/* 
 * NEBULA INK - Design System
 * Aesthetic: Calm, Dark, Cosmic Engineering
 */
:root {
    --bg-main: #0B0F17;
    --bg-surface: #131A26;
    --text-primary: #E9EDF5;
    --text-secondary: #8C96A8;
    --accent: #45E0C2;
    --border-hairline: rgba(233, 237, 245, 0.10);
    
    --font-heading: 'Space Grotesk', sans-serif;
    --font-mono: 'IBM Plex Mono', monospace;
    --font-body: 'Noto Sans SC', sans-serif;
}

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

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-family: var(--font-body);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: var(--text-primary);
    transition: color 0.3s ease;
}

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

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    letter-spacing: -0.02em;
    font-weight: 700;
}

.mono-label {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 100px 0;
}

.bg-panel {
    background-color: var(--bg-surface);
    border-top: 1px solid var(--border-hairline);
    border-bottom: 1px solid var(--border-hairline);
}

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

.section-title {
    font-size: 2.5rem;
    margin-top: 8px;
}

/* 按钮样式 - 无渐变 */
.btn {
    display: inline-block;
    padding: 14px 32px;
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 500;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
    border-radius: 4px;
}

.btn-primary {
    background-color: var(--accent);
    color: var(--bg-main);
    border: 1px solid var(--accent);
}

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

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

.btn-outline:hover {
    border-color: var(--accent);
    color: var(--accent);
}


/* 利益披露 (Affiliate Disclosure) */
.aff-disclosure {
    font-size: 0.8rem;
    color: var(--text-secondary);
    text-align: center;
    padding: 10px 24px;
    background-color: var(--bg-surface);
    border-bottom: 1px solid var(--border-hairline);
    font-family: var(--font-body);
}
.aff-disclosure a {
    color: var(--accent);
    text-decoration: underline;
}

/* 导航栏 */
.navbar {
    border-bottom: 1px solid var(--border-hairline);
    background: rgba(11, 15, 23, 0.8);
    backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px;
}

.logo-link {
    display: flex;
    align-items: center;
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 700;
    gap: 12px;
}

.logo-link:hover {
    color: var(--text-primary);
}

.logo-svg {
    width: 32px;
    height: 24px;
}

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

.navbar nav a {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.navbar nav a:hover, .navbar nav a.active {
    color: var(--accent);
}

.nav-new {
    border: 1px solid var(--border-hairline);
    padding: 2px 12px;
    border-radius: 4px;
    font-size: 0.85rem !important;
}

/* 主视觉区 (Hero) */
.hero {
    position: relative;
    padding: 120px 0 100px;
    overflow: hidden;
}

/* 星空背景与动画 */
.starfield {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: radial-gradient(circle at center, #E9EDF5 1px, transparent 1px);
    background-size: 40px 40px;
    opacity: 0.03;
    animation: drift 100s linear infinite;
    z-index: -1;
}

@keyframes drift {
    0% { transform: translateY(0); }
    100% { transform: translateY(-40px); }
}

.hero-content {
    display: flex;
    align-items: center;
    gap: 60px;
}

.hero-text {
    flex: 1;
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
}

.hero-image img {
    max-width: 100%;
    border-radius: 12px;
    box-shadow: 0 0 40px rgba(69, 224, 194, 0.15);
    border: 1px solid var(--border-hairline);
    transition: transform 0.3s ease;
}

.hero-image img:hover {
    transform: scale(1.02);
}

.hero h1 {
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: 24px;
}

.hero .highlight {
    color: var(--accent);
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 680px;
    margin-bottom: 48px;
    font-weight: 400;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
}

.hero-resources {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.resource-link {
    color: var(--text-secondary);
    font-size: 0.95rem;
    text-decoration: underline;
    text-decoration-color: var(--border-hairline);
    text-underline-offset: 4px;
}

.resource-link:hover {
    color: var(--accent);
    text-decoration-color: var(--accent);
}

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

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

/* 卡片 */
.card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-hairline);
    padding: 40px 32px;
    border-radius: 8px;
    transition: border-color 0.3s ease;
}

.card:hover {
    border-color: rgba(69, 224, 194, 0.3);
}

.card-icon {
    font-size: 2rem;
    margin-bottom: 24px;
    opacity: 0.8;
}

.card h3 {
    font-size: 1.3rem;
    margin-bottom: 16px;
}

.card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* 定价卡片 */
.pricing-card {
    display: flex;
    flex-direction: column;
    position: relative;
}

.pricing-card.featured {
    border-color: var(--accent);
}

.pricing-card .badge {
    position: absolute;
    top: -10px;
    left: 32px;
    background-color: var(--accent);
    color: var(--bg-main);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 700;
    padding: 4px 8px;
    border-radius: 2px;
    letter-spacing: 0.05em;
}

.pricing-card .price {
    font-family: var(--font-heading);
    font-size: 3.5rem;
    margin: 16px 0 32px;
    line-height: 1;
}

.pricing-card .price .currency {
    font-size: 1.5rem;
    color: var(--text-secondary);
    vertical-align: super;
}

