@import url('https://fonts.googleapis.com/css2?family=Cormorant+Garamond:wght@600&family=Noto+Sans+SC:wght@400;500&family=Noto+Serif+SC:wght@600;900&display=swap');

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px; /* offset for sticky header */
}

:root {
    --rice-paper: #F4F0E6;
    --surface: #FCFAF3;
    --pine-soot: #2B2A26;
    --indigo-slate: #35566B;
    --cinnabar: #B23A2F;
    --hairline: rgba(43, 42, 38, 0.16);
    --shadow: 0 2px 4px rgba(0,0,0,0.06);
}

body {
    font-family: 'Noto Sans SC', sans-serif;
    background-color: var(--rice-paper);
    color: var(--pine-soot);
    line-height: 1.8;
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 { font-family: 'Noto Serif SC', serif; font-weight: 600; color: var(--pine-soot); margin-top: 0; }
a { color: var(--indigo-slate); text-decoration: none; transition: color 0.3s ease; }
a:hover { color: var(--pine-soot); }
.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }
.small-label { font-size: 0.75rem; letter-spacing: 0.1em; text-transform: uppercase; font-family: 'Noto Sans SC', sans-serif; color: var(--pine-soot); opacity: 0.8; }

/* Header */
.site-header { border-bottom: 1px solid var(--hairline); background-color: var(--rice-paper); padding: 20px 0; position: sticky; top: 0; z-index: 200; backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); }
.header-inner { display: flex; justify-content: space-between; align-items: center; }
.logo { display: flex; align-items: center; gap: 12px; font-family: 'Noto Serif SC', serif; font-weight: 900; font-size: 1.6rem; color: var(--pine-soot); }
.logo:hover { color: var(--indigo-slate); }
.main-nav { display: flex; gap: 32px; align-items: center; }
.main-nav a { font-size: 0.95rem; color: var(--pine-soot); position: relative; padding-bottom: 4px; }
.main-nav a::after { content: ""; position: absolute; left: 0; bottom: 0; width: 0; height: 1px; background-color: var(--indigo-slate); transition: width 0.3s ease; }
.main-nav a:hover::after, .main-nav a.active::after { width: 100%; }
.main-nav a:hover, .main-nav a.active { color: var(--indigo-slate); }

/* Hero Split Layout */
.hero { padding: 80px 0; background-color: var(--surface); border-bottom: 1px solid var(--hairline); }
.hero-inner { display: flex; align-items: center; gap: 48px; text-align: left; }
.hero-content { flex: 1; }
.hero-content h1 { font-size: 3.5rem; font-weight: 900; margin-bottom: 24px; letter-spacing: 0.05em; text-align: left; }
.hero-content p { font-size: 1.25rem; max-width: 100%; margin: 0 0 40px 0; opacity: 0.9; text-align: left; }
.hero-content .btn-group { display: flex; justify-content: flex-start; gap: 16px; flex-wrap: wrap; }
.hero-image { flex: 1; text-align: center; }
.hero-image img { width: 100%; height: auto; border-radius: 8px; box-shadow: var(--shadow); object-fit: cover; aspect-ratio: 4/3; border: 1px solid var(--hairline); }

/* Buttons */
.btn { display: inline-block; padding: 12px 28px; font-size: 1rem; border-radius: 6px; border: 1px solid var(--indigo-slate); cursor: pointer; transition: all 0.3s ease; box-sizing: border-box; }
.btn-primary { background-color: var(--indigo-slate); color: var(--surface); }
.btn-primary:hover { background-color: #274051; border-color: #274051; color: var(--surface); }
.btn-secondary { background-color: transparent; color: var(--indigo-slate); }
.btn-secondary:hover { background-color: rgba(53, 86, 107, 0.05); }

/* Floating Back Button */
.floating-back { position: fixed; bottom: 40px; right: 40px; background-color: var(--surface); border: 1px solid var(--hairline); width: 48px; height: 48px; border-radius: 50%; display: flex; align-items: center; justify-content: center; color: var(--pine-soot); box-shadow: 0 4px 12px rgba(0,0,0,0.1); transition: all 0.3s; z-index: 100; text-decoration: none; }
.floating-back:hover { background-color: var(--indigo-slate); color: var(--surface); transform: translateY(-4px); }
.floating-back svg { width: 24px; height: 24px; }

