/* CSS Reset & Variables */
:root {
    --primary-color: #1a73e8;
    --primary-hover: #1765cc;
    --secondary-color: #5f6368;
    --text-color: #202124;
    --bg-color: #ffffff;
    --bg-light-gray: #f8f9fa;
    --border-color: #dadce0;
    --google-red: #ea4335;
    --google-yellow: #fbbc04;
    --google-green: #34a853;
    --font-family: 'Noto Sans SC', 'Roboto', 'Arial', sans-serif;
    --shadow-sm: 0 1px 2px 0 rgba(60,64,67,0.3), 0 1px 3px 1px rgba(60,64,67,0.15);
    --shadow-md: 0 4px 6px rgba(60,64,67,0.3);
    --transition: all 0.3s ease;
}

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

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

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Typography */
h1, h2, h3, h4 {
    font-weight: 500; /* Google style tends to use lighter weights for headings */
    color: var(--text-color);
}

h1 { font-size: 3.5rem; line-height: 1.2; letter-spacing: -0.02em; }
h2 { font-size: 2.25rem; margin-bottom: 1rem; }
h3 { font-size: 1.5rem; margin-bottom: 0.5rem; }
p { color: var(--secondary-color); margin-bottom: 1rem; }

.blue-text { color: var(--primary-color); }

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 4px;
    font-weight: 500;
    cursor: pointer;
    text-align: center;
    transition: var(--transition);
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    border: 1px solid var(--primary-color);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    box-shadow: 0 1px 3px rgba(60,64,67,0.3);
}

.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
    border: 1px solid var(--border-color);
}

.btn-outline:hover {
    background-color: rgba(26,115,232,0.04);
    border-color: var(--primary-color);
}

/* Header */
.site-header {
    background-color: white;
    box-shadow: 0 1px 0 rgba(0,0,0,0.08); /* Subtle border-like shadow */
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    height: 64px;
    display: flex;
    align-items: center;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--secondary-color);
    display: flex;
    align-items: center;
}

.logo-text {
    letter-spacing: -0.5px;
}

.logo .highlight {
    color: var(--primary-color);
    font-weight: 700;
}

.main-nav ul {
    display: flex;
    gap: 32px;
}

.main-nav a {
    color: var(--secondary-color);
    font-weight: 500;
    font-size: 1rem;
}

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

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    flex-direction: column;
    gap: 4px;
}

.bar {
    width: 24px;
    height: 2px;
    background-color: var(--secondary-color);
    transition: var(--transition);
}

/* Hero Section */
.hero {
    padding: 160px 0 120px;
    text-align: center;
    background-color: white;
}

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

.hero-subtitle {
    font-size: 1.25rem;
    margin: 24px 0 40px;
    color: var(--secondary-color);
    font-weight: 300;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
}

/* Featured Product */
.hero-featured {
    margin-bottom: 48px;
    display: flex;
    justify-content: center;
}

.featured-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px 32px;
    text-align: left;
    max-width: 600px;
    display: flex;
    gap: 24px;
    align-items: center;
    transition: var(--transition);
    box-shadow: 0 1px 2px 0 rgba(60,64,67,0.3);
}

.featured-card:hover {
    box-shadow: 0 4px 12px 0 rgba(60,64,67,0.15);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.featured-icon {
    flex-shrink: 0;
    width: 64px;
    height: 64px;
    background: rgba(26,115,232,0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.featured-info {
    flex: 1;
}

.featured-info h3 {
    font-size: 1.25rem;
    margin-bottom: 8px;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 12px;
}

.featured-info .tag {
    font-size: 0.75rem;
    background: var(--google-red);
    color: white;
    padding: 2px 8px;
    border-radius: 4px;
    font-weight: 700;
}

.featured-info p {
    font-size: 0.95rem;
    margin-bottom: 12px;
    color: var(--secondary-color);
    line-height: 1.5;
}

.featured-link {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 4px;
}

@media (max-width: 600px) {
    .featured-card {
        flex-direction: column;
        text-align: center;
        padding: 20px;
    }
    .featured-icon {
        margin-bottom: 16px;
    }
}

/* Sections General */
.section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 64px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.section-header p {
    font-size: 1.125rem;
}

.gray-bg {
    background-color: var(--bg-light-gray);
}

/* Services Grid */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 32px;
    transition: var(--transition);
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

