:root {
    --primary-red: #d32f2f;
    --light-red: #ff6659;
    --soft-red: #ffebee;
    --accent-gold: #ffb300;
    --text-dark: #333333;
    --text-medium: #555555;
    --text-light: #777777;
    --border-color: #eaeaea;
    --bg-white: #ffffff;
    --bg-section: #f5f7fa;
    --shadow-light: rgba(0, 0, 0, 0.08);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Microsoft YaHei', '微软雅黑', sans-serif;
}

body {
    background: var(--bg-section);
    color: var(--text-dark);
    line-height: 1.7;
}

header {
    background: var(--bg-white);
    position: fixed;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 15px var(--shadow-light);
    border-bottom: 1px solid var(--border-color);
}

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

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo-link {
    display: flex;
    align-items: center;
}

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

.nav-links li {
    margin-left: 28px;
}

.nav-links a {
    color: var(--text-dark);
    text-decoration: none;
    font-size: 17px;
    padding: 5px 10px;
    border-radius: 4px;
    font-weight: 500;
    transition: all 0.3s;
}

.nav-links a:hover,
.nav-links a.nav-active {
    color: var(--primary-red);
    background: var(--soft-red);
}

.download-btn {
    background: var(--primary-red);
    color: #fff;
    padding: 10px 25px;
    border-radius: 30px;
    font-weight: bold;
    text-decoration: none;
    font-size: 16px;
}

.kb-layout {
    display: grid;
    grid-template-columns: 240px 1fr;
    gap: 32px;
    padding: 120px 0 80px;
    align-items: start;
}

.kb-sidebar {
    position: sticky;
    top: 100px;
    background: var(--bg-white);
    border-radius: 12px;
    padding: 24px 20px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 16px var(--shadow-light);
}

.kb-sidebar h2 {
    font-size: 15px;
    color: var(--primary-red);
    margin-bottom: 16px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--soft-red);
}

.kb-sidebar a {
    display: block;
    color: var(--text-medium);
    text-decoration: none;
    font-size: 14px;
    padding: 8px 0;
    border-left: 3px solid transparent;
    padding-left: 10px;
    transition: all 0.2s;
}

.kb-sidebar a:hover,
.kb-sidebar a.active {
    color: var(--primary-red);
    border-left-color: var(--primary-red);
    background: var(--soft-red);
    margin-left: -10px;
    padding-left: 10px;
}

.kb-main {
    min-width: 0;
}

.kb-hero {
    background: linear-gradient(135deg, #c70707 0%, #661010 60%);
    color: #fff;
    border-radius: 16px;
    padding: 48px 40px;
    margin-bottom: 32px;
}

.kb-hero h1 {
    font-size: 32px;
    margin-bottom: 12px;
}

.kb-hero p {
    font-size: 17px;
    opacity: 0.95;
    max-width: 720px;
}

.kb-hero .kb-tags {
    margin-top: 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.kb-hero .kb-tag {
    background: rgba(255, 255, 255, 0.2);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 13px;
}

.kb-section {
    background: var(--bg-white);
    border-radius: 12px;
    padding: 36px 32px;
    margin-bottom: 24px;
    border: 1px solid var(--border-color);
    scroll-margin-top: 100px;
}

.kb-section h2 {
    font-size: 24px;
    color: var(--primary-red);
    margin-bottom: 8px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.kb-section h3 {
    font-size: 18px;
    color: var(--text-dark);
    margin: 24px 0 12px;
}

.kb-section p {
    color: var(--text-medium);
    margin-bottom: 14px;
}

.kb-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 16px;
    margin: 20px 0;
}

.kb-stat {
    background: var(--bg-section);
    border-radius: 10px;
    padding: 20px 16px;
    text-align: center;
    border: 1px solid var(--border-color);
}

.kb-stat strong {
    display: block;
    font-size: 22px;
    color: var(--primary-red);
    margin-bottom: 6px;
}

.kb-stat span {
    font-size: 13px;
    color: var(--text-light);
}

.kb-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
    margin: 16px 0;
}

.kb-table th,
.kb-table td {
    border: 1px solid var(--border-color);
    padding: 12px 14px;
    text-align: left;
}

.kb-table th {
    background: var(--soft-red);
    color: var(--primary-red);
    font-weight: 600;
}

.kb-table td {
    color: var(--text-medium);
}

.kb-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 16px;
    margin-top: 16px;
}

.kb-card {
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 20px;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.kb-card:hover {
    border-color: var(--primary-red);
    box-shadow: 0 6px 20px var(--shadow-light);
}

.kb-card h4 {
    font-size: 16px;
    color: var(--primary-red);
    margin-bottom: 8px;
}

.kb-card p {
    font-size: 14px;
    margin: 0;
}

.kb-list {
    padding-left: 20px;
    color: var(--text-medium);
}

.kb-list li {
    margin-bottom: 8px;
}

.kb-quote {
    background: var(--soft-red);
    border-left: 4px solid var(--primary-red);
    padding: 16px 20px;
    margin: 16px 0;
    border-radius: 0 8px 8px 0;
    color: var(--text-medium);
    font-style: italic;
}

.kb-faq details {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 10px;
    overflow: hidden;
}

.kb-faq summary {
    padding: 14px 18px;
    cursor: pointer;
    font-weight: 600;
    color: var(--text-dark);
    background: var(--bg-section);
    list-style: none;
}

.kb-faq summary::-webkit-details-marker {
    display: none;
}

.kb-faq details[open] summary {
    color: var(--primary-red);
    border-bottom: 1px solid var(--border-color);
}

.kb-faq .kb-faq-a {
    padding: 14px 18px;
    font-size: 14px;
    color: var(--text-medium);
}

.site-footer {
    background: var(--bg-white);
    padding: 40px 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-light);
    font-size: 14px;
}

.site-footer a {
    color: var(--text-light);
}

@media (max-width: 992px) {
    .nav-links {
        display: none;
    }

    .kb-layout {
        grid-template-columns: 1fr;
        padding-top: 110px;
    }

    .kb-sidebar {
        position: static;
    }

    .kb-sidebar nav {
        display: flex;
        flex-wrap: wrap;
        gap: 8px;
    }

    .kb-sidebar a {
        border: 1px solid var(--border-color);
        border-radius: 20px;
        padding: 6px 12px;
        border-left: 1px solid var(--border-color);
        margin: 0;
    }

    .kb-sidebar a:hover,
    .kb-sidebar a.active {
        margin: 0;
    }
}

@media (max-width: 576px) {
    .kb-hero {
        padding: 32px 24px;
    }

    .kb-hero h1 {
        font-size: 26px;
    }

    .kb-section {
        padding: 24px 18px;
    }

    .kb-table {
        font-size: 12px;
    }

    .kb-table th,
    .kb-table td {
        padding: 8px;
    }
}