/* CSS Variables for a modern, vibrant theme */
:root {
    --primary-color: #6a0dad; /* Deep Purple */
    --primary-color-dark: #4a087a; /* Darker Purple */
    --accent-color: #00bcd4; /* Cyan/Turquoise */
    --bg-light: #f5f7fa; /* Light Grayish Blue */
    --text-light: #2c3e50; /* Dark Blue Gray */
    --card-bg-light: #ffffff;
    --card-shadow-light: rgba(0, 0, 0, 0.15);
    --input-border-light: #d1d8e0;
    --button-bg-light: #6a0dad;
    --button-text-light: #ffffff;
    --secondary-button-bg-light: #e0e6ed;
    --secondary-button-text-light: #2c3e50;
    --placeholder-bg-light: #e0e0e0;
    --placeholder-text-light: #616161;
    --toast-bg-success: #4CAF50;
    --toast-bg-error: #f44336;
    --toast-bg-warning: #ff9800;
    --toast-bg-info: #2196F3;
}

.dark {
    --primary-color: #9b59b6; /* Lighter Purple */
    --primary-color-dark: #8e44ad; /* Slightly Darker Purple */
    --accent-color: #00e5ff; /* Brighter Cyan */
    --bg-light: #1a202c; /* Dark Blue Gray */
    --text-light: #e2e8f0; /* Light Gray */
    --card-bg-light: #2d3748; /* Darker Gray Blue */
    --card-shadow-light: rgba(0, 0, 0, 0.4);
    --input-border-light: #4a5568;
    --button-bg-light: #9b59b6;
    --button-text-light: #ffffff;
    --secondary-button-bg-light: #4a5568;
    --secondary-button-text-light: #e2e8f0;
    --placeholder-bg-light: #3a475a;
    --placeholder-text-light: #a0aec0;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-light);
    color: var(--text-light);
    transition: background-color 0.4s ease, color 0.4s ease;
}

h1, h2, h3 {
    font-family: 'Poppins', sans-serif;
    color: var(--text-light);
}

.header-content h1 {
    font-weight: 700; /* Poppins Bold */
}

.news-card {
    border-radius: 1.25rem; /* More rounded */
    box-shadow: 0 10px 20px -5px var(--card-shadow-light); /* Deeper shadow */
    transition: transform 0.3s ease-in-out, box-shadow 0.3s ease, background-color 0.3s ease;
    overflow: hidden;
    opacity: 0; 
    animation: fadeIn 0.6s ease-out forwards; 
    animation-delay: var(--animation-delay); 
    background-color: var(--card-bg-light);
    position: relative; /* For potential overlay effects */
}
.news-card:hover {
    transform: translateY(-8px) scale(1.02); /* More pronounced lift and slight scale */
    box-shadow: 0 15px 30px -8px var(--card-shadow-light);
}
.news-card img {
    width: 100%;
    height: 200px; /* Slightly taller default */
    object-fit: cover;
    border-top-left-radius: 1.25rem;
    border-top-right-radius: 1.25rem;
    margin-bottom: 1rem;
    transition: transform 0.3s ease; /* Smooth image zoom */
}
.news-card:hover img {
    transform: scale(1.05); /* Subtle zoom on image hover */
}

/* Responsive image heights */
.news-card.large-card img {
    height: 280px; 
}
.news-card.medium-card img {
    height: 220px; 
}

/* Placeholder image styling */
.news-card .placeholder-image {
    width: 100%;
    height: 200px; 
    background-color: var(--placeholder-bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--placeholder-text-light);
    font-weight: 600; /* Bolder text */
    border-top-left-radius: 1.25rem;
    border-top-right-radius: 1.25rem;
    margin-bottom: 1rem;
    text-align: center; 
    padding: 15px; 
    font-size: 1.1rem;
}
.news-card.large-card .placeholder-image {
    height: 280px;
}
.news-card.medium-card .placeholder-image {
    height: 220px;
}

.loading-spinner {
    border: 5px solid rgba(0, 0, 0, 0.1);
    border-left-color: var(--primary-color);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
}
.dark .loading-spinner {
    border-color: rgba(255, 255, 255, 0.1);
    border-left-color: var(--primary-color);
}
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Buttons Styling */
.nav-button, .search-button, .author-search-button, .date-quick-button, #selectSourcesButton, #loadMoreButton, .summarize-button, .original-link {
    border-radius: 0.75rem; /* More rounded buttons */
    font-weight: 600; /* Bolder text */
    transition: all 0.2s ease-in-out;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

.nav-button {
    background-color: var(--secondary-button-bg-light);
    color: var(--secondary-button-text-light);
}
.nav-button:hover {
    background-color: var(--secondary-button-bg-light);
    transform: translateY(-2px);
    box-shadow: 0 6px 10px -2px rgba(0, 0, 0, 0.15);
}
.nav-button.active {
    background-color: var(--primary-color);
    color: var(--button-text-light);
    box-shadow: 0 6px 10px -2px rgba(0, 0, 0, 0.2);
    transform: translateY(-2px);
}