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

.card-icon {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
}

.blue-bg { background-color: rgba(26,115,232,0.1); }
.green-bg { background-color: rgba(52,168,83,0.1); }
.red-bg { background-color: rgba(234,67,53,0.1); }
.yellow-bg { background-color: rgba(251,188,4,0.1); }

.card h3 {
    font-size: 1.25rem;
    margin-bottom: 12px;
}

.card p {
    font-size: 0.95rem;
    margin-bottom: 0;
    line-height: 1.6;
}

/* Solutions Section */
.solutions-grid {
    display: flex;
    flex-direction: column;
    gap: 64px;
}

.solution-item {
    display: flex;
    align-items: center;
    gap: 64px;
}

.solution-item.reverse {
    flex-direction: row-reverse;
}

.solution-content {
    flex: 1;
}

.solution-content h3 {
    font-size: 2rem;
    margin-bottom: 16px;
    color: var(--text-color);
}

.solution-image-placeholder {
    flex: 1;
    height: 300px;
    border-radius: 16px;
    background-color: #e0e0e0;
}

.solution-image {
    flex: 1;
    width: 100%;
    height: 300px;
    object-fit: cover;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
}

.blue-gradient { background: linear-gradient(135deg, #e8f0fe 0%, #d2e3fc 100%); }
.red-gradient { background: linear-gradient(135deg, #fce8e6 0%, #fad2cf 100%); }
.yellow-gradient { background: linear-gradient(135deg, #fef7e0 0%, #feefc3 100%); }
.green-gradient { background: linear-gradient(135deg, #e6f4ea 0%, #ceead6 100%); }

.link-arrow {
    color: var(--primary-color);
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    margin-top: 16px;
}

.link-arrow:hover .arrow {
    transform: translateX(4px);
}

.arrow { transition: transform 0.2s; }

/* About Section */
.about-section {
    background-color: white;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.about-text .lead {
    font-size: 1.25rem;
    color: var(--text-color);
    margin-bottom: 24px;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

.stat-item {
    text-align: center;
    padding: 32px;
    background-color: var(--bg-light-gray);
    border-radius: 8px;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.stat-label {
    color: var(--secondary-color);
    font-weight: 500;
}

/* Footer */
.site-footer {
    background-color: #f8f9fa;
    padding: 64px 0 32px;
    border-top: 1px solid var(--border-color);
}

.footer-top {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-col h4 {
    font-size: 1rem;
    color: var(--text-color);
    margin-bottom: 24px;
    font-weight: 500;
}

.footer-col ul li {
    margin-bottom: 12px;
}

.footer-col ul li a {
    color: var(--secondary-color);
    font-size: 0.9rem;
}

.footer-col ul li a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 32px;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px;
    font-size: 0.85rem;
    color: var(--secondary-color);
}

/* Responsive */
@media (max-width: 900px) {
    h1 { font-size: 2.5rem; }
    .solution-item, .solution-item.reverse {
        flex-direction: column;
        gap: 32px;
        text-align: center;
    }
    .solution-image-placeholder {
        width: 100%;
        height: 200px;
    }
    .about-content {
        grid-template-columns: 1fr;
    }
    .footer-top {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
    }
    .main-nav {
        position: fixed;
        top: 64px;
        left: 0;
        width: 100%;
        background: white;
        padding: 24px;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        transform: translateY(-150%);
        transition: transform 0.3s ease;
        z-index: 999;
    }
    .main-nav.active {
        transform: translateY(0);
    }
    .main-nav ul {
        flex-direction: column;
        gap: 24px;
        text-align: center;
    }
    .hero {
        padding: 120px 0 80px;
    }
}


/* 减小 hero 与后续 section 之间的垂直间距 */
.hero {
    padding-bottom: 20px; /* 原来是 120px，改为 60px 可视需要再微调 */
}

.hero-featured {
    margin-bottom: 20px; /* 原来 48px，减小以压缩内间距 */
}

.section {
    padding-top: 30px; /* 原来 80px，改为 60px */
}

/* 移动端再收紧一些 */
@media (max-width: 768px) {
    .hero {
        padding-bottom: 20px; /* 原来 80px */
    }
    .section {
        padding-top: 20px;
    }
}