/* --- Global Styles & Variables --- */
:root {
    --primary-font: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    
    /* Light Theme (Default) */
    --bg-color: #f8f9fa;
    --card-bg-color: #ffffff;
    --text-color-primary: #212529;
    --text-color-secondary: #495057;
    --accent-color: #007bff; /* Primary blue */
    --accent-color-darker: #0056b3;
    --accent-color-rgb: 0, 123, 255; /* For rgba box-shadow */
    --gradient-start: #007bff;
    --gradient-end: #0056b3;
    --success-color: #28a745;
    --danger-color: #dc3545;

    --border-radius-lg: 16px;
    --border-radius-md: 12px;
    --border-radius-sm: 8px;
    
    --shadow-color-light: rgba(0, 0, 0, 0.05);
    --shadow-color-medium: rgba(0, 0, 0, 0.1);
    --card-shadow: 0 4px 12px var(--shadow-color-light);
    --card-hover-shadow: 0 8px 25px var(--shadow-color-medium);
    --card-focus-shadow: 0 0 0 3px rgba(var(--accent-color-rgb), 0.4);
}

*, *::before, *::after {
    box-sizing: border-box;
}

body {
    font-family: var(--primary-font);
    background-color: var(--bg-color);
    color: var(--text-color-primary);
    margin: 0;
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* General hidden class */
.hidden {
    display: none !important;
}

/* --- Header --- */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    color: white;
    box-shadow: 0 2px 8px var(--shadow-color-medium);
    position: sticky;
    top: 0;
    z-index: 100; /* Ensure header is above other content, but custom dropdown listbox will need higher */
}
.logo-placeholder {
    font-size: 1.5rem;
    font-weight: bold;
    color: white;
    text-decoration: none;
}
.header-nav { display: flex; align-items: center; gap: 1.5rem; }

/* Wrapper for version selector to allow hiding */
#version-selector-wrapper.hidden {
    display: none !important;
}

/* Custom Searchable Dropdown Styles (Header) */
.custom-select-wrapper {
    position: relative;
    min-width: 200px; /* Adjust as needed, e.g., 220px */
    color: white; /* Text color for placeholder and input */
}

.custom-select-input {
    font-size: 0.95rem;
    padding: 0.6rem 2.5rem 0.6rem 0.8rem; /* Right padding for toggle button */
    border-radius: var(--border-radius-sm);
    border: 1px solid rgba(255,255,255,0.3);
    background-color: rgba(255,255,255,0.1);
    color: white; /* Text color for input */
    width: 100%;
    transition: background-color 0.2s ease, border-color 0.2s ease;
    /* cursor: pointer; Remove if you want text cursor for typing */
}
.custom-select-input::placeholder {
    color: rgba(255,255,255,0.7);
}
.custom-select-input:hover {
    background-color: rgba(255,255,255,0.2);
}
.custom-select-input:focus {
    background-color: rgba(255,255,255,0.25);
    border-color: white;
    outline: none;
    box-shadow: 0 0 0 2px rgba(255,255,255,0.5);
}

.custom-select-toggle {
    position: absolute;
    right: 1px; /* Align with input border */
    top: 1px;
    bottom: 1px;
    padding: 0 0.75rem;
    background: transparent; /* Or match input background slightly darker on hover */
    border: none;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}
.custom-select-toggle svg {
    width: 1em;
    height: 1em;
    transition: transform 0.2s ease;
}
/* Rotate arrow when dropdown is open */
.custom-select-wrapper[aria-expanded="true"] .custom-select-toggle svg {
    transform: rotate(180deg);
}