.search-button, .author-search-button, #selectSourcesButton, #loadMoreButton, #applySourcesButton, #applyFavoriteCategoriesButton, #applyFavoriteSourcesButton {
    background-color: var(--primary-color);
    color: var(--button-text-light);
}
.search-button:hover, .author-search-button:hover, #selectSourcesButton:hover, #loadMoreButton:hover, #applySourcesButton:hover, #applyFavoriteCategoriesButton:hover, #applyFavoriteSourcesButton:hover {
    background-color: var(--primary-color-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 10px -2px rgba(0, 0, 0, 0.15);
}

.date-quick-button, .category-button {
    background-color: var(--secondary-button-bg-light);
    color: var(--secondary-button-text-light);
    border-radius: 9999px; /* Pill shape */
    padding: 0.6rem 1.2rem;
    font-size: 0.9rem;
}
.date-quick-button:hover, .category-button:hover {
    background-color: var(--secondary-button-bg-light);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px -2px rgba(0, 0, 0, 0.1);
}
.category-button.active {
    background-color: var(--accent-color); /* Use accent color for active category */
    color: white;
    box-shadow: 0 4px 8px -2px rgba(0, 0, 0, 0.2);
    transform: translateY(-2px);
}

/* Input fields */
input[type="text"], input[type="date"], select {
    border: 1px solid var(--input-border-light);
    background-color: var(--card-bg-light);
    color: var(--text-light);
    border-radius: 0.75rem;
    padding: 0.8rem 1rem;
    transition: all 0.2s ease;
}
input[type="text"]:focus, input[type="date"]:focus, select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(106, 13, 173, 0.2); /* Purple glow */
    outline: none;
}

/* Share buttons */
.share-button {
    color: var(--text-light);
    background-color: var(--secondary-button-bg-light);
}
.share-button:hover {
    background-color: var(--primary-color);
    color: white;
}
.share-button.twitter { color: #1DA1F2; } .share-button.twitter:hover { background-color: #1DA1F2; color: white; }
.share-button.facebook { color: #1877F2; } .share-button.facebook:hover { background-color: #1877F2; color: white; }
.share-button.whatsapp { color: #25D366; } .share-button.whatsapp:hover { background-color: #25D366; color: white; }
.share-button.viber { color: #7360F2; } .share-button.viber:hover { background-color: #7360F2; color: white; }
.share-button.telegram { color: #0088CC; } .share-button.telegram:hover { background-color: #0088CC; color: white; }
.share-button.vk { color: #4C75A3; } .share-button.vk:hover { background-color: #4C75A3; color: white; }
.share-button.copy { color: #6B7280; } .share-button.copy:hover { background-color: #6B7280; color: white; }

/* Bookmark button */
.bookmark-button {
    color: var(--primary-color); /* Always purple */
    background-color: var(--secondary-button-bg-light);
}
.bookmark-button:hover {
    background-color: var(--primary-color);
    color: white;
}
.bookmark-button i.fas {
    color: var(--primary-color); /* Active bookmark icon color */
}
.dark .bookmark-button i.fas {
    color: var(--accent-color); /* Active bookmark icon color in dark mode */
}


/* General UI Polish */
.main-title {
    font-size: 3.2rem; /* Larger title */
    line-height: 1.1;
    font-weight: 700;
}
.subtitle {
    font-size: 1.25rem; 
    color: var(--text-light);
    opacity: 0.8;
}
.news-card h2 {
    font-size: 1.4rem; 
    line-height: 1.3;
    font-weight: 600;
}
.news-card p {
    font-size: 1rem; 
    line-height: 1.5;
    color: var(--text-light);
    opacity: 0.9;
}
.read-more-button {
    font-size: 1rem; 
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s ease;
}
.read-more-button:hover {
    color: var(--accent-color);
    transform: translateX(3px);
}

/* Header Layout */
.header-content {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1.5rem; /* More space */
    padding: 2rem 0;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-color-dark)); /* Gradient background */
    border-radius: 1.5rem;
    box-shadow: 0 10px 20px -5px rgba(0, 0, 0, 0.25);
    color: white;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.2);
}
.header-content img {
    border: 4px solid white; /* White border for logo */
    box-shadow: 0 0 15px rgba(255,255,255,0.3);
}
.header-content h1, .header-content p {
    color: white; /* Ensure text is white on dark gradient */
}

@media (max-width: 640px) { 
    .header-content {
        flex-direction: column;
        text-align: center;
        padding: 1.5rem 0;
    }
    .main-title {
        font-size: 2.5rem;
    }
    .subtitle {
        font-size: 1rem;
    }
}

