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

        :root {
            --color-primary: #1D4ED8;
            --color-primary-light: #3B82F6;
            --color-accent: #0EA5E9;
            --color-cat: #1D4ED8;
            --color-cat-light: #3B82F6;
            --color-cat-bg: #EFF6FF;
            --color-cat-vivid: #1E3A8A;
            --color-bg: #F8FAFC;
            --color-surface: #FFFFFF;
            --color-border: #E2E8F0;
            --color-border-strong: #CBD5E1;
            --color-text: #0F172A;
            --color-text-muted: #475569;
            --color-text-light: #94A3B8;
            --shadow-sm: 0 1px 2px 0 rgba(15,23,42,0.05);
            --shadow-md: 0 4px 6px -1px rgba(15,23,42,0.08), 0 2px 4px -2px rgba(15,23,42,0.05);
            --shadow-lg: 0 10px 25px -5px rgba(15,23,42,0.10), 0 8px 10px -6px rgba(15,23,42,0.04);
            --shadow-hover: 0 20px 40px -10px rgba(29,78,216,0.22);
            --radius-sm: 8px;
            --radius-md: 12px;
            --radius-lg: 16px;
            --container-max: 960px;
            --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
        }

        html { scroll-behavior: smooth; }

        body {
            font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
            font-size: 16px; line-height: 1.6;
            color: var(--color-text); background-color: var(--color-bg);
            -webkit-font-smoothing: antialiased; min-height: 100vh;
        }

        a { color: var(--color-primary); text-decoration: none; transition: color var(--transition); }
        .container { width: 100%; max-width: var(--container-max); margin: 0 auto; padding: 0 20px; }

        /* =========== HEADER =========== */
        .header {
            position: sticky; top: 0; background-color: var(--color-surface);
            border-bottom: 1px solid var(--color-border); box-shadow: var(--shadow-sm); z-index: 50;
        }
        .header__inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
        .logo {
            display: flex; align-items: center; gap: 10px;
            font-size: 1.25rem; font-weight: 800; color: var(--color-primary); letter-spacing: -0.02em;
        }
        .logo__icon {
            width: 34px; height: 34px;
            background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
            border-radius: 10px; display: grid; place-items: center; color: #fff;
            font-size: 1.1rem; font-weight: 700;
        }
        .back-btn {
            display: inline-flex; align-items: center; gap: 6px; padding: 8px 14px;
            border-radius: 999px; font-size: 0.875rem; font-weight: 600;
            color: var(--color-text-muted); background-color: var(--color-bg); transition: all var(--transition);
        }
        .back-btn:hover { background-color: var(--color-primary); color: #fff; }
        .back-btn__icon { transition: transform var(--transition); }
        .back-btn:hover .back-btn__icon { transform: translateX(-3px); }
        @media (max-width: 380px) { .back-btn__text { display: none; } .back-btn { padding: 8px 12px; } }

        /* =========== HERO =========== */
        .hero {
            padding: 48px 0 40px; text-align: center;
            background: linear-gradient(180deg, #FFFFFF 0%, var(--color-cat-bg) 100%);
            border-bottom: 1px solid var(--color-border);
        }
        .hero__icon {
            width: 64px; height: 64px; margin: 0 auto 16px;
            background: linear-gradient(135deg, var(--color-cat) 0%, var(--color-cat-light) 100%);
            border-radius: var(--radius-lg); display: grid; place-items: center;
            font-size: 1.75rem; color: #fff; box-shadow: 0 8px 20px -6px rgba(29,78,216,0.3);
        }
        .hero__title {
            font-size: clamp(1.5rem, 5vw, 2.25rem); font-weight: 800;
            line-height: 1.2; letter-spacing: -0.02em; margin-bottom: 12px;
        }
        .hero__subtitle {
            font-size: 1rem; color: var(--color-text-muted); max-width: 600px; margin: 0 auto;
        }
        .hero__count {
            display: inline-block; margin-top: 16px; padding: 6px 14px;
            background-color: var(--color-cat-bg); color: var(--color-cat);
            font-size: 0.8125rem; font-weight: 600; border-radius: 999px;
        }

