:root {
    --bg-color: #f8fcfd;
    --surface-color: #ffffff;
    --surface-light: #f1f5f9;
    --primary-color: #007bc7;
    --primary-dark: #005a9c;
    --secondary-color: #2ab6eb;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --glass-bg: rgba(255, 255, 255, 0.95);
    --glass-border: rgba(0, 0, 0, 0.05);
}

body {
    margin: 0;
    font-family: 'KaiTi', '楷体', STKaiti, serif;
    background: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

.article-meta {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 30px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
}
.article-date {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-bottom: 8px;
}

#tsparticles {
    position: fixed;
    width: 100%;
    height: 100%;
    z-index: -1;
    top: 0;
    left: 0;
}

nav {
    position: fixed;
    top: 0;
    width: 100%;
    padding: 15px 40px;
    background: var(--glass-bg);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border-bottom: 1px solid var(--glass-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 1000;
    box-sizing: border-box;
}
nav .logo {
    font-size: 24px;
    font-weight: bold;
    color: #003057;
    text-decoration: none;
    letter-spacing: 1px;
    display: flex;
    align-items: center;
    gap: 8px;
}
nav .logo svg {
    width: 24px;
    height: 24px;
    fill: var(--primary-color);
}
nav ul {
    list-style: none;
    display: flex;
    gap: 40px;
    margin: 0;
    padding: 0;
    align-items: center;
}
nav ul li a {
    text-decoration: none;
    color: var(--text-muted);
    font-size: 1rem;
    transition: color 0.3s ease;
}
nav ul li a:hover {
    color: var(--primary-color);
}
.nav-btn {
    background: var(--primary-color);
    padding: 10px 25px;
    border-radius: 30px;
    color: white !important;
    font-weight: bold;
    transition: background 0.3s ease;
    text-decoration: none;
}
.nav-btn:hover {
    background: var(--primary-dark);
}

.hero {
    min-height: 80vh;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 120px 80px 60px 80px;
    position: relative;
    max-width: 1200px;
    margin: 0 auto;
}
.hero-content {
    flex: 1;
    text-align: left;
    max-width: 550px;
}
.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    font-weight: 900;
    line-height: 1.3;
    color: #003057;
}
.hero h1 span {
    color: var(--primary-color);
}
.hero p {
    font-size: 1.1rem;
    color: var(--text-muted);
    margin-bottom: 40px;
    line-height: 1.8;
}
.hero-image {
    flex: 1;
    display: flex;
    justify-content: flex-end;
}
.hero-image svg {
    max-width: 400px;
    width: 100%;
}

.btn {
    padding: 12px 35px;
    font-size: 1.1rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 30px;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.3s ease;
    font-family: inherit;
    font-weight: bold;
    display: inline-block;
    box-shadow: 0 4px 10px rgba(0, 123, 199, 0.3);
}
.btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}
.btn-outline {
    background: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-main);
    box-shadow: none;
    margin-left: 15px;
}
.btn-outline:hover {
    border-color: var(--primary-color);
    background: rgba(0, 123, 199, 0.05);
    color: var(--primary-color);
}

section {
    padding: 80px 20px;
    max-width: 1200px;
    margin: 0 auto;
}
.section-header {
    text-align: center;
    margin-bottom: 60px;
}
.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: var(--text-main);
}
.section-header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}
.feature-card {
    background: var(--surface-color);
    padding: 40px 30px;
    border-radius: 16px;
    border: 1px solid var(--glass-border);
    transition: transform 0.3s, border-color 0.3s;
}
.feature-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
}
.feature-icon {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}
.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
}
.feature-card p {
    color: var(--text-muted);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    align-items: center;
}
.pricing-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 40px 30px;
    text-align: center;
    transition: transform 0.3s ease;
    position: relative;
}
.pricing-card.popular {
    background: linear-gradient(180deg, var(--surface-color) 0%, rgba(14, 165, 233, 0.1) 100%);
    border-color: var(--primary-color);
    transform: scale(1.05);
}
.pricing-card:hover {
    transform: translateY(-10px);
}
.pricing-card.popular:hover {
    transform: scale(1.05) translateY(-10px);
}
.popular-badge {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--primary-color);
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: bold;
}
.pricing-card h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--text-muted);
}
.pricing-card .price {
    font-size: 3.5rem;
    font-weight: bold;
    margin-bottom: 30px;
    color: var(--text-main);
}
.pricing-card .price span {
    font-size: 1rem;
    color: var(--text-muted);
    font-weight: normal;
}
.pricing-card ul {
    list-style: none;
    padding: 0;
    margin-bottom: 40px;
    text-align: left;
}
.pricing-card ul li {
    margin-bottom: 15px;
    color: var(--text-main);
    display: flex;
    align-items: center;
}
.pricing-card ul li::before {
    content: '✓';
    color: var(--primary-color);
    margin-right: 10px;
    font-weight: bold;
}
.pricing-card .btn {
    width: 100%;
    box-sizing: border-box;
}

