:root {
    --primary-color: #4361ee;
    --secondary-color: #3a0ca3;
    --accent-color: #7209b7;
    --background-color: #f8f9fa;
    --card-color: #ffffff;
    --text-color: #333333;
    --light-text: #6c757d;
    --border-color: #e0e0e0;
    --success-color: #4caf50;
    --warning-color: #ff9800;
    --danger-color: #f44336;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
    --radius: 8px;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
}

#app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    text-align: center;
    padding: 3rem 1rem;
    box-shadow: var(--shadow);
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

header p {
    font-size: 1.2rem;
    opacity: 0.9;
}

.search-container {
    background-color: var(--card-color);
    padding: 1.5rem;
    max-width: 1200px;
    margin: -2rem auto 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    position: relative;
    z-index: 10;
}

.search-box {
    display: flex;
    align-items: center;
    background-color: var(--background-color);
    border-radius: var(--radius);
    padding: 0.8rem 1.2rem;
    margin-bottom: 1rem;
}

.search-box i {
    color: var(--light-text);
    margin-right: 0.8rem;
}

.search-box input {
    width: 100%;
    border: none;
    background: transparent;
    font-size: 1rem;
    color: var(--text-color);
    outline: none;
}

.filter-container {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

select {
    padding: 0.6rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background-color: var(--card-color);
    color: var(--text-color);
    font-size: 0.9rem;
    cursor: pointer;
    outline: none;
    flex-grow: 1;
}

.reset-btn {
    padding: 0.6rem 1rem;
    background-color: var(--light-text);
    color: white;
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
}

.reset-btn:hover {
    background-color: var(--text-color);
}

main {
    flex: 1;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 1rem 3rem;
    width: 100%;
    display: flex;
    gap: 2rem;
}

.categories-nav {
    position: sticky;
    top: 2rem;
    height: fit-content;
    width: 230px;
    background-color: var(--card-color);
    border-radius: var(--radius);
    padding: 1rem;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.category-button {
    padding: 0.8rem 1rem;
    text-align: left;
    background: transparent;
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-color);
    font-size: 0.9rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.category-button:hover {
    background-color: rgba(67, 97, 238, 0.1);
}

.category-button.active {
    background-color: var(--primary-color);
    color: white;
}

.tools-container {
    flex: 1;
}

.category-section {
    margin-bottom: 3rem;
    scroll-margin-top: 2rem;
}

.category-section h2 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-color);
    color: #D81B60; 
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.tool-card {
    background-color: var(--card-color);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.tool-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.tool-header h3 {
    font-size: 1.3rem;
    color: var(--primary-color);
}

.tool-logo {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-color);
}

.tool-description {
    margin-bottom: 1.2rem;
    color: var(--light-text);
    flex-grow: 1;
}

.tool-meta {
    margin-bottom: 1.2rem;
}

.tool-access {
    display: inline-block;
    font-size: 0.8rem;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    margin-bottom: 0.8rem;
    font-weight: bold;
}

.gratuita {
    background-color: rgba(76, 175, 80, 0.2);
    color: var(--success-color);
}

.freemium {
    background-color: rgba(255, 152, 0, 0.2);
    color: var(--warning-color);
}

.premium {
    background-color: rgba(244, 67, 54, 0.2);
    color: var(--danger-color);
}

.tool-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tag {
    font-size: 0.75rem;
    padding: 0.2rem 0.6rem;
    background-color: rgba(67, 97, 238, 0.1);
    color: var(--primary-color);
    border-radius: 20px;
}

.tool-link {
    display: inline-flex;
    align-items: center;
    background-color: var(--primary-color);
    color: white;
    padding: 0.6rem 1.2rem;
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    margin-top: auto;
    justify-content: center;
}

.tool-link i {
    margin-left: 0.5rem;
    font-size: 0.8rem;
}

.tool-link:hover {
    background-color: var(--secondary-color);
}

footer {
    background-color: var(--card-color);
    text-align: center;
    padding: 1.5rem;
    margin-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--light-text);
}

.scroll-top-btn {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    box-shadow: var(--shadow);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.scroll-top-btn.visible {
    opacity: 1;
    visibility: visible;
}

/* Responsive adjustments */
@media (max-width: 1200px) {
    main {
        flex-direction: column;
    }

    .categories-nav {
        width: 100%;
        position: relative;
        top: 0;
        flex-direction: row;
        overflow-x: auto;
        padding: 0.8rem;
        margin-bottom: 1rem;
    }

    .category-button {
        width: auto;
        flex-shrink: 0;
    }
}

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

    .filter-container {
        flex-direction: column;
    }

    .search-container {
        margin-top: -1rem;
    }

    header {
        padding: 2rem 1rem;
    }

    h1 {
        font-size: 2rem;
    }
}