.back-home {
    display: inline-block;
    margin: 15px 20px;
    padding: 10px 15px;
    background-color: #34495e;
    color: #ecf0f1;
    text-decoration: none;
    font-weight: bold;
    border-radius: 4px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: background-color 0.3s ease, transform 0.2s ease;
}
.back-home:hover {
    background-color: #2c3e50;
    transform: translateX(-3px);
}



:root {
    --bg-color: #f9f9f9;     
    --text-color: #333333;   
    
    --card-bg: #ffffff;      
    --card-border: #dddddd;  
    
    --primary-color: #3498db;
    --btn-text: #ffffff;     
}


[data-theme="dark"] {
    --bg-color: #121212;     
    --text-color: #e0e0e0;   
    
    --card-bg: #1e1e1e;      
    --card-border: #333333;  
    
    --primary-color: #2980b9;
    --btn-text: #f1f1f1;
}


* {
    box-sizing: border-box;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;

    
    background-color: var(--bg-color);
    color: var(--text-color);
    
    
    transition: background-color 0.3s, color 0.3s;
}

.page-title {
    background-color: var(--card-bg); 
    color: var(--primary-color);      
    text-align: center;
    padding: 20px 0;
    margin-bottom: 20px;
    border-bottom: 2px solid var(--card-border);
}

.content {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

h2 {
    color: var(--primary-color); 
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 5px;
    margin-bottom: 20px;
}


.theme-card {
    
    padding: 20px;
    margin-top: 20px;
    border-radius: 4px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    
    
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    transition: background-color 0.3s, border-color 0.3s;
}

.theme-card h3 {
    margin-top: 0;
}


.btn-theme {
    display: inline-block;
    padding: 10px 15px;
    margin: 10px 0;
    cursor: pointer;
    font-weight: bold;
    border-radius: 4px;
    border: none;
    
    
    background-color: var(--primary-color);
    color: var(--btn-text);
}

.btn-theme:hover {
    filter: brightness(0.9); 
}


.back-btn {
    position: absolute;
    top: 15px;
    left: 15px;
    width: 40px;
    height: 40px;
    background-color: #fff;
    color: #333;
    border: 1px solid #ddd;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    text-decoration: none;
    font-size: 1.2rem;
    font-weight: bold;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: transform 0.2s;
    z-index: 1000;
}
.back-btn:hover {
    transform: scale(1.1);
    background-color: #f4f4f4;
}