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

:root {
    --primary-gradient-start: #667eea;
    --primary-gradient-end: #764ba2;
    --ios-black: #000000;
    --ios-gray: #434343;
    --android-green: #3DDC84;
    --android-blue: #4285F4;
    --text-primary: #333333;
    --text-secondary: #666666;
    --bg-white: #ffffff;
    --shadow-light: rgba(0, 0, 0, 0.1);
    --shadow-medium: rgba(0, 0, 0, 0.2);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    background: linear-gradient(135deg, var(--primary-gradient-start) 0%, var(--primary-gradient-end) 100%);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    color: var(--text-primary);
    line-height: 1.6;
}

/* 容器 */
.container {
    flex: 1;
    max-width: 480px;
    width: 100%;
    margin: 0 auto;
    padding: 40px 20px;
}

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

.logo {
    width: 100px;
    height: 100px;
    border-radius: 22px;
    box-shadow: 0 10px 30px var(--shadow-medium);
    margin-bottom: 20px;
    background: white;
    padding: 10px;
}

h1 {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 10px;
    letter-spacing: -0.5px;
}

.subtitle {
    font-size: 16px;
    opacity: 0.95;
    font-weight: 300;
}

/* 介绍区域 */
.intro {
    background: var(--bg-white);
    padding: 25px;
    border-radius: 20px;
    margin-bottom: 30px;
    box-shadow: 0 10px 30px var(--shadow-light);
    line-height: 1.8;
    color: var(--text-secondary);
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.intro p {
    text-align: justify;
}

/* 下载按钮 */
.download-buttons {
    display: flex;
    gap: 15px;
    margin-bottom: 40px;
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 18px;
    border-radius: 15px;
    text-decoration: none;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 5px 15px var(--shadow-light);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

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

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

.btn-android {
    background: linear-gradient(135deg, var(--android-green) 0%, var(--android-blue) 100%);
    color: white;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px var(--shadow-medium);
}

.btn:active {
    transform: translateY(-1px);
}

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

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

.small {
    display: block;
    font-size: 12px;
    opacity: 0.9;
    line-height: 1.2;
}

.large {
    display: block;
    font-size: 18px;
    font-weight: 600;
    line-height: 1.2;
}

/* 功能特点 */
.features {
    display: grid;
    gap: 20px;
    margin-bottom: 40px;
    animation: fadeInUp 0.8s ease 0.6s backwards;
}

.feature {
    background: var(--bg-white);
    padding: 25px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 15px var(--shadow-light);
    transition: all 0.3s ease;
}

.feature:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px var(--shadow-medium);
}

.feature-icon {
    font-size: 42px;
    display: block;
    margin-bottom: 15px;
    filter: drop-shadow(0 2px 4px rgba(0,0,0,0.1));
}

.feature h3 {
    margin-bottom: 10px;
    color: var(--text-primary);
    font-size: 18px;
    font-weight: 600;
}

.feature p {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.6;
}

/* 使用场景 */
.scenarios {
    background: var(--bg-white);
    padding: 30px;
    border-radius: 20px;
    margin-bottom: 20px;
    box-shadow: 0 10px 30px var(--shadow-light);
    animation: fadeInUp 0.8s ease 0.8s backwards;
}

.scenarios h2 {
    text-align: center;
    margin-bottom: 25px;
    color: var(--text-primary);
    font-size: 24px;
    font-weight: 600;
}

.scenario-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.scenario-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 15px;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    border-radius: 12px;
    transition: all 0.3s ease;
}

.scenario-item:hover {
    transform: scale(1.05);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.scenario-emoji {
    font-size: 28px;
}

/* 页脚 */
.footer {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 25px 20px;
    text-align: center;
    color: white;
    font-size: 14px;
}

.footer p {
    margin: 5px 0;
}

.footer a {
    color: white;
    text-decoration: none;
    transition: opacity 0.3s ease;
}

.footer a:hover {
    opacity: 0.8;
    text-decoration: underline;
}

.copyright {
    opacity: 0.9;
}

/* 动画 */
@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式设计 */
@media (max-width: 480px) {
    .container {
        padding: 30px 15px;
    }

    h1 {
        font-size: 30px;
    }

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

    .btn {
        padding: 16px;
    }

    .features {
        gap: 15px;
    }

    .feature {
        padding: 20px;
    }

    .scenario-list {
        grid-template-columns: 1fr;
        gap: 15px;
    }
}

@media (max-width: 360px) {
    h1 {
        font-size: 26px;
    }

    .subtitle {
        font-size: 14px;
    }

    .intro {
        padding: 20px;
        font-size: 14px;
    }

    .large {
        font-size: 16px;
    }

    .feature h3 {
        font-size: 16px;
    }

    .scenarios h2 {
        font-size: 20px;
    }
}

/* 深色模式支持 */
@media (prefers-color-scheme: dark) {
    :root {
        --shadow-light: rgba(0, 0, 0, 0.3);
        --shadow-medium: rgba(0, 0, 0, 0.5);
    }
}

/* 打印样式 */
@media print {
    body {
        background: white;
    }

    .download-buttons,
    .footer {
        display: none;
    }
}