/* ================================================================
   apps-google-zh.hl.cn — Modern Clean Chrome-style Landing Page
   Clean blue gradients, card design, professional and trustworthy
   ================================================================ */

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: "Segoe UI", "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
    color: #202124;
    background: #f8f9fa;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

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

button {
    cursor: pointer;
    font-family: inherit;
    border: none;
    background: none;
}

/* Animation */
@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

/* ==================== NAVIGATION ==================== */
.topnav {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid #dadce0;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.topnav .wrap {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 68px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.35rem;
    font-weight: 700;
    color: #1a73e8;
    letter-spacing: -0.5px;
}

.brand svg {
    width: 32px;
    height: 32px;
}

.navlist {
    display: flex;
    align-items: center;
    gap: 8px;
}

.navlist a {
    padding: 8px 20px;
    font-size: 0.95rem;
    font-weight: 500;
    color: #5f6368;
    border-radius: 9999px;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.navlist a:hover {
    background: #f1f3f4;
    color: #202124;
}

.navlist a.on {
    background: #1a73e8;
    color: white;
    font-weight: 600;
    box-shadow: 0 1px 3px rgba(26, 115, 232, 0.3);
}

/* ==================== HERO SECTION ==================== */
.hero {
    background: linear-gradient(135deg, #1a73e8 0%, #4285f4 100%);
    color: white;
    padding: 110px 0 90px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    filter: blur(80px);
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-text h1 {
    font-size: 3.1rem;
    line-height: 1.15;
    font-weight: 700;
    margin-bottom: 24px;
    letter-spacing: -1.5px;
}

.hero-text p {
    font-size: 1.25rem;
    opacity: 0.95;
    margin-bottom: 32px;
    max-width: 460px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 32px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 50px;
    transition: all 0.3s cubic-bezier(0.4, 0.0, 0.2, 1);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.btn-primary {
    background: white;
    color: #1a73e8;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid rgba(255,255,255,0.8);
}

.btn-secondary:hover {
    background: rgba(255,255,255,0.1);
    border-color: white;
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.chrome-logo {
    width: 280px;
    height: 280px;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 25px 50px -12px rgb(0 0 0 / 0.4);
    position: relative;
}

.chrome-logo svg {
    width: 160px;
    height: 160px;
}

/* ==================== FEATURES ==================== */
.features {
    padding: 90px 0;
    background: white;
}

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

.section-title h2 {
    font-size: 2.4rem;
    font-weight: 700;
    color: #202124;
    margin-bottom: 16px;
}

.section-title p {
    font-size: 1.2rem;
    color: #5f6368;
    max-width: 580px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 28px;
}

.feature-card {
    background: white;
    border-radius: 16px;
    padding: 40px 32px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
    border: 1px solid #e8eaed;
    transition: all 0.3s ease;
    height: 100%;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(26, 115, 232, 0.12);
    border-color: #1a73e8;
}

.feature-card svg {
    width: 52px;
    height: 52px;
    margin-bottom: 24px;
    color: #1a73e8;
}

.feature-card h3 {
    font-size: 1.45rem;
    margin-bottom: 16px;
    color: #202124;
    font-weight: 600;
}

.feature-card p {
    color: #5f6368;
    line-height: 1.65;
}

/* ==================== PLATFORMS / DOWNLOADS ==================== */
.platforms {
    padding: 90px 0;
    background: #f8f9fa;
}

.platforms-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
    margin-top: 50px;
}

.platform-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.07);
    text-align: center;
    transition: all 0.3s;
}

.platform-card:hover {
    transform: scale(1.03);
    box-shadow: 0 15px 35px rgba(26, 115, 232, 0.15);
}

.platform-icon {
    height: 160px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #f1f3f4, #e8eaed);
}

.platform-card h3 {
    padding: 24px 20px 8px;
    font-size: 1.35rem;
    color: #202124;
}

.platform-card .btn {
    margin: 0 auto 32px;
    font-size: 1rem;
    padding: 12px 36px;
}

/* ==================== TESTIMONIALS ==================== */
.testimonials {
    padding: 90px 0;
    background: white;
}

.testimonial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 30px;
}

.testimonial-card {
    background: #f8f9fa;
    padding: 36px;
    border-radius: 16px;
    border-left: 5px solid #1a73e8;
}

.testimonial-card p {
    font-size: 1.1rem;
    font-style: italic;
    margin-bottom: 24px;
    color: #3c4043;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 14px;
}

.testimonial-author .avatar {
    width: 48px;
    height: 48px;
    background: #1a73e8;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
}

/* ==================== FAQ ==================== */
.faq {
    padding: 100px 0;
    background: #f8f9fa;
}

.faq-item {
    background: white;
    margin-bottom: 16px;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.faq-question {
    padding: 24px 28px;
    font-size: 1.15rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: white;
}

.faq-answer {
    padding: 0 28px 28px;
    color: #5f6368;
    display: none;
    line-height: 1.75;
}

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

/* ==================== FOOTER ==================== */
.footer {
    background: #202124;
    color: #dadce0;
    padding: 70px 0 40px;
    font-size: 0.95rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 60px;
}

.footer h4 {
    color: white;
    margin-bottom: 18px;
    font-size: 1.05rem;
}

.footer ul {
    list-style: none;
}

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

.footer ul a {
    color: #9aa0a6;
    transition: color 0.2s;
}

.footer ul a:hover {
    color: #8ab4f8;
}

.footer-notice {
    border-top: 1px solid #3c4043;
    padding-top: 32px;
    text-align: center;
    color: #9aa0a6;
    font-size: 0.9rem;
    line-height: 1.7;
}

.footer-notice strong {
    color: #8ab4f8;
}

/* Responsive */
@media (max-width: 768px) {
    .hero-content,
    .features-grid,
    .testimonial-grid,
    .footer-content {
        grid-template-columns: 1fr;
    }

    .hero-text h1 {
        font-size: 2.4rem;
    }

    .hero {
        padding: 80px 0 70px;
    }
}

/* Utility */
.text-center { text-align: center; }
.mt-2 { margin-top: 2rem; }
.mb-3 { margin-bottom: 3rem; }