:root {
    --primary-color: #3b82f6;
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-color: #1f2937;
    --text-secondary: #6b7280;
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --transition: 0.3s ease;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background-color: var(--card-bg);
    padding: 40px 0;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    margin-bottom: 40px;
    text-align: center;
}

header h1 {
    margin: 0;
    font-size: 2.5rem;
    color: var(--text-color);
}

header p {
    color: var(--text-secondary);
    margin-top: 10px;
}

#filter-container {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 30px;
}

.filter-btn {
    padding: 8px 16px;
    border: none;
    background-color: var(--card-bg);
    color: var(--text-secondary);
    border-radius: 20px;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.filter-btn:hover,
.filter-btn.active {
    background-color: var(--primary-color);
    color: white;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
    padding-bottom: 60px;
}

.card {
    background-color: var(--card-bg);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform var(--transition), box-shadow var(--transition);
    display: flex;
    flex-direction: column;
    height: 100%;
    text-decoration: none;
    color: inherit;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

.card-content {
    padding: 24px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin: 0 0 10px 0;
    color: var(--text-color);
}

.card-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
    flex-grow: 1;
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: auto;
    font-size: 0.85rem;
}

.card-tags {
    display: flex;
    gap: 8px;
}

.tag {
    background-color: #e5e7eb;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    font-weight: 600;
}

.card-date {
    color: #9ca3af;
}

footer {
    text-align: center;
    padding: 20px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    background-color: var(--card-bg);
    margin-top: auto;
}