    
    @keyframes slideUp {
        to {
            transform: translateY(-50px);
        }
    }
    
    .download-title {
        font-size: 2rem;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .footer-links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero {
        padding-top: 60px;
    }
    
    .hero-slogan {
        font-size: 2rem;
    }
    
    .phone-mockup {
        width: 300px;
        height: 600px;
    }
    
    .download-buttons {
        flex-direction: column;
        align-items: center;
    }
}

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

.feature-card,
.language-item {
    animation: fadeInUp 0.6s ease-out;
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--gray-100);
}

::-webkit-scrollbar-thumb {
    background: var(--gray-400);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--gray-500);
}