:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #0ea5e9;
    --light: #f0f9ff;
    --dark: #1e293b;
    --accent: #f59e0b;
    --gray: #64748b;
    --light-gray: #f1f5f9;
    --font-family: "Noto Sans SC", "仿宋", "FangSong", serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family);
    line-height: 1.8;
    color: var(--dark);
    background-color: #ffffff;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* 导航栏样式 */
header {
    background: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
    display: flex;
    align-items: center;
}

.logo i {
    margin-right: 0.5rem;
    font-size: 1.8rem;
}

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

.nav-links li {
    margin-left: 2rem;
}

.nav-links a {
    color: var(--dark);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: var(--primary);
}

.nav-links a.active {
    color: var(--primary);
    border-bottom: 2px solid var(--primary);
}

/* 英雄区域样式 */
.hero {
    background: linear-gradient(135deg, var(--light) 0%, #e6f0ff 100%);
    padding: 8rem 0 6rem;
    margin-top: 70px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 60%;
    height: 200%;
    background: linear-gradient(45deg, rgba(37, 99, 235, 0.1) 0%, rgba(14, 165, 233, 0.1) 100%);
    transform: rotate(15deg);
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.2rem;
    color: var(--gray);
    margin-bottom: 2rem;
    line-height: 1.8;
}

.btn {
    display: inline-block;
    padding: 1rem 2rem;
    background: var(--primary);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

.btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

/* 章节样式 */
.section {
    padding: 5rem 0;
}

.section-title {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 1rem;
    position: relative;
    display: inline-block;
}

.section-title h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--accent);
    border-radius: 2px;
}

/* 介绍区域样式 */
.intro-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.intro-content h3 {
    font-size: 1.8rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
    font-weight: 600;
}

.intro-content p {
    font-size: 1.1rem;
    color: var(--gray);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.intro-image img {
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

/* 级别体系样式 */
.levels-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.level-card {
    background: white;
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.level-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary) 0%, var(--secondary) 100%);
}

.level-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
    border-color: var(--primary);
}

.level-card h3 {
    font-size: 1.5rem;
    color: var(--primary);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
}

.level-card h3 i {
    color: var(--accent);
    margin-right: 0.5rem;
}

.level-card p {
    color: var(--gray);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.level-card ul {
    list-style: none;
    margin-bottom: 2rem;
}

.level-card li {
    display: flex;
    align-items: center;
    margin-bottom: 0.8rem;
    color: var(--dark);
}

.level-card li i {
    color: var(--primary);
    margin-right: 0.8rem;
    font-size: 0.9rem;
}

.level-link {
    display: inline-flex;
    align-items: center;
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
}

.level-link:hover {
    color: var(--primary-dark);
    transform: translateX(5px);
}

.level-link i {
    margin-left: 0.5rem;
    transition: transform 0.3s ease;
}

.level-link:hover i {
    transform: translateX(3px);
}

/* 特色功能样式 */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-box {
    background: white;
    padding: 2.5rem;
    border-radius: 16px;
    text-align: center;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.feature-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
    border-color: var(--primary);
}

.feature-box i {
    font-size: 3rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
}

.feature-box h3 {
    font-size: 1.3rem;
    color: var(--dark);
    margin-bottom: 1rem;
    font-weight: 600;
}

.feature-box p {
    color: var(--gray);
    line-height: 1.6;
}

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

.faq-item {
    background: white;
    border-radius: 12px;
    margin-bottom: 1rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 1.5rem;
    background: white;
    border: none;
    text-align: left;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--dark);
    transition: all 0.3s ease;
}

.faq-question:hover {
    background: var(--light);
}

.faq-question.active {
    background: var(--primary);
    color: white;
}

.faq-question i {
    transition: transform 0.3s ease;
}

.faq-question.active i {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-answer.active {
    max-height: 200px;
    padding: 0 1.5rem 1.5rem;
}

.faq-answer p {
    color: var(--gray);
    line-height: 1.6;
}

/* 页脚样式 */
footer {
    background: var(--dark);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-col h3 {
    color: var(--accent);
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.footer-col ul {
    list-style: none;
}

.footer-col li {
    margin-bottom: 0.5rem;
}

.footer-col a {
    color: #cbd5e1;
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.copyright {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #334155;
    color: #94a3b8;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .intro-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .levels-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .nav-links {
        display: none;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 6rem 0 4rem;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .section {
        padding: 3rem 0;
    }
    
    .level-card,
    .feature-box {
        padding: 1.5rem;
    }
}