:root {
    /* Color Palette - Official & Aesthetic */
    --bg-color: #f8fafc;
    --surface-color: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    
    --header-bg: #ffffff;
    --header-text: #1e293b;
    
    /* Brand accents for tags */
    --color-bbc: #b91c1c;
    --color-cnn: #c2410c;
    --color-elmundo: #0369a1;
    --color-aljazeera: #ca8a04;
    --color-nyt: #1f2937;
    --color-dw: #047857;
    --color-default: #475569;

    /* Typography */
    --font-heading: 'Playfair Display', serif;
    --font-body: 'Inter', sans-serif;

    /* Styling values */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.05), 0 1px 2px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.05), 0 2px 4px -1px rgba(0,0,0,0.03);
    --shadow-hover: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -2px rgba(0,0,0,0.04);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

[data-theme="dark"] {
    --bg-color: #1e293b;
    --surface-color: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --border-color: #475569;
    
    --header-bg: #1e293b;
    
    /* Adjust brand colors for dark mode visibility if necessary */
    --color-bbc: #ef4444;
    --color-cnn: #f97316;
    --color-elmundo: #38bdf8;
    --color-aljazeera: #facc15;
    --color-nyt: #e2e8f0;
    --color-dw: #34d399;
    --color-default: #94a3b8;
}

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

body {
    font-family: var(--font-body);
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
    -webkit-font-smoothing: antialiased;
}

/* Header */
.app-header {
    background-color: var(--header-bg);
    color: var(--header-text);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.5rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo h1 {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    margin-bottom: 0.25rem;
}

.logo p {
    font-size: 0.875rem;
    color: #94a3b8;
    text-transform: uppercase;
    letter-spacing: 1px;
}

#theme-toggle {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: var(--header-text);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
}

#theme-toggle:hover {
    background: rgba(255, 255, 255, 0.2);
}

/* Source Filters */
.source-filters {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
}

.filter-scroll-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0.75rem 2rem;
    display: flex;
    gap: 0.5rem;
    overflow-x: auto;
    scrollbar-width: none; /* Firefox */
}

.filter-scroll-container::-webkit-scrollbar {
    display: none; /* Chrome/Safari */
}

.filter-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    white-space: nowrap;
    transition: var(--transition);
    font-family: var(--font-body);
}

.filter-btn:hover {
    border-color: var(--text-secondary);
    color: var(--text-primary);
}

.filter-btn.active {
    background: var(--text-primary);
    color: var(--bg-color);
    border-color: var(--text-primary);
}

/* Main Content */
.content-wrapper {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 2rem;
    min-height: 60vh;
}

/* Status / Loader */
.status-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 4rem 0;
    color: var(--text-secondary);
}

.loader {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-color);
    border-top-color: var(--text-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* News Grid */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
}

/* News Card */
.news-card {
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: var(--transition);
    height: 100%;
    text-decoration: none;
    color: inherit;
}

.news-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
    border-color: transparent;
}

.card-img-wrapper {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background-color: var(--border-color);
    position: relative;
}

.card-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.news-card:hover .card-img {
    transform: scale(1.05);
}

.no-image-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-family: var(--font-heading);
    font-size: 1.5rem;
    background: linear-gradient(135deg, var(--bg-color), var(--border-color));
}

.card-content {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.source-tag {
    padding: 0.2rem 0.6rem;
    border-radius: var(--radius-sm);
    color: white;
}

.source-tag.bbc { background-color: var(--color-bbc); }
.source-tag.cnn { background-color: var(--color-cnn); }
.source-tag.el-mundo { background-color: var(--color-elmundo); }
.source-tag.al-jazeera { background-color: var(--color-aljazeera); color: #000; }
[data-theme="dark"] .source-tag.al-jazeera { color: #000; }
.source-tag.nyt { background-color: var(--color-nyt); color: #fff;}
[data-theme="dark"] .source-tag.nyt { color: #000; }
.source-tag.dw { background-color: var(--color-dw); }
.source-tag.default { background-color: var(--color-default); }

.pub-date {
    color: var(--text-secondary);
}

.card-title {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    line-height: 1.3;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.card-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin-bottom: 1rem;
    flex-grow: 1;
}

.card-footer {
    margin-top: auto;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-primary);
    display: inline-flex;
    align-items: center;
}

.card-footer::after {
    content: "→";
    margin-left: 0.5rem;
    transition: transform 0.2s;
}

.news-card:hover .card-footer::after {
    transform: translateX(4px);
}

/* Footer */
.app-footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
    border-top: 1px solid var(--border-color);
    margin-top: 4rem;
}

/* Responsive */
@media (max-width: 768px) {
    .header-container {
        padding: 1rem 1.5rem;
    }
    
    .logo h1 {
        font-size: 1.5rem;
    }
    
    .content-wrapper {
        padding: 0 1.5rem;
    }
    
    .news-grid {
        gap: 1.5rem;
    }
}