:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-500: #6b7280;
    --gray-800: #1f2937;
    --white: #ffffff;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    color: var(--gray-800);
    background: #fff;
}

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

.container {
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.top-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
}

.brand {
    font-weight: 600;
    font-size: 20px;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 18px;
    margin: 0;
    padding: 0;
}

.nav-links a {
    color: var(--gray-500);
    padding: 6px 12px;
    border-radius: 999px;
    transition: background 0.2s, color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary);
    background: rgba(37, 99, 235, 0.12);
}

/* Hero */
.hero {
    background: linear-gradient(120deg, rgba(37, 99, 235, 0.12), rgba(37, 99, 235, 0));
    padding-bottom: 60px;
}

.hero-content {
    padding: 80px 0 60px;
    max-width: 640px;
}

.hero h1 {
    font-size: 40px;
    margin-bottom: 16px;
}

.hero p {
    font-size: 18px;
    line-height: 1.6;
    color: var(--gray-500);
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-top: 28px;
}

.sub-hero {
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.14), rgba(37, 99, 235, 0));
    padding-bottom: 48px;
}

.sub-hero-content {
    padding: 60px 0 40px;
    max-width: 720px;
}

.sub-hero-content h1 {
    font-size: 36px;
    margin-bottom: 14px;
}

.sub-hero-content p {
    color: var(--gray-500);
    font-size: 17px;
    line-height: 1.6;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 999px;
    font-weight: 600;
    text-align: center;
    transition: transform 0.18s, box-shadow 0.18s;
}

.btn.primary {
    background: var(--primary);
    color: var(--white);
    box-shadow: 0 10px 20px rgba(37, 99, 235, 0.25);
}

.btn.primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

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

.btn.outline:hover {
    background: rgba(37, 99, 235, 0.08);
}

.btn.block {
    width: 100%;
}

.btn.small {
    padding: 8px 18px;
    font-size: 14px;
}

/* Sections */
.section {
    padding: 72px 0;
}

.section.bg-light {
    background: var(--gray-100);
}

.section-title {
    font-size: 28px;
    text-align: center;
    margin-bottom: 12px;
}

.section-subtitle {
    text-align: center;
    color: var(--gray-500);
    margin-bottom: 36px;
}

.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
}

.card {
    background: var(--white);
    border-radius: 16px;
    box-shadow: 0 8px 18px rgba(15, 23, 42, 0.08);
    padding: 24px;
}

.split {
    display: grid;
    gap: 32px;
}

.split .panel {
    background: var(--white);
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 12px 24px rgba(15, 23, 42, 0.08);
}

/* Lists */
.feature-list {
    list-style: none;
    padding: 0;
    margin: 18px 0;
}

.feature-list li {
    padding: 8px 0;
    color: var(--gray-500);
}

.feature-list.small li {
    padding: 4px 0;
    font-size: 15px;
}

/* Contact */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
}

.contact-card {
    background: var(--white);
    border-radius: 14px;
    padding: 20px;
    box-shadow: 0 12px 22px rgba(15, 23, 42, 0.08);
}

.contact-card h4 {
    margin-top: 0;
}

/* Pricing */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 26px;
}

.pricing-card {
    background: var(--white);
    border-radius: 18px;
    padding: 28px 24px;
    box-shadow: 0 14px 30px rgba(37, 99, 235, 0.12);
    position: relative;
}

.pricing-card.featured {
    border: 2px solid rgba(37, 99, 235, 0.2);
    transform: translateY(-6px);
}

.pricing-card .badge {
    position: absolute;
    top: -14px;
    right: 24px;
    background: var(--primary);
    color: var(--white);
    padding: 4px 12px;
    border-radius: 999px;
    font-size: 13px;
}

.pricing-card .price {
    font-size: 32px;
    font-weight: 700;
    margin: 12px 0;
}

.pricing-card .subtitle {
    color: var(--gray-500);
    margin-bottom: 20px;
}

.pricing-card ul {
    list-style: none;
    padding: 0;
    margin: 16px 0 26px;
}

.pricing-card ul li {
    padding: 8px 0;
    color: var(--gray-500);
}

/* FAQ */
.faq {
    display: grid;
    gap: 18px;
}

.faq-item {
    background: var(--white);
    border-radius: 14px;
    padding: 20px;
    box-shadow: 0 10px 20px rgba(15, 23, 42, 0.06);
}

.faq-item h3 {
    margin-top: 0;
}

/* Download */
.downloads .download-card {
    display: flex;
    align-items: center;
    gap: 26px;
    padding: 26px;
    border-radius: 18px;
    background: var(--white);
    box-shadow: 0 16px 32px rgba(15, 23, 42, 0.1);
}

.download-actions {
    flex: 0 0 220px;
    text-align: right;
}

.build-info {
    display: inline-block;
    margin-top: 10px;
    color: var(--gray-500);
    font-size: 14px;
}

.changelog article {
    background: var(--white);
    padding: 20px;
    border-radius: 14px;
    box-shadow: 0 10px 24px rgba(15, 23, 42, 0.08);
    margin-bottom: 18px;
}

.changelog h3 {
    margin-top: 0;
}

/* Footer */
.footer {
    background: var(--gray-800);
    color: #d1d5db;
    padding: 28px 0;
    text-align: center;
    font-size: 14px;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 30px;
    }

    .hero-content {
        padding: 60px 0 40px;
    }

    .top-nav {
        flex-direction: column;
        gap: 12px;
    }

    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
    }

    .hero-actions {
        flex-direction: column;
        width: 100%;
    }

    .downloads .download-card {
        flex-direction: column;
        align-items: flex-start;
    }

    .download-actions {
        width: 100%;
        text-align: left;
    }
}