@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;500;600;700&display=swap');

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

body {
    font-family: 'Noto Serif SC', serif;
    line-height: 1.8;
    color: #2c1810;
    background: linear-gradient(135deg, #f5f1eb 0%, #ede4d3 100%);
    background-attachment: fixed;
    position: relative;
    overflow-x: hidden;
}

/* 皱纹纸纹理背景 */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(120, 119, 108, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(120, 119, 108, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 40% 80%, rgba(120, 119, 108, 0.03) 0%, transparent 50%),
        linear-gradient(90deg, transparent 79px, rgba(120, 119, 108, 0.04) 79px, rgba(120, 119, 108, 0.04) 81px, transparent 81px),
        linear-gradient(0deg, transparent 79px, rgba(120, 119, 108, 0.04) 79px, rgba(120, 119, 108, 0.04) 81px, transparent 81px);
    background-size: 200px 200px, 180px 180px, 220px 220px, 80px 80px, 80px 80px;
    pointer-events: none;
    z-index: -1;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 40px 20px;
    background: rgba(255, 255, 255, 0.85);
    box-shadow: 0 0 50px rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    backdrop-filter: blur(10px);
    position: relative;
    margin-top: 20px;
    margin-bottom: 20px;
}

/* 主标题样式 - 居中且高对比度 */
.main-title {
    text-align: center;
    margin-bottom: 50px;
    padding: 30px 20px;
    background: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 100%);
    color: #ffffff;
    border-radius: 12px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
    position: relative;
    overflow: hidden;
}

.main-title::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, rgba(255, 255, 255, 0.1) 0%, transparent 50%, rgba(255, 255, 255, 0.1) 100%);
    pointer-events: none;
}

.main-title h1 {
    font-size: 2.8rem;
    font-weight: 700;
    margin-bottom: 15px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    letter-spacing: 2px;
    position: relative;
    z-index: 1;
}

.main-title .subtitle {
    font-size: 1.2rem;
    font-weight: 400;
    color: #e0e0e0;
    font-style: italic;
    position: relative;
    z-index: 1;
}

h2 {
    color: #8b4513;
    font-size: 1.8rem;
    font-weight: 600;
    margin: 40px 0 20px 0;
    padding-bottom: 10px;
    border-bottom: 3px solid #d2b48c;
    position: relative;
}

h2::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    width: 60px;
    height: 3px;
    background: #8b4513;
}

h3 {
    color: #a0522d;
    font-size: 1.4rem;
    font-weight: 600;
    margin: 30px 0 15px 0;
    padding-left: 15px;
    border-left: 4px solid #d2b48c;
}

h4 {
    color: #8b4513;
    font-size: 1.2rem;
    font-weight: 500;
    margin: 25px 0 12px 0;
}

p {
    margin-bottom: 15px;
    text-align: justify;
    color: #3d2914;
}

ul, ol {
    margin: 15px 0;
    padding-left: 30px;
}

li {
    margin-bottom: 8px;
    color: #3d2914;
}

strong {
    color: #8b4513;
    font-weight: 600;
}

.highlight {
    background: linear-gradient(120deg, #fff8dc 0%, #f5deb3 100%);
    padding: 20px;
    border-radius: 8px;
    border-left: 5px solid #d2b48c;
    margin: 20px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.story-section {
    background: linear-gradient(135deg, #faf6f0 0%, #f0e6d6 100%);
    padding: 25px;
    border-radius: 10px;
    margin: 20px 0;
    border: 1px solid #e6d3b7;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

.knowledge-section {
    background: linear-gradient(135deg, #f8f5f0 0%, #ede4d3 100%);
    padding: 25px;
    border-radius: 10px;
    margin: 20px 0;
    border: 1px solid #d6c7b0;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

.tool-section {
    background: linear-gradient(135deg, #fff9f0 0%, #f5e6d3 100%);
    padding: 25px;
    border-radius: 10px;
    margin: 20px 0;
    border: 1px solid #e0c9a6;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

.section-title {
    color: #8b4513;
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 15px;
    padding-bottom: 8px;
    border-bottom: 2px solid #d2b48c;
}

.book-overview {
    background: linear-gradient(135deg, #f9f6f0 0%, #f0e8d8 100%);
    padding: 30px;
    border-radius: 12px;
    margin: 30px 0;
    border: 2px solid #d2b48c;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
}

.value-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 25px;
    margin: 25px 0;
}

.value-box {
    background: rgba(255, 255, 255, 0.7);
    padding: 20px;
    border-radius: 8px;
    border: 1px solid #e6d3b7;
}

.innovation-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin: 30px 0;
}

.innovation-card {
    background: linear-gradient(135deg, #ffffff 0%, #f8f5f0 100%);
    padding: 25px;
    border-radius: 10px;
    border: 1px solid #e0c9a6;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

@media (max-width: 768px) {
    .container {
        margin: 10px;
        padding: 20px 15px;
    }
    
    .main-title h1 {
        font-size: 2.2rem;
    }
    
    .main-title .subtitle {
        font-size: 1rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    h3 {
        font-size: 1.2rem;
    }
    
    .value-section {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .innovation-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
}