:root {
    --google-blue: #4285f4;
    --google-red: #ea4335;
    --google-yellow: #fbbc05;
    --google-green: #34a853;
    --white: #ffffff;
    --light-gray: #f8f9fa;
    --dark-gray: #202124;
    --medium-gray: #5f6368;
    --card-border-radius: 8px;
    --shadow-1: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
    --shadow-2: 0 3px 6px rgba(0,0,0,0.16), 0 3px 6px rgba(0,0,0,0.23);
    --shadow-3: 0 10px 20px rgba(0,0,0,0.19), 0 6px 6px rgba(0,0,0,0.23);
    --shadow-4: 0 14px 28px rgba(0,0,0,0.25), 0 10px 10px rgba(0,0,0,0.22);
}

body {
    font-family: 'Roboto', 'PingFang SC', 'Helvetica Neue', Helvetica, 'Microsoft YaHei', Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--light-gray);
    color: var(--dark-gray);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
}

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

a {
    text-decoration: none;
    color: var(--google-blue);
    transition: color 0.3s ease;
}

a:hover {
    color: #1a73e8; /* Slightly darker blue */
}

button, .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: var(--card-border-radius);
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    border: none;
    outline: none;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-1);
}

.btn-primary {
    background-color: var(--google-blue);
    color: var(--white);
}

.btn-primary:hover {
    background-color: #1a73e8;
    box-shadow: var(--shadow-2);
}

.card {
    background-color: var(--white);
    border-radius: var(--card-border-radius);
    box-shadow: var(--shadow-1);
    transition: all 0.3s ease;
}

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

section {
    padding: 80px 0;
    text-align: center;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 500;
    color: var(--dark-gray);
    margin-top: 0;
    margin-bottom: 20px;
}

h1 { font-size: 3.5em; }
h2 { font-size: 2.5em; }
h3 { font-size: 1.8em; }
p {
    font-size: 1.1em;
    color: var(--medium-gray);
    margin-bottom: 20px;
}

/* Material Icons sizing */
.material-icons {
    vertical-align: middle;
    margin-right: 8px;
    font-size: 24px;
}

/* Structured Data (hidden) */
.seo-structured-data {
    display: none;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }

    h1 { font-size: 2.5em; }
    h2 { font-size: 2em; }
    h3 { font-size: 1.5em; }
    p { font-size: 1em; }

    /* 导航栏 */
    header .container {
        flex-direction: column;
        align-items: flex-start;
    }
    header nav {
        width: 100%;
        flex-direction: column;
        align-items: flex-start;
        margin-top: 15px;
    }
    header nav ul {
        flex-direction: column;
        width: 100%;
        margin-right: 0;
    }
    header nav ul li {
        margin-right: 0;
        margin-bottom: 10px;
    }
    header nav ul li:last-child {
        margin-bottom: 0;
    }
    header nav .btn {
        width: 100%;
        margin-top: 10px;
    }

    /* Hero区 */
    #hero-section .container {
        flex-direction: column;
        text-align: center;
    }
    #hero-section .hero-content {
        padding-right: 0;
        margin-bottom: 40px;
    }
    #hero-section .hero-image {
        width: 100%;
    }

    /* 功能区, 用户评价区, 套餐价格区 */
    .card {
        padding: 30px 20px;
    }

    /* 跨平台区 */
    #cross-platform-section .card {
        min-width: 120px;
    }
}