/* VARIABLES DE DISEÑO (Basadas en tu original) */
:root {
    --primary: #4f46e5;
    --primary-light: #818cf8;
    --primary-bg: #eef2ff;
    --bg: #f8fafc;
    --surface: #ffffff;
    --text: #0f172a;
    --text-secondary: #64748b;
    --border: #e2e8f0;
    --radius: 16px;
    --shadow-lg: 0 10px 25px -3px rgba(0,0,0,0.08);
}

/* ESTILOS BASE */
body { 
    font-family: 'Inter', sans-serif; 
    background: var(--bg); 
    color: var(--text); 
    margin: 0; 
    line-height: 1.6;
}

/* HERO SECTION (El degradado superior) */
.hero {
    background: linear-gradient(135deg, #312e81 0%, #4f46e5 50%, #6366f1 100%);
    padding: 60px 20px 80px; 
    text-align: center; 
    color: white;
}

.logo-main { 
    font-size: 3rem; 
    font-weight: 900; 
    letter-spacing: -0.05em; 
}

.logo-main span { color: var(--primary-light); }

/* CONTENEDOR PRINCIPAL */
.main-container { 
    max-width: 1200px; 
    margin: -40px auto 0; 
    padding: 0 20px 60px; 
}

/* CUADRÍCULA DE CATEGORÍAS */
.main-grid { 
    display: grid; 
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); 
    gap: 20px; 
}

.cat-card {
    background: var(--surface); 
    padding: 30px; 
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg); 
    cursor: pointer; 
    transition: all 0.3s ease; 
    text-align: center;
    border: 1px solid var(--border);
}

.cat-card:hover { 
    transform: translateY(-10px); 
    border-color: var(--primary-light);
}

.cat-card i { 
    font-size: 2.5rem; 
    display: block; 
    margin-bottom: 10px; 
}

/* PANEL DE SUBCATEGORÍAS */
.sub-panel { 
    background: white; 
    padding: 30px; 
    border-radius: var(--radius); 
    display: none; 
    margin-top: 30px; 
    box-shadow: var(--shadow-lg); 
}

.sub-grid { 
    display: grid; 
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); 
    gap: 12px; 
}

.sub-button {
    background: var(--bg); 
    border: 1.5px solid var(--border); 
    padding: 14px; 
    border-radius: 10px;
    font-weight: 700; 
    cursor: pointer; 
    transition: 0.2s; 
    font-family: inherit;
    text-align: left;
}

.sub-button:hover { 
    border-color: var(--primary); 
    color: var(--primary); 
    background: var(--primary-bg); 
}

/* ÁREA DE RESULTADOS / CALCULADORA */
.content-area { margin-top: 30px; }

.calc-card { 
    background: white; 
    padding: 30px; 
    border-radius: var(--radius); 
    box-shadow: var(--shadow-lg); 
}