.custom-select-options {
    position: absolute;
    top: calc(100% + 4px); 
    left: 0;
    right: 0;
    background-color: var(--card-bg-color);
    border: 1px solid #ced4da; /* Border for the dropdown list */
    border-radius: var(--border-radius-sm);
    box-shadow: 0 4px 12px var(--shadow-color-medium);
    z-index: 1020; /* Higher than header, but lower than full screen modal if any */
    max-height: 250px; 
    overflow-y: auto;
    list-style: none;
    padding: 0.25rem 0;
    margin: 0;
}
/* Individual option styling */
.custom-select-options li {
    padding: 0.6rem 1rem;
    color: var(--text-color-primary); /* Text color for items in dropdown */
    cursor: pointer;
    transition: background-color 0.15s ease;
    outline: none; 
}
.custom-select-options li:hover,
.custom-select-options li.highlighted { /* Highlight for keyboard nav */
    background-color: var(--accent-color);
    color: white;
}
.custom-select-options li.selected { /* Style for the actually selected item */
    background-color: var(--accent-color-darker); /* Or a different subtle highlight */
    color: white;
    font-weight: 500;
}
.custom-select-options .no-options-message {
    padding: 0.6rem 1rem;
    color: var(--text-color-secondary);
    font-style: italic;
    cursor: default;
}

/* Search Bar in Header (Styles for the main page search) */
.search-bar-container { display: flex; } /* Ensures button and input are on same line */
#search-bar { /* This is the main page search, not the dropdown search */
    font-size: 0.95rem;
    padding: 0.6rem 0.8rem;
    border-radius: var(--border-radius-sm);
    border: 1px solid rgba(255,255,255,0.3);
    background-color: rgba(255,255,255,0.1);
    color: white;
    transition: background-color 0.2s ease, border-color 0.2s ease;
    min-width: 200px; /* Give it some default width */
}
#search-bar::placeholder { color: rgba(255,255,255,0.7); }
#search-bar:hover { background-color: rgba(255,255,255,0.2); }
#search-bar:focus {
    background-color: rgba(255,255,255,0.25);
    border-color: white;
    outline: none;
    box-shadow: 0 0 0 2px rgba(255,255,255,0.5);
}
#search-button { /* For the main page search */
    padding: 0.6rem 0.8rem;
    margin-left: -1px; 
    border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
    border: 1px solid rgba(255,255,255,0.3);
    background-color: rgba(255,255,255,0.15);
    color: white;
    cursor: pointer;
    transition: background-color 0.2s ease;
}
#search-button:hover { background-color: rgba(255,255,255,0.25); }
#search-button svg { display: block; }


/* --- Welcome Section --- */
.welcome-section {
    text-align: center;
    padding: 3rem 2rem 2rem;
    background-color: var(--bg-color); 
}
.welcome-content h1 {
    font-size: 2.8rem;
    margin-bottom: 0.75rem;
    font-weight: 700;
    background: linear-gradient(90deg, var(--accent-color), var(--accent-color-darker));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text; 
    text-fill-color: transparent; 
}
.welcome-content p { font-size: 1.15rem; color: var(--text-color-secondary); max-width: 750px; margin-left: auto; margin-right: auto; }

/* --- Product Navigation Pills --- */
.product-navigation {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 1.5rem 1rem 1rem; 
    gap: 0.75rem;
    border-bottom: 1px solid #dee2e6; 
    margin-bottom: 1rem; 
    flex-wrap: wrap; 
}
.product-pill {
    font-family: var(--primary-font);
    font-size: 1rem;
    font-weight: 500;
    padding: 0.65rem 1.3rem;
    border-radius: 50px; 
    border: 1px solid #ced4da; 
    background-color: var(--card-bg-color);
    color: var(--text-color-secondary);
    cursor: pointer;
    transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}
.product-pill:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
    background-color: #e9ecef; 
}
.product-pill.active {
    background-color: var(--accent-color);
    color: white;
    border-color: var(--accent-color-darker);
    box-shadow: 0 2px 5px rgba(var(--accent-color-rgb), 0.3);
}
.product-pill:focus-visible {
    outline: none;
    border-color: var(--accent-color-darker);
    box-shadow: 0 0 0 3px rgba(var(--accent-color-rgb), 0.4);
}

