/* 基础样式复位 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-color: #fcfcfc;
    --bg-dark: #f0f0f0;
    --text-color: #1a1a1a;
    --text-muted: #666;
    --accent: #000;
    --accent-hover: #333;
    --border-color: #e5e5e5;
    --card-bg: #fff;
    --nav-bg: rgba(255, 255, 255, 0.9);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #0a0a0a;
        --bg-dark: #141414;
        --text-color: #f5f5f5;
        --text-muted: #aaa;
        --accent: #fff;
        --accent-hover: #ccc;
        --border-color: #333;
        --card-bg: #1c1c1c;
        --nav-bg: rgba(10, 10, 10, 0.9);
    }
}

/* 强制使用黑白主题，也可以基于上面的响应式，为了彻底贯彻黑白设计，在此覆盖所有 */
:root {
    --bg-color: #050505;
    --bg-dark: #111111;
    --text-color: #ffffff;
    --text-muted: #aaaaaa;
    --accent: #ffffff;
    --accent-hover: #dddddd;
    --accent-dark: #222222;
    --border-color: #333333;
    --card-bg: #111111;
    --card-hover: #1a1a1a;
    --nav-bg: rgba(5, 5, 5, 0.85);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
    scroll-behavior: smooth;
}

/* 动态背景 Canvas */
#particle-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
    opacity: 0.4;
}

/* 布局与排版 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.text-center { text-align: center; }
.mt-2 { margin-top: 1rem; }
.mt-4 { margin-top: 2rem; }

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 1rem;
}

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

a:hover {
    color: var(--text-muted);
}

/* 按钮样式 */
.btn-primary, .btn-secondary {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 30px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
}

.btn-primary {
    background-color: var(--accent);
    color: var(--bg-color);
    border: 2px solid var(--accent);
}

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

.btn-primary.outline {
    background-color: transparent;
    color: var(--accent);
    border: 2px solid var(--border-color);
}

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

.btn-secondary {
    background-color: transparent;
    color: var(--accent);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    border-color: var(--accent);
    background-color: var(--accent-dark);
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 40px;
    background: var(--nav-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.navbar .logo {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: 2px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links a {
    font-size: 0.95rem;
    font-weight: 400;
    opacity: 0.8;
}

.nav-links a:hover {
    opacity: 1;
}

.nav-btn {
    padding: 8px 20px;
    font-size: 0.9rem;
}

/* 英雄板块 */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 80px; /* offset nav */
    position: relative;
    overflow: hidden;
}

.hero-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60vw;
    height: 60vw;
    background: radial-gradient(circle, rgba(255,255,255,0.06) 0%, rgba(0,0,0,0) 60%);
    z-index: -1;
    pointer-events: none;
}

.hero-badge {
    display: inline-block;
    padding: 8px 20px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 30px;
    font-size: 0.9rem;
    color: #ddd;
    margin-bottom: 2rem;
    backdrop-filter: blur(10px);
}

.hero-section h1 {
    font-size: 4.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    letter-spacing: -1px;
}

.gradient-text {
    background: linear-gradient(90deg, #ffffff, #666666);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-section p {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto 3rem auto;
}

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

.btn-large {
    padding: 16px 40px;
    font-size: 1.1rem;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 50px;
    margin-top: 5rem;
    border-top: 1px solid rgba(255,255,255,0.08);
    padding-top: 3rem;
    flex-wrap: wrap;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 12px;
    color: #999;
    font-size: 1rem;
    font-weight: 600;
}

.stat-icon {
    font-size: 1.5rem;
    filter: grayscale(100%);
}

/* 动画效果 */
.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }
.delay-4 { animation-delay: 0.8s; }

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 通用板块样式 */
.section {
    padding: 100px 0;
}

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

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.grid-4 {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

/* 卡片样式 */
.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 40px 30px;
    transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    border-color: #555;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    background-color: var(--card-hover);
}

/* 核心优势 */
.advantage-card .icon {
    font-size: 3rem;
    margin-bottom: 20px;
    filter: grayscale(100%); /* 黑白化表情符号 */
}

