/* Variables */
:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --text-color: #333;
    --background-color: #fff;
    --border-color: #eee;
    --header-height: 60px;
    --container-width: 1200px;
    --spacing-unit: 1rem;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-unit);
}

/* Header */
.site-header {
    background-color: var(--primary-color);
    color: white;
    height: var(--header-height);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.site-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.site-title {
    color: white;
    text-decoration: none;
    font-size: 1.5rem;
    font-weight: bold;
}

.site-nav a {
    color: white;
    text-decoration: none;
    margin-left: 2rem;
    opacity: 0.8;
    transition: opacity 0.2s;
}

.site-nav a:hover {
    opacity: 1;
}

/* Main content */
.site-content {
    margin-top: var(--header-height);
    padding: var(--spacing-unit) 0;
}

/* Framework navigation */
.framework-nav {
    background-color: var(--border-color);
    padding: var(--spacing-unit);
    margin-bottom: var(--spacing-unit);
    border-radius: 4px;
}

.breadcrumbs {
    margin-bottom: var(--spacing-unit);
}

.breadcrumbs a {
    color: var(--secondary-color);
    text-decoration: none;
}

.sibling-nav {
    border-top: 1px solid var(--border-color);
    padding-top: var(--spacing-unit);
}

.sibling-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.sibling-nav li {
    margin: 0.5rem 0;
}

.sibling-nav a {
    color: var(--text-color);
    text-decoration: none;
}

.sibling-nav li.active a {
    color: var(--secondary-color);
    font-weight: bold;
}

/* Content sections */
.group, .practice, .task {
    background: white;
    padding: var(--spacing-unit);
    border-radius: 4px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.group-header, .practice-header, .task-header {
    margin-bottom: 2rem;
}

h1 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

h2 {
    color: var(--primary-color);
    margin: 2rem 0 1rem;
}

h3 {
    color: var(--secondary-color);
    margin: 1.5rem 0 1rem;
}

/* Task details */
.detail-item {
    margin-bottom: 1.5rem;
}

.questions ol {
    list-style-position: inside;
    padding-left: 1rem;
}

.question {
    margin: 1rem 0;
    padding: 1rem;
    background: var(--border-color);
    border-radius: 4px;
}

/* Footer */
.site-footer {
    background-color: var(--primary-color);
    color: white;
    padding: 2rem 0;
    margin-top: 3rem;
}

/* Responsive design */
@media (max-width: 768px) {
    .site-nav a {
        margin-left: 1rem;
    }

    .container {
        padding: 0 1rem;
    }
}

@media (max-width: 480px) {
    .site-header {
        height: auto;
        padding: 1rem 0;
    }

    .site-header .container {
        flex-direction: column;
        height: auto;
    }

    .site-nav {
        margin-top: 1rem;
    }

    .site-nav a {
        margin: 0 0.5rem;
    }

    .site-content {
        margin-top: 120px;
    }
}