/* 
    Homepage-Specific Styles
    
    This file contains styles only used on the homepage.
    Students can learn how to organize page-specific styles separately
    from base and component styles.
*/

/* 
    Hero Section
    
    The hero is the large introductory section at the top of the homepage.
    This demonstrates gradient backgrounds, which create visual interest.
*/
.hero {
    /* 
        Linear gradient creates a smooth color transition.
        135deg is the angle (diagonal from top-left to bottom-right).
        Colors transition from purple-blue to purple from 0% to 100%.
    */
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;         /* White text for contrast against dark background */
    padding: 4rem 0;      /* Large vertical padding for breathing room */
    margin-bottom: 4rem;  /* Space below hero section */
}

.hero h2 {
    font-size: 3rem;
    margin-bottom: 1rem;
    text-align: center;
}

.hero-subtitle {
    font-size: 1.25rem;
    text-align: center;
    margin-bottom: 3rem;
    opacity: 0.95;
}

/* 
    CSS Grid Layout for Hero Content
    
    Grid creates a two-column layout automatically.
    1fr 1fr means two equal-width columns (1 fraction unit each).
    gap creates space between grid items.
    This is a modern alternative to floats or flexbox for complex layouts.
*/
.hero-content {
    display: grid;                    /* Creates grid layout */
    grid-template-columns: 1fr 1fr;   /* Two equal columns */
    gap: 3rem;                        /* Space between columns */
    align-items: center;              /* Vertically centers grid items */
    margin-top: 2rem;                 /* Space above grid */
}

.hero-text p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

.features-list {
    list-style: none;
    margin-bottom: 2rem;
}

.features-list li {
    padding: 0.5rem 0;
    font-size: 1.05rem;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

/* 
    Button Styles
    
    Buttons use inline-block so they behave like inline elements but
    can have width, height, and vertical margins set. This is useful
    for clickable elements that need padding.
*/
.btn {
    display: inline-block;    /* Allows setting width/height while staying inline */
    padding: 0.75rem 2rem;    /* Vertical and horizontal padding for clickable area */
    border-radius: 8px;       /* Rounds the corners for modern appearance */
    text-decoration: none;    /* Removes underline from links styled as buttons */
    font-weight: 600;         /* Bold text for emphasis */
    transition: transform 0.2s, box-shadow 0.2s;  /* Smooth animation effects */
}

/* 
    Primary Button Variant
    
    Different button styles for different purposes.
    This creates a white button with blue text.
*/
.btn-primary {
    background-color: white;           /* White background */
    color: var(--primary-color);      /* Blue text */
}

/* 
    Button Hover Effect
    
    Transform moves the button up slightly on hover, creating a
    "lifted" effect. Combined with increased shadow, this gives
    strong visual feedback when users hover.
*/
.btn-primary:hover {
    transform: translateY(-2px);      /* Moves button 2px up */
    box-shadow: var(--shadow-lg);     /* Increases shadow for depth effect */
}

/* 
    Focus State for Primary Buttons
    
    Focus styles are crucial for keyboard users. When a button receives focus
    (via Tab key), users need clear visual feedback. We use both an outline
    and a box-shadow to ensure the focus state is highly visible.
*/
.btn-primary:focus {
    outline: 3px solid var(--primary-color);  /* Solid blue outline */
    outline-offset: 2px;                      /* Space between outline and button */
    box-shadow: var(--shadow-lg), 0 0 0 2px rgba(37, 99, 235, 0.3);  /* Additional shadow for emphasis */
}

.btn-secondary {
    background-color: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

/* 
    Focus State for Secondary Buttons
    
    For buttons on dark backgrounds (like the hero section), we use a white
    outline to ensure visibility. The outline-offset creates space so the
    outline doesn't overlap the border.
*/
.btn-secondary:focus {
    outline: 3px solid white;         /* White outline for contrast on dark background */
    outline-offset: 2px;            /* Space between outline and button */
    background-color: rgba(255, 255, 255, 0.2);  /* Slightly lighter background on focus */
}