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}
.review-card {
    background: var(--surface-color);
    padding: 30px;
    border-radius: 16px;
    border: 1px solid var(--border-color);
}
.review-stars {
    color: #fbbf24;
    margin-bottom: 15px;
}
.review-text {
    font-style: italic;
    color: var(--text-main);
    margin-bottom: 20px;
}
.review-author {
    color: var(--text-muted);
    font-weight: bold;
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
}
.article-card {
    background: var(--surface-color);
    padding: 20px;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    text-decoration: none;
    color: var(--text-main);
    transition: all 0.3s;
}
.article-card:hover {
    border-color: var(--primary-color);
}
.article-card h4 {
    margin: 0 0 10px 0;
    color: var(--primary-color);
    font-size: 1.2rem;
}
.article-card p {
    color: var(--text-muted);
    margin: 0;
    font-size: 0.9rem;
}

.content-container {
    max-width: 900px;
    margin: 100px auto 40px;
    background: var(--surface-color);
    padding: 50px;
    border-radius: 16px;
    border: 1px solid var(--border-color);
}
.content-container h1 {
    text-align: center;
    margin-bottom: 30px;
    font-size: 2.2rem;
}
.content-container h2 {
    font-size: 1.8rem;
    color: var(--primary-color);
    margin-top: 40px;
    margin-bottom: 20px;
}
.content-container p {
    text-indent: 2em;
    margin-bottom: 20px;
    font-size: 1.15rem;
    color: var(--text-main);
    line-height: 1.8;
}
.content-container a {
    color: var(--secondary-color);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s;
}
.content-container a:hover {
    border-color: var(--secondary-color);
}

.faq-section {
    margin-top: 60px;
    padding-top: 40px;
    border-top: 1px solid var(--border-color);
}
.faq-section h2 {
    text-align: center;
    margin-bottom: 30px;
}
.faq-section dt {
    font-weight: bold;
    font-size: 1.2rem;
    margin-top: 25px;
    color: var(--primary-color);
    background: var(--surface-light);
    padding: 15px 20px;
    border-radius: 8px 8px 0 0;
}
.faq-section dd {
    margin-left: 0;
    margin-top: 0;
    margin-bottom: 25px;
    padding: 20px;
    background: rgba(51, 65, 85, 0.3);
    border: 1px solid var(--surface-light);
    border-top: none;
    border-radius: 0 0 8px 8px;
    color: var(--text-muted);
    font-size: 1.1rem;
}

footer {
    text-align: center;
    padding: 40px;
    background: var(--bg-color);
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
}
footer a {
    color: var(--primary-color);
    text-decoration: none;
}

@media (max-width: 768px) {
    nav { padding: 15px 20px; }
    nav ul { display: none; }
    .hero { flex-direction: column; text-align: center; padding: 100px 20px 40px; }
    .hero-content { max-width: 100%; margin-bottom: 40px; }
    .hero h1 { font-size: 2.5rem; }
    .pricing-card.popular { transform: none; }
    .pricing-card.popular:hover { transform: translateY(-5px); }
    .content-container { padding: 20px; margin: 80px 15px 40px; }
}