@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;700&display=swap');

:root {
    --primary-color: #4a90e2;
    --primary-hover: #357abd;
    --text-main: #ffffff;
    --text-muted: rgba(255, 255, 255, 0.7);
    --bg-glass: rgba(255, 255, 255, 0.1);
    --border-glass: rgba(255, 255, 255, 0.2);
    --nav-height: 80px;
}

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

body {
    font-family: "KaiTi", "BiauKai", "楷体", "Noto Serif SC", serif;
    background-color: #0f172a;
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

/* 动态背景 */
.bg-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-image: url('https://images.unsplash.com/photo-1513002749550-c59d786b8e6c?q=80&w=2000&auto=format&fit=crop');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    z-index: -2;
    animation: scaleBg 20s ease-in-out infinite alternate;
}

.bg-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: linear-gradient(135deg, rgba(15, 23, 42, 0.8) 0%, rgba(15, 23, 42, 0.4) 100%);
    z-index: -1;
    backdrop-filter: blur(2px);
}

@keyframes scaleBg {
    0% { transform: scale(1); }
    100% { transform: scale(1.05); }
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    height: var(--nav-height);
    z-index: 1000;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border-bottom: 1px solid transparent;
}

.navbar.scrolled {
    background: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-glass);
    height: 70px;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.logo a {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-main);
    text-decoration: none;
    letter-spacing: 2px;
}

.nav-links a {
    color: var(--text-main);
    text-decoration: none;
    margin-left: 30px;
    font-size: 16px;
    transition: color 0.3s;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 50%;
    background-color: var(--primary-color);
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

.nav-links a:hover::after {
    width: 100%;
}

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

/* 按钮 */
.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 30px;
    text-decoration: none;
    font-size: 16px;
    transition: all 0.3s ease;
    cursor: pointer;
    font-family: inherit;
    border: none;
}

.btn-primary {
    background: var(--primary-color);
    color: #fff;
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.3);
}

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(74, 144, 226, 0.4);
}

.btn-outline {
    background: transparent;
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.5);
}

.btn-outline:hover {
    border-color: #fff;
    background: rgba(255, 255, 255, 0.1);
}

.btn-full {
    width: 100%;
    text-align: center;
}

/* 首页视觉区 */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding-top: var(--nav-height);
}

.hero-title {
    font-size: 4rem;
    font-weight: 700;
    margin-bottom: 20px;
    letter-spacing: 4px;
    text-shadow: 0 4px 10px rgba(0,0,0,0.5);
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--text-muted);
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
}

/* 布局与通用类 */
.section {
    padding: 60px 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 35px;
    position: relative;
    display: inline-block;
    left: 50%;
    transform: translateX(-50%);
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--primary-color);
}

.grid {
    display: grid;
    gap: 30px;
}

.features-grid {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.articles-grid {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.pricing-grid {
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

.nodes-grid {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.latency-card {
    background: rgba(20, 20, 20, 0.85);
    border-radius: 12px;
    padding: 30px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    transition: transform 0.3s;
}

.latency-card:hover {
    transform: translateY(-5px);
}

.latency-title {
    font-size: 1.8rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 5px;
    font-family: 'Courier New', Courier, monospace;
}

.latency-subtitle {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 25px;
    font-family: 'Courier New', Courier, monospace;
}

.latency-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.latency-item {
    display: flex;
    justify-content: space-between;
    padding: 12px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    font-size: 1.1rem;
    color: #ccc;
    font-family: 'Courier New', Courier, monospace;
}

.latency-item:last-child {
    border-bottom: none;
}

.text-green { color: #00ff00; font-weight: bold; }
.text-orange { color: #ffaa00; font-weight: bold; }

/* 玻璃拟物化卡片与网格悬停效果 */
.glass-card {
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: 16px;
    padding: 40px 30px;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.glass-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(to right, rgba(255,255,255,0) 0%, rgba(255,255,255,0.1) 50%, rgba(255,255,255,0) 100%);
    transform: skewX(-25deg);
    transition: all 0.7s;
    z-index: 1;
}

.glass-card:hover::before {
    left: 200%;
}

.glass-card:hover {
    transform: translateY(-10px);
    border-color: rgba(255, 255, 255, 0.4);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4), 0 0 20px rgba(74, 144, 226, 0.2);
}

.card-glow {
    position: absolute;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(74,144,226,0.3) 0%, rgba(0,0,0,0) 70%);
    border-radius: 50%;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.3s;
    z-index: 0;
    transform: translate(-50%, -50%);
}

.glass-card:hover .card-glow {
    opacity: 1;
}

.glass-card > *:not(.card-glow) {
    position: relative;
    z-index: 2;
}

/* 套餐样式 */
.pricing-card {
    text-align: center;
    display: flex;
    flex-direction: column;
}

.pricing-card.recommended {
    border-color: var(--primary-color);
    background: rgba(74, 144, 226, 0.1);
    transform: scale(1.05);
}

.pricing-card.recommended:hover {
    transform: scale(1.05) translateY(-10px);
}

.plan-name {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.plan-tag {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    background: rgba(255,255,255,0.1);
    margin-bottom: 20px;
}

.plan-tag.popular {
    background: var(--primary-color);
}

.plan-price {
    font-size: 1rem;
    margin-bottom: 15px;
    color: var(--text-muted);
}

.plan-price span {
    font-size: 3rem;
    font-weight: 700;
    color: #fff;
}

.plan-desc {
    color: var(--text-muted);
    margin-bottom: 30px;
    min-height: 50px;
}

.plan-features {
    list-style: none;
    margin-bottom: 40px;
    text-align: left;
    flex-grow: 1;
}

.plan-features li {
    padding: 10px 0;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    position: relative;
    padding-left: 30px;
}

.plan-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* SEO Footer */
.footer {
    border-top: 1px solid var(--border-glass);
    padding: 40px 0;
    text-align: center;
    background: rgba(15, 23, 42, 0.9);
}

.seo-keywords {
    margin-bottom: 20px;
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 2;
}

.seo-keywords a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.3s;
}

.seo-keywords a:hover {
    color: var(--primary-color);
}

.copyright {
    font-size: 0.9rem;
    color: rgba(255,255,255,0.3);
}

/* 优雅过渡动画类 */
.fade-in {
    opacity: 0;
    transition: opacity 1s ease-in;
}

.fade-in.visible {
    opacity: 1;
}

.fade-in-up {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

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

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    .hero-title {
        font-size: 2.5rem;
    }
    .pricing-card.recommended {
        transform: scale(1);
    }
    .pricing-card.recommended:hover {
        transform: translateY(-10px);
    }
}