        /* =========== GRID DE CARDS =========== */
        .tools-section { padding: 40px 0; }
        .tools-grid {
            display: grid; grid-template-columns: 1fr; gap: 16px;
        }

        .tool-card {
            display: flex; flex-direction: column;
            background-color: var(--color-surface); border: 1.5px solid var(--color-border);
            border-radius: var(--radius-lg); padding: 28px 24px;
            transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
            position: relative; overflow: hidden;
        }
        .tool-card::before {
            content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 4px;
            background: linear-gradient(90deg, var(--color-cat) 0%, var(--color-cat-light) 100%);
            transform: scaleX(0); transform-origin: left; transition: transform var(--transition);
        }
        .tool-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); border-color: var(--color-cat-light); }
        .tool-card:hover::before { transform: scaleX(1); }

        .tool-card__icon {
            width: 52px; height: 52px; border-radius: var(--radius-md);
            background-color: var(--color-cat-bg); display: grid; place-items: center;
            font-size: 1.5rem; margin-bottom: 16px; flex-shrink: 0;
        }
        .tool-card__title {
            font-size: 1.125rem; font-weight: 700; margin-bottom: 8px; color: var(--color-text);
        }
        .tool-card__desc {
            font-size: 0.9375rem; color: var(--color-text-muted); line-height: 1.6;
            margin-bottom: 20px; flex-grow: 1;
        }
        .tool-card__btn {
            display: inline-flex; align-items: center; justify-content: center; gap: 6px;
            padding: 12px 20px; border-radius: var(--radius-sm);
            background: linear-gradient(135deg, var(--color-cat) 0%, var(--color-cat-light) 100%);
            color: #fff; font-weight: 700; font-size: 0.875rem;
            transition: box-shadow var(--transition), transform var(--transition);
            align-self: flex-start;
        }
        .tool-card__btn:hover { color: #fff; box-shadow: 0 6px 16px -4px rgba(29,78,216,0.4); transform: translateY(-1px); }
        .tool-card__btn-arrow { transition: transform var(--transition); }
        .tool-card:hover .tool-card__btn-arrow { transform: translateX(3px); }

        /* =========== SEO CONTENT =========== */
        .seo-section { padding: 0 0 60px; }
        .seo-card {
            background-color: var(--color-surface); border: 1px solid var(--color-border);
            border-radius: var(--radius-lg); padding: 28px 24px;
        }
        .seo-card h2 {
            font-size: 1.375rem; font-weight: 800; margin-bottom: 12px; color: var(--color-text);
        }
        .seo-card p {
            color: var(--color-text-muted); margin-bottom: 14px; line-height: 1.75;
        }
        .seo-card p:last-child { margin-bottom: 0; }
        .seo-card strong { color: var(--color-text); font-weight: 600; }

        /* =========== FOOTER =========== */
        .footer {
            background-color: #0F172A; color: #94A3B8; padding: 28px 0;
            text-align: center; font-size: 0.875rem;
        }
        .footer strong { color: #FFFFFF; font-weight: 600; }

        /* =========== UTILS =========== */
        :focus-visible { outline: 3px solid var(--color-accent); outline-offset: 2px; border-radius: 4px; }
        @media (prefers-reduced-motion: reduce) {
            *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
        }

        /* =========== BREAKPOINTS =========== */
        @media (min-width: 640px) {
            .container { padding: 0 32px; }
            .hero { padding: 64px 0 48px; }
            .tools-grid { grid-template-columns: repeat(2, 1fr); gap: 20px; }
            .seo-card { padding: 32px; }
        }
        @media (min-width: 960px) {
            .tools-grid { grid-template-columns: repeat(2, 1fr); gap: 24px; }
        }