.index_main {
    position: relative;
    width: 100%;
    min-height: 200px;
    display: block;
    margin: 0 auto;
    overflow: hidden; 
}
.index_mainbox {
    position: relative;
    width: 100%;
    max-width: 1200px;
    display: block;
    margin: 0 auto;

}

:root {
        /* 科技感深色背景 */
        --km-bg: #050b14;
        --km-surface: rgba(16, 24, 40, 0.6);
        --km-border: rgba(22, 194, 145, 0.15);
        --km-border-hover: rgba(22, 194, 145, 0.4);
        
        /* 翡翠绿霓虹色系 */
        --km-cyan: #16C291;
        --km-blue: #0E8A68;
        --km-purple: #0D6B52;
        --km-text: #f8fafc;
        --km-text-muted: #94a3b8;
        
        /* 弥散发光 */
        --km-glow-cyan: 0 0 20px rgba(22, 194, 145, 0.3), 0 0 40px rgba(22, 194, 145, 0.1);
        --km-glow-purple: 0 0 20px rgba(13, 107, 82, 0.3), 0 0 40px rgba(13, 107, 82, 0.1);
        --km-card-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.5);
    }

    .km-wrapper {
        font-family: "Segoe UI", "Helvetica Neue", -apple-system, sans-serif;
        background-color: var(--km-bg);
        color: var(--km-text);
        line-height: 1.6;
        position: relative;
        overflow: hidden;
        -webkit-font-smoothing: antialiased;
        /* 已移除高开销的背景渐变网格 */
    }

    /* 弥散静态光斑 - 移除动画以彻底解决卡顿 */
    .km-orb {
        position: absolute;
        border-radius: 50%;
        filter: blur(60px);
        z-index: 0;
        opacity: 0.5;
    }
    .km-orb-1 { width: 600px; height: 600px; background: rgba(22, 194, 145, 0.15); top: -200px; left: -100px; }
    .km-orb-2 { width: 500px; height: 500px; background: rgba(13, 107, 82, 0.15); bottom: 10%; right: -150px; animation-delay: -3s; }
    .km-orb-3 { width: 400px; height: 400px; background: rgba(14, 138, 104, 0.15); top: 40%; left: 30%; animation-delay: -5s; }

    @keyframes km-pulse {
        0% { transform: scale(1) translate(0, 0); opacity: 0.5; }
        100% { transform: scale(1.2) translate(30px, -30px); opacity: 0.8; }
    }

    .km-container {
        max-width: 1200px;
        margin: 0 auto;
        padding: 0 24px;
        position: relative;
        z-index: 1;
    }

    h1, h2, h3, h4, p { margin: 0; }
    a { text-decoration: none; color: var(--km-cyan); transition: all 0.3s; }
    a:hover { text-shadow: var(--km-glow-cyan); }

    /* ================= Hero Section ================= */
    .km-hero {
        padding: 120px 0 160px;
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 60px;
        align-items: center;
        min-height: 80vh;
    }
    
    .km-hero-content {
        position: relative;
        z-index: 2;
        /* 向右偏移文字区域 */
        transform: translateX(80px);
        display: flex;
        flex-direction: column;
        align-items: center; /* 确保子元素垂直排列并居中 */
    }

    .km-main-logo {
        width: 120px;
        height: auto;
        margin-bottom: 30px;
        /* 已移除发光滤镜等效果 */
    }
    
    .km-hero-content h1 {
        font-size: clamp(2.5rem, 5vw, 4rem);
        font-weight: 900;
        line-height: 1.1;
        margin-bottom: 24px;
        letter-spacing: -1px;
        text-align: center; /* 文字居中 */
    }
    .km-hero-content h1 span {
        color: transparent;
        -webkit-text-stroke: 1px var(--km-cyan);
        text-shadow: 0 0 20px rgba(22, 194, 145, 0.4);
    }
    