.hero-preview {
    background-color: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    padding: 1.5rem;
}

.code-preview {
    background-color: #1e293b;
    border-radius: 8px;
    padding: 1.5rem;
    overflow-x: auto;
}

.code-preview pre {
    margin: 0;
    color: #e2e8f0;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.6;
}

/* Sections */
section {
    padding: 4rem 0;
}

section h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.section-intro {
    text-align: center;
    color: var(--text-light);
    font-size: 1.1rem;
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* 
    Lessons Section
    
    This section demonstrates responsive grid layouts that automatically
    adjust the number of columns based on available space.
*/
.lessons-section {
    background-color: var(--bg-light);  /* Light gray background for contrast */
}

/* 
    Responsive Grid Layout
    
    repeat(auto-fit, minmax(280px, 1fr)) creates a flexible grid that:
    - Creates as many columns as can fit
    - Each column is minimum 280px wide
    - Columns share remaining space equally (1fr = 1 fraction)
    - Automatically wraps to new rows when needed
    This creates a responsive layout without media queries!
*/
.lessons-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;           /* Space between grid items */
    margin-top: 2rem;    /* Space above grid */
}

/* 
    Progress Tracking Styles
*/

.overall-progress {
    background-color: #e2e8f0;
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.progress-bar-container {
    width: 100%;
    height: 24px;
    background-color: #cbd5e1;
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, #2563eb 0%, #3b82f6 100%);
    border-radius: 12px;
    transition: width 0.5s ease;
    width: 0%;
}

.progress-text {
    text-align: center;
    color: var(--text-color);
    font-weight: 500;
    font-size: 0.95rem;
}

.progress-indicator {
    position: absolute;
    top: 1rem;
    right: 1rem;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.2rem;
    z-index: 10;
}

.progress-indicator.status-completed {
    background-color: #16a34a;
    color: white;
}

.progress-indicator.status-in-progress {
    background-color: #f59e0b;
    color: white;
}

.progress-indicator.status-not-started {
    background-color: #e2e8f0;
    color: #64748b;
}

.progress-icon {
    display: block;
    line-height: 1;
}

/* 
    Lesson Card Styles
    
    Cards are reusable components that contain related content.
    They have rounded corners, shadows, and hover effects for interactivity.
    The entire card is now a clickable link for better UX.
*/
.lesson-card {
    display: block;                         /* Makes the anchor tag display as block */
    background-color: white;
    border-radius: 12px;                    /* Rounded corners */
    padding: 2rem;                          /* Internal spacing */
    box-shadow: var(--shadow);              /* Subtle shadow for depth */
    transition: transform 0.3s, box-shadow 0.3s;  /* Smooth hover animation */
    border: 1px solid var(--border-color); /* Subtle border */
    text-decoration: none;                  /* Removes underline from link */
    color: inherit;                         /* Inherits text color from parent */
    cursor: pointer;                         /* Shows pointer cursor on hover */
}

/* 
    Card Hover Effect
    
    When users hover over a card, it lifts up and the shadow increases.
    This provides clear visual feedback that the card is interactive.
*/
.lesson-card:hover {
    transform: translateY(-5px);  /* Moves card 5px upward */
    box-shadow: var(--shadow-lg);  /* Larger shadow for more depth */
    text-decoration: none;         /* Ensures no underline appears */
    color: inherit;                /* Maintains text color */
}

.lesson-number {
    display: inline-block;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.lesson-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-color);
}

.lesson-card p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.lesson-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    display: inline-block;
    transition: transform 0.2s;
}

.lesson-card:hover .lesson-link {
    transform: translateX(5px);
}

/* 
    Focus State for Lesson Cards
    
    When navigating with keyboard, the entire card should show focus.
    This ensures keyboard users can see which card they're about to activate.
*/
.lesson-card:focus {
    outline: 3px solid var(--primary-color);
    outline-offset: 4px;
    border-radius: 12px;
}

