:root {
    --primary-color: #0A74DA;
    --secondary-color: #F5F5F5;
    --accent-color: #FF6B6B;
    --dark-text: #333333;
    --light-text: #FFFFFF;
    --font-primary: 'Open Sans', sans-serif;
    --font-secondary: 'Roboto', sans-serif;
    --border-radius: 12px;
    --box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@400;600&family=Roboto:wght@700;900&display=swap');

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

body {
    font-family: var(--font-primary);
    color: var(--dark-text);
    background: linear-gradient(135deg, var(--secondary-color) 70%, var(--primary-color) 25%, var(--accent-color) 5%);
    line-height: 1.6;
    padding: 0;
    overflow-x: hidden;
}

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

.header {
    position: relative;
    padding: 40px 0;
    text-align: center;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    margin-bottom: 60px;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.header h1 {
    font-family: var(--font-secondary);
    font-size: 2.8rem;
    color: var(--primary-color);
    margin-bottom: 20px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.header p {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto;
    color: var(--dark-text);
}

.notice {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--primary-color);
    color: white;
    padding: 10px 20px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    z-index: 1000;
    font-size: 0.9rem;
}

article {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 40px;
    margin-bottom: 60px;
}

article h2 {
    font-family: var(--font-secondary);
    color: var(--primary-color);
    font-size: 2rem;
    margin-bottom: 30px;
    position: relative;
    padding-bottom: 15px;
}

article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    border-radius: 2px;
}

article h3 {
    font-family: var(--font-secondary);
    color: var(--primary-color);
    font-size: 1.5rem;
    margin: 40px 0 20px;
}

article p {
    font-size: 1.1rem;
    margin-bottom: 20px;
    line-height: 1.8;
}

pre {
    background: #f8f9fa;
    border-radius: var(--border-radius);
    padding: 20px;
    margin: 30px 0;
    overflow: auto;
    border-left: 4px solid var(--primary-color);
}

code {
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    color: #333;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

th, td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #eee;
}

th {
    background-color: var(--primary-color);
    color: white;
    font-family: var(--font-secondary);
}

tr:nth-child(even) {
    background-color: #f9f9f9;
}

.image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
    margin: 40px 0;
}

.image-card {
    position: relative;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
}

.image-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

.image-card img {
    width: 100%;
    height: 300px;
    object-fit: cover;
    display: block;
}

.nav-tabs {
    display: flex;
    list-style: none;
    margin-bottom: 40px;
    border-bottom: 1px solid #eee;
}

.nav-tabs li {
    margin-right: 20px;
}

.nav-tabs a {
    display: block;
    padding: 10px 0;
    color: var(--dark-text);
    text-decoration: none;
    font-family: var(--font-secondary);
    position: relative;
    transition: var(--transition);
}

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

.nav-tabs a.active {
    color: var(--primary-color);
    font-weight: bold;
}

.nav-tabs a.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--primary-color);
}

@media (max-width: 768px) {
    .header h1 {
        font-size: 2rem;
    }
    
    article {
        padding: 30px 20px;
    }
    
    .image-grid {
        grid-template-columns: 1fr;
    }
    
    .nav-tabs {
        flex-wrap: wrap;
    }
    
    .nav-tabs li {
        margin-right: 15px;
        margin-bottom: 10px;
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

.floating {
    animation: float 6s ease-in-out infinite;
}

.highlight {
    color: var(--accent-color);
    font-weight: bold;
}

.accordion {
    margin: 30px 0;
}

.accordion-item {
    border: 1px solid #eee;
    border-radius: var(--border-radius);
    margin-bottom: 15px;
    overflow: hidden;
}

.accordion-header {
    padding: 15px 20px;
    background: #f9f9f9;
    cursor: pointer;
    font-family: var(--font-secondary);
    color: var(--primary-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.accordion-header:hover {
    background: #f0f0f0;
}

.accordion-content {
    padding: 0 20px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.accordion-item.active .accordion-content {
    padding: 20px;
    max-height: 1000px;
}

.accordion-icon {
    transition: transform 0.3s ease;
}

.accordion-item.active .accordion-icon {
    transform: rotate(180deg);
}

.gradient-text {
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    display: inline-block;
}