.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin: 20px 0;
}

.tool-card {
    background: white;
    border: 1px solid #e1e8ed;
    border-radius: 10px;
    padding: 25px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    border-color: #3498db;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #3498db, #2ecc71);
}

.tool-header {
    display: flex;
    align-items: flex-start;
    margin-bottom: 15px;
}

.tool-icon {
    width: 50px;
    height: 50px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 15px;
    font-size: 1.5rem;
    color: white;
    flex-shrink: 0;
}

.tool-icon.validation {
    background: linear-gradient(135deg, #e74c3c, #c0392b);
}

.tool-icon.formatting {
    background: linear-gradient(135deg, #3498db, #2980b9);
}

.tool-icon.conversion {
    background: linear-gradient(135deg, #9b59b6, #8e44ad);
}

.tool-icon.library {
    background: linear-gradient(135deg, #2ecc71, #27ae60);
}

.tool-icon.online {
    background: linear-gradient(135deg, #f39c12, #d35400);
}

.tool-icon.testing {
    background: linear-gradient(135deg, #1abc9c, #16a085);
}

.tool-title {
    font-size: 1.3rem;
    font-weight: bold;
    color: #2c3e50;
    margin-bottom: 5px;
}

.tool-description {
    color: #7f8c8d;
    font-size: 0.95rem;
    line-height: 1.5;
}

.tool-features {
    list-style: none;
    padding: 0;
    margin: 15px 0;
}

.tool-features li {
    padding: 5px 0;
    position: relative;
    padding-left: 20px;
    color: #5a6c7d;
}

.tool-features li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: #27ae60;
    font-weight: bold;
}

.tool-links {
    display: flex;
    gap: 10px;
    margin-top: 15px;
    flex-wrap: wrap;
}

.tool-link {
    padding: 8px 15px;
    background: #3498db;
    color: white;
    text-decoration: none;
    border-radius: 5px;
    font-size: 0.9rem;
    transition: background 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.tool-link:hover {
    background: #2980b9;
    color: white;
    text-decoration: none;
}

.tool-link.github {
    background: #333;
}

.tool-link.github:hover {
    background: #555;
}

.tool-link.website {
    background: #27ae60;
}

.tool-link.website:hover {
    background: #219a52;
}

.tool-link.docs {
    background: #f39c12;
}

.tool-link.docs:hover {
    background: #d68910;
}

.tool-badge {
    display: inline-block;
    padding: 3px 8px;
    background: #ecf0f1;
    border-radius: 4px;
    font-size: 0.8rem;
    color: #7f8c8d;
    margin-left: 10px;
}

.category-section {
    margin-bottom: 50px;
}

.category-header {
    display: flex;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 2px solid #ecf0f1;
}

.category-icon {
    font-size: 2rem;
    margin-right: 15px;
    color: #3498db;
}

.resource-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    border-radius: 8px;
    overflow: hidden;
}

.resource-table th {
    background: #3498db;
    color: white;
    padding: 15px;
    text-align: left;
    font-weight: 600;
}

.resource-table td {
    padding: 12px 15px;
    border-bottom: 1px solid #ecf0f1;
}

.resource-table tr:nth-child(even) {
    background: #f8f9fa;
}

.resource-table tr:hover {
    background: #e8f4fd;
}

.language-badge {
    display: inline-block;
    padding: 3px 8px;
    background: #3498db;
    color: white;
    border-radius: 4px;
    font-size: 0.8rem;
    margin-right: 5px;
}

.comparison-chart {
    background: white;
    border-radius: 10px;
    padding: 25px;
    margin: 25px 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.chart-row {
    display: flex;
    align-items: center;
    margin-bottom: 15px;
    padding: 10px;
    border-radius: 5px;
    transition: background 0.3s;
}

.chart-row:hover {
    background: #f8f9fa;
}

.chart-label {
    flex: 0 0 200px;
    font-weight: 500;
    color: #2c3e50;
}

.chart-bar {
    flex: 1;
    height: 20px;
    background: #ecf0f1;
    border-radius: 10px;
    overflow: hidden;
    position: relative;
}

.chart-fill {
    height: 100%;
    background: linear-gradient(90deg, #3498db, #2ecc71);
    border-radius: 10px;
    transition: width 1s ease-in-out;
}

.chart-value {
    flex: 0 0 60px;
    text-align: right;
    font-weight: bold;
    color: #2c3e50;
}

.online-demo {
    background: #e8f4fd;
    border: 1px solid #b8daff;
    border-radius: 10px;
    padding: 25px;
    margin: 25px 0;
}

.demo-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin: 20px 0;
}

.demo-card {
    background: white;
    border-radius: 8px;
    padding: 20px;
    text-align: center;
    transition: transform 0.3s;
    border: 1px solid #e1e8ed;
}

.demo-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.demo-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: #3498db;
}

.rating {
    color: #f39c12;
    margin: 10px 0;
}

.book-resource {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 10px;
    padding: 25px;
    margin: 25px 0;
}

.book-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin: 20px 0;
}

.book-card {
    background: rgba(255,255,255,0.1);
    border-radius: 8px;
    padding: 20px;
    text-align: center;
    backdrop-filter: blur(10px);
}

.book-cover {
    width: 120px;
    height: 160px;
    background: white;
    border-radius: 5px;
    margin: 0 auto 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #333;
    font-weight: bold;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

@media (max-width: 768px) {
    .tools-grid {
        grid-template-columns: 1fr;
    }

    .tool-header {
        flex-direction: column;
        text-align: center;
    }

    .tool-icon {
        margin-right: 0;
        margin-bottom: 10px;
    }

    .chart-label {
        flex: 0 0 120px;
    }

    .demo-grid {
        grid-template-columns: 1fr;
    }

    .resource-table {
        display: block;
        overflow-x: auto;
    }
}