/* Examples Section */
.examples-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.example-card {
    display: block;                         /* Makes the anchor tag display as block */
    background-color: white;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    transition: border-color 0.3s, transform 0.3s;
    text-decoration: none;                  /* Removes underline from link */
    color: inherit;                         /* Inherits text color from parent */
    cursor: pointer;                         /* Shows pointer cursor on hover */
}

.example-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-3px);
    text-decoration: none;         /* Ensures no underline appears */
    color: inherit;                /* Maintains text color */
}

/* Focus state for example cards */
.example-card:focus {
    outline: 3px solid var(--primary-color);
    outline-offset: 4px;
    border-radius: 12px;
}

.example-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.example-card p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
}

.example-link {
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 600;
}

.example-card:hover .example-link {
    text-decoration: underline;
}

/* Templates Section */
.templates-section {
    background-color: var(--bg-light);
}

.templates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.template-card {
    display: block;                         /* Makes the anchor tag display as block */
    background-color: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
    border-left: 4px solid var(--secondary-color);
    text-decoration: none;                  /* Removes underline from link */
    color: inherit;                         /* Inherits text color from parent */
    cursor: pointer;                         /* Shows pointer cursor on hover */
}

.template-card:hover {
    transform: translateY(-3px);
    text-decoration: none;         /* Ensures no underline appears */
    color: inherit;                /* Maintains text color */
}

/* Focus state for template cards */
.template-card:focus {
    outline: 3px solid var(--secondary-color);
    outline-offset: 4px;
    border-radius: 12px;
}

.template-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.template-card p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
}

.template-link {
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 600;
}

.template-card:hover .template-link {
    text-decoration: underline;
}

/* GitHub Section */
.github-guides-list {
    max-width: 800px;
    margin: 0 auto;
}

.guide-item {
    display: flex;
    gap: 1.5rem;
    background-color: white;
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
}

.guide-item:hover {
    transform: translateX(5px);
}

.guide-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    font-weight: 700;
    flex-shrink: 0;
}

.guide-content h3 {
    margin-bottom: 0.5rem;
}

.guide-content h3 a {
    color: var(--text-color);
    text-decoration: none;
    font-size: 1.25rem;
}

.guide-content h3 a:hover {
    color: var(--primary-color);
}

/* 
    Focus State for Guide Links
    
    Guide links in the GitHub section need visible focus indicators.
*/
.guide-content h3 a:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 4px;
    border-radius: 4px;
}

.guide-content p {
    color: var(--text-light);
}

/* Footer */
footer {
    background-color: var(--text-color);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

/* 
    Responsive Design with Media Queries
    
    Media queries allow us to apply different styles at different screen sizes.
    This ensures the site works well on phones, tablets, and desktops.
    
    max-width: 768px means "when screen is 768px or smaller, apply these styles"
    This is a mobile-first approach - we enhance for larger screens and
    simplify for smaller ones.
*/
@media (max-width: 768px) {
    /* Smaller heading on mobile to fit better */
    .hero h2 {
        font-size: 2rem;  /* Reduced from 3rem */
    }
    
    /* Stack hero content vertically on mobile */
    .hero-content {
        grid-template-columns: 1fr;  /* Single column instead of two */
    }
    
    /* Single column layout for all grids on mobile */
    .lessons-grid,
    .examples-grid,
    .templates-grid {
        grid-template-columns: 1fr;  /* One column on small screens */
    }
    
    /* Less vertical padding on mobile to fit more content */
    section {
        padding: 2rem 0;  /* Reduced from 4rem */
    }
    
    /* Stack buttons vertically on mobile */
    .cta-buttons {
        flex-direction: column;  /* Buttons stack instead of sitting side-by-side */
    }
}