    .km-hero-desc {
        font-size: 1.15rem;
        color: var(--km-text-muted);
        margin-bottom: 40px;
        max-width: 500px;
        text-align: center; /* 文字居中 */
        margin-left: auto;  /* 配合 max-width 居中 */
        margin-right: auto;
    }

    .km-dl-group {
        display: flex;
        flex-direction: column;
        gap: 16px;
        max-width: 400px;
        margin-left: auto;  /* 容器居中 */
        margin-right: auto;
    }

    .km-btn-main {
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 12px;
        background: linear-gradient(90deg, var(--km-blue), var(--km-cyan));
        color: #fff;
        padding: 18px 32px;
        border-radius: 12px;
        font-size: 1.1rem;
        font-weight: bold;
        border: none;
        cursor: pointer;
        box-shadow: var(--km-glow-cyan);
        transition: all 0.3s ease;
        text-transform: uppercase;
        letter-spacing: 1px;
    }
    .km-btn-main:hover {
        transform: translateY(-2px) scale(1.02);
        box-shadow: 0 0 30px rgba(0, 240, 255, 0.6);
    }
    
    .km-btn-sub-group {
        display: flex;
        gap: 12px;
    }
    .km-btn-sub {
        flex: 1;
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 8px;
        background: var(--km-surface);
        border: 1px solid var(--km-border);
        color: var(--km-text);
        padding: 12px 0;
        border-radius: 8px;
        font-size: 0.9rem;
        backdrop-filter: blur(10px);
        transition: all 0.3s;
    }
    .km-btn-sub:hover {
        border-color: var(--km-cyan);
        background: rgba(0, 240, 255, 0.1);
    }
    
    .km-security-note {
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 8px;
        margin-top: 20px;
        font-size: 0.85rem;
        color: var(--km-text-muted);
    }
    .km-security-note svg {
        color: var(--km-cyan);
    }

    .km-hero-visual {
        position: relative;
        display: flex;
        justify-content: center;
        align-items: center;
        /* 进一步放大缩放倍率，并微调偏移 */
        transform: scale(1.6) translateX(50%);
        transform-origin: center right;
    }
    
    /* ================= CSS 勾画动画 ================= */
    .km-hero-drawing {
        position: absolute;
        width: 140%;
        height: 140%;
        top: -20%;
        left: -20%;
        z-index: 0;
        pointer-events: none;
        animation: km-spin 40s linear infinite;
        will-change: transform; /* 启用硬件加速 */
    }
    .km-hero-drawing path {
        fill: none;
        stroke: var(--km-cyan);
        stroke-width: 0.8; /* 线条更细 */
        stroke-dasharray: 1500;
        stroke-dashoffset: 1500;
        animation: km-draw 5s ease-in-out infinite alternate;
        /* 降低透明度 */
        stroke-opacity: 0.4;
    }
    .km-hero-drawing circle.solid-circle {
        fill: none;
        stroke: var(--km-purple);
        stroke-width: 0.8; /* 线条更细 */
        stroke-dasharray: 1200;
        stroke-dashoffset: 1200;
        animation: km-draw 6s ease-in-out infinite alternate-reverse;
        /* 降低透明度 */
        stroke-opacity: 0.3;
    }
    .km-hero-drawing circle.dashed-circle {
        fill: none;
        stroke: rgba(22, 194, 145, 0.1); /* 降低透明度 */
        stroke-width: 0.4; /* 线条更细 */
        stroke-dasharray: 4 4;
        transform-origin: center;
        animation: km-spin 20s linear infinite reverse;
    }
    @keyframes km-draw {
        0% { stroke-dashoffset: 1500; }
        100% { stroke-dashoffset: 0; }
    }
    @keyframes km-spin {
        0% { transform: rotate(0deg); }
        100% { transform: rotate(360deg); }
    }

