/* "Strata" UI Kit */
@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;700&family=Noto+Sans+SC:wght@400;500;700&family=Sora:wght@400;600&display=swap');

:root {
    --bg-paper: #FAFAF7;
    --panel-white: #FFFFFF;
    --text-ink: #111417;
    --text-muted: #737B85;
    --hairline: #E3E1DB;
    --accent: #0E9F8A;

    --font-heading: 'Sora', 'Noto Sans SC', sans-serif;
    --font-body: 'Noto Sans SC', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

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

body {
    background-color: var(--bg-paper);
    color: var(--text-ink);
    font-family: var(--font-body);
    line-height: 1.6;
    font-size: 15px;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--text-ink);
    font-weight: 600;
}

a {
    color: var(--text-ink);
    text-decoration: underline;
    text-decoration-color: var(--hairline);
    text-underline-offset: 4px;
    transition: text-decoration-color 0.2s;
}

a:hover {
    text-decoration-color: var(--accent);
}

a.no-underline {
    text-decoration: none;
}

.container {
    max-width: 1024px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Header */
.header {
    background: var(--bg-paper);
    border-bottom: 1px solid var(--hairline);
    padding: 24px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo-wrapper {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

.logo-text {
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 18px;
    letter-spacing: -0.02em;
}

.nav {
    display: flex;
    gap: 32px;
}

.nav a {
    text-decoration: none;
    font-size: 14px;
    color: var(--text-muted);
}

.nav a:hover {
    color: var(--text-ink);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    font-family: var(--font-mono);
    font-size: 13px;
    font-weight: 700;
    text-transform: uppercase;
    text-decoration: none;
    text-align: center;
    cursor: pointer;
    border: 1px solid var(--text-ink);
    background: transparent;
    color: var(--text-ink);
    transition: all 0.2s;
}

.btn:hover {
    background: var(--text-ink);
    color: var(--bg-paper);
}

.btn-primary {
    background: var(--accent);
    color: var(--panel-white);
    border-color: var(--accent);
}

.btn-primary:hover {
    background: transparent;
    color: var(--accent);
}

.btn-large {
    padding: 16px 32px;
    font-size: 14px;
}

/* Hero Section */
.hero {
    padding: 120px 0 80px;
    border-bottom: 1px solid var(--hairline);
    background: var(--panel-white);
}

.hero h1 {
    font-size: 42px;
    line-height: 1.4;
    margin-bottom: 24px;
    letter-spacing: -0.02em;
    max-width: 800px;
}

.hero p {
    font-size: 18px;
    color: var(--text-muted);
    max-width: 600px;
    margin-bottom: 48px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    align-items: center;
}

/* Sections */
.section {
    padding: 80px 0;
    border-bottom: 1px solid var(--hairline);
}

.section-title {
    font-size: 24px;
    margin-bottom: 48px;
    display: flex;
    align-items: center;
    gap: 16px;
}

.section-title::before {
    content: '';
    display: block;
    width: 24px;
    height: 1px;
    background: var(--accent);
}

/* Grids */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

/* Cards */
.card {
    background: var(--panel-white);
    border: 1px solid var(--hairline);
    padding: 32px;
}

.card h3 {
    font-size: 18px;
    margin-bottom: 16px;
}

.card p {
    color: var(--text-muted);
    font-size: 14px;
}

/* Pricing Table */
.pricing-wrapper {
    display: flex;
    flex-direction: column;
}

.price-card {
    background: var(--panel-white);
    border: 1px solid var(--hairline);
    padding: 40px;
    display: flex;
    flex-direction: column;
}

.price-card.popular {
    border-color: var(--accent);
    position: relative;
}

.price-card.popular::before {
    content: '推荐购买';
    position: absolute;
    top: 0;
    left: 0;
    background: var(--accent);
    color: var(--panel-white);
    font-family: var(--font-mono);
    font-size: 10px;
    padding: 4px 8px;
    letter-spacing: 0.05em;
}

.price-header {
    margin-bottom: 32px;
}

.price-header h3 {
    font-family: var(--font-mono);
    font-size: 14px;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 8px;
}

.price {
    font-family: var(--font-mono);
    font-size: 40px;
    font-weight: 400;
    letter-spacing: -0.05em;
}