/* --- Guide Cards Container --- */
.guide-cards-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.8rem;
    padding: 2rem;
    max-width: 1300px;
    margin: 0 auto;
}
.no-results {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-color-secondary);
    padding: 2rem;
    width: 100%; 
}

.guide-card {
    background-color: var(--card-bg-color);
    border-radius: var(--border-radius-lg);
    padding: 1.8rem;
    box-shadow: var(--card-shadow);
    transition: transform 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    cursor: pointer;
    border: 1px solid transparent; 
    position: relative;
    overflow: hidden; 
    display: flex;
    flex-direction: column;
}
.guide-card:hover, .guide-card:focus-visible {
    transform: translateY(-6px);
    box-shadow: var(--card-hover-shadow);
}
.guide-card:focus-visible {
    outline: none; 
    box-shadow: var(--card-hover-shadow), var(--card-focus-shadow);
}
.guide-card-icon {
    width: 36px;
    height: 36px;
    margin-bottom: 1rem;
    color: var(--accent-color); 
}
.guide-card-icon svg, .guide-card-icon-emoji { 
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}
.guide-card-icon-emoji {
    font-size: 24px; /* Adjust emoji size if using text emoji */
}
.guide-card-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin-top: 0;
    margin-bottom: 0.6rem;
    color: var(--text-color-primary);
}
.guide-card-description {
    font-size: 0.95rem;
    color: var(--text-color-secondary);
    flex-grow: 1; 
    margin-bottom: 1rem;
}
.version-badge {
    align-self: flex-start; 
    background-color: var(--accent-color);
    color: white;
    padding: 0.3em 0.7em;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: var(--border-radius-sm);
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease;
    margin-top: auto; 
}
.guide-card.version-selected .version-badge {
    opacity: 1;
    transform: translateY(0);
}

/* --- Quick Links Section --- */
.quick-links-section {
    text-align: center;
    padding: 2.5rem 1rem;
    background-color: #e9ecef; 
    border-top: 1px solid #dee2e6;
    border-bottom: 1px solid #dee2e6;
}
.quick-link {
    display: inline-block;
    margin: 0.5rem 1rem;
    color: var(--accent-color-darker);
    text-decoration: none;
    font-weight: 500;
    padding: 0.6rem 1.2rem;
    border-radius: var(--border-radius-sm);
    border: 1px solid transparent;
    transition: background-color 0.2s ease, color 0.2s ease, transform 0.2s ease, border-color 0.2s ease;
}
.quick-link:hover, .quick-link:focus-visible {
    background-color: var(--accent-color);
    color: white;
    text-decoration: none;
    transform: translateY(-2px);
    border-color: var(--accent-color-darker);
}
.quick-link:focus-visible {
    outline: none;
    box-shadow: var(--card-focus-shadow);
}

/* --- Footer --- */
.page-footer-bottom {
    text-align: center;
    padding: 2rem 1rem;
    font-size: 0.9rem;
    color: var(--text-color-secondary);
}
.page-footer-bottom a {
    color: var(--text-color-secondary);
    text-decoration: none;
}
.page-footer-bottom a:hover {
    color: var(--accent-color);
    text-decoration: underline;
}

/* --- Modal Styles --- */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.55); 
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0s 0.3s linear;
    z-index: 1030; /* Ensure modal is on top of everything, including custom dropdown listbox */
    padding: 1rem; 
}
.modal.open {
    opacity: 1;
    visibility: visible;
    transition-delay: 0s; 
}
.modal-content {
    background-color: var(--card-bg-color);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.25);
    width: 100%;
    max-width: 480px;
    position: relative;
    transform: scale(0.9);
    opacity: 0;
    transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275), opacity 0.3s ease;
    display: flex; 
    flex-direction: column; 
}
.modal.open .modal-content {
    transform: scale(1);
    opacity: 1;
}
.modal-close-button {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: transparent;
    border: none;
    font-size: 1.5rem; 
    cursor: pointer;
    color: var(--text-color-secondary);
    padding: 0.5rem;
    line-height: 1;
    border-radius: 50%;
    transition: background-color 0.2s ease, color 0.2s ease;
}
.modal-close-button:hover, .modal-close-button:focus-visible {
    color: var(--text-color-primary);
    background-color: rgba(0,0,0,0.05);
}
.modal-close-button:focus-visible {
    outline: none;
    box-shadow: var(--card-focus-shadow);
}
#modal-title {
    margin-top: 0;
    margin-bottom: 1rem; 
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-color-primary);
}
.modal-guide-name-highlight { color: var(--accent-color); }

