/* 
   一云梯 1yunti.my - Premium Promotion Style
   Author: Antigravity Code Design
   Style Strategy: Dark cybertech aesthetic, Glassmorphism, Neon glows, Smooth transitions.
*/

/* ==========================================
   1. 设计系统变量 & 全局配置
   ========================================== */
:root {
    /* 核心调色盘 - 渐变与状态色 */
    --bg-dark: #070a13;
    --bg-card: rgba(17, 24, 39, 0.6);
    --bg-navbar: rgba(7, 10, 19, 0.75);
    
    --accent-cyan: #00e5ff;
    --accent-cyan-glow: rgba(0, 229, 255, 0.3);
    --accent-purple: #7c4dff;
    --accent-purple-glow: rgba(124, 77, 255, 0.3);
    --accent-gold: #ffb300;
    
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    --border-color: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(0, 229, 255, 0.25);
    
    --grad-primary: linear-gradient(135deg, #00e5ff 0%, #7c4dff 100%);
    --grad-text: linear-gradient(135deg, #ffffff 30%, #a5b4fc 100%);
    --grad-accent-text: linear-gradient(135deg, #00e5ff 0%, #7c4dff 100%);
    --grad-card-bg: linear-gradient(180deg, rgba(255, 255, 255, 0.04) 0%, rgba(255, 255, 255, 0.01) 100%);
    
    /* 动效与阴影 */
    --transition-smooth: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    --transition-fast: all 0.2s ease;
    --glow-shadow: 0 0 20px var(--accent-cyan-glow);
    --purple-glow-shadow: 0 0 30px var(--accent-purple-glow);
}

/* 基础重置 */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: 'Outfit', 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

/* 隐藏横向滚动条的通用背景网格 */
body::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    background-image: 
        radial-gradient(circle at 50% 120px, rgba(124, 77, 255, 0.15), transparent 600px),
        radial-gradient(circle at 10% 40%, rgba(0, 229, 255, 0.08), transparent 500px),
        radial-gradient(circle at 90% 80%, rgba(124, 77, 255, 0.1), transparent 600px);
    z-index: -2;
    pointer-events: none;
}

a {
    color: inherit;
    text-decoration: none;
    transition: var(--transition-fast);
}

/* ==========================================
   2. 极简复用原子组件 & 按钮 (Buttons)
   ========================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: 99px;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition-smooth);
    cursor: pointer;
    border: 1px solid transparent;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: var(--grad-primary);
    color: #ffffff;
    box-shadow: 0 4px 20px rgba(0, 229, 255, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px rgba(0, 229, 255, 0.45);
}

.btn-primary::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: 0.6s;
}

.btn-primary:hover::after {
    left: 100%;
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    backdrop-filter: blur(8px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
}

.btn-outline-primary {
    background: transparent;
    border: 1px solid rgba(0, 229, 255, 0.4);
    color: var(--accent-cyan);
}

.btn-outline-primary:hover {
    background: rgba(0, 229, 255, 0.05);
    border-color: var(--accent-cyan);
    transform: translateY(-2px);
}

.btn-arrow {
    width: 18px;
    height: 18px;
    transition: transform 0.3s ease;
}

.btn:hover .btn-arrow {
    transform: translateX(4px);
}

/* ==========================================
   3. 导航栏样式 (Navbar)
   ========================================== */
.navbar {
    position: sticky;
    top: 0;
    width: 100%;
    background: var(--bg-navbar);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition-smooth);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    width: 28px;
    height: 28px;
    color: var(--accent-cyan);
}

.brand-name {
    font-size: 1.25rem;
    font-weight: 800;
    background: var(--grad-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: 1px;
}

.brand-domain {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--accent-cyan);
    background: rgba(0, 229, 255, 0.1);
    padding: 2px 6px;
    border-radius: 4px;
    border: 1px solid rgba(0, 229, 255, 0.2);
    letter-spacing: 0.5px;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
}

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

.btn-nav {
    padding: 8px 20px;
    font-size: 0.9rem;
    background: var(--grad-primary);
    color: #ffffff;
}

/* ==========================================
   4. 首屏主视觉区 (Hero Section)
   ========================================== */
.hero-section {
    padding: 120px 24px 80px;
    position: relative;
}