.price span {
    font-size: 16px;
    color: var(--text-muted);
}

.price-features {
    list-style: none;
    margin-bottom: 40px;
    flex-grow: 1;
}

.price-features li {
    font-family: var(--font-mono);
    font-size: 13px;
    padding: 12px 0;
    border-bottom: 1px solid var(--hairline);
    color: var(--text-ink);
    display: flex;
    justify-content: space-between;
}

.price-features li span {
    color: var(--text-muted);
}

.price-card .btn {
    width: 100%;
}

/* FAQ */
.faq-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.faq-item {
    border-top: 1px solid var(--hairline);
    padding-top: 24px;
}

.faq-item h4 {
    font-size: 16px;
    margin-bottom: 12px;
}

.faq-item p {
    color: var(--text-muted);
    font-size: 14px;
}

/* Footer */
.footer {
    padding: 80px 0 40px;
    background: var(--bg-paper);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 80px;
}

.footer-brand p {
    color: var(--text-muted);
    font-size: 14px;
    margin-top: 16px;
    max-width: 240px;
}

.footer-links h4 {
    font-family: var(--font-mono);
    font-size: 12px;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 24px;
}

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

.footer-links li {
    margin-bottom: 12px;
    font-size: 14px;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 24px;
    border-top: 1px solid var(--hairline);
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
}

/* Responsive */
@media (max-width: 768px) {
    .nav {
        display: none;
    }
    
    .hero {
        padding: 64px 0;
    }

    .hero h1 {
        font-size: 32px;
        line-height: 1.4;
    }
    
    .grid-3, .grid-2, .faq-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }

    .hero-actions {
        flex-direction: column;
        align-items: stretch;
    }
}

/* Blog & Articles */
.blog-card {
    display: flex;
    flex-direction: column;
}
.blog-meta {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    text-transform: uppercase;
    margin-bottom: 16px;
}
.blog-cat { color: var(--accent); font-weight: 700; }
.blog-title h3 {
    font-size: 18px;
    line-height: 1.4;
    margin-bottom: 12px;
}
.blog-excerpt {
    font-size: 14px;
    color: var(--text-muted);
    flex-grow: 1;
    margin-bottom: 24px;
}
.blog-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--hairline);
    padding-top: 16px;
    font-family: var(--font-mono);
    font-size: 12px;
}
.read-more { color: var(--accent); font-weight: 700; text-decoration: none; }
.read-more:hover { text-decoration: underline; }
.blog-date { color: var(--text-muted); }

/* Article Page */
.article-container .container {
    display: grid;
    grid-template-columns: 3fr 1fr;
    gap: 60px;
}
.article-h1 {
    font-size: 36px;
    line-height: 1.3;
    margin-bottom: 24px;
}
.article-meta {
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--text-muted);
    padding-bottom: 32px;
    border-bottom: 1px solid var(--hairline);
    margin-bottom: 40px;
}
.article-body h2 {
    font-size: 24px;
    margin: 40px 0 20px;
}
.article-body h3 {
    font-size: 18px;
    margin: 30px 0 16px;
}
.article-body p {
    margin-bottom: 20px;
    font-size: 16px;
}
.article-body ul, .article-body ol {
    margin-bottom: 20px;
    padding-left: 20px;
}
.article-body li {
    margin-bottom: 10px;
}
.article-sidebar h3 {
    font-family: var(--font-mono);
    font-size: 14px;
    text-transform: uppercase;
    margin-bottom: 20px;
    color: var(--text-muted);
}
.sidebar-links {
    list-style: none;
}
.sidebar-links li {
    margin-bottom: 16px;
    font-size: 14px;
}
.text-center { text-align: center; }
.mt-48 { margin-top: 48px; }

@media (max-width: 768px) {
    .article-container .container { grid-template-columns: 1fr; }
}


.hero .container { display: flex; align-items: center; gap: 60px; text-align: left; }
.hero-content { flex: 1; }
.hero-img-box { flex: 1; text-align: center; }
.hero-img-box img { max-width: 100%; height: auto; border: 1px solid var(--hairline); }
.hero p { margin: 0 0 40px; }
@media (max-width: 768px) {
    .hero .container { flex-direction: column; text-align: left; gap: 30px; }
    .hero-img-box { order: -1; }
}