/* Modal styles */
.modal {
    position: fixed;
    z-index: 100; /* High z-index to be on top */
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.8); /* Darker overlay */
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}
.modal.show {
    opacity: 1;
    visibility: visible;
}
.modal-content {
    background-color: var(--card-bg-light);
    margin: auto;
    padding: 20px;
    border-radius: 1.5rem; /* More rounded */
    width: 90%;
    max-width: 700px; /* Slightly wider */
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
    transform: translateY(-50px); /* Initial state for animation */
    transition: transform 0.3s ease;
    position: relative;
    max-height: 80vh; /* Limit height for scrollable content */
    display: flex;
    flex-direction: column;
    color: var(--text-light);
}
.modal.show .modal-content {
    transform: translateY(0); /* Animate to original position */
}
.close-button {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 32px; /* Larger close button */
    font-weight: bold;
    color: var(--text-light); /* Use main text color */
    cursor: pointer;
    transition: color 0.2s ease, transform 0.2s ease;
}
.close-button:hover,
.close-button:focus {
    color: var(--primary-color);
    transform: scale(1.2);
    text-decoration: none;
    cursor: pointer;
}
.sources-list {
    max-height: 50vh; /* Make list scrollable */
    overflow-y: auto;
    padding-right: 10px; /* For scrollbar */
    margin-bottom: 1rem;
}
.sources-list label {
    display: flex;
    align-items: center;
    margin-bottom: 0.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 0.5rem;
    transition: background-color 0.2s ease;
}
.sources-list label:hover {
    background-color: var(--secondary-button-bg-light);
}
.sources-list input[type="checkbox"] {
    margin-right: 0.75rem;
    transform: scale(1.2);
    accent-color: var(--primary-color); /* Style checkbox */
}

/* Summarization */
.summary-content {
    margin-top: 1rem;
    padding: 1rem;
    background-color: rgba(0, 189, 212, 0.1); /* Lighter accent color */
    border-radius: 0.75rem;
    font-style: italic;
    color: var(--text-light);
    border-left: 4px solid var(--accent-color); /* Accent border */
}
.dark .summary-content {
    background-color: rgba(0, 229, 255, 0.1);
}
.summary-loading-spinner {
    border: 2px solid rgba(0, 0, 0, 0.1);
    border-left-color: var(--primary-color);
    border-radius: 50%;
    width: 20px;
    height: 20px;
    animation: spin 1s linear infinite;
    display: inline-block;
    margin-left: 0.5rem;
}
.dark .summary-loading-spinner {
    border-color: rgba(255, 255, 255, 0.1);
    border-left-color: var(--primary-color);
}

/* Toast Notification Styles */
.toast-notification {
    position: fixed;
    bottom: 30px; /* Slightly higher */
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--toast-bg-success); 
    color: white;
    padding: 12px 25px; /* More padding */
    border-radius: 10px; /* More rounded */
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.5s ease-in-out, visibility 0.5s ease-in-out;
    z-index: 1000;
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.3); /* Deeper shadow */
    font-weight: 500;
}
.toast-notification.show {
    opacity: 1;
    visibility: visible;
}

/* Scroll to Top Button */
#scrollToTopBtn {
    display: none; 
    position: fixed; 
    bottom: 40px; 
    right: 40px; 
    z-index: 99; 
    border: none; 
    outline: none; 
    background-color: var(--accent-color);
    color: white;
    cursor: pointer; 
    padding: 18px; /* Larger button */
    border-radius: 50%; 
    font-size: 20px; 
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    transition: background-color 0.3s, opacity 0.3s, transform 0.2s ease;
}

#scrollToTopBtn:hover {
    background-color: var(--primary-color);
    transform: translateY(-3px);
}

/* Full Article Modal Specific Styles */
#articleDetailModal .modal-content {
    max-width: 900px;
    max-height: 90vh;
    overflow-y: auto;
    text-align: left;
    padding: 30px; /* More padding */
}
#articleDetailModal img {
    max-width: 100%;
    height: auto;
    border-radius: 0.75rem; /* More rounded */
    margin-bottom: 1.5rem;
}
#articleDetailModal h2 {
    font-size: 2.5rem; /* Larger title */
    font-weight: bold;
    margin-bottom: 1rem;
}
#articleDetailModal p {
    font-size: 1.1rem; /* Slightly larger text */
    line-height: 1.7;
    margin-bottom: 1.5rem;
}
#articleDetailModal .original-link {
    display: inline-block;
    margin-top: 1rem;
    padding: 0.8rem 1.8rem; /* More padding */
    background-color: var(--primary-color); 
    color: white;
    border-radius: 0.75rem; 
    text-decoration: none;
    font-weight: bold;
    transition: background-color 0.2s ease, transform 0.2s ease;
}
#articleDetailModal .original-link:hover {
    background-color: var(--primary-color-dark);
    transform: translateY(-2px);
}
/* Placeholder for modal image */
#articleDetailImageContainer .placeholder-image {
    width: 100%;
    height: 300px; /* Taller placeholder for modal */
    background-color: var(--placeholder-bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--placeholder-text-light);
    font-weight: 600;
    border-radius: 0.75rem;
    margin-bottom: 1.5rem;
    text-align: center;
    padding: 15px;
    font-size: 1.2rem;
}