.hero-bg-glow {
    position: absolute;
    top: 5%;
    left: 45%;
    width: 450px;
    height: 450px;
    background: radial-gradient(circle, rgba(124, 77, 255, 0.2) 0%, rgba(0, 229, 255, 0.05) 50%, transparent 70%);
    filter: blur(80px);
    z-index: -1;
    pointer-events: none;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 48px;
    align-items: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(0, 229, 255, 0.06);
    border: 1px solid rgba(0, 229, 255, 0.15);
    padding: 6px 16px;
    border-radius: 99px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--accent-cyan);
    margin-bottom: 24px;
}

.badge-dot {
    width: 6px;
    height: 6px;
    background-color: var(--accent-cyan);
    border-radius: 50%;
    animation: pulse-glow 2s infinite;
}

@keyframes pulse-glow {
    0% { transform: scale(1); opacity: 0.6; box-shadow: 0 0 0 0 rgba(0, 229, 255, 0.4); }
    50% { transform: scale(1.2); opacity: 1; box-shadow: 0 0 8px 4px rgba(0, 229, 255, 0.2); }
    100% { transform: scale(1); opacity: 0.6; box-shadow: 0 0 0 0 rgba(0, 229, 255, 0.4); }
}

.hero-title {
    font-family: 'Outfit', sans-serif;
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.25;
    background: var(--grad-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -1px;
    margin-bottom: 20px;
}

.gradient-text {
    background: var(--grad-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    position: relative;
    display: inline-block;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 540px;
    margin-bottom: 32px;
}

.hero-bullets {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 40px;
}

.bullet-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1rem;
    color: var(--text-primary);
}

.bullet-icon {
    width: 18px;
    height: 18px;
    color: var(--accent-cyan);
    flex-shrink: 0;
}

.hero-actions {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 48px;
}

.hero-stats {
    display: flex;
    align-items: center;
    gap: 32px;
    border-top: 1px solid var(--border-color);
    padding-top: 32px;
}

.stat-box {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat-num {
    font-family: 'Outfit', sans-serif;
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--text-primary);
    background: var(--grad-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.stat-divider {
    width: 1px;
    height: 32px;
    background: var(--border-color);
}

/* 首屏主视觉 - 纯 CSS 霓虹动态节点星云 */
.hero-visual-wrapper {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.tech-card {
    width: 100%;
    max-width: 440px;
    height: 380px;
    background: var(--grad-card-bg);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 24px;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
    position: relative;
    overflow: hidden;
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0% { transform: translateY(0px) rotate(0.5deg); }
    50% { transform: translateY(-10px) rotate(-0.5deg); }
    100% { transform: translateY(0px) rotate(0.5deg); }
}

.tech-card-inner {
    width: 100%;
    height: 100%;
    position: relative;
}

.grid-overlay {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
    background-size: 20px 20px;
    z-index: 1;
}

.glowing-orb-cyan {
    position: absolute;
    width: 180px;
    height: 180px;
    background: radial-gradient(circle, rgba(0, 229, 255, 0.12) 0%, transparent 70%);
    top: 10%;
    left: 15%;
    animation: orbit-1 8s infinite linear;
}

.glowing-orb-purple {
    position: absolute;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(124, 77, 255, 0.1) 0%, transparent 70%);
    bottom: 10%;
    right: 10%;
    animation: orbit-2 10s infinite linear;
}

@keyframes orbit-1 {
    0% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(30px, 20px) scale(1.2); }
    100% { transform: translate(0, 0) scale(1); }
}

@keyframes orbit-2 {
    0% { transform: translate(0, 0) scale(1.1); }
    50% { transform: translate(-20px, -30px) scale(0.9); }
    100% { transform: translate(0, 0) scale(1.1); }
}

/* 网络节点渲染 */
.node-system {
    position: absolute;
    inset: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 5;
}

.central-cloud {
    width: 110px;
    height: 110px;
    background: rgba(11, 15, 25, 0.85);
    border: 2px solid var(--accent-cyan);
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    box-shadow: 0 0 24px var(--accent-cyan-glow);
    z-index: 10;
}

.central-cloud svg {
    width: 38px;
    height: 38px;
    color: var(--accent-cyan);
    animation: pulse 2.5s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.08); filter: drop-shadow(0 0 6px var(--accent-cyan)); }
}

.node-label {
    font-size: 0.65rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-top: 6px;
    letter-spacing: 0.5px;
    text-align: center;
}

