:root {
    --ei-primary-color: #1a365d;
    --ei-accent-color: #c5a059;
    --ei-text-dark: #333333;
    --ei-text-light: #666666;
    --ei-bg-light: #f8f9fa;
    --ei-white: #ffffff;
    --ei-shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --ei-shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.ei-preview-header {
    background: var(--ei-white);
    box-shadow: var(--ei-shadow-sm);
    height: 80px;
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.ei-preview-header-inner {
    width: 100%;
    max-width: 1600px;
    margin: 0 auto;
    padding: 0 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 24px;
}

.ei-preview-logo {
    color: var(--ei-primary-color);
    font-size: 24px;
    font-weight: 700;
    text-decoration: none;
    white-space: nowrap;
}

.ei-preview-main-nav {
    display: flex;
    gap: 28px;
    list-style: none;
    margin: 0;
    padding: 0;
    align-items: center;
}

.ei-preview-main-nav a {
    color: var(--ei-text-dark);
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
}

.ei-preview-main-nav a.active,
.ei-preview-main-nav a:hover {
    color: var(--ei-accent-color);
}

.ei-intro-hero {
    height: 300px;
    background: linear-gradient(rgba(26, 54, 93, 0.8), rgba(26, 54, 93, 0.6)), url('/assetsNew/img/intro/hero_bg.png') center/cover;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: var(--ei-white);
    margin-bottom: 60px;
    padding: 0 20px;
}

.ei-intro-hero h1 {
    font-size: 42px;
    margin: 0 0 15px;
    line-height: 1.25;
    word-break: keep-all;
    color: var(--ei-white);
}

.ei-intro-breadcrumbs {
    font-size: 14px;
    opacity: 0.85;
    display: flex;
    gap: 10px;
    align-items: center;
    flex-wrap: wrap;
    justify-content: center;
}

.ei-intro-breadcrumbs span {
    color: var(--ei-accent-color);
}

.ei-intro-nav-wrap {
    background: #fff;
    border-bottom: 1px solid #eee;
    margin-bottom: 60px;
    position: sticky;
    top: 80px;
    z-index: 900;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.03);
}

.ei-intro-nav {
    display: flex;
    justify-content: center;
    gap: 0;
    list-style: none;
    max-width: 1100px;
    margin: 0 auto;
    padding: 0;
}

.ei-intro-nav li {
    flex: 1;
    text-align: center;
    max-width: 200px;
}

.ei-intro-nav a {
    display: block;
    padding: 20px 0;
    font-size: 16px;
    font-weight: 500;
    color: var(--ei-text-light);
    border-bottom: 3px solid transparent;
    transition: all 0.3s ease;
    text-decoration: none;
}

.ei-intro-nav a:hover,
.ei-intro-nav a.active {
    color: var(--ei-primary-color);
    border-bottom-color: var(--ei-primary-color);
    background: #fcfcfc;
    font-weight: 700;
}

.ei-intro-content {
    max-width: 1100px;
    margin: 0 auto 100px;
    padding: 0 20px;
}

.ei-intro-content-header {
    margin-bottom: 40px;
    padding-bottom: 20px;
    border-bottom: 1px solid #eaeaea;
}

.ei-intro-content-header h2 {
    font-size: 32px;
    color: var(--ei-text-dark);
    margin: 0;
}

.ei-intro-content-header .subtitle {
    display: block;
    margin-top: 10px;
    color: var(--ei-text-light);
    font-size: 16px;
    line-height: 1.8;
}

.ei-intro-content-body {
    font-size: 17px;
    line-height: 1.8;
    color: #444;
    word-break: keep-all;
}

.ei-intro-content-body p {
    margin: 0 0 1em;
    line-height: inherit;
}

.ei-intro-content-body p:last-child {
    margin-bottom: 0;
}

.ei-intro-content-body img {
    max-width: 100%;
    height: auto;
}

.ei-intro-content-body [style*="width"] {
    max-width: 100%;
    box-sizing: border-box;
}

.ei-intro-content-body table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
}

.ei-intro-content-body th,
.ei-intro-content-body td {
    border: 1px solid #ddd;
    padding: 12px 14px;
}

.ei-intro-content-body th {
    background: #f8f9fa;
}

.ei-intro-content-body blockquote {
    margin: 24px 0;
    padding: 18px 22px;
    border-left: 4px solid var(--ei-accent-color);
    background: #f8fafc;
}

@media (max-width: 1024px) {
    .ei-preview-header-inner {
        padding: 0 20px;
    }

    .ei-preview-main-nav {
        gap: 18px;
        flex-wrap: wrap;
        justify-content: flex-end;
    }
}

@media (max-width: 768px) {
    .ei-preview-header {
        height: auto;
        padding: 16px 0;
    }

    .ei-preview-header-inner {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .ei-preview-main-nav {
        width: 100%;
        justify-content: flex-start;
        gap: 14px;
    }

    .ei-intro-hero {
        height: auto;
        padding: 70px 20px 60px;
    }

    .ei-intro-hero h1 {
        font-size: 34px;
    }

    .ei-intro-nav {
        flex-wrap: wrap;
    }

    .ei-intro-nav li {
        min-width: 50%;
        max-width: none;
    }

    .ei-intro-content {
        padding: 0 16px;
        margin-bottom: 70px;
    }

    .ei-intro-content-header h2 {
        font-size: 28px;
    }

    .ei-intro-content-body {
        font-size: 16px;
    }
}