/* 全局 CSS 设计系统 - Apple 极简与黑客科技风 */

:root {
    --bg-color: #000000;
    --card-bg: rgba(22, 22, 23, 0.8);
    --card-border: rgba(255, 255, 255, 0.08);
    --text-primary: #f5f5f7;
    --text-secondary: #86868b;
    --accent-color: #00f2fe;
    --accent-gradient: linear-gradient(135deg, #00f2fe 0%, #4facfe 100%);
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    --max-width: 1200px;
}

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

html {
    scroll-behavior: smooth;
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-primary);
    -webkit-font-smoothing: antialiased;
}

body {
    overflow-x: hidden;
}

/* 导航栏 */
header {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--card-border);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0.8rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 1.25rem;
    gap: 0.5rem;
}

.logo-img {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 1px solid var(--accent-color);
    box-shadow: 0 0 10px rgba(0, 242, 254, 0.3);
}

.nav-menu {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-menu a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
}

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

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 0.75rem 1.75rem;
    border-radius: 980px;
    font-size: 0.95rem;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    text-align: center;
}

.btn-primary {
    background: var(--accent-gradient);
    color: #000;
    box-shadow: 0 4px 15px rgba(0, 242, 254, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 242, 254, 0.6);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

/* 英雄板块 */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 8rem 1.5rem 4rem 1.5rem;
    background: radial-gradient(circle at center, rgba(0, 242, 254, 0.05) 0%, rgba(0, 0, 0, 0) 70%);
}

.hero-tag {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    font-weight: 600;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin-bottom: 1.5rem;
    background: linear-gradient(180deg, #ffffff 0%, #a1a1a6 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

@media (min-width: 768px) {
    .hero-title {
        font-size: 5rem;
    }
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin-bottom: 2.5rem;
    line-height: 1.5;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

/* 核心特性与服务卡片 */
.section {
    padding: 6rem 1.5rem;
    max-width: var(--max-width);
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-tag {
    font-size: 0.9rem;
    color: var(--accent-color);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 1rem;
}

.section-title {
    font-size: 2.25rem;
    font-weight: 700;
    background: linear-gradient(180deg, #ffffff 0%, #a1a1a6 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

@media (min-width: 768px) {
    .grid-3 {
        grid-template-columns: repeat(3, 1fr);
    }
    .grid-2 {
        grid-template-columns: repeat(2, 1fr);
    }
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 18px;
    padding: 2.5rem 2rem;
    transition: var(--transition);
    backdrop-filter: blur(10px);
}

.card:hover {
    transform: translateY(-5px);
    border-color: rgba(0, 242, 254, 0.3);
    box-shadow: 0 10px 30px rgba(0, 242, 254, 0.05);
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.card-text {
    color: var(--text-secondary);
    line-height: 1.6;
    font-size: 0.95rem;
}

/* 价格模块 */
.pricing-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    align-items: stretch;
}

@media (min-width: 768px) {
    .pricing-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.price-card {
    position: relative;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.price-card.featured {
    border-color: var(--accent-color);
    box-shadow: 0 10px 40px rgba(0, 242, 254, 0.1);
}

.badge {
    position: absolute;
    top: 1rem;
    right: 1.5rem;
    background: var(--accent-gradient);
    color: #000;
    padding: 0.25rem 0.75rem;
    border-radius: 980px;
    font-size: 0.75rem;
    font-weight: 700;
}

.price-header {
    margin-bottom: 2rem;
}

.price-name {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.price-amount {
    font-size: 3rem;
    font-weight: 800;
    color: var(--text-primary);
}

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

.price-features {
    list-style: none;
    margin-bottom: 2.5rem;
    flex-grow: 1;
}

.price-features li {
    padding: 0.75rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.price-features li::before {
    content: "✓";
    color: var(--accent-color);
    font-weight: bold;
}

.price-cta {
    width: 100%;
    margin-top: auto;
}

/* 文章区块 */
.article-card {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    height: 100%;
}

.article-link {
    color: var(--accent-color);
    text-decoration: none;
    margin-top: 1.5rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.95rem;
    transition: var(--transition);
}

.article-link:hover {
    gap: 0.5rem;
}

/* 评价与常见问题 */
.testimonial-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

@media (min-width: 768px) {
    .testimonial-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.testimonial-card {
    font-style: italic;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-top: 1.5rem;
    font-style: normal;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: var(--accent-color);
    border: 1px solid var(--accent-color);
}

.user-meta h4 {
    font-size: 0.95rem;
    font-weight: 600;
}

.user-meta span {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* FAQ 折叠面板 */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    margin-bottom: 1rem;
    overflow: hidden;
}

.faq-question {
    padding: 1.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    user-select: none;
}

.faq-question::after {
    content: "+";
    font-size: 1.5rem;
    transition: var(--transition);
    color: var(--accent-color);
}

.faq-answer {
    padding: 0 1.5rem;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s cubic-bezier(0, 1, 0, 1);
    color: var(--text-secondary);
    line-height: 1.6;
    font-size: 0.95rem;
}

.faq-item.active .faq-question::after {
    transform: rotate(45deg);
}

.faq-item.active .faq-answer {
    padding: 0 1.5rem 1.5rem 1.5rem;
    max-height: 1000px;
    transition: max-height 0.3s cubic-bezier(1, 0, 1, 0);
}

/* 页脚与 PBN */
footer {
    background: #000;
    border-top: 1px solid var(--card-border);
    padding: 4rem 1.5rem;
    text-align: center;
}

.footer-container {
    max-width: var(--max-width);
    margin: 0 auto;
}

.footer-logo {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
}

.footer-logo .logo-img {
    width: 28px;
    height: 28px;
}

.footer-pbn {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    font-size: 0.8rem;
}

.footer-pbn span {
    color: var(--text-secondary);
}

.footer-pbn a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
}

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

.copyright {
    color: var(--text-secondary);
    font-size: 0.8rem;
    margin-top: 1.5rem;
}

/* 文章页专属样式 */
.article-page {
    padding-top: 8rem;
}

.article-header {
    max-width: 800px;
    margin: 0 auto 3rem auto;
    text-align: center;
}

.article-meta {
    margin-top: 1rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.article-body {
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.8;
    color: #e3e3e6;
    font-size: 1.1rem;
}

.article-body h2 {
    font-size: 1.75rem;
    margin: 2.5rem 0 1rem 0;
    color: var(--text-primary);
}

.article-body p {
    margin-bottom: 1.5rem;
}

.article-body a {
    color: var(--accent-color);
    text-decoration: underline;
}

.article-body ul, .article-body ol {
    margin-left: 2rem;
    margin-bottom: 1.5rem;
}

.article-body li {
    margin-bottom: 0.5rem;
}

.back-to-home {
    display: inline-block;
    margin-top: 3rem;
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 600;
}