.node {
    position: absolute;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background-color: var(--accent-purple);
    box-shadow: 0 0 10px var(--accent-purple-glow);
    z-index: 8;
}

.node::before {
    content: attr(data-label);
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text-secondary);
    white-space: nowrap;
    background: rgba(7, 10, 19, 0.8);
    padding: 3px 8px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
}

.node-1 { top: 15%; left: 15%; background-color: var(--accent-cyan); box-shadow: 0 0 12px var(--accent-cyan-glow); }
.node-2 { top: 18%; right: 15%; }
.node-3 { bottom: 15%; left: 20%; }
.node-4 { bottom: 18%; right: 18%; background-color: var(--accent-cyan); box-shadow: 0 0 12px var(--accent-cyan-glow); }

/* 节点连线 */
.connection-line {
    position: absolute;
    background: linear-gradient(to right, rgba(0,229,255,0.4), rgba(124,77,255,0.4));
    height: 2px;
    z-index: 6;
    transform-origin: left center;
}

.line-1 { top: 15%; left: 15%; width: 140px; transform: rotate(28deg); }
.line-2 { top: 18%; right: 15%; width: 145px; transform: rotate(-148deg); }
.line-3 { bottom: 15%; left: 20%; width: 120px; transform: rotate(-32deg); }
.line-4 { bottom: 18%; right: 18%; width: 130px; transform: rotate(145deg); }

/* 连接线动效 - 模拟流动光束 */
.connection-line::after {
    content: '';
    position: absolute;
    width: 15px;
    height: 100%;
    background: #ffffff;
    box-shadow: 0 0 8px 1px #00e5ff;
    animation: flow-beam 2.5s infinite linear;
}

.line-1::after { animation-delay: 0s; }
.line-2::after { animation-delay: 0.6s; }
.line-3::after { animation-delay: 1.2s; }
.line-4::after { animation-delay: 1.8s; }

@keyframes flow-beam {
    0% { left: 0%; opacity: 0; }
    5% { opacity: 1; }
    95% { opacity: 1; }
    100% { left: 100%; opacity: 0; }
}

.tech-overlay-text {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--border-color);
    padding-top: 14px;
    z-index: 10;
}

.terminal-tag {
    font-family: monospace;
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--accent-cyan);
    letter-spacing: 1px;
}

.terminal-desc {
    font-family: monospace;
    font-size: 0.65rem;
    color: var(--text-muted);
}

/* ==========================================
   5. 品牌核心优势区 (Features Section)
   ========================================== */
.features-section {
    padding: 100px 24px;
    position: relative;
    background-color: rgba(11, 15, 25, 0.3);
}

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

.section-header {
    text-align: center;
    max-width: 650px;
    margin: 0 auto 64px;
}

.section-tag {
    font-family: 'Outfit', sans-serif;
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--accent-cyan);
    letter-spacing: 2px;
    text-transform: uppercase;
    display: block;
    margin-bottom: 12px;
}

.section-title {
    font-size: 2.25rem;
    font-weight: 800;
    background: var(--grad-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 16px;
    letter-spacing: -0.5px;
}

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

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.feature-card {
    background: var(--grad-card-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 36px 28px;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(300px circle at var(--x, 50%) var(--y, 50%), rgba(0, 229, 255, 0.04), transparent);
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.5s;
}

.feature-card:hover::before {
    opacity: 1;
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: var(--border-hover);
    box-shadow: 0 12px 30px rgba(0, 229, 255, 0.05);
}

.feature-icon-wrapper {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: rgba(124, 77, 255, 0.06);
    border: 1px solid rgba(124, 77, 255, 0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-purple);
    margin-bottom: 24px;
    transition: var(--transition-smooth);
}

.feature-card:hover .feature-icon-wrapper {
    color: var(--accent-cyan);
    background: rgba(0, 229, 255, 0.08);
    border-color: rgba(0, 229, 255, 0.25);
    transform: rotate(5deg) scale(1.05);
    box-shadow: 0 0 15px rgba(0, 229, 255, 0.15);
}

.feature-icon-wrapper svg {
    width: 24px;
    height: 24px;
}

.feature-card-title {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

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

/* ==========================================
   6. 套餐价格区 (Pricing Section)
   ========================================== */
.pricing-section {
    padding: 100px 24px;
    position: relative;
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    align-items: stretch;
    margin-bottom: 48px;
}