/* Sections */
.section { padding: 80px 0; border-bottom: 1px solid var(--hairline); }
.section.surface { background-color: var(--surface); }
.section-title { text-align: center; font-size: 2.2rem; margin-bottom: 60px; position: relative; }
.section-title::after { content: ""; display: block; width: 32px; height: 1px; background-color: var(--cinnabar); margin: 24px auto 0 auto; }

/* Features */
.features { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--hairline); border-bottom: 1px solid var(--hairline); }
.feature-card { padding: 48px 32px; text-align: center; border-right: 1px solid var(--hairline); }
.feature-card:last-child { border-right: none; }
.feature-card h3 { font-size: 1.4rem; margin-bottom: 16px; }
.feature-card p { opacity: 0.85; margin: 0; }

/* Streaming */
.streaming-ai { text-align: center; max-width: 800px; margin: 0 auto; }
.streaming-ai h3 { font-size: 1.8rem; margin-bottom: 24px; }

/* Pricing */
.pricing { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.pricing-card { background-color: var(--surface); border: 1px solid var(--hairline); border-radius: 6px; padding: 48px 32px; text-align: center; box-shadow: var(--shadow); position: relative; }
.pricing-card.popular { border-color: var(--indigo-slate); }
.pricing-card.popular::before { content: "推荐"; position: absolute; top: -12px; left: 50%; transform: translateX(-50%); background-color: var(--cinnabar); color: var(--surface); font-size: 0.8rem; padding: 4px 12px; border-radius: 2px; letter-spacing: 0.1em; font-family: 'Noto Serif SC', serif; }
.pricing-card h3 { font-size: 1.4rem; margin-bottom: 12px; }
.price-wrap { margin-bottom: 24px; }
.price { font-family: 'Cormorant Garamond', serif; font-size: 3.5rem; color: var(--indigo-slate); line-height: 1; }
.price-currency { font-family: 'Noto Sans SC', sans-serif; font-size: 1.2rem; vertical-align: super; color: var(--pine-soot); opacity: 0.6; }
.price-period { font-family: 'Noto Sans SC', sans-serif; font-size: 1rem; color: var(--pine-soot); opacity: 0.6; }
.pricing-list { list-style: none; padding: 0; margin: 0 0 32px 0; text-align: left; }
.pricing-list li { padding: 12px 0; border-bottom: 1px solid var(--hairline); font-size: 0.95rem; opacity: 0.9; }
.pricing-list li:last-child { border-bottom: none; }
.pricing-list li::before { content: "•"; color: var(--cinnabar); margin-right: 12px; font-weight: bold; }

/* Articles Grid (Blog) */
.article-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.article-card { background-color: var(--surface); border: 1px solid var(--hairline); border-radius: 6px; padding: 32px; text-decoration: none; color: inherit; display: flex; flex-direction: column; transition: transform 0.3s, box-shadow 0.3s; box-shadow: var(--shadow); }
.article-card:hover { transform: translateY(-4px); box-shadow: 0 6px 12px rgba(0,0,0,0.08); color: inherit; }
.article-meta { font-size: 0.85rem; color: var(--pine-soot); opacity: 0.7; margin-bottom: 16px; display: flex; gap: 16px; align-items: center; }
.article-category { font-weight: bold; color: var(--cinnabar); font-family: 'Noto Serif SC', serif; opacity: 1; border: 1px solid var(--cinnabar); padding: 2px 6px; border-radius: 4px;}
.article-card h3 { font-size: 1.3rem; margin-bottom: 16px; line-height: 1.5; transition: color 0.3s; }
.article-card:hover h3 { color: var(--indigo-slate); }
.article-card p { font-size: 0.95rem; opacity: 0.8; margin-bottom: 24px; flex-grow: 1; }
.article-cta { margin-top: auto; font-weight: bold; font-size: 0.95rem; color: var(--indigo-slate); display: flex; align-items: center; gap: 8px;}
.article-cta::after { content: "→"; transition: transform 0.3s; }
.article-card:hover .article-cta::after { transform: translateX(4px); }

