/* --- VARIABLES CSS --- */
:root {
    --primary-color: #0f172a; /* Azul oscuro elegante */
    --accent-color: #38bdf8;  /* Azul cielo */
    --text-color: #334155;    /* Gris oscuro para texto */
    --bg-light: #f8fafc;      /* Blanco humo */
    --white: #ffffff;
}

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

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-light);
}

/* --- NAVEGACIÓN --- */
nav {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 1rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky; /* Se queda pegado arriba al hacer scroll */
    top: 0;
    z-index: 1000;
}

nav h1 { font-size: 1.5rem; font-weight: 700; }
nav ul { list-style: none; display: flex; gap: 20px; }
nav a { text-decoration: none; color: var(--white); transition: color 0.3s; }
nav a:hover { color: var(--accent-color); }

/* --- HERO SECTION (Portada) --- */
.hero {
    /* Imagen de fondo de tecnología/servidores */
    background: linear-gradient(rgba(15, 23, 42, 0.9), rgba(15, 23, 42, 0.9)), url('https://images.unsplash.com/photo-1558494949-ef526b0042a0?ixlib=rb-1.2.1&auto=format&fit=crop&w=1950&q=80');
    background-size: cover;
    background-position: center;
    height: 90vh; /* 90% del alto de la pantalla */
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: var(--white);
    padding: 0 20px;
}

.hero h2 { font-size: 3rem; margin-bottom: 10px; }
.hero p { font-size: 1.5rem; color: var(--accent-color); margin-bottom: 20px; }
.hero .tagline { font-size: 1.1rem; max-width: 600px; opacity: 0.8; }

/* --- BOTONES --- */
.btn {
    display: inline-block;
    margin-top: 20px;
    padding: 10px 25px;
    background-color: var(--accent-color);
    color: var(--primary-color);
    text-decoration: none;
    font-weight: bold;
    border-radius: 5px;
    transition: transform 0.2s;
}
.btn:hover { transform: scale(1.05); }

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--accent-color);
    color: var(--accent-color);
}

/* --- SECCIONES GENERALES --- */
section { padding: 60px 10%; }

.bg-alt { background-color: #e2e8f0; } /* Fondo alternativo grisáceo */

h3.section-title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 40px;
    color: var(--primary-color);
    text-transform: uppercase;
    letter-spacing: 2px;
}

/* --- EXPERIENCIA DESTACADA --- */
.highlight-box {
    background: var(--white);
    border-left: 5px solid var(--accent-color);
    padding: 30px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-top: 20px;
    text-align: center;
}

.stat-item h4 { font-size: 2.5rem; color: var(--accent-color); }
.stat-item p { font-weight: bold; }

/* --- SKILLS GRID --- */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.skill-card {
    background: var(--white);
    padding: 25px;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    transition: transform 0.3s;
}
.skill-card:hover { transform: translateY(-5px); box-shadow: 0 10px 15px rgba(0,0,0,0.1); }
.skill-icon { font-size: 2rem; margin-bottom: 15px; }

/* --- CONTACTO & FOOTER --- */
.contact { background-color: var(--primary-color); color: var(--white); text-align: center; }
.contact h3 { color: var(--white); }

footer {
    text-align: center;
    padding: 20px;
    background-color: #0f172a;
    color: #888;
    border-top: 1px solid #1e293b;
    font-size: 0.9rem;
}

/* --- RESPONSIVE MOBILE --- */
@media (max-width: 768px) {
    .hero h2 { font-size: 2rem; }
    nav ul { display: none; } /* Ocultar menú en móviles por simplicidad */
    section { padding: 40px 5%; }
}