    .km-hero-logo-css {
        width: 500px;
        height: 500px;
        position: relative;
        transform: translateX(-50%);
        z-index: 1;
        display: flex;
        align-items: center;
        justify-content: center;
        animation: km-float 6s ease-in-out infinite;
    }
    .km-cat-head {
        width: 180px;
        height: 160px;
        background: linear-gradient(135deg, var(--km-blue), var(--km-purple));
        border-radius: 50% 50% 45% 45%;
        position: relative;
        /* 移除动态阴影，改用静态阴影减少计算量 */
        box-shadow: 0 0 30px rgba(0, 71, 255, 0.3);
    }
    .km-cat-head::before, .km-cat-head::after {
        content: '';
        position: absolute;
        top: -20px;
        width: 60px;
        height: 80px;
        background: linear-gradient(135deg, var(--km-blue), var(--km-purple));
        z-index: -1;
    }
    .km-cat-head::before {
        left: 10px;
        border-radius: 50% 50% 0 50%;
        transform: rotate(-15deg);
    }
    .km-cat-head::after {
        right: 10px;
        border-radius: 50% 50% 50% 0%;
        transform: rotate(15deg);
    }
    .km-cat-eyes {
        display: flex;
        justify-content: space-around;
        width: 100%;
        margin-top: 50px;
    }
    .km-cat-eye {
        width: 30px;
        height: 30px;
        background: var(--km-cyan);
        border-radius: 50%;
        /* 移除高开销滤镜 */
        position: relative;
    }
    .km-cat-eye::after {
        content: '';
        position: absolute;
        width: 10px;
        height: 10px;
        background: #000;
        border-radius: 50%;
        top: 10px;
        left: 10px;
    }
    .km-cat-nose {
        width: 16px;
        height: 10px;
        background: #ff69b4;
        border-radius: 50%;
        margin: 15px auto 0;
    }
    .km-cat-mouth {
        width: 40px;
        height: 20px;
        border-bottom: 3px solid rgba(255,255,255,0.3);
        border-radius: 50%;
        margin: 0 auto;
    }
    
    @keyframes km-float {
        0%, 100% { transform: translateY(0) rotate(0deg); }
        50% { transform: translateY(-10px) rotate(1deg); } /* 减小浮动幅度 */
    }

    /* ================= Stats Section ================= */
    .km-stats {
        padding: 60px 0;
        border-top: 1px solid rgba(255,255,255,0.05);
        border-bottom: 1px solid rgba(255,255,255,0.05);
        background: rgba(0,0,0,0.3);
        backdrop-filter: blur(10px);
    }
    .km-stats-grid {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 30px;
        text-align: center;
    }
    .km-stat-num {
        font-size: 2.5rem;
        font-weight: 900;
        color: var(--km-cyan);
        text-shadow: 0 0 15px rgba(0, 240, 255, 0.3);
        margin-bottom: 8px;
    }
    .km-stat-label {
        font-size: 0.9rem;
        color: var(--km-text-muted);
        text-transform: uppercase;
        letter-spacing: 2px;
    }

    /* ================= Features Section ================= */
    .km-features {
        padding: 120px 0;
    }
    .km-section-title {
        text-align: center;
        font-size: 2.5rem;
        font-weight: 800;
        margin-bottom: 80px;
    }
    .km-feature-row {
        display: flex;
        align-items: center;
        gap: 60px;
        margin-bottom: 100px;
    }
    .km-feature-row:nth-child(even) {
        flex-direction: row-reverse;
    }
    .km-feature-text {
        flex: 1;
    }
    .km-feature-text h2 {
        font-size: 2rem;
        color: var(--km-text);
        margin-bottom: 20px;
        display: flex;
        align-items: center;
        gap: 16px;
    }
    .km-feature-text h2::before {
        content: '';
        display: block;
        width: 8px;
        height: 32px;
        background: var(--km-cyan);
        box-shadow: 0 0 10px var(--km-cyan);
        border-radius: 4px;
    }
    .km-feature-text p {
        font-size: 1.1rem;
        color: var(--km-text-muted);
        margin-bottom: 24px;
    }
    .km-feature-visual {
        flex: 1;
        display: flex;
        justify-content: center;
        position: relative;
    }
    .km-feature-visual::before {
        content: '';
        position: absolute;
        width: 300px;
        height: 300px;
        background: radial-gradient(circle, rgba(138,43,226,0.2) 0%, transparent 70%);
        z-index: 0;
    }
    .km-feature-card {
        background: var(--km-surface);
        border: 1px solid var(--km-border);
        backdrop-filter: blur(16px);
        padding: 40px;
        border-radius: 20px;
        box-shadow: var(--km-card-shadow);
        z-index: 1;
        width: 100%;
        max-width: 400px;
        text-align: center;
        transition: transform 0.3s;
    }
    .km-feature-card:hover {
        transform: translateY(-10px);
        border-color: var(--km-cyan);
        box-shadow: var(--km-glow-cyan);
    }
    .km-feature-icon {
        width: 80px;
        height: 80px;
        margin: 0 auto 20px;
        filter: drop-shadow(0 0 15px rgba(0, 240, 255, 0.5));
    }

