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

body {
    font-family: 'Georgia', 'Times New Roman', serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.cover-container {
    width: 100%;
    max-width: 900px;
    perspective: 1000px;
}

.cover-page {
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3), 
                0 0 0 1px rgba(255, 255, 255, 0.1) inset,
                0 0 0 2px rgba(0, 0, 0, 0.05);
    overflow: hidden;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.3s ease;
    border: 1px solid rgba(0, 0, 0, 0.1);
}

.cover-page::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 8px;
    background: linear-gradient(90deg, #3498db 0%, #2980b9 50%, #3498db 100%);
}

.cover-content {
    padding: 60px 50px;
    min-height: 80vh;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    position: relative;
    background: linear-gradient(to bottom, 
        rgba(255, 255, 255, 0.98) 0%,
        rgba(255, 255, 255, 1) 50%,
        rgba(248, 249, 250, 1) 100%);
}

.cover-header {
    text-align: center;
    margin-bottom: 50px;
    padding-bottom: 40px;
    border-bottom: 3px solid #e0e0e0;
}

.main-title {
    font-size: 4rem;
    font-weight: 700;
    color: #2c3e50;
    margin-bottom: 15px;
    letter-spacing: 3px;
    text-transform: uppercase;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.sub-title {
    font-size: 1.8rem;
    font-weight: 400;
    color: #34495e;
    letter-spacing: 2px;
    font-style: italic;
    margin-top: 10px;
}

.cover-body {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 40px;
}

.author-section {
    text-align: center;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 8px;
    border: 1px solid #e9ecef;
}

.author-label, .collaboration-label {
    font-size: 0.9rem;
    text-transform: uppercase;
    color: #7f8c8d;
    letter-spacing: 1px;
    margin-bottom: 5px;
}

.author-name, .collaboration-name {
    font-size: 1.4rem;
    font-weight: 600;
    color: #2c3e50;
}

.collaboration-section {
    margin-top: 15px;
    padding-top: 15px;
    border-top: 1px dashed #ced4da;
}

.description-section {
    text-align: center;
    line-height: 1.8;
    color: #555;
    max-width: 700px;
    margin: 0 auto;
}

.description-text {
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.highlight {
    font-weight: 600;
    color: #3498db;
    font-size: 1.2rem;
    margin-top: 30px;
}

.cover-footer {
    text-align: center;
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid #e0e0e0;
    font-size: 0.9rem;
    color: #7f8c8d;
}

.enter-button-container {
    text-align: center;
    margin-top: 40px;
}

.enter-button {
    display: inline-block;
    padding: 15px 40px;
    background: linear-gradient(135deg, #3498db 0%, #2980b9 100%);
    color: white;
    text-decoration: none;
    font-size: 1.2rem;
    font-weight: 600;
    border-radius: 50px;
    box-shadow: 0 10px 20px rgba(52, 152, 219, 0.3);
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.enter-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 30px rgba(52, 152, 219, 0.4);
    background: linear-gradient(135deg, #2980b9 0%, #3498db 100%);
}

.cover-links {
    margin-top: 20px;
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.about-link-cover {
    color: #7f8c8d;
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.3s;
    font-weight: 500;
}

.about-link-cover:hover {
    color: #3498db;
    text-decoration: underline;
}

.ai-alert {
    background: linear-gradient(135deg, #fff3e0 0%, #ffe0b2 100%);
    border-left: 5px solid #ff9800;
    color: #e65100;
    padding: 15px 20px;
    border-radius: 4px;
    margin: 20px auto;
    text-align: center;
    font-weight: bold;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    max-width: 80%;
}

@media (max-width: 768px) {
    .main-title {
        font-size: 2.5rem;
    }
    
    .sub-title {
        font-size: 1.2rem;
    }
    
    .cover-content {
        padding: 30px 20px;
    }
    
    .enter-button {
        padding: 12px 30px;
        font-size: 1rem;
    }
}