.advantage-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
}

.advantage-card p {
    color: var(--text-muted);
}

/* 节点状态板 */
.status-board {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
}

.status-row {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    padding: 20px 30px;
    border-bottom: 1px solid var(--border-color);
}

.status-row:last-child {
    border-bottom: none;
}

.status-row.header {
    background-color: var(--bg-dark);
    font-weight: 600;
    color: var(--text-muted);
}

.status-ok { color: #aaaaaa; display: flex; align-items: center; }
.status-dot {
    display: inline-block;
    width: 8px;
    height: 8px;
    background-color: #4ade80;
    border-radius: 50%;
    margin-right: 8px;
    box-shadow: 0 0 8px #4ade80;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { opacity: 1; box-shadow: 0 0 8px #4ade80; }
    50% { opacity: 0.4; box-shadow: 0 0 2px #4ade80; }
    100% { opacity: 1; box-shadow: 0 0 8px #4ade80; }
}

.ping-good { color: #ffffff; font-weight: bold; }
.ping-avg { color: #aaaaaa; }
.ping-bad { color: #ef4444; }

/* 套餐价格 */
.pricing-card {
    text-align: center;
    position: relative;
}

.pricing-card.popular {
    border-color: #666;
    background-color: #141414;
    transform: scale(1.05);
}

.pricing-card.popular:hover {
    transform: scale(1.05) translateY(-5px);
}

.badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--accent);
    color: var(--bg-color);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: bold;
}

.pricing-card h3 {
    font-size: 1.5rem;
    color: var(--text-muted);
}

.pricing-card .price {
    font-size: 3.5rem;
    font-weight: 800;
    margin: 20px 0;
}

.pricing-card .price span {
    font-size: 1rem;
    font-weight: 400;
    color: var(--text-muted);
}

.pricing-features {
    list-style: none;
    margin-bottom: 30px;
    text-align: left;
}

.pricing-features li {
    padding: 10px 0;
    border-bottom: 1px dashed var(--border-color);
    color: #ccc;
}

.pricing-features li:last-child {
    border-bottom: none;
}

/* 用户评价 */
.review-card .stars {
    color: #fff;
    font-size: 1.2rem;
    margin-bottom: 15px;
    letter-spacing: 2px;
}

.review-card .review-text {
    font-style: italic;
    margin-bottom: 20px;
    color: #ddd;
}

.review-card .reviewer {
    font-weight: 600;
    color: var(--text-muted);
}

/* FAQ */
.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 15px;
    background-color: var(--card-bg);
}

.faq-question {
    padding: 20px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    user-select: none;
}

.faq-answer {
    padding: 0 20px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    color: var(--text-muted);
}

.faq-item.active .faq-answer {
    padding: 0 20px 20px 20px;
    max-height: 200px;
}

.toggle-icon {
    font-size: 1.5rem;
    transition: transform 0.3s ease;
}

.faq-item.active .toggle-icon {
    transform: rotate(45deg);
}

/* 知识库 */
.article-card {
    display: block;
    padding: 25px;
}

.article-card h4 {
    font-size: 1.1rem;
    margin-bottom: 10px;
    transition: color 0.3s ease;
}

.article-card:hover h4 {
    color: #888;
}

.article-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* 页脚 */
.footer {
    padding: 40px 0;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* 响应式调整 */
@media (max-width: 992px) {
    .grid-3, .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }
    .pricing-card.popular {
        transform: scale(1);
    }
    .pricing-card.popular:hover {
        transform: translateY(-5px);
    }
}

@media (max-width: 768px) {
    .navbar {
        padding: 15px 20px;
    }
    .nav-links {
        display: none; /* 移动端可以加汉堡菜单，为简化此处隐藏 */
    }
    .hero-section h1 {
        font-size: 2.5rem;
    }
    .grid-3, .grid-4 {
        grid-template-columns: 1fr;
    }
    .status-row {
        grid-template-columns: 1fr 1fr;
        gap: 10px;
        text-align: center;
    }
}