:root {
    --chrome-blue: #4285F4;
    --chrome-red: #EA4335;
    --chrome-yellow: #FBBC05;
    --chrome-green: #34A853;
    --dark-bg: #202124;
    --light-bg: #f8f9fa;
    --text-dark: #3c4043;
    --text-light: #5f6368;
    --border-color: #dadce0;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: #fff;
}

/* Header Styles */
header {
    background: linear-gradient(135deg, var(--chrome-blue) 0%, #3367d6 100%);
    color: white;
    padding: 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-top {
    background: rgba(0,0,0,0.1);
    padding: 8px 0;
    font-size: 14px;
}

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

.header-main {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 24px;
    font-weight: 700;
    text-decoration: none;
    color: white;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--chrome-red), var(--chrome-yellow), var(--chrome-green), var(--chrome-blue));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: white;
    font-size: 20px;
}

/* Navigation */
nav ul {
    display: flex;
    list-style: none;
    gap: 5px;
    flex-wrap: wrap;
}

nav a {
    color: white;
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 4px;
    transition: all 0.3s;
    font-weight: 500;
    font-size: 15px;
}

nav a:hover, nav a.active {
    background: rgba(255,255,255,0.2);
    transform: translateY(-2px);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 24px;
    cursor: pointer;
}

/* Breadcrumb */
.breadcrumb {
    background: var(--light-bg);
    padding: 15px 0;
    border-bottom: 1px solid var(--border-color);
    font-size: 14px;
}

.breadcrumb a {
    color: var(--chrome-blue);
    text-decoration: none;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

.breadcrumb span {
    color: var(--text-light);
    margin: 0 8px;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #f8f9fa 0%, #e8f0fe 100%);
    padding: 60px 0;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

.hero h1 {
    font-size: 42px;
    margin-bottom: 20px;
    color: var(--dark-bg);
    font-weight: 700;
}

.hero p {
    font-size: 18px;
    color: var(--text-light);
    max-width: 700px;
    margin: 0 auto 30px;
}

/* Download Buttons */
.download-section {
    background: white;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    max-width: 800px;
    margin: 0 auto;
}

.download-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 30px;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 16px;
    transition: all 0.3s;
    border: 2px solid transparent;
}

.btn-quark {
    background: linear-gradient(135deg, #00b4ff, #0088cc);
    color: white;
}

.btn-baidu {
    background: linear-gradient(135deg, #2932e1, #1a1ab3);
    color: white;
}

.btn-xunlei {
    background: linear-gradient(135deg, #00a4ff, #0077cc);
    color: white;
}

.download-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

.version-info {
    margin-top: 20px;
    padding: 15px;
    background: var(--light-bg);
    border-radius: 8px;
    font-size: 14px;
    color: var(--text-light);
}

/* Content Sections */
.section {
    padding: 60px 0;
}

.section-title {
    text-align: center;
    font-size: 32px;
    margin-bottom: 40px;
    color: var(--dark-bg);
    position: relative;
    padding-bottom: 15px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--chrome-red), var(--chrome-yellow), var(--chrome-green), var(--chrome-blue));
    border-radius: 2px;
}

/* Grid Layouts */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.grid-4 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
}

/* Cards */
.card {
    background: white;
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.06);
    transition: all 0.3s;
    border: 1px solid var(--border-color);
    text-decoration: none;
    color: inherit;
    display: block;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
    border-color: var(--chrome-blue);
}

.card-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--chrome-blue), #3367d6);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 28px;
    margin-bottom: 20px;
}

.card h3 {
    font-size: 20px;
    margin-bottom: 12px;
    color: var(--dark-bg);
}

.card p {
    color: var(--text-light);
    font-size: 15px;
    line-height: 1.6;
}

/* Sub-nav in pages */
.sub-nav {
    background: white;
    padding: 20px 0;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 40px;
}

.sub-nav ul {
    display: flex;
    gap: 10px;
    list-style: none;
    flex-wrap: wrap;
    justify-content: center;
}

.sub-nav a {
    color: var(--text-dark);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    font-size: 14px;
    transition: all 0.3s;
}

.sub-nav a:hover, .sub-nav a.active {
    background: var(--chrome-blue);
    color: white;
    border-color: var(--chrome-blue);
}