.pricing-card .price .period {
    font-size: 1rem;
    color: var(--text-secondary);
    font-family: var(--font-body);
}

.pricing-card ul {
    list-style: none;
    margin-bottom: 40px;
    flex-grow: 1;
}

.pricing-card li {
    margin-bottom: 16px;
    font-size: 0.95rem;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.pricing-card li .mono-label {
    font-size: 0.7rem;
    opacity: 0.7;
}

/* 评价卡片 */
.review-card {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.review-card p {
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.review-card .author {
    text-align: right;
}

/* 常见问题 */
.faq-list {
    max-width: 760px;
    margin: 0 auto;
}

.faq-item {
    padding: 32px 0;
    border-bottom: 1px solid var(--border-hairline);
}

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

.faq-item h4 {
    font-size: 1.2rem;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.faq-item p {
    color: var(--text-secondary);
}

/* 页脚 */
footer {
    padding: 80px 0 40px;
    border-top: 1px solid var(--border-hairline);
}

.footer-container {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.footer-links {
    display: flex;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-links a {
    color: var(--text-secondary);
    font-family: var(--font-mono);
    font-size: 0.9rem;
}

.footer-links a:hover {
    color: var(--accent);
}

.copyright {
    opacity: 0.5;
}

/* 滚动动画效果 - Fade & Rise */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 1s cubic-bezier(0.16, 1, 0.3, 1), transform 1s cubic-bezier(0.16, 1, 0.3, 1);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 推荐资讯卡片 (Insights) */
.insights-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.insight-card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-hairline);
    border-radius: 8px;
    padding: 32px 24px;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.insight-card:hover {
    border-color: var(--accent);
    transform: translateY(-4px);
}

.insight-meta {
    display: flex;
    justify-content: space-between;
    margin-bottom: 16px;
    font-size: 0.8rem;
}

.insight-category {
    color: var(--accent);
}

.insight-card h3 {
    font-size: 1.25rem;
    margin-bottom: 12px;
    line-height: 1.4;
}

.insight-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 24px;
    flex-grow: 1;
}

.insight-link {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--text-primary);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.insight-link:hover {
    color: var(--accent);
}

.view-more-container {
    text-align: center;
    margin-top: 48px;
}

/* 文章详情页 (Article) */
.article-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 100px 24px;
}

.article-header {
    margin-bottom: 48px;
    text-align: center;
}

.article-header h1 {
    font-size: 2.5rem;
    margin: 16px 0;
}

.article-meta {
    color: var(--text-secondary);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    display: flex;
    justify-content: center;
    gap: 24px;
}

.article-content {
    font-size: 1.1rem;
    line-height: 1.8;
    color: #D1D5DB;
}

.article-content h2 {
    font-size: 1.8rem;
    margin: 48px 0 24px;
    color: var(--text-primary);
}

.article-content h3 {
    font-size: 1.4rem;
    margin: 32px 0 16px;
    color: var(--text-primary);
}

.article-content p {
    margin-bottom: 20px;
}

.article-content ul, .article-content ol {
    margin-bottom: 24px;
    padding-left: 24px;
}

.article-content li {
    margin-bottom: 8px;
}

.article-content a {
    color: var(--accent);
    text-decoration: underline;
    text-underline-offset: 4px;
}

.article-content a:hover {
    text-decoration: none;
}

/* 悬浮按钮 (Floating Button) */
.floating-btn {
    position: fixed;
    bottom: 40px;
    right: 40px;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-hairline);
    color: var(--accent);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}

.floating-btn.show {
    opacity: 1;
    visibility: visible;
}

.floating-btn:hover {
    border-color: var(--accent);
    transform: translateY(-3px);
}

.floating-btn svg {
    width: 24px;
    height: 24px;
    fill: currentColor;
}

/* 文章底部导航 (Article Nav) */
.article-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 60px;
    padding-top: 30px;
    border-top: 1px solid var(--border-hairline);
}

.article-nav a {
    display: flex;
    flex-direction: column;
    gap: 8px;
    color: var(--text-secondary);
    max-width: 48%;
}

.article-nav a span {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--accent);
}

.article-nav a strong {
    font-size: 1.1rem;
    color: var(--text-primary);
    line-height: 1.4;
}

.article-nav a:hover strong {
    color: var(--accent);
}

.article-nav a.next {
    text-align: right;
    align-items: flex-end;
}

/* 响应式媒体查询 */
@media (max-width: 992px) {
    .grid-3, .insights-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .hero-content {
        flex-direction: column;
        text-align: center;
    }
    .hero-buttons {
        justify-content: center;
    }
    .hero-resources {
        align-items: center;
    }
    .hero h1 {
        font-size: 2.8rem;
    }
    .hero p {
        font-size: 1.1rem;
    }
    .grid-3, .grid-2 {
        grid-template-columns: 1fr;
    }
    .nav-container {
        flex-direction: column;
        height: auto;
        padding: 20px 0;
    }
    .navbar nav {
        margin-top: 20px;
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        gap: 16px;
    }
    .footer-links {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }
    .hero-buttons {
        flex-direction: column;
    }
    .btn {
        width: 100%;
    }
}