.pricing-card {
    background: var(--grad-card-bg);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 40px 32px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: var(--transition-smooth);
    position: relative;
}

.pricing-card:hover {
    transform: translateY(-4px);
    border-color: rgba(255, 255, 255, 0.15);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.3);
}

/* 热门卡片高亮样式 */
.pricing-card.popular {
    background: rgba(11, 15, 25, 0.85);
    border: 2px solid var(--accent-purple);
    box-shadow: 0 15px 45px rgba(124, 77, 255, 0.15);
    transform: scale(1.03);
    z-index: 10;
}

.pricing-card.popular:hover {
    transform: scale(1.03) translateY(-4px);
    box-shadow: 0 20px 50px rgba(124, 77, 255, 0.25);
    border-color: var(--accent-cyan);
}

.popular-tag {
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--grad-primary);
    color: #ffffff;
    font-size: 0.8rem;
    font-weight: 700;
    padding: 6px 20px;
    border-radius: 99px;
    white-space: nowrap;
    letter-spacing: 1px;
    box-shadow: 0 4px 15px rgba(124, 77, 255, 0.4);
}

.pricing-header {
    margin-bottom: 32px;
}

.plan-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    display: block;
    margin-bottom: 12px;
}

.text-gradient-neon {
    background: var(--grad-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.price-box {
    display: flex;
    align-items: baseline;
    gap: 2px;
    margin-bottom: 16px;
}

.currency {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

.price {
    font-family: 'Outfit', sans-serif;
    font-size: 3.5rem;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1;
}

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

.plan-desc {
    font-size: 0.85rem;
    color: var(--text-secondary);
    min-height: 40px;
}

.pricing-body {
    flex-grow: 1;
    margin-bottom: 40px;
}

.feature-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.feature-list li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-size: 0.9rem;
    color: var(--text-primary);
}

.check-icon {
    width: 16px;
    height: 16px;
    color: var(--accent-cyan);
    margin-top: 3px;
    flex-shrink: 0;
}

.cross-icon {
    width: 16px;
    height: 16px;
    color: var(--text-muted);
    margin-top: 3px;
    flex-shrink: 0;
}

.feature-list li.unsupported {
    color: var(--text-muted);
}

.pricing-footer .btn {
    width: 100%;
}

.pricing-note {
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-muted);
    max-width: 800px;
    margin: 48px auto 0;
    line-height: 1.5;
}

/* ==========================================
   7. 常见问题解答区 (FAQ Section)
   ========================================== */
.faq-section {
    padding: 100px 24px;
    background-color: rgba(11, 15, 25, 0.3);
    border-top: 1px solid var(--border-color);
}

.faq-accordion-wrapper {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

/* 完美高亮的原生 Details 样式 */
.faq-item {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
    transition: var(--transition-smooth);
}

.faq-item[open] {
    background: rgba(255, 255, 255, 0.03);
    border-color: rgba(124, 77, 255, 0.2);
    box-shadow: 0 4px 20px rgba(0,0,0,0.2);
}

.faq-item:hover {
    border-color: var(--border-hover);
}

.faq-question {
    padding: 24px;
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-primary);
    cursor: pointer;
    list-style: none; /* 隐藏原生三角 */
    display: flex;
    align-items: center;
    justify-content: space-between;
    user-select: none;
}

.faq-question::-webkit-details-marker {
    display: none; /* 隐藏 Safari 的原生三角 */
}

.faq-icon {
    width: 20px;
    height: 20px;
    color: var(--text-secondary);
    transition: transform 0.3s ease;
}

.faq-item[open] .faq-icon {
    transform: rotate(180deg);
    color: var(--accent-cyan);
}

.faq-answer {
    padding: 0 24px 24px;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
    border-top: 1px solid rgba(255, 255, 255, 0.04);
    margin-top: -4px;
    padding-top: 20px;
    animation: slideDown 0.35s ease-out;
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-5px); }
    to { opacity: 1; transform: translateY(0); }
}

.faq-footer-cta {
    max-width: 800px;
    margin: 64px auto 0;
    background: var(--grad-card-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 40px;
    text-align: center;
}

.faq-footer-cta p {
    font-size: 1.1rem;
    color: var(--text-primary);
    margin-bottom: 24px;
}

