/* Global Styles */
:root {
    --primary-color: #e53935;
    --secondary-color: #f4d03f;
    --bg-color: #fef9e7;
    --text-color: #333;
    --light-text: #666;
    --white: #fff;
    --font-main: "Helvetica Neue", Helvetica, Arial, sans-serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

/* Header */
.header {
    background-color: var(--white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

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

.logo-img {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    object-fit: cover;
}

.logo h1 {
    font-size: 1.2rem;
    color: var(--primary-color);
    font-weight: bold;
    letter-spacing: 0.5px;
}

.nav ul {
    display: flex;
    gap: 30px;
}

.nav a {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-color);
    transition: color 0.3s;
}

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

/* Hero Section */
.hero {
    background:
        linear-gradient(rgba(229, 57, 53, 0.9), rgba(229, 57, 53, 0.7)),
        url("https://images.unsplash.com/photo-1550751827-4bd374c3f58b?ixlib=rb-1.2.1&auto=format&fit=crop&w=1350&q=80");
    background-size: cover;
    background-position: center;
    color: var(--white);
    padding: 100px 0;
    text-align: center;
}

.hero-content h2 {
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 40px;
    opacity: 0.9;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 30px;
    font-weight: bold;
    transition:
        transform 0.3s,
        box-shadow 0.3s;
    margin: 0 10px;
}

.btn-primary {
    background-color: var(--secondary-color);
    color: var(--text-color);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.btn-android {
    background-color: #4caf50; /* 安卓绿 */
    color: var(--white);
}

.btn-android:hover {
    background-color: #45a049;
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

/* Features Section */
.features {
    padding: 80px 0;
    background-color: var(--white);
}

.section-title {
    text-align: center;
    margin-bottom: 60px;
}

.section-title h3 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.section-title p {
    color: var(--light-text);
}

.feature-grid {
    display: flex;
    justify-content: space-between;
    gap: 30px;
    flex-wrap: wrap;
}

.feature-item {
    flex: 1;
    min-width: 300px;
    text-align: center;
    padding: 40px 20px;
    background-color: var(--bg-color);
    border-radius: 10px;
    transition: transform 0.3s;
}

.feature-item:hover {
    transform: translateY(-10px);
}

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

.feature-item h4 {
    font-size: 1.4rem;
    margin-bottom: 15px;
    color: var(--text-color);
}

.feature-item p {
    color: var(--light-text);
}

/* About Section */
.about {
    padding: 80px 0;
    text-align: center;
    background-color: var(--bg-color);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about h3 {
    font-size: 2rem;
    margin-bottom: 30px;
    color: var(--primary-color);
}

.about p {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-color);
}

/* Footer */
.footer {
    background-color: #2c3e50;
    color: rgba(255, 255, 255, 0.7);
    padding: 40px 0;
    text-align: center;
}

.footer p {
    font-size: 0.9rem;
}
@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        height: auto;
        padding: 15px 20px;
    }

    .nav {
        margin-top: 15px;
        width: 100%;
        overflow-x: auto; /* 允许小屏幕横向滚动 */
        -webkit-overflow-scrolling: touch;
    }

    .nav ul {
        justify-content: center;
        gap: 20px;
        padding-bottom: 5px; /* 滚动条间距 */
    }

    .nav a {
        white-space: nowrap; /* 防止文字换行 */
    }

    .hero-content h2 {
        font-size: 2rem;
    }

    .feature-grid {
        flex-direction: column;
    }

    .feature-item {
        min-width: 100%;
        margin-bottom: 20px;
    }

    .btn {
        display: block;
        margin: 10px auto;
        width: 100%;
        max-width: 280px;
    }
}