/* Single Post Layout */
.post-content { padding: 40px 0 80px 0; }
.post-header { text-align: center; margin-bottom: 48px; border-bottom: 1px solid var(--hairline); padding-bottom: 40px; }
.post-header h1 { font-size: 2.8rem; line-height: 1.35; margin-bottom: 24px; max-width: 900px; margin-left: auto; margin-right: auto; }
.post-body { max-width: 800px; margin: 0 auto; font-size: 1.15rem; line-height: 1.9; color: var(--pine-soot); }
.post-body h2 { font-size: 1.8rem; margin: 60px 0 24px 0; padding-bottom: 12px; border-bottom: 1px solid var(--hairline); color: var(--indigo-slate); }
.post-body h3 { font-size: 1.4rem; margin: 40px 0 16px 0; }
.post-body p { margin-bottom: 24px; }
.post-body ul, .post-body ol { margin-bottom: 24px; padding-left: 24px; }
.post-body li { margin-bottom: 12px; }
.post-body blockquote { border-left: 4px solid var(--cinnabar); padding-left: 20px; margin: 0 0 24px 0; font-style: italic; opacity: 0.9; background-color: var(--surface); padding: 16px 20px; border-radius: 0 6px 6px 0;}
.post-body img { max-width: 100%; height: auto; border-radius: 6px; margin-bottom: 24px; border: 1px solid var(--hairline); box-shadow: var(--shadow); }
.post-footer-nav { border-top: 1px solid var(--hairline); padding-top: 32px; margin-top: 60px; display: flex; justify-content: space-between; font-size: 1.05rem; font-weight: bold; }

/* FAQ & Reviews */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { padding: 32px 0; border-bottom: 1px solid var(--hairline); }
.faq-item:last-child { border-bottom: none; }
.faq-item h4 { font-size: 1.25rem; color: var(--indigo-slate); margin-bottom: 16px; }
.faq-item p { opacity: 0.9; margin: 0; }

.reviews { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.review-card { padding: 32px; border: 1px solid var(--hairline); border-radius: 6px; background-color: var(--surface); box-shadow: var(--shadow); }
.review-text { font-style: italic; opacity: 0.85; margin-bottom: 20px; }
.review-author { font-weight: 500; text-align: right; color: var(--indigo-slate); }

/* Footer */
footer { padding: 60px 0; text-align: center; }
.footer-links { display: flex; justify-content: center; gap: 32px; margin-bottom: 24px; flex-wrap: wrap; }
.footer-links a { color: var(--pine-soot); font-size: 0.95rem; opacity: 0.8; }
.footer-links a:hover { opacity: 1; color: var(--indigo-slate); }
.copyright { opacity: 0.5; font-size: 0.85rem; }

@media (max-width: 768px) {
    .header-inner { flex-direction: column; gap: 16px; }
    .hero-inner { flex-direction: column; text-align: center; gap: 32px; }
    .hero-content h1, .hero-content p { text-align: center; }
    .hero-content .btn-group { justify-content: center; }
    .hero h1 { font-size: 2.5rem; }
    .features { grid-template-columns: 1fr; border-right: none; }
    .feature-card { border-right: none; border-bottom: 1px solid var(--hairline); }
    .feature-card:last-child { border-bottom: none; }
    .pricing, .reviews, .article-grid { grid-template-columns: 1fr; }
    .btn { width: 100%; text-align: center; }
    .main-nav { flex-wrap: wrap; justify-content: center; gap: 16px; }
    .post-header h1 { font-size: 2rem; }
    .floating-back { bottom: 20px; right: 20px; width: 40px; height: 40px; }
    .floating-back svg { width: 20px; height: 20px; }
    [style*="grid-template-columns: repeat(4"] { grid-template-columns: repeat(2,1fr) !important; }
}