/* ==========================================
   8. 页脚区 (Footer)
   ========================================== */
.footer {
    background-color: #04060b;
    border-top: 1px solid var(--border-color);
    padding: 80px 24px 40px;
}

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

.footer-top {
    display: grid;
    grid-template-columns: 1.2fr 1.8fr;
    gap: 64px;
    margin-bottom: 64px;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.text-white {
    background: #ffffff !important;
    -webkit-background-clip: initial !important;
    -webkit-text-fill-color: initial !important;
    color: #ffffff;
}

.brand-slogan {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.footer-links-group {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.link-col {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.link-col h4 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-primary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.link-col a {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.link-col a:hover {
    color: var(--accent-cyan);
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 32px;
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    gap: 24px;
}

.copyright {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.copyright p {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.disclaimer {
    max-width: 800px;
}

.scroll-top-btn {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: var(--transition-smooth);
}

.scroll-top-btn:hover {
    background: var(--accent-purple);
    color: #ffffff;
    box-shadow: 0 0 15px rgba(124, 77, 255, 0.4);
    transform: translateY(-4px);
}

.scroll-top-btn svg {
    width: 20px;
    height: 20px;
}

/* ==========================================
   9. 移动端与平板响应式适配
   ========================================== */

/* 平板与中等屏幕 (max-width: 1024px) */
@media (max-width: 1024px) {
    .nav-menu {
        gap: 20px;
    }
    
    .hero-container {
        grid-template-columns: 1fr;
        gap: 64px;
        text-align: center;
    }
    
    .hero-content {
        display: flex;
        flex-direction: column;
        align-items: center;
    }
    
    .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-bullets {
        align-items: flex-start;
        display: inline-flex;
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-stats {
        justify-content: center;
        width: 100%;
    }
    
    .pricing-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
    
    .pricing-card.popular {
        transform: scale(1);
        grid-column: span 2;
    }
    
    .pricing-card.popular:hover {
        transform: translateY(-4px);
    }
    
    .footer-top {
        grid-template-columns: 1fr;
        gap: 48px;
    }
}

/* 移动端 (max-width: 768px) */
@media (max-width: 768px) {
    html {
        font-size: 15px;
    }
    
    .navbar {
        padding: 8px 0;
    }
    
    .nav-menu {
        display: none; /* 移动端精简菜单以突出主 CTA */
    }
    
    .hero-section {
        padding: 100px 16px 60px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-actions {
        flex-direction: column;
        width: 100%;
        gap: 12px;
    }
    
    .hero-actions .btn {
        width: 100%;
    }
    
    .hero-stats {
        flex-wrap: wrap;
        gap: 20px;
        justify-content: space-around;
    }
    
    .stat-divider {
        display: none;
    }
    
    .stat-box {
        align-items: center;
        min-width: 120px;
    }
    
    .tech-card {
        height: 320px;
        padding: 16px;
    }
    
    .central-cloud {
        width: 90px;
        height: 90px;
    }
    
    .central-cloud svg {
        width: 32px;
        height: 32px;
    }
    
    .node::before {
        display: none; /* 移动端隐藏节点小标签防止重叠 */
    }
    
    .line-1 { width: 100px; transform: rotate(26deg); }
    .line-2 { width: 110px; transform: rotate(-146deg); }
    .line-3 { width: 90px; transform: rotate(-28deg); }
    .line-4 { width: 100px; transform: rotate(143deg); }
    
    .features-section, .pricing-section, .faq-section {
        padding: 64px 16px;
    }
    
    .section-title {
        font-size: 1.85rem;
    }
    
    .pricing-grid {
        grid-template-columns: 1fr;
    }
    
    .pricing-card.popular {
        grid-column: span 1;
    }
    
    .faq-question {
        padding: 18px;
        font-size: 0.95rem;
    }
    
    .faq-answer {
        padding: 0 18px 18px;
        font-size: 0.9rem;
    }
    
    .faq-footer-cta {
        padding: 24px;
    }
    
    .footer {
        padding: 60px 16px 30px;
    }
    
    .footer-links-group {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    
    .footer-bottom {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 20px;
    }
}

/* 针对小屏手机优化 (max-width: 375px) */
@media (max-width: 375px) {
    .hero-title {
        font-size: 2.2rem;
    }
    
    .brand-domain {
        display: none; /* 空间极度受限时隐藏域名标签 */
    }
    
    .brand-name {
        font-size: 1.1rem;
    }
}