    /* ================= Reviews Section ================= */
    .km-reviews {
        padding: 100px 0;
        background: linear-gradient(180deg, transparent, rgba(0, 71, 255, 0.05), transparent);
    }
    .km-review-grid {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 30px;
    }
    .km-review-card {
        background: rgba(255,255,255,0.02);
        border: 1px solid rgba(255,255,255,0.05);
        padding: 30px;
        border-radius: 16px;
        position: relative;
    }
    .km-review-card::after {
        content: '\"';
        position: absolute;
        top: 10px;
        right: 20px;
        font-size: 4rem;
        color: rgba(0, 240, 255, 0.1);
        font-family: serif;
    }
    .km-stars {
        color: #fbbf24;
        margin-bottom: 16px;
        font-size: 1.2rem;
    }
    .km-review-text {
        font-size: 1rem;
        color: var(--km-text-muted);
        margin-bottom: 24px;
        font-style: italic;
    }
    .km-reviewer {
        display: flex;
        align-items: center;
        gap: 12px;
    }
    .km-reviewer-avatar {
        width: 40px;
        height: 40px;
        border-radius: 50%;
        background: linear-gradient(45deg, var(--km-blue), var(--km-cyan));
        display: flex;
        align-items: center;
        justify-content: center;
        font-weight: bold;
    }

    /* ================= FAQ Section ================= */
    .km-faq {
        padding: 120px 0;
    }
    .km-faq-grid {
        max-width: 800px;
        margin: 0 auto;
        display: flex;
        flex-direction: column;
        gap: 20px;
    }
    .km-faq-item {
        background: rgba(16, 24, 40, 0.4);
        border: 1px solid rgba(255,255,255,0.1);
        border-radius: 12px;
        padding: 24px 32px;
        transition: all 0.3s;
    }
    .km-faq-item:hover {
        background: rgba(16, 24, 40, 0.8);
        border-color: rgba(0, 240, 255, 0.3);
        box-shadow: 0 0 20px rgba(0, 240, 255, 0.1);
    }
    .km-faq-q {
        font-size: 1.2rem;
        font-weight: bold;
        color: var(--km-text);
        margin-bottom: 12px;
        display: flex;
        align-items: center;
        gap: 12px;
    }
    .km-faq-q::before {
        content: 'Q';
        color: var(--km-cyan);
        font-family: monospace;
        font-size: 1.5rem;
    }
    .km-faq-a {
        color: var(--km-text-muted);
        padding-left: 30px;
        line-height: 1.7;
    }

