/* ================= VARIABLES DE COLOR ================= */
:root {
    --color-primary: #2563EB;
    --color-secondary: #06B6D4;
    --color-success: #10B981;
    
    /* Modo Claro (Por defecto) */
    --bg-body: #ffffff;
    --bg-secondary: #F8FAFC;
    --bg-header: rgba(255, 255, 255, 0.8);
    --text-heading: #111827;
    --text-body: #374151;
    --text-muted: #6b7280;
    --border-color: #f1f5f9;
    --card-bg: rgba(255,255,255,0.7);
    --btn-dark-bg: #111827;
    --btn-dark-text: #ffffff;
}

/* Modo Oscuro */
body.dark-mode {
    --bg-body: #0f172a;
    --bg-secondary: #111827;
    --bg-header: rgba(15, 23, 42, 0.8);
    --text-heading: #f8fafc;
    --text-body: #94a3b8;
    --text-muted: #64748b;
    --border-color: rgba(255,255,255,0.1);
    --card-bg: rgba(30,41,59,0.7);
    --btn-dark-bg: #f8fafc;
    --btn-dark-text: #0f172a;
}

body {
    background-color: var(--bg-body);
    color: var(--text-body);
    font-family: 'Inter', sans-serif;
    -webkit-font-smoothing: antialiased;
    transition: background-color 0.3s ease, color 0.3s ease;
}

h1, h2, h3, h4, h5 {
    font-family: 'Poppins', sans-serif;
    color: var(--text-heading);
}

.text-muted { color: var(--text-muted) !important; }

/* ================= NAVBAR ================= */
.ai-header {
    background: var(--bg-header);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    padding: 15px 0;
}

.logo-text {
    font-family: 'Poppins', sans-serif;
    font-weight: 700;
    font-size: 1.4rem;
    color: var(--text-heading);
    letter-spacing: -0.5px;
}

.ai-header .nav-link {
    color: var(--text-body);
    font-weight: 500;
    font-size: 0.95rem;
    margin: 0 10px;
    transition: color 0.2s;
}

.ai-header .nav-link:hover { color: var(--color-primary); }

/* Botón Modo Oscuro */
.btn-theme-toggle {
    background: transparent;
    border: none;
    color: var(--text-heading);
    font-size: 1.2rem;
    padding: 5px 10px;
    border-radius: 8px;
    transition: background 0.2s;
    cursor: pointer;
}

.btn-theme-toggle:hover {
    background: var(--bg-secondary);
}

.btn-ghost {
    color: var(--text-heading);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    padding: 8px 16px;
}

.btn-ghost:hover { color: var(--color-primary); }

.btn-primary-sm {
    background: var(--btn-dark-bg);
    color: var(--btn-dark-text);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    padding: 8px 18px;
    border-radius: 8px;
    transition: transform 0.2s, box-shadow 0.2s;
}

.btn-primary-sm:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    color: var(--btn-dark-text);
}

/* ================= HERO ================= */
.hero-ai {
    padding: 100px 0 120px 0;
    background: radial-gradient(circle at 80% 20%, rgba(6, 182, 212, 0.05) 0%, transparent 50%),
                radial-gradient(circle at 20% 80%, rgba(37, 99, 235, 0.05) 0%, transparent 50%);
    overflow: hidden;
}

.hero-grid { display: flex; align-items: center; justify-content: space-between; }
.hero-text { max-width: 600px; }

.hero-text h1 {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    letter-spacing: -1.5px;
}

.hero-text .lead {
    font-size: 1.25rem;
    color: var(--text-body);
    margin-bottom: 2rem;
}

.hero-features { list-style: none; padding: 0; margin-bottom: 2.5rem; }

.hero-features li {
    display: flex;
    align-items: center;
    font-size: 1.1rem;
    margin-bottom: 12px;
    color: var(--text-heading);
}

.hero-features li i { color: var(--color-success); margin-right: 12px; font-size: 1.3rem; }

.btn-hero-primary {
    background: var(--color-primary);
    color: white;
    padding: 14px 28px;
    border-radius: 10px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}

.btn-hero-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
    color: white;
}

.btn-hero-secondary {
    background: transparent;
    color: var(--text-heading);
    padding: 14px 28px;
    border-radius: 10px;
    font-weight: 600;
    text-decoration: none;
    border: 1px solid var(--border-color);
    margin-left: 10px;
    transition: all 0.3s ease;
}

.btn-hero-secondary:hover {
    border-color: var(--text-heading);
    background: var(--bg-secondary);
    color: var(--text-heading);
}

/* Ilustración CSS */
.hero-visual { position: relative; width: 400px; height: 400px; display: flex; align-items: center; justify-content: center; }
.orb { position: absolute; border-radius: 50%; filter: blur(40px); animation: float 6s infinite ease-in-out; }
.orb-1 { width: 300px; height: 300px; background: linear-gradient(135deg, var(--color-primary), var(--color-secondary)); opacity: 0.8; }
.orb-2 { width: 150px; height: 150px; background: var(--color-success); top: 20%; right: 10%; animation-delay: -2s; opacity: 0.6; }

.glow-card {
    position: relative;
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border-color);
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    z-index: 10;
    text-align: center;
}

.glow-card i {
    font-size: 3rem;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 15px;
}

.glow-card p { font-weight: 600; color: var(--text-heading); margin: 0; }

@keyframes float { 0%, 100% { transform: translateY(0px); } 50% { transform: translateY(-20px); } }

/* ================= FOOTER ================= */
.ai-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 30px 0;
}

/* Responsive */
@media (max-width: 768px) {
    .hero-text h1 { font-size: 2.5rem; }
    .hero-visual { display: none; }
    .btn-hero-secondary { margin-left: 0; margin-top: 15px; display: inline-block; }
}