:root {
            --primary-color: #2193b0; /* Azul vibrante */
            --secondary-color: #6dd5ed; /* Azul claro */
            --accent-color: #3f51b5; /* Azul índigo para botones */
            --text-dark: #333;
            --text-light: #f8f8f8;
            --bg-light: #f5f7f9; /* Fondo general suave */
            --bg-card: #ffffff;
            --shadow-light: rgba(0,0,0,0.06);
            --shadow-medium: rgba(0,0,0,0.1);
            --border-color: #e0e0e0;
        }

        body {
            font-family: 'Montserrat', sans-serif;
            margin: 0;
            padding: 0;
            background-color: var(--bg-light);
            color: var(--text-dark);
            line-height: 1.6;
            scroll-behavior: smooth;
        }

        /* --- Header --- */
        header {
            background-image: linear-gradient(135deg, var(--secondary-color) 0%, var(--primary-color) 100%);
            color: var(--text-light);
            padding: 80px 20px;
            text-align: center;
            box-shadow: 0 6px 20px var(--shadow-medium);
            position: relative;
            overflow: hidden;
        }
        header::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: radial-gradient(circle at top left, rgba(255,255,255,0.15) 0%, transparent 70%);
            pointer-events: none;
        }
        header h1 {
            font-size: 4em;
            margin-bottom: 15px;
            font-weight: 700;
            letter-spacing: -1.5px;
            text-shadow: 2px 2px 5px rgba(0,0,0,0.3);
        }
        header p {
            font-size: 1.5em;
            opacity: 0.95;
            max-width: 900px;
            margin: 0 auto;
            font-weight: 300;
            line-height: 1.4;
        }

        /* --- Main Content --- */
        main {
            padding: 60px 20px;
            max-width: 1200px;
            margin: 0 auto;
        }

        h2 {
            font-size: 3em;
            color: var(--primary-color);
            text-align: center;
            margin-bottom: 50px;
            font-weight: 700;
            letter-spacing: -1px;
            position: relative;
            padding-bottom: 15px;
        }
        h2::after {
            content: '';
            display: block;
            width: 80px;
            height: 4px;
            background-color: var(--accent-color);
            margin: 15px auto 0;
            border-radius: 2px;
        }

        /* --- API Grid --- */
        #api-list {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 30px;
        }

        .api-card {
            background-color: var(--bg-card);
            border-radius: 18px;
            box-shadow: 0 10px 35px var(--shadow-light);
            padding: 30px;
            display: flex;
            flex-direction: column;
            align-items: center;
            text-align: center;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            border: 1px solid var(--border-color);
        }
        .api-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 50px var(--shadow-medium);
        }

        .api-card img {
            width: 100px;
            height: 100px;
            object-fit: contain;
            margin-bottom: 20px;
            border-radius: 15px; /* Sutil redondeo para imágenes */
            box-shadow: 0 4px 10px rgba(0,0,0,0.1);
        }

        .api-card h3 {
            font-size: 1.8em;
            color: var(--accent-color);
            margin-bottom: 15px;
            font-weight: 600;
        }

        .api-card p {
            font-size: 1.05em;
            color: #555;
            margin-bottom: 25px;
            flex-grow: 1; /* Permite que el párrafo ocupe el espacio restante */
        }

        .api-card .btn-docs {
            display: inline-block;
            background-color: var(--accent-color);
            color: var(--text-light);
            padding: 12px 25px;
            border: none;
            border-radius: 8px;
            font-size: 1em;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.2s ease;
            box-shadow: 0 4px 10px rgba(63, 81, 181, 0.3);
            text-decoration: none;
            font-weight: 500;
        }
        .api-card .btn-docs:hover {
            background-color: #303f9f;
            transform: translateY(-2px);
            box-shadow: 0 6px 15px rgba(63, 81, 181, 0.45);
        }
        
        /* --- Loading/Error State --- */
        #loading-message, #error-message {
            text-align: center;
            font-size: 1.2em;
            color: #777;
            padding: 50px;
        }
        #error-message {
            color: #d9534f; /* Rojo para errores */
        }

        /* --- Footer --- */
        footer {
            text-align: center;
            padding: 40px 20px;
            background-color: #2c3e50; /* Azul oscuro para el footer */
            color: #bbb;
            font-size: 0.95em;
            margin-top: 60px;
            box-shadow: inset 0 8px 20px rgba(0,0,0,0.2);
        }
        footer a {
            color: var(--secondary-color);
            text-decoration: none;
            font-weight: 500;
            transition: color 0.3s ease;
        }
        footer a:hover {
            color: #a0e6ff;
            text-decoration: underline;
        }

        /* --- Responsive Design --- */
        @media (max-width: 768px) {
            header h1 { font-size: 3em; }
            header p { font-size: 1.2em; }
            h2 { font-size: 2.5em; margin-bottom: 40px; }
            #api-list {
                grid-template-columns: 1fr; /* Una columna en móviles */
            }
            .api-card {
                padding: 25px;
            }
            .api-card img {
                width: 80px;
                height: 80px;
            }
            .api-card h3 {
                font-size: 1.5em;
            }
            .api-card p {
                font-size: 0.95em;
            }
            .api-card .btn-docs {
                padding: 10px 20px;
                font-size: 0.9em;
            }
        }