.modal-search-container {
    margin-bottom: 1rem; 
}
#modal-version-search {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
    border: 1px solid #ced4da;
    border-radius: var(--border-radius-md);
    background-color: var(--bg-color); 
}
#modal-version-search:focus {
    border-color: var(--accent-color);
    outline: none;
    box-shadow: 0 0 0 3px rgba(var(--accent-color-rgb), 0.25);
}

#modal-version-list {
    max-height: 300px; 
    overflow-y: auto;  
    scrollbar-width: thin; 
    scrollbar-color: var(--accent-color) var(--bg-color); 
}
#modal-version-list::-webkit-scrollbar { width: 8px; }
#modal-version-list::-webkit-scrollbar-track { background: var(--bg-color); border-radius: 4px; }
#modal-version-list::-webkit-scrollbar-thumb { background-color: var(--accent-color); border-radius: 4px; border: 2px solid var(--bg-color); }

.modal-no-results { 
    text-align: center;
    padding: 1rem;
    color: var(--text-color-secondary);
    font-style: italic;
}

.version-list .version-link-button {
    display: block;
    width: 100%;
    padding: 0.85rem 1.2rem;
    margin-bottom: 0.75rem;
    text-align: left;
    font-size: 1rem;
    font-weight: 500;
    background-color: var(--bg-color);
    border: 1px solid #dee2e6;
    border-radius: var(--border-radius-md);
    cursor: pointer;
    color: var(--text-color-primary);
    transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.1s ease,
                opacity 0.2s ease, height 0.2s ease, margin 0.2s ease, padding 0.2s ease; 
}
.version-list .version-link-button:hover,
.version-list .version-link-button:focus-visible {
    background-color: var(--accent-color);
    border-color: var(--accent-color-darker);
    color: white;
    transform: scale(1.02);
}
.version-list .version-link-button:focus-visible {
    outline: none;
    box-shadow: var(--card-focus-shadow);
}
.version-list .version-link-button:last-child { margin-bottom: 0; }

.version-list .version-link-button.hidden {
    opacity: 0;
    height: 0 !important; 
    padding-top: 0 !important;
    padding-bottom: 0 !important;
    margin-top: 0 !important;
    margin-bottom: 0 !important;
    border-width: 0 !important; 
    overflow: hidden; 
    pointer-events: none; 
}


/* Responsive adjustments */
@media (max-width: 768px) {
    .page-header {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    .header-nav {
        flex-direction: column;
        width: 100%;
        gap: 1rem;
    }
    .custom-select-wrapper, /* Ensure custom dropdown is full width on mobile */
    #search-bar { 
        width: 100%; 
    } 
    .search-bar-container { width: 100%; } /* Make search bar container full width */

    .welcome-content h1 { font-size: 2.2rem; }
    .welcome-content p { font-size: 1rem; }
    .guide-cards-container {
        grid-template-columns: 1fr; 
        padding: 1.5rem 1rem;
        gap: 1.5rem;
    }
    .product-navigation {
        padding: 1rem 0.5rem;
        gap: 0.5rem;
    }
    .product-pill {
        font-size: 0.9rem;
        padding: 0.5rem 1rem;
    }
    .modal-content { padding: 1.5rem; }
    #modal-title { font-size: 1.3rem; }
}

@media (max-width: 480px) {
    .welcome-content h1 { font-size: 1.8rem; }
    .quick-links-section { padding: 1.5rem 0.5rem; }
    .quick-link { margin: 0.5rem; }
}