:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-hover: #e8e8e8;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --border-color: #e0e0e0;
    --accent-color: #0066cc;
    --accent-hover: #0052a3;
}

[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-hover: #3d3d3d;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --border-color: #404040;
    --accent-color: #4da6ff;
    --accent-hover: #66b3ff;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

header {
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 2px solid var(--border-color);
}

h1 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.header-info {
    display: flex;
    gap: 20px;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.controls {
    display: flex;
    gap: 15px;
    margin-bottom: 25px;
    flex-wrap: wrap;
    align-items: center;
}

.search-container {
    flex: 1;
    min-width: 200px;
}

#search {
    width: 100%;
    padding: 10px 15px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 1rem;
    transition: border-color 0.2s ease;
}

#search:focus {
    outline: none;
    border-color: var(--accent-color);
}

.filter-container {
    display: flex;
    align-items: center;
    gap: 8px;
}

.filter-container label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

#category-filter {
    padding: 10px 15px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 1rem;
    cursor: pointer;
    transition: border-color 0.2s ease;
}

#category-filter:focus {
    outline: none;
    border-color: var(--accent-color);
}

.theme-toggle {
    padding: 10px 15px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 1.2rem;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.theme-toggle:hover {
    background-color: var(--bg-hover);
}

.feed-container {
    min-height: 400px;
}

.loading {
    text-align: center;
    padding: 40px;
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.feed-item {
    padding: 16px 0;
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.2s ease;
}

.feed-item:hover {
    background-color: var(--bg-hover);
    margin-left: -10px;
    margin-right: -10px;
    padding-left: 10px;
    padding-right: 10px;
    border-radius: 4px;
}

.feed-item-title {
    font-size: 1.1rem;
    font-weight: 500;
    margin-bottom: 8px;
}

.feed-item-title a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.2s ease;
}

.feed-item-title a:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

.feed-item-title a:visited {
    color: var(--text-secondary);
}

.feed-item-title .source-link {
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-decoration: none;
    margin-left: 8px;
}

.feed-item-title .source-link:hover {
    color: var(--accent-color);
    text-decoration: underline;
}

.feed-item-title .source-link:visited {
    color: var(--text-secondary);
}

.feed-item-meta {
    display: flex;
    gap: 15px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.feed-item-source {
    font-weight: 500;
}

.feed-item-time {
    font-style: italic;
}

.no-results {
    text-align: center;
    padding: 40px;
    color: var(--text-secondary);
    font-size: 1.1rem;
}

@media (max-width: 600px) {
    .container {
        padding: 15px;
    }

    h1 {
        font-size: 1.5rem;
    }

    .controls {
        flex-direction: column;
        align-items: stretch;
    }

    .search-container {
        width: 100%;
    }

    .filter-container {
        width: 100%;
        justify-content: space-between;
    }

    #category-filter {
        flex: 1;
    }

    .header-info {
        flex-direction: column;
        gap: 5px;
    }
}