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

/* 根元素和基础样式 */
:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --gradient-start: #667eea;
    --gradient-end: #764ba2;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --white: #ffffff;
    --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);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    min-height: 100vh;
    padding: 20px;
    position: relative;
    overflow-x: hidden;
}

/* 背景装饰 */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 255, 255, 0.1) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

/* 容器 */
.container {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

/* 页面头部 */
.header {
    text-align: center;
    margin-bottom: 40px;
    animation: fadeInDown 0.8s ease-out;
}

.logo-container {
    margin-bottom: 20px;
}

.logo {
    width: 120px;
    height: 120px;
    border-radius: 24px;
    box-shadow: var(--shadow-xl);
    object-fit: cover;
    background: var(--white);
    padding: 8px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.logo:hover {
    transform: translateY(-5px) scale(1.05);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
}

.app-name {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--white);
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    margin-top: 10px;
    letter-spacing: 2px;
}

/* 主要内容区域 */
.main-content {
    margin-bottom: 40px;
}

.description-section {
    margin-bottom: 40px;
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.description-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 30px;
    box-shadow: var(--shadow-xl);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.description-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
}

.section-title {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 20px;
    text-align: center;
}

.description-text {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    text-align: justify;
}

/* 底部关于我们区域 */
.description-section.footer-section {
    margin: 48px auto 0;
    padding: 28px 20px 22px;
    max-width: 760px;
    text-align: center;
    color: rgba(255, 255, 255, 0.9);
    animation: fadeIn 1s ease-out 0.5s both;
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.06);
    backdrop-filter: blur(4px);
}

.footer-section-title {
    font-size: 1.4rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.95);
    margin-bottom: 14px;
    text-align: center;
}

.footer-description-text {
    font-size: 1.05rem;
    color: rgba(255, 255, 255, 0.85);
    line-height: 1.9;
    text-align: left;
    max-width: 680px;
    margin: 0 auto;
}

/* 下载区域 */
.download-section {
    animation: fadeInUp 0.8s ease-out 0.4s both;
}

.download-buttons {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-top: 30px;
}

.download-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    padding: 20px 30px;
    border-radius: 16px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
}

.download-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s ease;
}

.download-btn:hover::before {
    left: 100%;
}

.ios-btn {
    background: linear-gradient(135deg, #000000 0%, #333333 100%);
    color: var(--white);
}

.ios-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 30px -5px rgba(0, 0, 0, 0.3);
}

.android-btn {
    background: linear-gradient(135deg, #3ddc84 0%, #2bb673 100%);
    color: var(--white);
}

.android-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 30px -5px rgba(59, 220, 132, 0.4);
}

.btn-icon {
    width: 32px;
    height: 32px;
    flex-shrink: 0;
}

.btn-content {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
}

.btn-label {
    font-size: 1.1rem;
    font-weight: 600;
}

.btn-subtitle {
    font-size: 0.9rem;
    opacity: 0.9;
    font-weight: 400;
}

/* 页面底部 */
.footer {
    text-align: center;
    padding: 20px 20px 24px;
    color: rgba(255, 255, 255, 0.9);
    animation: fadeIn 1s ease-out 0.7s both;
    margin-top: 14px;
}

.footer-content {
    max-width: 760px;
    margin: 0 auto;
    padding: 20px 16px 14px;
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-radius: 14px;
    background: rgba(255, 255, 255, 0.04);
}

.copyright {
    font-size: 1rem;
    margin-bottom: 8px;
    font-weight: 500;
}

.rights {
    font-size: 0.9rem;
    opacity: 0.8;
    margin-bottom: 14px;
}

.icp-info {
    margin: 14px 0 0;
    padding-top: 14px;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
}

.icp-item {
    font-size: 0.9rem;
    margin-bottom: 4px;
    line-height: 1.75;
}

.icp-link {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    transition: color 0.3s ease;
}

.icp-link:hover {
    color: rgba(255, 255, 255, 1);
    text-decoration: underline;
}

.license-info {
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px solid rgba(255, 255, 255, 0.15);
}

.license-item {
    font-size: 0.88rem;
    margin-bottom: 6px;
    opacity: 0.85;
    line-height: 1.7;
}

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

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

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

/* 响应式设计 */
@media (min-width: 768px) {
    .app-name {
        font-size: 3.5rem;
    }

    .download-buttons {
        flex-direction: row;
        justify-content: center;
    }

    .download-btn {
        flex: 1;
        max-width: 300px;
    }

    .description-card {
        padding: 40px;
    }

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

    .description-text {
        font-size: 1.15rem;
    }

    .description-section.footer-section {
        padding: 36px 34px 30px;
    }

    .footer-section-title {
        font-size: 1.65rem;
    }

    .footer-description-text {
        font-size: 1.1rem;
    }
}

@media (min-width: 1024px) {
    body {
        padding: 40px;
    }

    .logo {
        width: 150px;
        height: 150px;
    }

    .app-name {
        font-size: 4rem;
    }
}

@media (max-width: 480px) {
    .app-name {
        font-size: 2rem;
    }

    .logo {
        width: 100px;
        height: 100px;
    }

    .description-card {
        padding: 20px;
    }

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

    .description-text {
        font-size: 1rem;
    }

    .download-btn {
        padding: 18px 24px;
        font-size: 1rem;
    }

    .btn-label {
        font-size: 1rem;
    }

    .footer {
        padding: 16px 8px 18px;
    }

    .copyright {
        font-size: 0.9rem;
    }

    .icp-item {
        font-size: 0.86rem;
    }

    .license-item {
        font-size: 0.82rem;
    }

    .description-section.footer-section {
        padding: 22px 14px 18px;
        margin-top: 34px;
        border-radius: 12px;
    }

    .footer-section-title {
        font-size: 1.45rem;
    }

    .footer-description-text {
        font-size: 1.08rem;
        line-height: 1.85;
    }

    .footer-content {
        padding: 16px 12px 12px;
        border-radius: 12px;
    }
}

/* 加载动画 */
@media (prefers-reduced-motion: no-preference) {
    .header,
    .description-section,
    .download-section,
    .footer {
        animation-play-state: running;
    }
}

@media (prefers-reduced-motion: reduce) {
    .header,
    .description-section,
    .download-section,
    .footer {
        animation: none;
    }
    
    .logo,
    .download-btn,
    .description-card {
        transition: none;
    }
}