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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

header {
    text-align: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

.header-nav {
    position: absolute;
    top: 20px;
    left: 20px;
}

.back-btn {
    padding: 10px 20px;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    text-decoration: none;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 25px;
    font-size: 0.95rem;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.back-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    border-color: rgba(255, 255, 255, 0.5);
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.2);
}

main {
    padding: 30px;
}

/* Tool Cards Grid */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    margin-top: 30px;
}

.tool-card {
    background: white;
    border-radius: 15px;
    padding: 30px 25px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    cursor: pointer;
    border: 2px solid transparent;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(102, 126, 234, 0.3);
    border-color: #667eea;
}

.tool-card-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    color: #667eea;
}

.tool-card-title {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: #333;
}

.tool-card-description {
    font-size: 0.95rem;
    color: #666;
    line-height: 1.5;
    margin-bottom: 20px;
}

.tool-card-features {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px;
    margin-bottom: 25px;
}

.tool-card-features .feature-badge {
    padding: 5px 12px;
    background: #f0f2ff;
    color: #667eea;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 600;
}

.tool-card-btn {
    padding: 12px 35px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 30px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.tool-card-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.5);
}

/* Footer */
footer {
    text-align: center;
    padding: 20px;
    color: #999;
    font-size: 0.9rem;
    border-top: 1px solid #eee;
}

/* Responsive Design */
@media (max-width: 992px) {
    .tools-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    header {
        padding: 30px 15px;
    }

    header h1 {
        font-size: 1.8rem;
    }

    header p {
        font-size: 0.95rem;
    }

    main {
        padding: 20px;
    }

    .tools-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .tool-card {
        padding: 25px 20px;
    }

    .tool-card-icon {
        width: 70px;
        height: 70px;
    }

    .tool-card-title {
        font-size: 1.2rem;
    }

    .tool-card-btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    header {
        padding: 25px 15px;
    }

    .header-nav {
        top: 10px;
        left: 10px;
    }

    .back-btn {
        padding: 8px 15px;
        font-size: 0.85rem;
    }

    .tool-card {
        padding: 20px 15px;
    }

    .tool-card-icon {
        width: 60px;
        height: 60px;
    }

    .tool-card-title {
        font-size: 1.1rem;
    }

    .tool-card-description {
        font-size: 0.85rem;
    }

    .tool-card-features .feature-badge {
        padding: 4px 10px;
        font-size: 0.75rem;
    }
}