:root {
    --primary-color: #4CAF50;
    --secondary-color: #2196F3;
    --background-color: #f5f5f5;
    --text-color: #333;
    --border-color: #ddd;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

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

header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

header h1 {
    color: var(--primary-color);
    margin-bottom: 10px;
}

header h2 {
    color: var(--secondary-color);
    font-size: 1.5em;
}

#menu {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 30px;
}

.tab-button {
    padding: 10px 30px;
    font-size: 1.1em;
    border: none;
    border-radius: 5px;
    background-color: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-button:hover {
    background-color: var(--primary-color);
    color: white;
}

.tab-button.active {
    background-color: var(--primary-color);
    color: white;
}

.tab-content {
    display: none;
    background-color: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.tab-content.active {
    display: block;
}

.meal-section, .exercise-section {
    margin-bottom: 30px;
    padding: 20px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

h2 {
    color: var(--primary-color);
    margin-bottom: 20px;
}

h3 {
    color: var(--secondary-color);
    margin-bottom: 15px;
}

h4 {
    color: var(--text-color);
    margin: 10px 0;
}

ul {
    list-style-position: inside;
    margin-left: 20px;
}

li {
    margin-bottom: 10px;
}

.tips-section {
    background-color: #e8f5e9;
    padding: 20px;
    border-radius: 8px;
    margin-top: 30px;
}

.exercise-item {
    margin: 20px 0;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: 5px;
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    .tab-content {
        padding: 15px;
    }
    
    .meal-section, .exercise-section {
        padding: 15px;
    }
    
    h1 {
        font-size: 1.8em;
    }
    
    h2 {
        font-size: 1.5em;
    }
    
    h3 {
        font-size: 1.2em;
    }
}