/* Content Styles */
.content-box {
    background: white;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.06);
    margin-bottom: 30px;
}

.content-box h2 {
    color: var(--dark-bg);
    margin-bottom: 20px;
    font-size: 28px;
    border-left: 4px solid var(--chrome-blue);
    padding-left: 15px;
}

.content-box h3 {
    color: var(--text-dark);
    margin: 30px 0 15px;
    font-size: 22px;
}

.content-box p {
    margin-bottom: 15px;
    color: var(--text-light);
    line-height: 1.8;
}

.content-box ul, .content-box ol {
    margin-left: 25px;
    margin-bottom: 20px;
}

.content-box li {
    margin-bottom: 10px;
    color: var(--text-light);
}

/* Screenshot Placeholder */
.screenshot-placeholder {
    background: linear-gradient(135deg, #e8f0fe, #f8f9fa);
    border: 2px dashed var(--chrome-blue);
    border-radius: 12px;
    padding: 60px 20px;
    text-align: center;
    margin: 30px 0;
    position: relative;
    overflow: hidden;
}

.screenshot-placeholder::before {
    content: '🖼️';
    font-size: 48px;
    display: block;
    margin-bottom: 15px;
    opacity: 0.5;
}

.screenshot-placeholder p {
    color: var(--chrome-blue);
    font-weight: 500;
    margin: 0;
}

/* Keyword Links */
.keyword-link {
    color: var(--chrome-blue);
    text-decoration: none;
    border-bottom: 1px dotted var(--chrome-blue);
    transition: all 0.3s;
}

.keyword-link:hover {
    color: var(--chrome-red);
    border-bottom-color: var(--chrome-red);
}

/* Tags */
.tag {
    display: inline-block;
    padding: 4px 12px;
    background: #e8f0fe;
    color: var(--chrome-blue);
    border-radius: 20px;
    font-size: 13px;
    margin: 5px 5px 5px 0;
    text-decoration: none;
    transition: all 0.3s;
}

.tag:hover {
    background: var(--chrome-blue);
    color: white;
}

/* FAQ Styles */
.faq-item {
    border-bottom: 1px solid var(--border-color);
    padding: 20px 0;
}

.faq-question {
    font-weight: 600;
    color: var(--dark-bg);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 18px;
}

.faq-answer {
    margin-top: 15px;
    color: var(--text-light);
    line-height: 1.8;
    display: none;
}

.faq-answer.active {
    display: block;
}

.faq-toggle {
    font-size: 24px;
    color: var(--chrome-blue);
    transition: transform 0.3s;
}

.faq-item.active .faq-toggle {
    transform: rotate(45deg);
}

/* Footer */
footer {
    background: var(--dark-bg);
    color: white;
    padding: 50px 0 20px;
    margin-top: 80px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h4 {
    margin-bottom: 20px;
    color: var(--chrome-yellow);
    font-size: 18px;
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: 10px;
}

.footer-section a {
    color: #9aa0a6;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid #5f6368;
    padding-top: 20px;
    text-align: center;
    color: #9aa0a6;
    font-size: 14px;
}

/* Responsive */
@media (max-width: 768px) {
    .mobile-menu-btn {
        display: block;
    }

    nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--chrome-blue);
        padding: 20px;
    }

    nav.active {
        display: block;
    }

    nav ul {
        flex-direction: column;
    }

    .hero h1 {
        font-size: 28px;
    }

    .download-section {
        padding: 20px;
    }

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

    .download-btn {
        width: 100%;
        justify-content: center;
    }

    .grid-3, .grid-4 {
        grid-template-columns: 1fr;
    }

    .content-box {
        padding: 20px;
    }
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

th, td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background: var(--light-bg);
    font-weight: 600;
    color: var(--dark-bg);
}

tr:hover {
    background: #f8f9fa;
}

/* Alert Boxes */
.alert {
    padding: 15px 20px;
    border-radius: 8px;
    margin: 20px 0;
    border-left: 4px solid;
}

.alert-info {
    background: #e8f0fe;
    border-left-color: var(--chrome-blue);
    color: #1967d2;
}

.alert-success {
    background: #e6f4ea;
    border-left-color: var(--chrome-green);
    color: #137333;
}

.alert-warning {
    background: #fef3e8;
    border-left-color: var(--chrome-yellow);
    color: #b06000;
}