* {
    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;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
    min-height: calc(100vh - 40px);
    display: flex;
    flex-direction: column;
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 60px 30px;
    text-align: center;
}

header h1 {
    font-size: 3rem;
    margin-bottom: 15px;
    font-weight: 700;
    letter-spacing: -1px;
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.95;
    font-weight: 300;
}

main {
    flex: 1;
    padding: 40px 30px;
}

.tools-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 25px;
    margin-bottom: 30px;
}

.tool-card {
    background: white;
    border: 2px solid #e0e0e0;
    border-radius: 15px;
    padding: 30px;
    text-align: center;
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
    display: block;
    cursor: pointer;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(102, 126, 234, 0.3);
    border-color: #667eea;
}

.tool-icon {
    font-size: 3.5rem;
    margin-bottom: 15px;
    display: block;
}

.tool-name {
    font-size: 1.5rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
}

.tool-description {
    font-size: 1rem;
    color: #666;
    margin-bottom: 15px;
    line-height: 1.5;
}

.tool-url {
    font-size: 0.9rem;
    color: #667eea;
    font-weight: 500;
    margin-top: 10px;
}

.tool-category {
    display: inline-block;
    background: #f0f0f0;
    color: #666;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    margin-top: 10px;
}

.loading {
    text-align: center;
    padding: 40px;
    color: #666;
    font-size: 1.1rem;
    grid-column: 1 / -1;
}

.error-message {
    background: #fee;
    color: #c33;
    padding: 20px;
    border-radius: 10px;
    border: 1px solid #fcc;
    text-align: center;
    margin: 20px 0;
    grid-column: 1 / -1;
}

footer {
    background: #f5f5f5;
    padding: 30px;
    text-align: center;
    color: #666;
    margin-top: auto;
}

footer p {
    margin-bottom: 10px;
}

.footer-note {
    font-size: 0.9rem;
    color: #999;
}

@media (max-width: 768px) {
    header {
        padding: 40px 20px;
    }

    header h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    main {
        padding: 30px 20px;
    }

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

    .tool-card {
        padding: 25px;
    }

    .tool-icon {
        font-size: 3rem;
    }
}

@media (max-width: 480px) {
    body {
        padding: 10px;
    }

    .container {
        border-radius: 15px;
        min-height: calc(100vh - 20px);
    }

    header h1 {
        font-size: 1.75rem;
    }

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

/* Animación de entrada */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tool-card {
    animation: fadeIn 0.5s ease-out;
}

.tool-card:nth-child(1) {
    animation-delay: 0.1s;
}

.tool-card:nth-child(2) {
    animation-delay: 0.2s;
}

.tool-card:nth-child(3) {
    animation-delay: 0.3s;
}

.tool-card:nth-child(4) {
    animation-delay: 0.4s;
}

.tool-card:nth-child(n+5) {
    animation-delay: 0.5s;
}