    /* ================= Pricing Section ================= */
    .km-pricing {
        padding: 80px 0;
        background-color: rgba(255, 255, 255, 0.01);
        border-top: 1px solid rgba(255,255,255,0.05);
        border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    .km-pricing-grid {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 30px;
        margin-top: 50px;
    }
    .km-pricing-card {
        background: rgba(16, 24, 40, 0.4);
        border: 1px solid rgba(255, 255, 255, 0.08);
        border-radius: 20px;
        padding: 40px 30px;
        text-align: center;
        transition: all 0.3s ease;
        position: relative;
    }
    .km-pricing-card:hover {
        transform: translateY(-5px);
        border-color: rgba(22, 194, 145, 0.3);
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    }
    .km-pricing-card.featured {
        background: rgba(22, 194, 145, 0.05);
        border-color: var(--km-cyan);
        transform: scale(1.05);
    }
    .km-pricing-card.featured:hover {
        transform: scale(1.05) translateY(-5px);
        box-shadow: 0 10px 40px rgba(22, 194, 145, 0.15);
    }
    .km-pricing-badge {
        position: absolute;
        top: -15px;
        left: 50%;
        transform: translateX(-50%);
        background: var(--km-cyan);
        color: #fff;
        padding: 5px 15px;
        border-radius: 20px;
        font-size: 0.85rem;
        font-weight: 600;
        letter-spacing: 1px;
        box-shadow: 0 0 15px rgba(22, 194, 145, 0.5);
    }
    .km-pricing-title {
        font-size: 1.25rem;
        font-weight: 600;
        color: var(--km-text-muted);
        margin-bottom: 15px;
    }
    .km-pricing-card.featured .km-pricing-title {
        color: var(--km-cyan);
    }
    .km-pricing-price {
        font-size: 3rem;
        font-weight: 700;
        color: #fff;
        margin-bottom: 20px;
        display: flex;
        align-items: center;
        justify-content: center;
    }
    .km-pricing-price span {
        font-size: 1rem;
        color: var(--km-text-muted);
        margin: 0 5px;
        font-weight: normal;
    }
    .km-pricing-desc {
        font-size: 0.85rem;
        color: var(--km-cyan);
        margin-top: -10px;
        margin-bottom: 20px;
    }
    .km-pricing-features {
        list-style: none;
        padding: 0;
        margin: 0 0 30px 0;
        text-align: left;
    }
    .km-pricing-features li {
        margin-bottom: 15px;
        font-size: 0.95rem;
        color: var(--km-text);
        display: flex;
        align-items: center;
        gap: 10px;
    }
    .km-pricing-features svg {
        color: var(--km-cyan);
        flex-shrink: 0;
    }
    .km-btn-pricing {
        display: inline-block;
        width: 100%;
        padding: 12px 0;
        border-radius: 8px;
        font-weight: 600;
        text-decoration: none;
        transition: all 0.3s ease;
        text-align: center;
        cursor: pointer;
    }
    .km-btn-pricing.primary {
        background: var(--km-cyan);
        color: #fff;
        box-shadow: 0 0 20px rgba(22, 194, 145, 0.3);
        border: 1px solid var(--km-cyan);
    }
    .km-btn-pricing.primary:hover {
        background: transparent;
        color: var(--km-cyan);
        box-shadow: 0 0 30px rgba(22, 194, 145, 0.5);
    }
    .km-btn-pricing.outline {
        background: transparent;
        color: #fff;
        border: 1px solid rgba(255, 255, 255, 0.2);
    }
    .km-btn-pricing.outline:hover {
        border-color: var(--km-cyan);
        color: var(--km-cyan);
        background: rgba(22, 194, 145, 0.05);
    }

    /* ================= Responsive ================= */
    @media (max-width: 992px) {
        .km-pricing-grid { grid-template-columns: 1fr; max-width: 400px; margin-left: auto; margin-right: auto; }
        .km-pricing-card.featured { transform: scale(1); }
        .km-pricing-card.featured:hover { transform: translateY(-5px); }
        .km-hero { grid-template-columns: 1fr; text-align: center; }
        .km-dl-group { margin: 0 auto; }
        .km-stats-grid { grid-template-columns: repeat(2, 1fr); gap: 40px; }
        .km-feature-row, .km-feature-row:nth-child(even) { flex-direction: column; text-align: center; }
        .km-feature-text h2 { justify-content: center; }
        .km-feature-text h2::before { display: none; }
        .km-review-grid { grid-template-columns: 1fr; }
    }